Treated Control Rats Research Articles

TAG-FREE GLYCOSYLATED RHMFG-E8 AS A THERAPY FOR ACUTE KIDNEY INJURY.

Background: Acute kidney injury (AKI) can result from renal ischemia and reperfusion (I/R) and often occurs during surgical procedures in cardiac, liver, kidney transplantation, and trauma-hemorrhage. Milk fat globule epidermal growth factor-factor VIII (MFG-E8) functions as a bridging molecule to promote the removal of dying cells by professional phagocytes. Because MFG-E8 promotes clearance of apoptotic cells, we have explored its therapeutic potential in various organ injury conditions. To develop human MFG-E8 as a potential therapy, we have generated a human cell-expressed, and thus glycosylated, tag-free recombinant human (rh) MFG-E8 and tested its safety and biological activity in vitro . We hypothesize that the tag-free glycosylated rhMFG-E8 is protective in I/R-induced AKI and it can be developed as an effective therapy for AKI. Methods: To assess the pharmacokinetic properties of the tag-free rhMFG-E8, Sprague-Dawley rats were either untreated or treated with a bolus dose of the tag-free rhMFG-E8, blood collected at various time points and the recovery of human MFG-E8 in the blood were measured by ELISA. Adult male C57BL6 mice underwent bilateral renal ischemia for 30 min, and immediately upon reperfusion, mice were treated intraperitoneally with either normal saline (vehicle) or 20 μg/kg human cell expressed, glycosylated tag-free rhMFG-E8. At either 24 h or 48 h after I/R, blood and kidneys were harvested for further analysis. In separate cohorts of mice after I/R and treatment, mice were observed for 10 days, and survival recorded. Results: AKI rats treated with the tag-free rhMFG-E8 had similar half-life as those in the treated control rats. At 48 h after I/R-induced AKI, renal function markers, blood urea nitrogen, and creatinine were increased and treatment with the tag-free rhMFG-E8 significantly decreased these markers. At both 24 h and 48 h after AKI, inflammatory cytokines, TNF-α, IL-6, and IL-1β were increased and treatment decreased these levels. The kidney mRNA expressions of these cytokines were also increased at 24 h after AKI and treatment significantly decreased those mRNA expressions. Histologically, at 48 h after AKI, tubular damage, and the number of TUNEL staining cells were increased and treatment markedly decreased these measurements. Administration of tag-free rhMFG-E8 at the time of reperfusion improved survival in a 10-day survival study. Conclusion: Our new human cell-expressed tag-free rhMFG-E8 is protective in I/R-induced AKI and it may have the potential to be further developed as a safe and effective therapy for AKI.

Empagliflozin: Potential Protective Effects on Hepatocytes and Liver Outcomes in Streptozotocin -Diabetic Rats.

The current study investigated the potential positive impact of EMPA, an antidiabetic medication, on hepatocytes and liver outcomes in STZ-induced diabetic rats. Male Wistar rats were randomly assigned into four groups: control, DM (received 40mg/kg streptozotocin IP injection), DM+EMPA (received 40mg/kg streptozotocin and 10 mg/kg EMPA), and EMPA (received 10 mg/kg EMPA). Here, liver functional tests were assessed spectrophotometrically, while histological analysis of liver tissues was evaluated using light microscopy. Treated diabetic rats significantly reduced AST levels compared to treated control rats (p < 0.05). DM rats, with or without EMPA treatment, showed significantly elevated ALT levels compared to control rats (p < 0.005). Also, LDH levels were found to be lower in both treated and untreated diabetic rats compared to control rats (p < 0.0001; p < 0.05, respectively), while ALP levels were higher in both groups of diabetic rats relative to control rats (p < 0.0001; p < 0.005). Interestingly, the data showed clear trends indicating that empagliflozin-treated diabetic rats had improved liver parameters compared to untreated diabetic rats, although statistically significant differences were not observed. Remarkably, histological examination showed significant sinusoidal dilation and infiltration of inflammatory cells in hepatocytes in diabetic rats, whereas treated diabetic rats exhibited a normal hepatocyte arrangement with minor sinusoidal dilation. Altogether, the observed results suggest that EMPA may possess a protective effect on hepatocytes, thereby highlighting its potential as a therapeutic intervention for diabetes-related liver complications.

Inhibition of focal adhesion kinase 2 results in a macrophage polarization shift to M2 which attenuates local and systemic inflammation and reduces heterotopic ossification after polysystem extremity trauma.

Heterotopic ossification (HO) is a complex pathology often observed in combat injured casualties who have sustained severe, high energy polytraumatic extremity injuries. Once HO has developed, prophylactic therapies are limited outside of surgical excision. Tourniquet-induced ischemia injury (IR) exacerbates trauma-mediated musculoskeletal tissue injury, inflammation, osteogenic progenitor cell development and HO formation. Others have shown that focal adhesion kinase-2 (FAK2) plays a key role in regulating early inflammatory signaling events. Therefore, we hypothesized that targeting FAK2 prophylactically would mitigate extremity trauma induced IR inflammation and HO formation. We tested whether the continuous infusion of a FAK2 inhibitor (Defactinib, PF-573228; 6.94 µg/kg/min for 14 days) can mitigate ectopic bone formation (HO) using an established blast-related extremity injury model involving femoral fracture, quadriceps crush injury, three hours of tourniquet-induced limb ischemia, and hindlimb amputation through the fracture site. Tissue inflammation, infiltrating cells, osteogenic progenitor cell content were assessed at POD-7. Micro-computed tomography imaging was used to quantify mature HO at POD-56. In comparison to vehicle control-treated rats, FAK2 administration resulted in no marked wound healing complications or weight loss. FAK2 treatment decreased HO by 43%. At POD-7, marked reductions in tissue proinflammatory gene expression and assayable osteogenic progenitor cells were measured, albeit no significant changes in expression patterns of angiogenic, chondrogenic and osteogenic genes. At the same timepoint, injured tissue from FAK-treated rats had fewer infiltrating cells. Additionally, gene expression analyses of tissue infiltrating cells resulted in a more measurable shift from an M1 inflammatory to an M2 anti-inflammatory macrophage phenotype in the FAK2 inhibitor-treated group. Our findings suggest that FAK2 inhibition may be a novel strategy to dampen trauma-induced inflammation and attenuate HO in patients at high risk as a consequence of severe musculoskeletal polytrauma.

SARS-CoV-2 Spike Protein S1 Exposure Increases Susceptibility to Angiotensin II-Induced Hypertension in Rats by Promoting Central Neuroinflammation and Oxidative Stress.

The SARS-CoV-2 spike S1 subunit (S1) can cross the blood-brain barrier and elicit neuroinflammatory response independent of viral infection. Here we examined whether S1 influences blood pressure (BP) and sensitizes the hypertensive response to angiotensin (ANG) II by enhancing neuroinflammation and oxidative stress in hypothalamic paraventricular nucleus (PVN), a key brain cardiovascular regulatory center. Rats received central S1 or vehicle (VEH) injection for 5days. One week after injection, ANG II or saline (control) was subcutaneously delivered for 2weeks. S1 injection induced greater increases in BP, PVN neuronal excitation and sympathetic drive in ANG II rats but had no effects in control rats. One week after S1 injection, mRNA for proinflammatory cytokines and oxidative stress marker were higher but mRNA of Nrf2, the master regulator of inducible antioxidant and anti-inflammatory responses, was lower in the PVN in S1-injected rats than in VEH-injected rats. Three weeks after S1 injection, mRNA for proinflammatory cytokines and oxidative stress marker, microglia activation and reactive oxygen species in the PVN were comparable between S1 and VEH treated control rats but were elevated in two groups of ANG II rats. Notably, ANG II-induced elevations in these parameters were exaggerated by S1. Interestingly, ANG II increased PVN Nrf2 mRNA in VEH-treated rats but not in S1-treated rats. These data suggest that S1 exposure has no effect on BP, but post-S1 exposure increases susceptibility to ANG II-induced hypertension by downregulating PVN Nrf2 to promote neuroinflammation and oxidative stress and augment sympathetic excitation.

Spinal adenosine 2A receptor inhibition restores phrenic long-term facilitation during mild systemic inflammation

Inflammation undermines several forms of neuroplasticity, including phrenic long-term facilitation (pLTF), a form of respiratory motor plasticity elicited by moderate acute intermittent hypoxia (mAIH; 3, 5-min episodes, 5 min intervals; arterial PO2 ~ 40–50 mmHg). Mild inflammation elicited by a low dose of the TLR-4 receptor agonist lipopolysaccharide (LPS; 100 mg/kg, i.p.) abolishes mAIH-induced pLTF by a mechanism that requires spinal p38 MAP kinase and protein phosphatase activity. Neuroinflammation activates microglia and other cells in the CNS, elevating extracellular levels of adenosine—a purine nucleoside known to suppress mAIH-induced pLTF. We hypothesized basal adenosine levels in ventral spinal C 3 -C 5 segments are increased in adult male Sprague-Dawley rats 24 hours post-LPS administration, thereby undermining mAIH-induced pLTF via adenosine 2A receptor (A 2A ) activation. Thus, we predicted that cervical intrathecal administration of the A 2A receptor inhibitor MSX-3 (10 μM, 12 μL) would rescue mAIH-induced pLTF in rats pre-treated with LPS. As predicted, LPS significantly increased basal ventral C 3 -C 5 adenosine levels (p=0.010 vs controls; n=7 per group). In control rats (saline injection, i.p.), MSX-3 enhanced pLTF versus vehicle controls (LPS: 110 ± 16% baseline; controls: 53 ± 6%; p=0.002; each n=6). As expected, mAIH-induced pLTF was abolished in LPS-treated rats (4 ± 6% baseline; n=6). MSX-3 restored mAIH-induced pLTF to levels equivalent to MSX-3 treated control rats (120 ± 14%; p<0.001; n=6; versus LPS controls with MSX-3: p=0.539). Thus, mild LPS-induced inflammation abolishes mAIH-induced pLTF by a mechanism associated with increased spinal adenosine levels and A 2A receptor activation. As we move mAIH forward as a therapeutic modality to improve breathing and non-respiratory movements in people with spinal cord injury or ALS, pretreatment with A 2A receptor inhibitors may offset the undermining effects of systemic inflammation associated with these severe neuromuscular disorders. NIH HL147554, HL148030, T32HL134621 (ABM) and the UF McKnight Brain Institute This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dose-dependent effects of taurine against testicular damage in a streptozotocin-induced type 1 diabetes mellitus rat model.

Testicular dysfunction has been associated with chronic hyperglycemia in diabetes mellitus patients. We investigated taurine's possible mechanisms and protective effects against testicular damage using a rat model of streptozotocin-induced diabetes. Wistar rats (N = 56) were divided into seven equal groups. Untreated control rats received saline, and treated control rats received taurine 50mg/kg orally. To induce diabetes, rats received a single dose of streptozotocin. Metformin-treated diabetic rats received metformin at a dose of 300mg/kg. Taurine-treated groups received 10, 25, or 50mg/kg. All treatments were provided orally once a day for 9weeks following the streptozotocin injection. Levels of blood glucose, serum insulin, cholesterol, testicular tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1beta (IL-1β), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), and catalase (CAT) were examined. Sperm count, progressive sperm motility, and sperm abnormalities were examined. Body and relative reproductive gland weights were assessed. Histopathological examinations of the testes and epididymis were performed. Metformin as well as taurine (in a dose-dependent manner) resulted in significant improvements in body and relative reproductive gland weights, blood glucose, serum cholesterol, and insulin levels, as well as cytokine and oxidative parameters. These findings were associated with significant improvement in sperm count, progressive sperm motility, sperm abnormalities, and histopathological lesions in the testes and epididymis. Taurine can potentially improve hyperglycemia, hypercholesterolemia, and testicular damage associated with diabetes mellitus, possibly by controlling inflammation and oxidative stress.

Deficient Central Leptin Signaling “In Vivo” Alters Hypothalamic Levels of Circadian Clock Proteins Changing the Diurnal Eating Behavior in Rats

BackgroundLeptin, acting at CNS, decreases food intake (FI), body weight (BW) and adiposity, while circadian dysfunction induces hypothalamic leptin resistance associated to increased adiposity. Hence, we hypothesized that partial inhibition of hypothalamic leptin signaling “in vivo” would alter circadian rhythms resulting in changes in diurnal eating behaviors leading to increased adiposity and peripheral insulin resistance.Methods3‐months‐old Wistar rats were randomly assigned in two different groups: rats infused “in vivo” with saline (PBS) (n=12) or rats infused with a leptin antagonist (SLA) (0.2 micrograms/day) (n=12) via icv minipump insertion for 21 days. On day 0, rats were individually housed in metabolic cages and maintained for 21 days measuring daily BW, FI and locomotor activity. Hypothalamic proteomic analysis (n=6 per group) was carried out to determine if hypothalamic circadian proteins could be altered upon chronic SLA infusion. On day 21 and before sacrifice, one group of rats infused with PBS or SLA (n=6 per group) were injected icv with 100 ng of rat leptin in a volume of 2 microliters. 30 min later rats were euthanatized.ResultsSLA infusion decreased leptin‐induced phosphorylation of pY705‐STAT3 at the hypothalamus sustaining the induction of central leptin resistance upon chronic SLA administration. As a result, daily FI, final BW and visceral adiposity increased in SLA‐infused rats. Remarkedly, the diurnal eating behavior was altered in the SLA group of rats. In fact, daily FI was significantly increased by 48% only during the light phase in SLA infused vs PBS treated control rats, while in the dark phase FI increased less than 10% in the SLA group compared with control PBS‐infused rats. Moreover, SLA‐infused rats develop peripheral insulin resistance assessed by HOMA‐IR at the end of the treatment. Hypothalamic proteomic analysis revealed significant changes in 446 proteins, 266 were up‐regulated and 180 down‐regulated upon SLA infusion. Interestingly, proteins involved in the transcriptional activity of BMAL1/CLOCK were altered in SLA‐infused rats. Paraspeckle component 1, involved in the negative regulation of BMAL1/CLOCK, was over‐represented, while vasopressin‐neurophysin 2 copeptin, a positive regulator of circadian gene expression, was under‐represented.ConclusionOur results suggest that deficient hypothalamic leptin signaling is associated to circadian dysfunction which leads to changes in the diurnal eating behavior in rats resulting in increased adiposity and peripheral insulin resistance.

Abstract WMP9: Pharmacological Characterization Of The Water Soluble Neurosteroid NTS-104 In The Rat Embolic Stroke Model

Background: Our objective was to characterize the pharmacodynamic changes induced by NTS-104/105 within the brain and plasma in rats following embolic middle cerebral artery occlusion (eMCAO). Previous pharmacokinetic analysis indicated that NTS-104 is rapidly metabolized in the blood to form the active compound NTS-105, which is readily detected in the brain. In contrast, NTS-104 does not cross the blood-brain barrier. Methods: Adult, male Wistar rats were subjected to eMCAO. Stroke severity was defined by Neurological Severity Score (NSS) assessment. Only rats that scored >8 on a 13-point scale were included. Rats were dosed IM with vehicle, or NTS-104 (5mg/kg or 20mg/kg) at 6 hours after stroke. Brain and plasma samples rats were collected at 6, 12, or 24hrs after injection. Samples were screened for expression of AKT, pAKT and against a panel of 67 cytokines by quantitative ELISA. Results: We found that NTS-104 treatment induced a significant reduction in IL-6, GM-CSF, MCP-1, IL-1α, RAGE, VEGF, and ICAM-1 levels within the brains of rats following intramuscular injection of 20 mg/kg NTS-104 at 6-hours after eMCAO compared to vehicle treated control rats. In contrast, treatment with 5mg/kg NTS-104 did not induce similar time and dose dependent changes in these specific cytokines relative to vehicle treated controls. NTS-104 treatment also significantly reduced IL-6 and GM-CSF levels, while increasing galectin-1 levels, within the plasma of these same rats in a time and dose dependent manner similar to what was observed within the brain. We further detected a significant increase in the levels of phosphorylated AKT (pAKT) within the brains of stroked rats treated with 20 mg/kg NTS-104 but not with 5 mg/kg. Conclusion: These data demonstrate that treatment with NTS-104 results in the significant activation of the AKT cell survival signaling pathway and significantly reduces critical neuroinflammatory signaling after stroke in a time and dose dependent manner.

Adolescent Binge-Type Ethanol Exposure in Rats Mirrors Age-Related Cognitive Decline by Suppressing Cholinergic Tone and Hippocampal Neurogenesis.

Heavy alcohol consumption followed by periods of abstinence (i.e., binge drinking) during adolescence is a concern for both acute and chronic health issues. Persistent brain damage after adolescent intermittent ethanol exposure in rodents, a model of binge drinking, includes reduced hippocampal neurogenesis and a loss of neurons in the basal forebrain that express the cholinergic phenotype. The circuit formed between those regions, the septohippocampal pathway, is critical for learning and memory. Furthermore, this circuit is also altered during the aging process. Thus, we examined whether pathology in septohippocampal circuit and impairments in spatial behaviors are amplified during aging following adolescent intermittent ethanol exposure. Female and male rats were exposed to intermittent intragastric gavage of water (control) or 20% ethanol (dose of 5 g/kg) for a 2 days on/off cycle from postnatal days 25–55. Either 2 (young adult) or 12–14 (middle-age) months post exposure, rats were tested on two spatial tasks: spontaneous alternation and novel object in place. Acetylcholine efflux was assessed in the hippocampus during both tasks. There was no adolescent ethanol-induced deficit on spontaneous alternation, but middle-aged male rats displayed lower alternation rates. Male rats exposed to ethanol during adolescence had blunted behavioral evoked acetylcholine during spontaneous alternation testing. All ethanol-exposed rats displayed suppression of the cholinergic neuronal phenotype. On the novel object in place task, regardless of sex, ethanol-exposed rats performed significantly worse than control-treated rats, and middle aged-rats, regardless of sex or ethanol exposure, were significantly impaired relative to young adult rats. These results indicate that male rats display earlier age-related cognitive impairment on a working memory task. Furthermore, male rats exposed to ethanol during adolescence have blunted behavior-evoked hippocampal acetylcholine efflux. In addition, middle-aged and ethanol-exposed rats, regardless of sex, are impaired at determining discrete spatial relationship between objects. This type of pattern separation impairment was associated with a loss of neurogenesis. Thus, binge-type adolescent ethanol exposure does affect the septohippocampal circuit, and can accelerate age-related cognitive impairment on select spatial tasks.

Methyl Gallate Mitigates Doxorubicin-Induced Peripheral Cytopenias: A Preclinical Experimental Study

Myelosuppression by doxorubicin is a life-threatening adverse effect in cancer patients undergoing chemotherapy. Methyl gallate is an antioxidant found in a variety of plant species. The study aimed to demonstrate the protective role of methyl gallate on doxorubicin-induced cytopenias in Wistar rats. The animals were prophylactically treated with two different doses of methyl gallate (150mg/kg/day and 300mg/kg/day) orally for seven days. Doxorubicin (25mg/kg; single dose) was administered through intraperitoneal route on the seventh day to induce cytopenias. Blood was collected 24 hours after the administration of doxorubicin and complete blood counts were estimated. There was significant (p≤0.05) development of peripheral cytopenias in doxorubicin treated control rats compared to normal saline treated control rats. Methyl gallate at both the doses significantly (p≤0.05) mitigated doxorubicin induced cytopenias compared to doxorubicin treated control rats. The findings of the present study revealed that methyl gallate has protective role in doxorubicin-induced cytopenias in Wistar rats. Following clinical studies, methyl gallate may serve as a viable alternative to growth factors in patients undergoing chemotherapy.

Modulation of OPRM1 Alternative Splicing by Morphine and HIV-1 Nef.

Clinically used opioids, such as morphine, activate the mu opioid receptor (MOR) encoded by Opioid Receptor Mu 1 (OPRM1) gene. Examination of the opioid receptor genes showed that the human OPRM1 pre-mRNA undergoes extensive alternative splicing events and capable of expressing 21 isoforms. However, characterization of OPRM1 signaling is generalized, and only one isoform (MOR-1) has been extensively studied. Compounding this issue is the increasing significance of intravenous drug abuse in HIV neuropathogenesis. Here, we investigated the molecular impact of morphine and HIV-1 on regulation of OPRM1 pre-mRNA splicing in in vitro and in vivo models. Our results suggested that morphine treatment specifically induces the alternative splicing of MOR-1X isoform among the other isoforms analyzed in neuronal cells. Interestingly, alternative splicing and expression of MOR-1X isoform was also induced in postmortem brain tissues obtained from people with HIV (PWH). Additionally, treatment of control rats with morphine induced alternative splicing of MOR-1X in the brain regions involved in the reward pathways. More interestingly, HIV-1 transgenic (HIV-1Tg) rats, showed an additive induction of MOR-1X isoform with the exposure to morphine. To further assess the possible role of HIV secretory proteins in alternative splicing of OPRM1 gene, we analyzed the impact of HIV-1 Tat, gp120 and Nef proteins on alternative splicing of MOR-1X isoform. While the Tat and gp120 had no visible effects, treatment of neurons with Nef induced MOR-1X alternative splicing that was comparable to treatment with morphine. Altogether, our results suggest that HIV-1 may alter MOR isoform expression with Nef protein by amplifying the rate of MOR-1X alternative splicing induced by morphine.

Key indicators of repetitive overuse-induced neuromuscular inflammation and fibrosis are prevented by manual therapy in a rat model

BackgroundWe examined the effectiveness of a manual therapy consisting of forearm skin rolling, muscle mobilization, and upper extremity traction as a preventive treatment for rats performing an intensive lever-pulling task. We hypothesized that this treatment would reduce task-induced neuromuscular and tendon inflammation, fibrosis, and sensorimotor declines.MethodsSprague-Dawley rats performed a reaching and lever pulling task for a food reward, 2 h/day, 3 days/week, for 12 weeks, while simultaneously receiving the manual therapy treatment 3 times per week for 12 weeks to either the task-involved upper extremities (TASK-Tx), or the lower extremities as an active control group (TASK-Ac). Results were compared to similarly treated control rats (C-Tx and C-Ac).ResultsMedian nerves and forearm flexor muscles and tendons of TASK-Ac rats showed higher numbers of inflammatory CD68+ and fibrogenic CD206+ macrophages, particularly in epineurium, endomysium and epitendons than TASK-Tx rats. CD68+ and CD206+ macrophages numbers in TASK-Tx rats were comparable to the non-task control groups. TASK-Ac rats had more extraneural fibrosis in median nerves, pro-collagen type I levels and immunoexpression in flexor digitorum muscles, and fibrogenic changes in flexor digitorum epitendons, than TASK-Tx rats (which showed comparable responses as control groups). TASK-Ac rats showed cold temperature, lower reflexive grip strength, and task avoidance, responses not seen in TASK-Tx rats (which showed comparable responses as the control groups).ConclusionsManual therapy of forelimbs involved in performing the reaching and grasping task prevented the development of inflammatory and fibrogenic changes in forearm nerves, muscle, and tendons, and sensorimotor declines.

Study of the Acute Toxicity and Antipyretic Activity of the Aqueous Extract of the Bark Distemonanthus benthamianus Baill (Caesalpiniaceae: Leguminosae -Caesalpinioideae)

Aims: Distemonanthus benthamianus is a widespread plant in West Africa. The bark of its stem is used popularly to treat a variety of illnesses, including fever, bronchitis, rheumatism and malaria. The objective of this work is to evaluate the antipyretic activity of the aqueous extract of the bark of Distemonanthus benthamianus.
 Materials and Methods: The aqueous extract of the bark of D. benthamianus was tested for their acute oral toxicity in rats. Antipyretic activity was studied in rats of the Wistar strain made feverish after subcutaneous injection of an aqueous suspension of brewer's yeast (Saccharomycete cerevisiae) 20% compared to aspirin.
 Results: This study showed that administration of the extract at doses of 300, 2000 and 5000 mg / kg / kg dry extract in rats showed no acute toxicity or adverse effects. The results showed that the best antipyretic activity of the extract was recorded at a dose of 800 mg / kg, at the third hour, with a decrease in fever from 39.29 ± 0.14°C to 37.75 ± 0.25°C, i.e. a percentage inhibition of 57% against 62% for the standard molecule (p> 0.05). At this dose, CRP was 3.85 ± 0.1 mg / L compared to that of the healthy control which was 2.78 ± 0.35 mg / L. The results of the albumin assay did not show a significant difference between the treated and untreated fever groups and the healthy control group. In addition, the results showed that the leukocyte level in the feverish control rats is very high (18.84 103 / mm3 of leukocytes) compared to the healthy and treated control rats.
 Conclusion: The aqueous extract of the bark of Distemonanthus benthamianus is not oral toxic and has interesting antipyretic activities similar to aspirin. The results obtained confirm the validity of the traditional indication of this plant in the management of fever by African populations.

NEUROCHEMICAL AND HISTOLOGICAL BRAIN ALTERATIONS AFTER TRAMADOL ADMINISTRATION TO ROTENONE- INDUCED PARKINSON'S DISEASE IN RATS

Objective: Tramadol is favorably used for relief of moderate and severe pain. Over 30% of Parkinson’s disease (PD) patients experience persistent pain that has a negative impact on their quality of life. However, its physiological effect in such disorder has not been studied. The current study aimed at investigating the neurochemical and histopathological changes resulting from tramadol administration to experimental PD- induced by rotenone in rats. Methodology: Forty adult male Sprague-Dawley rats were allocated into 5 equal groups; Group 1(control) received saline p.o and DMSO, s.c., Group 2(Rotenone) received rotenone (1.5 mg/kg, s.c., every other day for 12 days), Group 3 (Tramadol) received tramadol HCl given p.o., daily at doses of 20 mg/kg, Group 4 (Rot-Trama 10) PD-induced with rotenone and treated with tramadol HCl, 10 mg/kg, p.o., daily, Group 5(Rot-Trama 20) PD-induced with rotenone and treated with tramadol HCl, 20 mg/kg, p.o., daily. Results : PD-induced rats exhibited significantly reduced dopamine (DA) content (- 33.0%), increased serotonin ( 5-HT) content (+ 11.5%), but no change in 5-hydroxyindole acetic acid (5-HIAA) compared to vehicle-treated counterparts. Rotenone also inhibited both brain paraoxonase 1 (PON1) and acetylcholinesterase (AChE) activities and increased brain oxidative stress causing reduced glutathione depletion by 32% and increasing thiobarbituric acid reactive substances (TBARS), nitric oxide (NO) by 43% and 81%, respectively. Rotenone caused the appearance of apoptotic neurons with cytoplasmic vacoulations. On the other hand, tramadol -treated control rats showed increased DA (74%), 5-HT (23%), 5-HIAA (50%) contents and decreased serotonin turnover (18.0%) without causing oxidative stress. In rotenone-intoxicated rats, tramadol (10 or 20 mg/kg) increased brain dopamine and at 20 mg/kg increased 5-HT and 5-HIAA. The drug increased PON-1 activity, restored AChE activity and alleviated the changes in lipid peroxidation and reduced glutathione, increased tumour necrosis factor-alpha (TNF-α) without changing the histopathological changes caused by rotenone. Conclusion: These results indicate that short-term use of tramadol in an experimentally-induced PD has dual effects that should be carefully weighed. Tramadol decreased oxidative stress and restored normal DA content and AChE activity that can help in PD. However, the drug resulted in increased proinflammatory cytokine TNF-α and 5-HT level.

Antihypertensive and Renal Protective Effects of Oryeongsan in Spontaneously Hypertensive Rats.

Oryeongsan (ORS), a traditional medicine used to regulate body fluids, has a long history of use as a diuretic in Korea, China, and Japan. ORS is commonly thought to lower blood pressure, but high-quality data on its effects are sparse. The purpose of this study was to determine the antihypertensive and renal protective effects of ORS in rats with hypertension. Spontaneously hypertensive rats (SHR) were divided into two groups with similar mean baseline systolic blood pressure (SBP) and diastolic blood pressure (DBP). Then, 10 mL/kg of vehicle (distilled water) or 200 mg/kg of ORS extract were administered orally once a day for 3 weeks. SBP and DBP were measured at weeks 1, 2, and 3. At the end of the experiment, blood was collected, and kidneys were removed for histology. By the 2nd and 3rd week after initiation of treatment, the ORS-treated group had significantly lower SBP than control-treated rats (191.3 ± 6.5 vs. 206.3 ± 9.8 mmHg, p = 0.022 at the 2nd week; 195.8 ± 7.8 vs. 217.0 ± 8.1 mmHg, p = 0.003 at the 3rd week, respectively). The ORS-treated group trended toward having a lower DBP than control, but there was no significant difference. Blood urea nitrogen (BUN) and serum creatinine (Cr) were not different between the ORS-treated and control groups (BUN: 23.7 ± 1.1 vs. 22.7 ± 2.8 mg/dL, p = 0.508; Cr: 19.0 ± 2.2 vs. 21.6 ± 2.1 μM, p = 0.083, respectively). The percentage of renal tissue affected by tubulointerstitial fibrosis was significantly lower in the ORS-treated group (1.68 ± 0.60) compared to controls (3.17 ± 0.96, p = 0.019). These findings suggest that treatment with ORS reduces SBP and ameliorates renal damage in SHR.

Effects of thiamine treatment on oxidative stress in experimental diabetes.

Hyperglycemia, oxidative stress and hyperlipidemia are features of diabetes mellitus. Thiamine has beneficial effects on carbohydrate metabolism and it was proposed that this vitamin has antihyperlipidemic and antioxidant effects. Our aim was to investigate the effects of thiamine on oxidative stress and metabolic changes in streptozotocin (STZ) induced diabetic rats. Diabetes was induced by a single intraperitoneal injection of STZ. Thiamine (6 mg/kg) was added to drinking water for five weeks. The rats were divided into four groups: control rats; thiamine treated control rats; diabetic rats; thiamine treated diabetic rats. Plasma and tissue malondialdehyde (MDA) levels were measured by high-performance liquid chromatography and spectrophotometry, respectively. Paraoxonase (PON) and arylesterase (AE) activities were measured with spectrophotometric methods, and erythrocyte superoxide dismutase (SOD) and blood glutathione peroxidase (GSH-Px) activities were determined using commercial kits. Thiamine treatment reduced plasma and tissue MDA levels, serum glucose, total cholesterol and triglyceride levels, and increased serum high density lipoprotein- cholesterol and insulin levels, serum PON and AE, erythrocyte SOD and blood GSH-Px activities. Thiamine significantly improves oxidative stress and has hyperinsulinemic and antihyperlipidemic effects so we suggest that thiamine might be used as a supportive therapeutic agent in diabetes (Tab. 2, Fig. 3, Ref. 53).

P4466Empagliflozin improves heart function after myocardial infarction in the rat

Abstract Background Selective Sodium-glucose cotransporter 2 (SGLT2) inhibition with Empagliflozin reduced progression of left ventricular dysfunction and improved tolerance of physical exercise in heart failure by normoglycemic rats. Here, we hypothesized that Empagliflozin prevents cardiac dysfunction after myocardial infarction (MI). Purpose This study aimed to investigate whether Empagliflozin protects the heart in the early phase after experimental MI in normoglycemic rats. Methods MI was induced in Wistar rats via permanent ligation of the left coronary artery. Treatment with Empagliflozin (1 mg/kg/daily per os) was started after MI and continued for 7 days. Sham operated and vehicle treated animals served as controls (n=8). Hemodynamic parameters were measured via transthoracic echocardiography and intracardiac Samba catheter. Glucose concentration was determined in serum and urine. Protein expression of Na+/H+ exchanger isoform-1 (NHE-1), sodium bicarbonate co-transporter (NBC), Sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA), transforming growth factor beta 1 (TGF-beta1), Smad2 in the left ventricle were also studied. Additionally, NHE-1 regulation was investigated in cardiomyocyte cell line H9c2. Results Systolic heart function was improved in Empagliflozin treated MI animals compared to vehicle as demonstrated by Global Longitudinal Strain (GLS) (20,9% vs. 16,6%; p<0.05). E/A ratio was decreased by tendency and blood pressure was not affected. Ejection fraction (p<0.05), fractional shortening (p<0.05), stroke volume (p<0.01) were increased in Empagliflozin treated control rats as compared with the sham group. Moreover, application of Empagliflozin (1mg/kg, i.v. bolus) to healthy rats in 30 min increased maximal pressure in the left ventricle as compared with vehicle (110,5±15,3 mmHg vs 79,1±11,9 mmHg; p<0.05). Parallel, dP/dtmax was increased while dP/dtmin was decreased by tendency. Empagliflozin treatment did not affect glucose concentration in serum and urine. Treatment of cardiac H9c2 cells with Empagliflozin (1μM) down-regulated NHE-1 by 27%. Conclusion SGLT2 inhibitor Empagliflozin improved systolic function in the early phase post MI independently from glucose regulation. The cardioprotective mechanisms of SGLT2 inhibitors may involve cardiac NHE-1 exchanger inhibition.

Effects of Ethanolic Moringa Oleifera Extract on Melatonin, Liver and Kidney Function Tests in Alloxan-Induced Diabetic Rats

Moringa oleifera Lam. contains many active ingredients with nutritional and medicinal values. The aims of this study were to determine the effect of ethanolic moringa oleifera extract on glucose, melatonin, lipid profile, liver, and kidney function in alloxan induced diabetes Induced Diabetes in rats. Diabetes was induced in male Wistar rats by single intra peritoneal injection of alloxan (150 mg/kg b. wt.).The diabetic rats were administered orally with EMOE at two different doses (250 and 500 mg/kg b. wt./day) for 60 days. The alloxan treated control rats showed a significant increase in glucose (BS), total cholesterol (STC), triglycerides (STG), low density lipoprotein cholesterol (LDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatases (ALP), urea creatinine with a concomitant decrease in serum melatonin, lactate dehydrogenase (LDH), and high density lipoprotein cholesterol (HDL).Oral administration of MOLEt (250 and 500 mg/kg b. wt./day) for 60 days showed significant reduction in BS, STC, STG, LDL, ALP, ALT, AST and LDH, urea creatinine levels and an elevation in serum melatonin, LDH, and HDL levels in diabetic group as compared with control group.

Novel "Dual Hit" Rat Model of Diabetic Cardiomyopathy

The pathogenesis of diabetic cardiomyopathy (DC) is poorly understood and new drugs targeting the myocardium are absent. This may be ascribed to the failure of available pre-clinical models to recapitulate essential clinical features of DC and heart failure. We hypothesized that the combination of experimental diabetes and pharmacologically induced cardiac stress might provide a novel rat model displaying a distinct profile of DC. Non-insulin dependent type 1 like diabetes mellitus was induced by partial (90%) pancreatectomy (Px). Pronounced hyperglycemia was established within two weeks (blood glucose levels of 23.3 ± 3.7 mM). Five weeks post Px or sham surgery, vehicle or the sympathomimetic agent, isoproterenol (Iso, 1 mg/kg, SC) was administered for 10 days. Ten weeks after surgery, the heart was isolated for detailed histological and molecular characterization. The relative weight of the left ventricle (LV) was significantly increased in Px-Iso rats compared to sham-vehicle treated control rats (0.22 ± 0.03 vs. 0.25 ± 0.02 mg/g BW, p<0.05), indicating Px-Iso-induced cardiac hypertrophy. Compared to sham-vehicle rats, cardiac muscle fibers of Px-vehicle rats had attenuated respiratory function and increased reliance upon oxidation of fatty acid substrates, measured by high-resolution respirometry. Interestingly, this aggravation was reversed in Px-Iso rats. Moreover, Iso induced cardiac fibrosis demonstrated by quantitative histology (area fraction; Px-vehicle vs. Px-Iso: 3.1 ± 0.2% vs. 6.3 ± 0.5%; Sham-vehicle vs. Sham-Iso: 3.7 ± 0.4% vs. 7.6 ± 0.5%, p<0.001). Echo- and electrocardiography as well as transcriptome analyses were applied to further assess LV remodeling and cardiac function. In conclusion, the Px-Iso rat model may provide a state-of-the-art model of DC displaying key features of the clinical condition. Hereby, this model may be useful in the evaluation of cardiovascular effects of novel compounds in the pre-clinical phase of drug development. Disclosure L. Thisted: Employee; Self; Gubra. R.T. Lindsay: None. K. Fosgerau: Stock/Shareholder; Self; Novo Nordisk A/S. Employee; Self; Gubra. Stock/Shareholder; Self; Gubra. T. Secher: Employee; Self; Gubra. Employee; Spouse/Partner; Novo Nordisk A/S. M.B. Thomsen: None. T. Jespersen: None. A.J. Murray: None. P.J. Pedersen: None. N. Vrang: Board Member; Self; Gubra. Employee; Self; Gubra. Stock/Shareholder; Self; Gubra. L.N. Fink: Employee; Self; Gubra. Stock/Shareholder; Self; Novo Nordisk A/S. T.X. Pedersen: Employee; Self; Gubra. N.E. Zois: Employee; Self; Gubra.

Alleviative effect of resveratrol on polyvinyl chloride-induced reproductive toxicity in male Wistar rats

The present study was aimed to investigate the effect of PVC on reproductive competence in adult male Wistar rats. Further, the study also encompasses the protective effect of trans-resveratrol on PVC-induced reproductive toxicity in rats. Adult male rats weighing 210–240 g were administered with either PVC at two different doses 100 and 500 mg/kg body weight, orally, daily for 60 days or resveratrol (20 mg/kg body weight/day) through gavage for 60 days on alternate days or both PVC (500 mg/kg body weight) and resveratrol. The results revealed significant reduction in the weights of reproductive organs, epididymal sperm count, viable-, motile-, and HOS-tail coiled sperm and testicular daily sperm production, steroidogenic enzyme activities, serum testosterone levels in PVC treated rats. Conversely the levels of lipid peroxidation increased significantly with a decrease in activity levels of antioxidant enzymes in the testis of PVC exposed rats. Exposure to PVC resulted in reduction in epithelial thickness and seminiferous tubule diameter. No significant changes in the selected reproductive variables were observed in the resveratrol alone treated control rats, whereas, co-administration of resveratrol and PVC resulted in a significant improvement in steroidogenesis and spermatogenesis and mitigated oxidative stress over PVC exposed rats.