Aorta Of Male Rats Research Articles

Greater TIMP-1 protein levels and neointimal formation represent sex-dependent cellular events limiting aortic vessel expansion in female rats.

Fragmentation/loss of the structural protein elastin represents the precipitating event translating to aortic expansion and subsequent aneurysm formation. The present study tested the hypothesis that greater protein expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and neointimal growth secondary to a reduction of medial elastin content represent sex-dependent events limiting aortic vessel expansion in females. TIMP-1 protein levels were higher in the ascending aorta of female versus male patients diagnosed with a bicuspid aortic valve (BAV). The latter paradigm was recapitulated in the aorta of adult male and female rats complemented by greater TIMP-2 expression in females. CaCl2 (0.5 M) treatment of the infrarenal aorta of adult male and female rats increased the in situ vessel diameter and expansion was significantly smaller in females despite a comparable reduction of medial elastin content. The preferential appearance of a neointimal region of the CaCl2-treated infrarenal aorta of female rats may explain in part the smaller in situ expansion and neointimal growth correlated positively with the % change of the in situ diameter. Neointimal formation was secondary to a significant increase in the density of medial/neointimal vascular smooth muscle cells (VSMCs) that re-entered the G2-M phase whereas VSMC cell cycle re-entry was attenuated in the CaCl2-treated infrarenal aorta of male rats. Thus, greater TIMP-1 expression in the aorta of female BAV patients may prevent excessive elastin fragmentation and preferential neointimal growth following CaCl2-treatment of the infrarenal aorta of female rats represents a sex-dependent biological event limiting vessel expansion secondary to a significant loss of the structural protein.

Evaluation of the therapeutic effects of oestradiol on the systemic inflammatory response and on lung injury caused by the occlusion of the proximal descending aorta in male rats.

Ischaemia and reperfusion-induced microvascular dysfunction is a serious problem encountered during a variety surgical procedures, leading to systemic inflammation and affecting remote organs, specially the lungs. 17β-Oestradiol reduces pulmonary repercussions from various acute lung injury forms. Here, we focused on the 17β-oestradiol therapeutic effects after aortic ischaemia and reperfusion (I/R) by evaluating lung inflammation. Twenty-four Wistar rats were submitted to I/R by insufflation of a 2-F catheter in thoracic aorta for 20 min. Reperfusion took 4 h and 17β-oestradiol (280 µg/kg, i.v.) was administered after 1 h of reperfusion. Sham-operated rats were controls. Bronchoalveolar lavage was performed and lung samples were prepared for histopathological analysis and tissue culture (explant). Interleukin (IL)-1β, IL-10 and tumour necrosis factor-α were quantified. After I/R, higher number of leukocytes in bronchoalveolar lavage were reduced by 17β-oestradiol. The treatment also decreased leukocytes in lung tissue. I/R increased lung myeloperoxidase expression, with reduction by 17β-oestradiol. Serum cytokine-induced neutrophil chemoattractant 1 and IL-1β increased after I/R and 17β-oestradiol decreased cytokine-induced neutrophil chemoattractant 1. I/R increased IL-1β and IL-10 in lung explants, reduced by 17β-oestradiol. Our results showed that 17β-oestradiol treatment performed in the period of reperfusion, modulated the systemic response and the lung repercussions of I/R by thoracic aortic occlusion. Thus, we can suggest that 17β-oestradiol might be a supplementary approach leading the lung deterioration after aortic clamping in surgical procedures.

Gut Microbiota Perturbation in Early Life Could Influence Pediatric Blood Pressure Regulation in a Sex-Dependent Manner in Juvenile Rats.

The present study aimed to investigate whether gut dysbiosis induced by ceftriaxone in early life could influence pediatric blood pressure regulation in childhood with or without exposure to a high-fat diet (HFD). Sixty-three newborn pups of Sprague-Dawley rats were administered ceftriaxone sodium or saline solution until weaning at 3 weeks, and the rats were fed a HFD or regular diet from 3 to 6 weeks. Tail-cuff blood pressure, the expression levels of genes of the renin-angiotensin system (RAS), the concentrations of IL-1β, IL-6, and TNF-α in the colon and prefrontal cortex, and the composition of fecal microbiota were analyzed. Ceftriaxone treatment significantly increased the diastolic blood pressure of male rats at 3 weeks. At 6 weeks, systolic blood pressure (SBP) was significantly increased only in ceftriaxone treated male rats fed with HFD. The RAS showed increased activation in the kidney, heart, hypothalamus, and thoracic and abdominal aorta of male rats, but only in the kidney, heart, and hypothalamus of female rats. HFD-fed female rats showed a decreased level of IL-6 in the colon. α diversity of gut microbiota decreased and the Firmicutes to Bacteroidetes ratio increased in both male and female rats at 3 weeks; however, these parameters recovered to various degrees in female rats at 6 weeks. These results revealed that early-life gut dysbiosis induced by antibiotics combined with a HFD in childhood could be involved in pediatric blood pressure regulation and an increase in SBP in juvenile rats, and these effects occurred in a sex-dependent manner.

Sex-dependent vascular effects of cadmium sub-chronic exposure on rats.

Cadmium exposure is related to several cardiovascular diseases, such as hypertension, atherosclerosis and endothelial dysfunction. However, the toxic effect of cadmium can be dependent on the sex when examined sex in experimental models. The aim of this study was to analyze the effects of cadmium exposure on the cardiovascular system of male and female rodents. The experiments were carried out on both-sexes Wistar at 4months of age, where from 3months onwards, cadmium (CdCl2 100mg/l in placed the drinking water for 30days) or vehicle delivered (distilled water) was ingested. Before and after 30days of exposure to cadmium, systolic blood pressure was regularly measured. After exposure, blood was collected to measure dosage of cadmium, in male and female, and estrogen in females. Vascular reactivity to phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP) was studied at respective isolated aortic segments. After the period to Cd-exposure, systolic blood pressure was increased only in the male rats. Males also had higher levels of plasma cadmium than those of female rats, and exposure to the metal did not affect the amount of estrogen produced in the female rats. Increased myeloperoxidase (MPO) activity was also observed in both the males and females that had been exposed to the metal. Moreover, exposure to the cadmium reduced the ACh relaxation and increased vascular reactivity to Phe, resulting in an imbalance between nitric oxide superoxide anion in the isolated aorta of male rats. In female rats, sub-chronic cadmium exposure did not modify the vascular reactivity to Phe and neither to the ACh. The present study revealed that the Cd exposure for 30days induced sex-dependent cardiovascular abnormalities.

Modulatory effects of 17β-estradiol on acute lung inflammation after total occlusion of the descending aorta in male rats

As a consequence of systemic inflammation caused by ischemia and reperfusion (I/R) due to aortic occlusion, the lungs can exhibit increased microvascular permeability, local release of pro-inflammatory mediators, and leukocyte infiltration. Lung tissue infiltration by activated neutrophils is followed by acute respiratory distress syndrome, which is linked to acute pulmonary microvascular damage, high mortality rates, and organ dysfunction. Previous studies have demonstrated that female sex hormones modulate the inflammatory response and that prophylactic treatment with 17β-estradiol (E2) can prevent fatalities and preserve mesenteric perfusion and intestinal integrity after ischemia/reperfusion induced by aortic occlusion. In this study, we focused on the protective effects of estradiol after aortic ischemia/reperfusion by evaluating lung injury and endothelial alterations. Upon anesthesia and mechanical ventilation, male rats were subjected to aortic occlusion for 20 min, followed by 2 h of reperfusion. In parallel, one group of rats received a single injection of estradiol (280 µg/kg, i.v.) 30 min before ischemia. We observed increased serum concentrations of IL-1β, IL-6 and IL-10 in the I/R rats and E2 was able to reduce them. E2 effects after 2 h of reperfusion resulted mainly in decreasing of edema, iNOS expression and preventing leukocyte infiltration. Overall, our data indicate that estradiol might be a supplementary approach to deal with systemic processes and lung deterioration.

Aortic Relaxation in Castrated Male Rats and Responses to Estrogen Treatment

Previous studies suggest that risk factors for cardiovascular diseases (CVD) have increased in the transgender population after they undergo cross‐sex hormone therapy (CSHT). Several studies, including ours in animal models as well as in humans, have shown that estrogen exerts direct beneficial effects on the vessel wall in healthy females. A growing body of evidence also suggests that androgen exhibits protective actions on the cardiovascular system. However, the effects of CSHT in cardiovascular physiology in males or females are less understood.The current study was, therefore, undertaken to evaluate the effects of estrogen treatment on aortic reactivity in castrated (CAS) male rats. Specifically, we investigated the effects of in vivo treatment with 17β‐estradiol (E2) on the aortic responses of CAS male as well as ovariectomized (OVX) female rats.Age‐matched CAS male and OVX female rats were implanted subcutaneously with either 17β‐estradiol (E2,1.5 mg) or a placebo‐containing pellet for 30 days. Endothelium‐dependent vasorelaxation (EDV) in response to acetylcholine (ACh, 10‐8 to 10‐5 M) in aorta precontracted with phenylephrine (PE, 2 µM) was measured before and after pretreatment with indomethacin (10 µM, cyclooxygenase inhibitor), followed by N‐nitro‐ L‐arginine methyl ester [L‐NAME, 200 µM, a nonselective nitric oxide synthase (NOS) inhibitor]. Endothelium‐independent vasorelaxation was assessed by measuring sodium nitroprusside (SNP)‐induced relaxation response in endothelium‐denuded rings in addition to the contractile response curves to PE before and after pretreatment with L‐NAME in aortic rings.EDV to ACh was significantly impaired in aortic rings from E2‐treated CAS rats compared to their placebo‐treated counterparts and E2‐treated OVX rats. The impairment of EDV to ACh in E2‐treated CAS rats was accompanied by a significant decrease in nitric oxide (NO) contribution to ACh‐induced relaxation in this group. The smooth muscle sensitivity to NO as measured by SNP relaxation response curve was not altered, whereas the responsiveness to PE was slightly enhanced in the aortas of E2‐treated CAS group compared to those in other experimental groups. Endothelium‐derived NO release during smooth muscle contraction, as assessed by the potentiation of the response to PE after NOS inhibition, was not different in the aortas of experimental groups.Overall, our data demonstrate that aortic function was altered in E2‐treated CAS male rats. Here, we provide the first evidence of impairment in aortic relaxation in E2‐treated CAS male rats, possibly via a significant decrease in the relative contribution of NO to the regulation of vascular relaxation response. Furthermore, the comparison of current data in the CAS male rats with our recently published data on the aortic reactivity in the intact males appears to rule out any effect of testosterone deprivation on the stimulated release of NO in male rat aortas. Additional studies will be needed to document the direction and magnitude of CSHT interaction with vasculatures.

Effects of sub-chronic, in vivo administration of sigma non-opioid intracellular receptor 1 ligands on platelet and aortic arachidonate cascade in rats

Platelets regulate cell-cell interactions and local circulation through eicosanoids from arachidonic acid. Sigma non-opioid intracellular receptor 1 (sigma-1 receptor) expressed in platelets and endothelial cells can regulate intracellular signalization. Our aim was to examine the influence of sub-chronic, in vivo-administered sigma-1 receptor ligands 2-morpholin-4-ylethyl 1-phenylcyclohexane-1-carboxylate (PRE-084); N-benzyl-2-[(1S)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl]ethan-1-amine; dihydrochloride, a new compound ((S)-L1); and N-[2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethyl]-N-propylpropan-1-amine (NE-100) on the ex vivo arachidonic acid metabolism of the platelets and aorta of male rats. The serum level of sigma-1 receptor ligands was determined by liquid chromatography-mass spectrometry. Sigma-1 receptor and cyclooxygenase gene expression in the platelets were determined by a reverse transcription-coupled quantitative polymerase chain reaction. The eicosanoid synthesis was examined using a radiolabeled arachidonic acid substrate and enzyme-linked immunosorbent assay. We confirmed the absorption of sigma-1 receptor ligands and confirmed that the ligands were not present during the ex vivo studies, so their acute effect could be excluded. We detected no changes in either sigma-1 receptor or cyclooxygenase mRNA levels in the platelets. Nevertheless, (S)-L1 and NE-100 increased the quantity of cyclooxygenases there. Both platelet and aortic eicosanoid synthesis was modified by the ligands, although in different ways. The effect of the new sigma-1 receptor ligand, (S)-L1, was similar to that of PRE-084 in most of the parameters studied but was found to be more potent. Our results suggest that sigma-1 receptor ligands may act at multiple points in arachidonic acid metabolism and play an important role in the control of the microcirculation by modulating the eicosanoid synthesis of the platelets and vessels.

Histopathological and Morphometric Study of the Effect of Stanozolol on the Aorta of Male Rats

The study aimed to find the histopathological and morphological effects of stanozolol, with different concentrations and periods on the aorta in the male rats. The study comprised 80 white males which set into four groups, with 20 rats for each group. First group set as control group and was left only on tap water and fed with pellets. Second group was injected with stanozolol 25 mg / kgbw and the third group was injected with stanozolol 25 mg / kgbw with vit.E 600 mg / kgbw while fourth group was treated with vit.E 600 mg / kgbw. The period of treatment was extend for 8 weeks, animals were euthanized at fourth, eighth and twelfth week after starting treatment. Histological sections of the aorta in the second group showed the presence of histological changes in the aorta represented by the placement of the fat droplets in all layers of the aortic wall accompanied by the enlarged nuclei of the smooth muscle cells. It was observed that the intensity of histopathological changes increased in week 8 and even at 12 weeks despite of the treatment was interrupted. The proliferation of smooth muscle cells toward the endothelium was observed with endothelial cell enlargement. In the third group, after four and eight weeks, thickening of the aorta lining was found with the deposition of the fat droplets as well as elastic fibers degeneration. The fibers replaced by fat droplets in the middle layer. In the fourth group, no histopathological changes were observed for all periods. The micromorphometric measurements of the all groups presented a significant increment in aortic diameter at a level p≤ 0.05 when compared with the control group.

Protective effects of 17β-oestradiol on coagulation and systemic inflammation after total occlusion of the descending aorta in male rats.

The surgical treatment for diseases of the descending aorta is related to a high mortality rate because of the activation of a systemic inflammatory process due to ischaemia and reperfusion (I/R) injury. Activation of coagulation can contribute to the inflammatory process, resulting in microcirculatory damage and multiple organ failure. Our goal was to evaluate the role of prophylactic intravenous 17β-oestradiol (E2) in coagulation, the inflammatory response and hepatic injury after occlusion of the descendent proximal aorta in male rats. Wistar male rats were randomized and allocated to 3 groups (n = 8 per group): sham, surgically manipulated; IR, animals subjected to I/R; and E2, animals treated with E2 (280 µg/kg, intravenously) before I/R. I/R was induced by insertion of a 2-Fr Fogarty arterial embolectomy catheter in the descending aorta, which was occluded for 20 min, followed by a reperfusion period of 2 h. Serological markers, platelet aggregation, hepatic vascular flow, systemic and liver inflammatory response and apoptosis were analysed. The coagulation process was evaluated by thromboelastometry. The aortic occlusion led to a reduction in plasma fibrinogen concentration in parallel with increased clotting time, greater clot firmness and reduced lysis. E2 treatment was able to increase fibrinogen, prevent the increase in clotting time and normalize clot firmness, but it exerted only a mild effect on clot lysis. Platelet aggregation was increased by IR, and E2 treatment was able to reduce it. There was a reduction in flow percentage in the IR group that was not prevented by E2. In parallel, higher aggregate formation was observed in the vessels of the IR group of animals. There was increased systemic release of interleukin-1-β, interleukin-6 and interleukin-10 in the IR group, which was reduced in the treated animals. The current results suggest that pretreatment with E2 before an ischaemic period induced by occlusion of the proximal descending aorta is effective in preventing alterations in coagulation and systemic inflammation due to I/R injury.

Effect of Estrogen and Progesterone Hormones on the Expression of Angiotensin II Receptors in the Heart and Aorta of Male Rats.

Activation of the Angiotensin II type 1 receptor (AT1R) has been implicated in the pathogenesis of the cardiovascular disease, while activation of Angiotensin II type 2 receptor (AT2R) leads to effects that are opposite to those mediated by AT1R. The interaction between female sex hormones and the renin-angiotensin system was proven to play an essential role in the pathological changes in the cardiovascular system. To investigate the direct effect of estrogen and progesterone on arterial and cardiac AT1R and AT2R expression in vivo in male. Male adult rats were assigned into four groups: Group 1 (control), group 2 (progesterone treated group; 10mg/kg), group 3 (estrogen treated group; 20μg/kg) and group 4 (progesterone; 10mg/kg + estrogen; 20μg/kg treated group). All treatments were administrated subcutaneously every second day for 21days. Estrogen treatments increase the left ventricle (LV) protein expression of AT1R, and progesterone treatment decreased the LV protein expression of AT2R. In the aorta, estrogen treatment increased the mRNA expression levels of AT1R, while progesterone treatment increased the AT2R mRNA expression levels. Estrogen treatment decreases the LV and aortic endothelial nitric-oxide synthase (eNOS) mRNA levels while progesterone treatments decrease the LV eNOS mRNA levels but increase the aortic eNOS mRNA levels. The serum angiotensin II levels were increased by estrogen treatment only. Both estrogen and progesterone treatments appear to have a harmful effect on the male rat hearts, possibly by increasing the protein expression of AT1R (for estrogen), decrease the protein and mRNA expression of AT2R (for progesterone), and decrease the eNOS mRNA levels (for both). However, it seems that progesterone but not estrogen exerts a vascular protective effect in males.

Abstract P078: Sex Differences In Aortic Stiffness Following Simulated Microgravity In Middle Aged Rats

Men and women have different cardiovascular responses to spaceflight. We determined sex differences in arterial stiffness, an independent risk factor for cardiovascular dysfunction, in rats after the exposure to 14-days of simulated weightlessness via hindlimb unloading (HLU). Male and female Sprague-Dawley rats at 20 weeks of age were either tail suspended via HLU or remained full-weight bearing in similar cages. Female control rats had lower body weight compared with males. There was no significant effect of HLU on body weight in either male or female rats. Our data demonstrate that HLU increased aortic pulse wave velocity, an index of arterial stiffness, in female rats (2.7 fold vs. control female- adjusted for body weight, n=5-6), but not in males. HLU had no effect on the levels of structural proteins (alpha smooth muscle actin or myosin) in either female or male rats. The levels of G-protein-coupled estrogen receptor 1 (GPER) were lower in the thoracic aorta of female rats exposed to HLU compared with female controls (0.3±0.02 vs. 0.39±0.01 relative density, p<0.05, n=6-7); lower aortic GPER levels were associated with greater aortic media thickness (110.5±4.2 vs. 97.1±3.1 μm, p<0.05, n=5) and lower COX-2 protein levels (0.47±0.04 vs. 0.61±0.02 relative density, p<0.05, n=3-4). However, no differences in GPER, aortic media thickness, or COX-2 were observed in the aortas of male rats after HLU versus male controls. The administration of GPER agonist, G1 (400 ug/kg/day) prevented the increase in aortic pulse wave velocity in the intact females following HLU (2.2±0.2 vs. 9.7±1.8, p<0.05, n=4). Our data demonstrate sex differences in aortic stiffness in response to simulated microgravity. Since GPER has many protective actions in the cardiovascular system, a dysregulation of estrogen signaling may attenuate the protection of females from cardiovascular dysfunction following the exposure to spaceflight stressors.

Cholesterol Receptors Behavior In Aging Male Rat Aorta..The Effect Of Serum Factors From Patients With Lipid Metabolic Disorders

Cholesterol Receptors Behavior In Aging Male Rat Aorta..The Effect Of Serum Factors From Patients With Lipid Metabolic Disorders

Acute administration of oestradiol or progesterone in a spinal cord ischaemia–reperfusion model in rats

Despite research into protective pharmacological adjuncts, paraplegia persists as a dreaded complication after thoracic and thoracoabdominal aortic interventions. Reports on gender-related neurological outcomes after ischaemic and traumatic brain injuries have led to increased interest in hormonal neuroprotective effects and have generated other studies seeking to prove the neuroprotective effects of the therapeutic administration of 17β-oestradiol and of progesterone. We hypothesised that acute administration of oestradiol or progesterone would prevent or attenuate spinal cord ischaemic injury induced by occlusion of the descending thoracic aorta. Male rats were divided into groups receiving 280 µg/kg of 17β-oestradiol or 4 mg/kg of progesterone or vehicle 30 min before transitory endovascular occlusion of the proximal descending thoracic aorta for 12 min. Hindlimb motor function was assessed by a functional grading scale (that of Basso, Beattie and Bresnahan) for 14 days after reperfusion. On the 14th day, a segment of the thoracolumbar spinal cord was harvested and prepared for histological and immunohistochemical analyses. There was significant impairment of the motor function of the hindlimb in the 3 study groups, with partial improvement noticed over time, but no difference was detected between the groups. On Day 1 of assessment, the 17β-oestradiol group had a functional score of 9.8 (0.0-16.5); the progesterone group, a score of 0.0 (0-17.1) and the control group, a score of 6.5 (0-16.9); on the 14th day, the 17β-oestradiol group had a functional score of 18.0 (4.4-19.4); the progesterone group had a score of 7.5 (0-18.5) and the control group had a score of 17.0 (0-19.9). Analysis of the grey matter showed that the number of viable neurons per section was not different between the study groups on the 14th day. Immunostaining of the spinal cord grey matter was also similar among the 3 groups. Acute administration of oestradiol or of progesterone 30 min before transitory occlusion of the proximal descending thoracic aorta of male rats could not prevent or attenuate spinal cord ischaemic injury based on an analysis of functional and histological outcomes.

17β-Estradiol prevents mesenteric injury induced by occlusion of the proximal descending aorta in male rats

ObjectiveIn surgical aortic repair or cardiac surgery with aorta occlusion, the occurrence of mesenteric ischemia and bowel injury has been associated with higher short-term mortality. The vascular protection of estrogens has been investigated and is mainly mediated by increasing the availability of nitric oxide (NO). Therefore, this study investigated the role of 17β-estradiol on visceral ischemia-reperfusion (I/R) injury after descending aorta occlusion in male rats. MethodsMesenteric ischemia was induced in male Wistar rats by placing a 2F Fogarty arterial embolectomy catheter (Edwards Lifesciences, Irvine, Calif) in the descending aorta, which remained occluded for 15 minutes, followed by reperfusion for up to 2 hours. Rats were divided into four groups: (1) rats that underwent surgical manipulation only (sham, n = 22); (2) rats that underwent I/R injury (n = 22); (3) rats treated with intravenous 17β-estradiol (280 μg/kg) 30 minutes before I/R (n = 22); (4) or at the beginning of reperfusion (n = 22). Intestinal histopathologic changes were evaluated by histomorphometry. Mesenteric microcirculatory alterations were assessed by laser Doppler flowmetry and intravital microscopy technique. Protein expression of intercellular adhesion molecule-1, P-selectin, endothelial NO synthase (eNOS), and endothelin-1 was evaluated by immunohistochemistry; in addition, eNOS and endothelin-1 gene expressions were quantified by real-time polymerase chain reaction. Serum cytokines were measured by enzyme-linked immunosorbent assay. ResultsRelative to the sham group, the I/R group exhibited a highly pronounced loss of intestine mucosal thickness, a reduction in mesenteric blood flow (P = .0203), increased migrated leukocytes (P < .05), and high mortality rate (35%). Treatment with 17β-estradiol before aorta occlusion preserved intestine mucosal thickness (P = .0437) and mesenteric blood flow (P = .0251), reduced the number of migrated leukocytes (P < .05), and prevented any fatal occurrence. Furthermore, 17β-estradiol downregulated the expression of intercellular adhesion molecule-1 (P = .0001) and P-selectin (P < .0001) on the endothelium and increased the protein expression of eNOS (P < .0001). The gene expressions of eNOS and endothelin-1 did not differ between the groups. ConclusionsThe prophylactic treatment with 17β-estradiol showed better overall repercussions and was able to prevent any fatal occurrence, increase eNOS expression, thus preserving mesenteric perfusion and intestinal integrity, and reduce inflammation.

Fructose-rich diet induces gender-specific changes in expression of the renin-angiotensin system in rat heart and upregulates the ACE/AT1R axis in the male rat aorta.

Introduction:The cardiovascular renin–angiotensin system (RAS) could be affected by gender and dietary regime. We hypothesized that male rats will be more susceptible to activation of RAS in the heart and aorta, as a response to a fructose-rich diet (FRD).Materials and methods:Both male and female Wistar rats were given a 10% (w/v) fructose solution for 9 weeks. We measured the biochemical parameters, blood pressure (BP) and heart rate. We used Western blot and real-time polymerase chain reaction (PCR) to quantify protein and gene expression.Results:In the male rats, the FRD elevated BP and expression of cardiac angiotensin-converting enzyme (ACE), while the expression of angiotensin-converting enzyme 2 (ACE2) and angiotensin II Type 2 receptor (AT2R) were significantly decreased. In female rats, there were no changes in cardiac RAS expression due to FRD. Furthermore, the ACE/AT1R axis was overexpressed in the FRD male rats’ aortae, while only AT1R was upregulated in the FRD female rats’ aortae. ACE2 expression remained unchanged in the aortae of both genders receiving the FRD.Conclusions:The FRD induced gender-specific changes in the expression of the RAS in the heart and aortae of male rats. Further investigations are required in order to get a comprehensive understanding of the underlying mechanisms of gender-specific fructose-induced cardiovascular pathologies.

Evaluation of 17β-estradiol effects in mesenteric injury induced by occlusion of proximal descending aorta in male rats

Acute mesenteric ischemia is a life-threatening emergency with overall mortality ranging from 60% to 80%, and this survival rate has not improved substantially in recent decades. In surgical aortic reconstruction, occlusion of the aorta affects various organs through the ischemia reperfusion injury. Among these organs, the intestine is probably the most affected one. Several studies have proposed that oestradiol has a beneficial effect in the course of the inflammatory lesion.

Preparation of Rat Serum Suitable for Mammalian Whole Embryo Culture

Mammalian whole embryo culture (WEC) is a widely used technique for examining pharmacological toxicity in developing mouse and rat embryos and for investigating the mechanisms of developmental processes. Immediately centrifuged (IC) rat serum is commonly used for WEC and is essential for the growth and development of cultured mouse and rat embryos ex vivo. For the culture of midgestation embryos (i.e., E8.0-12.5 for the mouse, and E10.0-14.5 for the rat), 100% rat serum is the best media for supporting the growth of the embryo ex vivo. To prepare rat serum suitable for WEC, the collected blood should be centrifuged immediately to separate the blood cells from the plasma fraction. After centrifugation, the fibrin clot forms in the upper layer; this clot should be squeezed gently using a pair of sterile forceps and subsequently centrifuged to completely separate the blood cells from the serum. In this video article, we demonstrate our standard protocol for the preparation of optimal IC rat serum, including blood collection from the abdominal aorta of male rats and extraction of the serum by centrifugation.

Acrylamide-treatment and responses to phenylephrine and potassium in rat aorta

Acrylamide (ACR) is a chemical used in many industries around the world and was found to form naturally in foods cooked at high temperatures. The aim of the present study is to evaluate the influence of ACR treatment on vascular responses to phenylephrine (PHE; 10-9-3×10-4 M) and potassium chloride (KCl; 5-100 mM). We also examined the role of gender in these responses. The animals in both genders were divided into three groups as follows. (1) Control animals, (2) ACR-I; ACR-treated (2 mg/kg-d for 90 days), (3) ACR-II; ACR-treated (5 mg/kg-d for 90 days). Male rat aortas were more sensitive to PHE and KCl than female aortas. ACR-treatment increased the sensitivity to PHE and KCl, in both genders. Compared to the control group, ACR treatment significantly reduced the luminal area of both male and female rat aortas. Furthermore, the responses to PHE and KCl were similar in both 2 mg/kg-d ACR-treated rat aortas with 5 mg/kg-d ACR-treated rat aortas, in both genders. The results of this study suggest that ACR treatment affects vascular contractility and morphology in both gender of rat aorta.

Spasmolytic activity of trachylobanes ent-7α-acetoxytrachyloban-18-oic acid and ent-7α-hydroxytrachyloban-18-oic acid isolated from Xylopia langsdorfiana A. St-Hil. & Tul. (Annonaceae)

We aimed to investigate the possible spasmolytic activity of ent-7α-acetoxytrachyloban-18-oic acid (1) and ent-7α-hydroxytrachyloban-18-oic acid (2) on smooth muscle models. In male rat aorta and rat uterus, both diterpenes were unable to trigger spasmolytic action. However, 2 relaxed guinea-pig trachea: Compounds 1 and 2 antagonised, significantly and concentration-dependently, carbachol- and histamine-induced phasic contractions in guinea-pig ileum. Moreover, they induced a significant and concentration-dependent relaxation in pre-contracted (KCl, carbachol or histamine) guinea-pig ileum, with 2 being 15 times more potent than 1 in histamine-contracted ileum. These dissimilar results may be due to chemical differences between them. Thus, we demonstrated that 1 and 2 seem to be promising spasmolytic agents, although further studies are required to elucidate the spasmolytic action mechanism.

Spasmolytic effect of galetin 3,6-dimethyl ether, a flavonoid obtained from Piptadenia stipulacea (Benth) Ducke

Piptadenia stipulacea (Benth) Ducke is a tree of the Caatinga, in Northeast Brazil, popularly known as "Jurema-branca", "Jurema malícia-da-serra", "Carcará" and "Calumbi". In folk medicine, a decoction or tincture of its bark and leaves are used to treat wounds and as healing agents. Galetin 3,6-dimethyl ether (FGAL) is a flavonoid isolated from the aerial components of Piptadenia stipulacea (Benth) Ducke. We decided to investigate a possible FGAL spasmolytic effect on preparations of both the guinea pig ileum and trachea, the rat uterus and the male rat aorta. FGAL inhibited oxytocin (IC(50) = 2.2 ± 0.4 × 10(-5) M) and carbachol (CCh)-induced (IC(50) = 7.7 ± 1.3 × 10(-5) M) phasic contractions in the rat uterus, but was more effective in the inhibition of the oxytocin-induced contractions. In the guinea pig ileum, FGAL equipotently inhibited CCh (IC(50) = 2.8 ± 0.4 × 10(-5) M) and histamine-induced (IC(50) = 2.3 ± 0.5 × 10(-5) M) phasic contractions. FGAL equipotently and concentration-dependently relaxed guinea pig trachea preparations pre-contracted with CCh, both in the absence (EC(50) = 0.8 ± 0.1 × 10(-5) M) and presence (EC(50) = 1.0 ± 0.1 × 10(-5) M) of a functional epithelium. FGAL also relaxed preparations of the rat aorta pre-contracted with phenylephrine in both the absence (EC(50) = 5.0 ± 1.1 × 10(-6) M) and presence (EC(50) = 5.4 ± 1.2 × 10(-6) M) of a functional endothelium. FGAL shows a non-selective spasmolytic effect on each of the smooth muscle preparations we have tested, but with a greater effect on those from the rat aorta. The relaxant effect on preparations of both the guinea pig trachea and the rat aorta seems to not involve the epithelium or endothelium-derived relaxing factors.