Stress Status In Rats Research Articles

Neuroprotective potential of Costus speciosus on neurotransmitters levels in noise stress condition in rats

Exposure to overwhelming stress could lead to development of mental disorders and worsening of existing ones. The impact produced by exposure to stress might be affected by the seriousness of the stressor, the time amid which it is connected (acute vs. chronic). In traditional practice of medicine, C. speciosus extract exhibits antistress action so we aimed to test whether this extract plays a vital role in maintaining the brain's chemical transmitters levels during acute noise stress conditions. The levels of Dopamine (DA), Norepinephrine (NE) and Serotonin (5HT) were analysed by reverse phase HPLC in cerebral cortex and hippocampus brain tissue of acute noise stress exposed, C. speciosus extract (250mg and 500mg) and fluoxetine treated rats. Norepinephrine and dopamine were found to be increased in contrast to 5-HT levels in stressed group of rats, whereas CSE 500 mg could alleviate the said alteration. This study highlights the importance of C. speciosus extract therapy to noise stress induced rats by testing the neurotransmitters levels in brain tissue to understand its therapeutic potential.

Research Regarding the Effect of Vitamin E on Some Hematological Parameters in Toxic Stress Conditions in Rats

Cadmium’s mechanism of toxicity is manifested by its fixation in mitochondria, inhibition of cellular respiration and oxidative phosphorylation. Vitamin E could act as a protective factor against the harmful effect of Cadmium intoxication. The experimental animals were randomly allocated into 3 experimental groups of 6 rats. The collected blood samples were used to determine hematocrit, hemoglobin concentration, blood erythrocyte count and leukocyte count. The following derived red blood cell parameters were calculated in parallel according to the standard methodology. Between groups 1 and 2 there are no significant differences, a sign that vitamin E exerts an effective protective role. We found a significant increase in the white blood cell count and the neutrophil count in group 3 compared to group 1. Between groups 1 and 2 there are no significant differences, a sign that vitamin E has annihilated the cadmium-induced specific effect. In the case of cadmium poisoned rats, we found a decrease in the number of red blood cells, the hematocrit and the hemoglobin level, but also a significant increase in the number of white blood cells. If rats were treated with cadmium and vitamin E, there were not significant differences from the control group.

Oxytocin Differentiated Effects According to the Administration Route in a Prenatal Valproic Acid-Induced Rat Model of Autism.

Background and objectives: The hormone oxytocin (OXT) has already been reported in both human and animal studies for its promising therapeutic potential in autism spectrum disorder (ASD), but the comparative effectiveness of various administration routes, whether central or peripheral has been insufficiently studied. In the present study, we examined the effects of intranasal (IN) vs. intraperitoneal (IP) oxytocin in a valproic-acid (VPA) autistic rat model, focusing on cognitive and mood behavioral disturbances, gastrointestinal transit and central oxidative stress status. Materials and Methods: VPA prenatally-exposed rats (500 mg/kg; age 90 days) in small groups of 5 (n = 20 total) were given OXT by IP injection (10 mg/kg) for 8 days consecutively or by an adapted IN pipetting protocol (12 IU/kg, 20 μL/day) for 4 consecutive days. Behavioral tests were performed during the last three days of OXT treatment, and OXT was administrated 20 minutes before each behavioral testing for each rat. Biochemical determination of oxidative stress markers in the temporal area included superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA). A brief quantitative assessment of fecal discharge over a period of 24 hours was performed at the end of the OXT treatment to determine differences in intestinal transit. Results: OXT improved behavioral and oxidative stress status in both routes of administration, but IN treatment had significantly better outcome in improving short-term memory, alleviating depressive manifestations and mitigating lipid peroxidation in the temporal lobes. Significant correlations were also found between behavioral parameters and oxidative stress status in rats after OXT administration. The quantitative evaluation of the gastrointestinal (GI) transit indicated lower fecal pellet counts in the VPA group and homogenous average values for the control and both OXT treated groups. Conclusions: The data from the present study suggest OXT IN administration to be more efficient than IP injections in alleviating autistic cognitive and mood dysfunctions in a VPA-induced rat model. OXT effects on the cognitive and mood behavior of autistic rats may be associated with its effects on oxidative stress. Additionally, present results provide preliminary evidence that OXT may have a balancing effect on gastrointestinal motility.

Evaluation of the effects of different intensities of forced running wheel exercise on oxidative stress biomarkers in muscle, liver and serum of untrained rats.

Exercise induces different effects on antioxidant status depending on its intensity. The forced running wheel (FRW) model maintains a constant intensity and volume during exercise. The aim of the present study was to investigate the effects of FRW exercise at different running speeds on several serum biochemical parameters of liver and muscle functions and on oxidative stress biomarkers in skeletal muscle, liver and serum in the rat. Thirty-six male Wistar rats were randomly divided into six groups. Five groups participated in constant power tests at intensities of 10, 13, 14.5, 16, and 17.5 m/min, and a non-exercise group was chosen as the control. Serum, muscle and liver tissues were collected after the tests and analyzed. At speeds >16 m/min, exercise on an FRW significantly increased several serum biochemical parameters, malondialdehyde level and superoxide dismutase activity in all tissues of exercise rats compared with control rats; FRW exercise also increased catalase activity in the liver and glutathione S-transferase activity in muscle, whereas it decreased glutathione level in all tissues and catalase activity in muscle and serum. These data suggest that FRW exercise in rats activates an adaptation of the antioxidant system response in skeletal muscle at speeds <16 m/min, whereas it induces oxidative stress at higher speeds in muscle, liver and serum. In addition, we observed a correlation between the systematic and local oxidative stress status in rats after exercise on FRW.

Unexpected effects of metyrapone on corticosteroid receptor interaction with the genome and subsequent gene transcription in the hippocampus of male rats.

Glucocorticoid hormones (GCs) play a pivotal role in many stress-related biological processes. In the hippocampus, GCs act through mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) to modify gene transcription. The involvement of GCs in biological processes has been investigated using the corticosterone (CORT)-synthesis blocker metyrapone. How metyrapone affects the action of GC at the genomic level still remains unclear. Therefore, we investigated the effects of this enzyme blocker on plasma CORT levels and hippocampal MR and GR binding to GC responsive elements (GREs) within the GC target genes Fkbp5 (FK506-binding protein 5), Per1 (Period 1) and Sgk1 (Serum- and glucocorticoid-activated kinase 1), as well as the transcriptional responses of these genes under control and acute stress conditions in rats. For comparison, we also investigated these endpoints in rats that had undergone adrenalectomy (ADX). Although metyrapone had no effect on baseline levels of CORT, the drug increased MR and GR to GRE binding within the GC target genes and the transcriptional activity of these genes. As expected, acute forced swim (FS) stress strongly increased plasma CORT levels, hippocampal MR and GR to GRE binding within Fkbp5, Per1 and Sgk1, and the transcriptional activity (mainly hnRNA levels) of these genes. Metyrapone attenuated, but did not abolish, these effects of stress on plasma CORT and MR and GR to GRE binding. The drug effects on FS-induced transcriptional activity were gene-dependent with a reduction seen in Fkbp5 hnRNA (but not Fkbp5 mRNA), an enhancement in Per1 hnRNA (but not Per1 mRNA), and no effect on both Sgk1 hnRNA and mRNA levels. ADX however completely abrogated the effects of FS on plasma CORT, as well as hippocampal MR and GR to GRE binding and transcriptional responses. Thus, in contrast to ADX, metyrapone produced inconsistent effects on GC-sensitive genomic endpoints that question its suitability as a tool in neuroendocrine and other research.

Protective effects of L-arginine on the intestinal epithelial barrier under heat stress conditions in rats and IEC-6 cell line.

Heat stress (HS) and the associated restricted blood flow to the intestine have been proven to destroy intestinal integrity. Considering the beneficial properties of L-arginine on gut function, we investigated the protective effects of L-arginine on the intestine under HS conditions. In vivo, the serum cortisol level and the rectal temperature increased in response to HS. Under HS, the intestinal damage showed obvious morphological changes. Furthermore, HS decreased the mRNA and protein expression levels of Nurr1, ZO-1, occludin, claudin-6 and E-cadherin, increased the mRNA expression of NF-κB and IL-1β, and increased the protein expression of cleaved caspase-3. In contrast, L-arginine supplementation maintained intestinal integrity and increased the villus/crypt ratio. L-arginine also suppressed the expression of inflammation-related genes and the protein expression of cleaved caspase-3, whereas it upregulated the mRNA and protein expression of tight junction proteins and LC3B protein expression. In vitro, L-arginine attenuated HS-induced apoptosis as demonstrated by flow cytometry and decreased cleaved caspase-3 protein expression. L-arginine induced autophagy, which was demonstrated by decreased expression of p62 and p-mTOR/mTOR, and increased expression of LC3B. The protein expression levels of TJ proteins also enhanced by L-arginine in IEC-6 cells. Taken together, these results suggest that L-arginine can alleviate intestinal damage and protect the intestinal integrity by suppressing local inflammation response, promoting the production of TJs and facilitating autophagy under HS conditions.

The Сomparative Study of Vegetotropic Effects of Nonpharmacological Agents in Basal and Acute Stress Conditions in Rats of both Sexes

The Сomparative Study of Vegetotropic Effects of Nonpharmacological Agents in Basal and Acute Stress Conditions in Rats of both Sexes

Biomarkers of oxidative stress for in vivo assessment of toxicological effects of iron oxide nanoparticles.

Iron oxide nanoparticles (Fe2O3-IONPs) have revolutionized the industry by significant economic and scientific impacts. Enormous increase in the usage of IONPs has raised concerns about their unseen adverse effects. In the current study, we investigated the effects of IONPs and its bulk on oxidative stress biomarkers, histopathology and biodistribution in rats after 28 days repeated oral treatment at 30, 300 and 1000 mg/kg body weight (b.w.). IONPs size in dry, wet forms and crystallinity was determined using TEM, DLS and XRD. The investigation of oxidative stress biomarkers demonstrated significant increase in lipid peroxidation and decrease in reduced glutathione content in the liver, kidney and the brain of the treated groups in a dose dependant manner. Further, antioxidant enzymes catalase, glutathione S transferase, glutathione peroxidase and glutathione reductase activities were significantly elevated along with significant decrease in superoxide dismutase activity in treated rat organs. ICP-OES analysis revealed dose and size dependant accumulation of IONPs in the liver followed by kidney and the brain than bulk. Moreover, accumulation of IONPs at high dose brought pathological changes only in liver. A large fraction of IONPs was eliminated in urine. Bulk material was substantially excreted in faeces than IONPs suggesting increased absorption of IONPs. In conclusion accumulated IONPs and bulk in organs trigger free radical generation, leading to the induction of oxidative stress condition in rats. The results obtained highlight the importance of toxicity assessments in evaluating the efficiency of IONPs for the safe implementation for diversified applications.

Inhibitory Effects of Palm Tocotrienol-Rich Fraction Supplementation on Bilirubin-Metabolizing Enzymes in Hyperbilirubinemic Adult Rats

BackgroundPhenylhydrazine, a hemolytic agent, is widely used as a model of experimental hyperbilirubinemia. Palm tocotrienol-rich fraction (TRF) was shown to exert beneficial effects in hyperbilirubinemic rat neonates.AimTo investigate the effects of palm TRF supplementation on hepatic bilirubin-metabolizing enzymes and ocidative stress status in rats administered phenylhydrazine.MethodsTwenty-four male Wistar rats were divided into two groups; one group was intraperitoneally injected with palm TRF at the dose of 30 mg/kg/day, while another group was only given vehicle (control) (vitamin E-free palm oil) for 14 days. Twenty-four hours after the last dose, each group was further subdivided into another two groups. One group was administered phenylhydrazine (100 mg/kg, intraperitoneally) and another group was administered normal saline. Twenty-four hours later, blood and liver were collected for biochemical parameter measurements.ResultsPhenylhydrazine increased plasma total bilirubin level and oxidative stress in the erythrocytes as well as in the liver, which were reduced by the pretreatment of palm TRF. Palm TRF also prevented the increases in hepatic heme oxygenase, biliverdin reductase and UDP-glucuronyltransferase activities induced by phenylhydrazine.ConclusionPalm tocotrienol-rich fraction was able to afford protection against phenylhydrazine-induced hyperbilirubinemia, possibly by reducing oxidative stress and inhibiting bilirubin-metabolizing enzymes in the liver.

The effect of low‐level laser therapy on the healing of hard palate mucosa and the oxidative stress status of rats

The biostimulation effects of low-level laser therapy (LLLT) have been demonstrated recently. This study investigated the effects of LLLT on palatal mucoperiosteal wound healing and oxidative stress status in rats. Forty-two male Wistar rats weighing 250-300 g were used in this study. A standardized full-thickness wound was created in the mucoperiosteum of the hard palates of the rats using a 3-mm-diameter biopsy punch. Treatment using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) was initiated after surgery and repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were sacrificed on the 7th, 14th, and 21st days after surgery. Total antioxidant status and total oxidative status were measured in serum. The histopathological findings revealed reduced numbers of inflammatory cells on the 7th day, increased mitotic activity of fibroblasts on the 14th and 21st day, and the same degree of collagen synthesis and vascularization on the days 7, 14, and 21 in the LLLT group compared with the control group. No significant differences in total oxidative status and total antioxidant status were observed between the groups. LLLT using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) elicited a positive healing effect on palatal mucoperiosteal wounds likely via the induction of fibroblasts. The oxidative stress status was not affected by LLLT.

Sex‐dependent regulation of hippocampal neurogenesis under basal and chronic stress conditions in rats

Sex differences in basal as well as in stress-induced hippocampal neurogenesis processes have been reported in the literature. However, studies directly comparing sex differences on multiple neurogenesis processes under such conditions are lacking to date. Therefore, the aim of the present study was to directly compare cell proliferation and survival, neuronal and astroglial differentiation as well as stem cells quiescence in male and female Wistar rats under both basal and chronic stress conditions (12 days of 2 h restraint stress (RS)). In addition, corticosterone (CORT) levels and spatial working memory were assessed. Under baseline conditions, only the number of immature neurons within the hippocampal dentate gyrus was higher in males compared with females. In contrast, chronic stress resulted in a number of sex-specific alterations. Thus, stress exposure reduced cell proliferation in males with a concurrent increase in stem cell quiescence, while it did not alter either parameter in females but decreased cell survival. Analysis of astroglial and neuronal differentiation patterns revealed that chronic stress specifically diminished the number of mature neurons in females, with no effect in males. Despite the observed sex differences in adult hippocampal neurogenesis, spatial working memory was not altered by stress exposure in either sex. While basal CORT levels were higher, chronic stress exposure did not affect this parameter in either sex across the initial stress period. This study presents the first direct and detailed evaluation of sex-dependent and chronic stress-induced changes in adult hippocampal neurogenesis not only showing changes in cell proliferation and survival, but moreover immature neuron production, differentiation patterns, stem cell quiescence and therefore contributes to a better understanding of sex differences in neurogenesis processes.

Preventive Effects of Zinc Against Psychological Stress-Induced Iron Dyshomeostasis, Erythropoiesis Inhibition, and Oxidative Stress Status in Rats

Psychological stress (PS) could cause decreased iron absorption and iron redistribution in body resulting in low iron concentration in the bone marrow and inhibition of erythropoiesis. In the present study, we investigated the effect of zinc supplementation on the iron metabolism, erythropoiesis, and oxidative stress status in PS-induced rats. Thirty-two rats were divided into two groups randomly: control group and zinc supplementation group. Each group was subdivided into two subgroups: control group and PS group. Rats received zinc supplementation before PS exposure established by a communication box. We investigated the serum corticosterone (CORT) level; iron apparent absorption; iron contents in liver, spleen, cortex, hippocampus, striatum, and serum; hematological parameters; malondialdehyde (MDA); reduced glutathione (GSH); and superoxide dismutase (SOD). Compared to PS-treated rats with normal diet, the PS-treated rats with zinc supplementation showed increased iron apparent absorption, serum iron, hemoglobin, red blood cell, GSH, and SOD activities; while the serum CORT; iron contents in liver, spleen, and regional brain; and MDA decreased. These results indicated that dietary zinc supplementation had preventive effects against PS-induced iron dyshomeostasis, erythropoiesis inhibition, and oxidative stress status in rats.

Oxidative Stress Status in Rats After Intermittent Exposure to Hypobaric Hypoxia

Programs of intermittent hypobaric hypoxia (IHH) exposure are used to raise hemoglobin concentration and erythrocyte mass. Although acclimation response increases blood oxygen transport capacity leading to a VO(2max) increase, the effects of reactive oxygen species (ROS) might determine the behavior of erythrocytes and plasma, thus causing a worse peripheral blood flow. The goals of the study were to establish the hematological changes and to discern whether an IHH protocol modifies the antioxidant/pro-oxidant balance in laboratory rats. Male rats were subjected to an IHH program consisting of a daily 4-hour session for 5 days/week until completing 22 days of hypoxia exposure in a hypobaric chamber at a simulated altitude of 5000 m. Blood samples were taken at the end of the exposure period (H) and at 20 (P20) and 40 (P40) days after the end of the program, and compared to control (C), maintained at sea-level pressure. Hematological parameters were measured together with several oxidative stress indicators: plasma thiobarbituric acid reactive substances (TBARS) and erythrocyte catalase (CAT) and superoxide dismutase (SOD). Red blood cell (RBC) count, hemoglobin concentration and hematocrit were higher in H group as compared to all the other groups (p < 0.001). However, there were no significant differences between the 4 groups in any of the oxidative stress-related parameters. The absence of significant differences between groups indicates that our IHH program has little impact on the general redox status, even in the laboratory rat, which is more sensitive to hypoxia than humans. We conclude that IHH does not increase oxidative stress.

Functional Analysis of Active Urethral Closure Mechanisms Under Sneeze Induced Stress Condition in a Rat Model of Birth Trauma

We evaluated changes in the urethral closure mechanism under a sneeze induced stress condition in a rat model of birth trauma. Four days after vaginal distention induced by balloon catheter inflation in the vagina sneezing was induced while recording intravesical pressure with the rat under urethane anesthesia to evaluate sneeze induced leak point pressure, defined as the lowest pressure inducing fluid leakage from the urethral meatus during sneezing. Sneeze induced responses in the bladder and proximal or mid urethra were also measured using microtip transducer catheters. In 5 sham operated rats no leakage was observed from the urethral meatus during sneezing, which produced an increase in intravesical pressure of up to 34 cm H(2)O. However, in 5 of 6 rats with vaginal distention leakage during sneezing was observed with a sneeze leak point pressure of 26.2 cm H(2)O. In the mid urethra microtip transducer catheters revealed that pressure increases during sneezing were greater than those in the bladder but they were significantly decreased in the 5 incontinent vaginal distention rats. However, sneeze induced responses at the proximal urethra, which were similar to those in the bladder, were not different in sham operated and incontinent vaginal distention rats. Sneeze induced stress urinary incontinence in a rat model of birth trauma was caused by decreased active closure mechanisms at the mid urethra without affecting the passive transmission of abdominal pressure in the proximal urethra.

Hematological Parameters in Wistar Rats in Conditions of Stress and Treatment with Heparin

The effects on hematological measures of emotional tension arising during the formation of food-procuring behavior in a multiple-choice maze and in conditions of pain (injection of 0.85% physiological saline i.m., 0.3 ml, daily for five days) were studied in Wistar rats. Physiological saline and training of intact animals led to increases in RBC volume and mean corpuscular hemoglobin content, accompanied by significant increases in plasma corticosterone levels. At the same time, neither heparin (standard unfractionated heparin, Serva, doses of 64 and 640 IU/kg, daily for five days) nor training of heparinized rats produced any changes in these measures. The high levels of organization of the acquired behavior and the working capacity seen in heparinized rats were evidence for improvements in both the associative properties of conditioned reflex activity and the mechanisms supporting stable reproduction of the acquired habit. After administration of heparin, rats lost all types of manifestation reflecting psychoemotional tension as generally seen in animals in the active (administration of physiological saline) and passive (intact rats) controls.

Comparison of leak point pressure methods in an animal model of stress urinary incontinence

We compared three different methods of testing leak point pressure (LPP) in rats with or without the pudendal nerves and nerves to the iliococcygeus/pubococcygeus muscles transected: (1) sneeze induced with a whisker in the nostril (sneeze LPP), (2) manually increased abdominal pressure (Crede LPP), and (3) increased intravesical pressure using the vertical tilt table method (vertical tilt table LPP). In sham rats, passive intravesical pressure rises in Crede and vertical tilt table methods induced active urethral closure mechanisms that contributed to high LPPs (41.4 and 35.5 cm H2O, respectively), which were significantly reduced by nerve transection. During sneezing, leakage was observed in nerve-transected rats, but not in sham rats, indicating that sneezing can activate an additional urethral closure mechanism. Measuring LPP during sneezing or passive intravesical pressure rises in the vertical tilt table and Crede method seems to be useful for assessing the continence mechanisms under different stress conditions in rats.

P.5.054 Dopaminergic regulation of cognitive functions under acute stress conditions in rats

P.5.054 Dopaminergic regulation of cognitive functions under acute stress conditions in rats

Urethral closure mechanisms under sneeze-induced stress condition in rats: a new animal model for evaluation of stress urinary incontinence.

The urethral closure mechanism under a stress condition induced by sneezing was investigated in urethane-anesthetized female rats. During sneezing, while the responses measured by microtip transducer catheters in the proximal and middle parts of the urethra increased, the response in the proximal urethra was almost negligible when the bladder response was subtracted from the urethral response or when the abdomen was opened. In contrast, the response in the middle urethra during sneezing was still observed after subtracting the bladder response or after opening the abdomen. These responses in the middle urethra during sneezing were significantly reduced approximately 80% by bilateral transection of the pudendal nerves and the nerves to the iliococcygeous and pubococcygeous muscles but not by transection of the visceral branches of the pelvic nerves and hypogastric nerves. The sneeze leak point pressure was also measured to investigate the role of active urethral closure mechanisms in maintaining total urethral resistance against sneeze-induced urinary incontinence. In sham-operated rats, no urinary leakage was observed during sneeze, which produced an increase of intravesical pressure up to 37 +/- 2.2 cmH2O. However, in nerve-transected rats urinary leakage was observed when the intravesical pressure during sneezing exceeded 16.3 +/- 2.1 cmH2O. These results indicate that during sneezing, pressure increases elicited by reflex contractions of external urethral sphincter and pelvic floor muscles occur in the middle portion of the urethra. These reflexes in addition to passive transmission of increased abdominal pressure significantly contribute to urinary continence mechanisms under a sneeze-induced stress condition.

Chemical and biological properties of verapamil labeled with technetium-99m: A potential myocardial imaging agents

On the base of property to enter into myocardial cells as a calcium channel blocker, verapamil was labeled with technetium-99m in order to investigate the possibility to obtain new radiopharmaceutical for myocardial imaging. The conditions of labeling verapamil with technetium-99m for different ammounts of stannous(II) ion, mannitol, cystein and pH range 2.5–3.5 were examined. Investigation of radiochemical purity (>95%) and biodistribution of 99mTc-verapamil in rats showed that it was stable during 2 hours after labeling. Accumulation of 99mTc-verapamil in heart was 1.2% and in liver 9.4%, 5 minutes after injection. Biodistribution of 99mTc-verapamil in rats in conditions of stress, pharmacologically caused by dipiridamol, showed that the elimination of 99mTc-verapamil from the heart was slower related to the control group. In the group of rats previously treated with isoproterenol uptake of 99mTc-verapamil in heart was lower related to the control group (0.7% versus 1.0%) 5 minutes after injection. Lipophilicity of 99mTc-verapamil was examined by determination of partition coefficient (log P = 0.62) and protein binding (79%). Imaging studies on dogs provided relatively good myocardial images with partially overlap of activity in the lung and liver.

Periodic maternal deprivation and lesion of anterodorsal thalami nuclei induce alteration on hypophyso adrenal system activity in adult rats

The hypothalamic-pituitary-adrenal (HPA) axis is normally regulated by extrahypothalamic limbic structures, among these, the anterodorsal thalami nuclei (ADTN), which exert an inhibitory influence on HPA, in basal and acute stress conditions in rats. In the present work we have investigated whether neonatal maternal deprivation (MD) produces long-term changes in the ADTN regulation of HPA activity. Maternal deprivation, in female rats, for 4,5 hs daily, during the first 3 weeks of life, produced at 3 months old, a significant decrease in plasma ACTH concentration (p<0.001) and an increase in plasma corticosterone (C) (p<0.001), compared to control non-deprived rats (NMD). Also MD showed higher plasma epinephrine (E) and norepinephrine (NE) levels than NMD rats. The increase of NE (66.6% p<0.001) was higher than that observed in E (19%). After 30 days of ADTN lesion, plasma ACTH values were higher than in sham lesioned rats, in both NMD and MD animals. ACTH response was greater in MD rats. Plasma C, in NMD, was higher, whereas in MD lesioned animals, it was significantly lower than in sham lesioned. In MD rats, lesion produced a significant increase in plasma E and NE (p<0.001), and again, NE increase was higher than E increase. The more accentuated increase of NE than E, suggests sympathetic nervous system hyperactivity. In summary, neonatal maternal deprivation induces long-term alterations on HPA axis sensitivity and medullo adrenal secretion; enhanced sympathetic nervous system activity and, therefore affected the ADTN inhibitory influence on ACTH and adrenal glands secretion.