Wistar Rats Body Weight Research Articles

Safety evaluation of turmeric polysaccharide extract: assessment of mutagenicity and acute oral toxicity.

Curcuma longa Linn. (Zingiberaceae) commonly known as turmeric has long been used for centuries as a spice and household remedy. The present study was carried out to assess the possible mutagenic potential and acute oral toxicity of polysaccharide extract of turmeric rhizome (NR-INF-02) using standard tests. The standard battery of in vitro genotoxicity tests, bacterial reverse mutation test (BRMT), chromosome aberration (CA), and micronucleus (MN) tests were employed to assess the possible mutagenic activity of NR-INF-02 (Turmacin). The results showed no mutagenic effect with NR-INF-02 up to a dose of 5000 µg/mL in BRMT. The results on CA and MN tests revealed the non clastogenic activity of NR-INF-02 in a dose range of 250.36 to 2500 µg/mL with and without metabolic activation (S9). In acute oral toxicity study, NR-INF-02 was found to be safe up to 5 g/kg body weight in Wistar rats. Overall, results indicated that polysaccharide extract of C. longa was found to be genotoxically safe and also exhibited maximum tolerable dose of more than 5 g/kg rat body weight.

Biological evaluation of a siliconized analog of clofibrate (silafibrate) in rodents.

Silicon is the element very similar to carbon, and bioactive siliconized compounds have therefore received much attention. Siliconization of a compound enhances its biological activities. In the present study the hypolipidemic effect and toxicity of clofibrate and its siliconized analog, silafibrate, were compared. The experiments were performed in hypercholesterolemicWistar rats. Animals received high fat diet with 62.75% normal chow, 2% cholesterol, 0.25% cholic acid, 15% lard oil, 10% wheat flour and 10% sucrose.Silafibrate(40 mg/kg/day) produced a predominant reduction in the serum levels of total cholesterol (28.4%, p < 0.001), triglycerides (62%, p < 0.0001) and low-density lipoproteins (27%, p < 0.001) being more effective than the reference drug clofibrate (20%, 40%, 14.5%; p < 0.05). Similarly, it increased the total antioxidant levels in serum by 40% (p < 0.05). Simultaneously, treatment with silafibrate also reduced the malondialdehyde(MDA) concentration by 41% (p < 0.05). LD50 of silafibrate, given orally,was greater than 2000 mg/kg body weight inalbino mice while LD50 for clofibrate was calculated to be 1220 mg/kg. Thirty-day subacute toxicity was also evaluated with oral daily dose at 25, 50 and 100 mg/kg body weight in Wistarrats. No significant changes in body weight, food intake, behavior, mortality, hematology, blood biochemistry, vital organ weight were detected. The results of this study indicate that the effectiveness and safety of thehypolipidemic drug, clofibrate, were enhanced remarkably by replacing chlorine atom in its phenoxy ring with trimethylsilyl.

Toxicity profile of ethanolic extract of Azadirachta indica stem bark in male Wistar rats

ObjectiveTo investigate the toxic implications of ethanolic stem bark extract of Azadirachta indica (A. indica) at 50, 100, 200 and 300 mg/kg body weight in Wistar rats. MethodsFifty male rats of Wistar strains were randomly grouped into five (A-E) of ten animals each. Animals in Group A (control) were orally administered 1 mL of distilled water on daily basis for 21 days while those in Groups B-E received same volume of the extract corresponding to 50, 100, 200 and 300 mg/kg body weight. ResultsThe extract did not significantly (P>0.05) alter the levels of albumin, total protein, red blood cells and factors relating to it whereas the white blood cell, platelets, serum triacylglycerol and high-density lipoprotein cholesterol decreased significantly (P<0.05). In contrast, the final body weights, absolute weights of the liver, kidney, lungs and heart as well as their organ-body weight ratios, serum globulins, total and conjugated bilirubin, serum cholesterol, low-density lipoprotein cholesterol and computed atherogenic index increased significantly. The spleen-body weight ratio, alkaline phosphatase, alanine and aspartate transaminases, sodium, potassium, calcium, feed and water intake were altered at specific doses. ConclusionOverall, the alterations in the biochemical parameters of toxicity have consequential effects on the normal functioning of the organs of the animals. Therefore, the ethanolic extract of A. indica stem bark at the doses of 50, 100, 200 and 300 mg/kg body weight may not be completely safe as an oral remedy and should be taken with caution if absolutely necessary.

Studies Of Analgesic and Anti-Inflammatory Effects of Aqueous Extract Of Ganoderma Lucidum in Mice and Wister Rats

The aqueous extract of Ganoderma lucidum was investigated for analgesic and anti-inflammatory effects in rodents. Investigations for analgesic effect was carried out employing the acetic acid- induced writhing in mice and the anti-inflammatory effect the hind paw edema method was employed in Wistar rats Results showed the aqueous extract to have a significant (p<0.05) analgesic activity at the doses of 50, 100 and 150mg/kg body weight intraperitoneally in mice. Also, the extract showed a significant (p<0.05) anti- inflammatory activity at doses of 50, 100 and 150mg/kg body weight. Preliminary phytochemical screening of the aqueous extract revealed the presences of Glycosides, Saponins, Flavonoids, Alkaloids, Steroids and Reducing sugars. The extract had an LD50 of 3.5g/kg body weight in Wistar rats. The results of this study confirms that the aqueous extract of Ganoderma lucidum have analgesic and anti-inflammatory activities in mice and rats.

Preventive effect of Catharanthus roseus (Linn.) against high-fructose diet-induced insulin resistance and oxida-tive stress in male Wistar rats

High intake of dietary fructose has been shown to exert a number of adverse metabolic effects in humans and experimental animals. The aim of the present study was to investigate whether Catharanthus roseus (L.) G. Don (Apocynaceae) leaf powder alleviates high-fructose diet-induced insulin resistance and oxidative stress in rats. Adult male Wistar rats of body weight around 200 g were divided into four groups, two of which were fed with standard pellet diet and the other two with high fructose (66%) diet. C. roseus leaf powder suspension in water (100 mg/kg body weight/day) was administered orally to each group of the standard pellet diet fed rats and the high fructose diet fed rats for 60 days. Fructose fed rats (F-group) showed hyperglycemia, hyperinsulinemia, insulin resistance and hyperlipidemia (P < 0.05). C. roseus treatment in fructose fed rats (F+CR-group) prevented the rise in glucose levels by 32.2%, insulin by 46.4%, and impaired insulin sensitivity by 63.6%. C. roseus treatment completely prevented the fructose induced plasma lipid alterations. Regarding liver antioxidant status, oxidative stress was observed in fructose fed rats (F-group), while C. roseus treatment in F+CR-group prevented the fructose induced oxidative stress. Our data indicate the preventive role of C. roseus against fructose-induced insulin resistance and oxidative stress; hence this plant can be used as an adjuvant for the prevention and/or management of insulin resistance and disorders related to it.

Developmental Toxicity of Homobrassinolide in Wistar Rats

Brassinosteroids (BRs) are close analogues of animal cholesterol. Brassinosteroids have shown their great value as yield promoters of a variety of plants. In view of its steroidal moiety and recent use in agriculture in many countries, the teratogenic potential of homobrassinolide (HBR) was evaluated in Wistar rats. Homobrassinolide was administered by oral gavage at doses 0, 100, and 1000 mg/kg body weight in water during gestation days (GD) 6 to 15 in groups of 20 mated females. Maternal and embryo-fetal toxicity was analyzed by studying the effects such as clinical signs, mortality/morbidity, abortions, body weight, feed consumption, and pregnancy data, gravid uterine weights, implantation losses, litter size, external, visceral, and skeletal malformations. No treatment-related effect was observed on any of the maternal/fetal end points in any dose group. From the results, it can be concluded that HBR is nonteratogenic at doses as high as up to 1000 mg/kg body weight in Wistar rats.

Suppression of hepatic oxidative events and regulation of eNOS expression in the liver by naringenin in fructose-administered rats

Previous studies show that naringenin promotes insulin sensitivity in fructose-fed rats. This study investigates whether naringenin prevents oxidative events and apoptotic changes triggered in the rat liver by a high fructose diet. Male Wistar rats of body weight 150–180 g were fed either diet containing starch (60% carbohydrate) or fructose (60% fructose diet). From the 16th day of feeding, rats in each dietary group were divided into two, and treated or not with naringenin (50 mg/kg b.w/day). After 60 days, oxidative and nitrosative damage and endothelial nitric oxide synthase (eNOS) expression and hepatocyte apoptosis were determined. To evaluate whether nitric oxide (NO) plays a role in naringenin action, insulin sensitivity indices, fasting plasma glucose and insulin were assessed in response to co-administration of l-nitro-arginine methyl ester (L-NAME), a NOS inhibitor. Fructose feeding caused oxidative damage to proteins and lipids and resulted in reduced antioxidant status, eNOS expression and nitrite level. Increased formation of 4-hydroxy nonenal (4-HNE), 2, 4-dinitrophenol (2, 4-DNP) and 3-nitrotyrosine (3-NT)-modified proteins and the presence of apoptotic nuclei were observed in the liver. Treatment with naringenin attenuated all these parameters to levels not significantly different from control. Treatment with naringenin improved insulin sensitivity. However, L-NAME plus naringenin administration abolished the insulin-sensitizing effects of naringenin in fructose-fed rats. Reduced oxidative events with simultaneous increase in NO bioavailability may be involved in the insulin-sensitizing and cytoprotective effects of naringenin in fructose-fed rats.

Carbohydrate-to-fat ratio affects food intake and body weight in Wistar rats

The aim of the study was to evaluate the impact of carbohydrate-to-fat ratio on body weight and appetite regulation in Wistar rats. Twenty-four Wistar rats were randomized to three dietary groups (n = 8): normal carbohydrate diet (NC), low-carbohydrate diet (LC) and high-carbohydrate diet (HC) for 12 weeks. Body weight and food intake were recorded. Circulating leptin and insulin levels were measured by radioimmunoassay method. The expression levels of leptin receptor, insulin receptor, orexin, neuropeptide Y (NPY), agouti-related protein (AgRP) and melanocortin-4 receptor (MC-4R) in the hypothalamus were also measured by realtime polymerase chain reaction (PCR). In the LC group, food intake reduced while body weight increased significantly compared with the NC and HC groups. Plasma leptin levels increased in the LC (18.5 +/- 8.2 ng/mL) group compared with the NC (8.6 +/- 3.8 ng/mL, P < 0.001) and HC (6.6 +/- 1.9 ng/mL, P < 0.001) groups. Realtime reverse transcription-PCR revealed a decrease in the hypothalamic expression level of only leptin receptor in the LC (0.764, 0.471-4.648 copy/mL) and HC (0.357, 0.129-0.781 copy/mL) groups compared with the NC (1.323, 0.616-2.392 copy/mL; P = 0.01) group, and that there was no significant change in those of insulin receptor, AgRP, Orexin, NPY and MC-4R. Low-carbohydrate, high-fat diet raised body weight, which led to a rising of circulating leptin levels and a reduced expression of leptin receptor in the hypothalamus.

Investigation of antioxidant, anti-inflammatory and DNA-protective properties of eugenol in thioacetamide-induced liver injury in rats

The present study investigated the preventive effect of eugenol, a naturally occurring food flavouring agent on thioacetamide (TA)-induced hepatic injury in rats. Adult male Wistar rats of body weight 150–180 g were used for the study. Eugenol (10.7 mg/kg b.w./day) was administered to rats by oral intubation for 15 days. TA was administered (300 mg/kg b.w., i.p.) for the last 2 days at 24 h interval and the rats were sacrificed on the 16th day. Markers of liver injury (aspartate transaminase, alanine transaminase, alkaline phosphatase, γ-glutamyl transferase and bilirubin), inflammation (myeloperoxidase, tumor necrosis factor-α and interleukin-6), oxidative stress (lipid peroxidation indices, protein carbonyl and antioxidant status) and cytochrome P4502E1 activity were assessed. Expression of cyclooxygenase-2 (COX-2) and the extent of DNA damage were analyzed using immunoblotting and comet assay, respectively. Liver injury and collagen accumulation were assessed using histological studies by hematoxylin and eosin and Masson trichrome staining. Rats exposed to TA alone showed increased activities of hepatocellular enzymes in plasma, lipid peroxidation indices, inflammatory markers and pro-inflammatory cytokines and decreased antioxidant status in circulation and liver. Hepatic injury and necrosis were also evidenced by histology. Eugenol pretreatment prevented liver injury by decreasing CYP2E1 activity, lipid peroxidation indices, protein oxidation and inflammatory markers and by improving the antioxidant status. Single-cell gel electrophoresis revealed that eugenol pretreatment prevented DNA strand break induced by TA. Increased expression of COX-2 gene induced by TA was also abolished by eugenol. These findings suggest that eugenol curtails the toxic effects of TA in liver.

Beneficiary Effect ofTinospora cordifoliaAgainst High-fructose Diet Induced Abnormalities in Carbohydrate and Lipid Metabolism in Wistar Rats

High intake of dietary fructose has been shown to exert a number of adverse metabolic eff ects in humans and experimental animals. The present study was designed to investigate the eff ect of the aqueous extract of Tinospora cordifolia stem (TCAE) on the adverse eff ects of fructose loading toward carbohydrate and lipid metabolism in rats. Adult male Wistar rats of body weight around 200 g were divided into four groups, two of which were fed with starch diet and the other two with high fructose (66 %) diet. Plant extract of TC (400 mg/kg/day) was administered orally to each group of the starch fed rats and the highfructose fed rats. At the end of 60 days of experimental period, biochemical parameters related to carbohydrate and lipid metabolism were assayed. Hyperglycemia, hyperinsulinemia, hypertriglyceridemia, insulin resistance, and elevated levels of hepatic total lipids, cholesterol, triglycerides, and free fatty acids (p < 0.05) observed in fructose-fed rats were completely prevented with TCAE treatment. Alterations in the activities of enzymes of glucose metabolism (hexokinase, phosphofructokinase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and glucose-6-phosphate dehydrogenase) and lipid metabolism (fatty acid synthetase, lipoprotein lipase, and malic enzyme) as observed in the high fructose-fed rats were prevented with TCAE administration. In conclusion, our fi ndings indicate improvement of glucose and lipid metabolism in high-fructose fed rats by treatment with Tinospora cordifolia, and suggest that the plant can be used as an adjuvant for the prevention and/or management of insulin resistance and disorders related to it.

Toxicological evaluation of the aqueous extract of Felicia muricata Thunb. leaves in Wistar rats.

The effect of the aqueous extract of Felicia muricata leaves at 50, 100 and 200 mg/kg body weight in Wistar rats was evaluated for 14 days. The extract caused significant increase in white blood cell (WBC) while it decreased the large unstained cells (LUC). The red blood cell (RBC), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), neurophils, eosinophils and gamma-glutamyl transferase (GGT) compared favourably with the control. There was no significant difference in haemoglobin (Hb) and alanine aminotransferase (ALT) at both 50 and 100 mg/kg, but at 200 mg/kg, there was slight reduction in both parameters. The extract caused progressive significant increase in platelets concentration. The lymphocytes level was significantly higher at 50 and 100 mg/kg. The extract at all doses did not significantly alter the levels of Na, K, Cl, inorganic phosphorus, urea, creatinine, total bilirubin, globulin, total protein, total cholesterol, high density lipoprotein-cholesterol (HDCL-C) and low density lipoprotein-cholesterol (LDL-C). The liver- and kidneybody weight ratios were not altered by all the doses except an increase in kidney-body weight ratio by the 200 mg/kg body weight of the extract. The concentration of triacylglycerol was increased by the 50 and 100 mg/kg body weight, while that of alkaline phophatase did not follow any regular pattern. There was reduction in the concentration of aspartate aminotransferase (ALT) from 50 to 200 mg/kg body weight. The alterations on some hematological and liver function parameters were an indication that the extract possessed selective toxicity.

Pharmacokinetics and Pharamcodynamics of Recombinant Human Thrombopoietin Following Single Injection in Rats

Background: Thrombopoietin (TPO) is the primary regulator of platelet production. Recombinant human thrombopoietin (rHuTPO) and its derivative have been reported as potent drugs in treatment of chemotherapy induced thrombocytopenia and idiopathic thrombocytopenic purpura. Due to severe immunogenic adverse affects clinical applications of rHuTPO have been limited. However, new TPO receptor agonists that lack this adverse effect are developed. RHuTPO exhibits nonlinear kinetics and complex dynamics both mediated by binding to TPO receptor. Studies of rHuTPO pharmacokinetics (PK) and pharmacodynamics (PD) will facilitate future use of new TPO receptor agonists.Purpose: To analyze PK and PD of rHuTPO following a single IV bolus administration in rats.Methods: Adult male Wistar rats of body weight 300–600 g received a single dose of rHuTPO (ProSpec Ltd) (2.4, 4.8 and 9.6 μg/kg) and a placebo via an intravenous injection in tail. Blood samples (100–200μL) were collected at various hours during 3 days for PK analysis and every day for consecutive 14 days for PD assessment. RHuTPO plasma concentrations were measured using ELISA (R&D Systems Inc). Platelet count was determined using hematology analyzer (BC-2800 VET, Mindray). Noncompartmental parameters such as area under concentration curve (AUC), clearance (CL), volume at steady-state (Vss), and terminal half-life (t1/2) were calculated by WinNonlin 5.2 (Pharsight). Percent increase over the baseline for platelet maximum (%MPC) and area under the platelet response curve (%AUCPLT) were applied as PD markers. Student t-test was used to compare the means between control and treatment groups (SAS 9.1, SAS Institute).Results: CL decreased with increasing dose (0.185, 0.131, and 0.047 L/h/kg), similarly to Vss (3.28, 1.10, and 0.51 L). The t1/2 values were also dose dependent (13.2, 6.1, and 8.2 h). The %MPC values were 43, 77, and 45% for corresponding doses and the peaks occurred on days 5, 6, and 6 following rHuTPO administration. The %AUCPLT values were relatively insensitive to increasing doses (20, 23, and 13%). Both mean peak platelet counts and mean AUCPLT were significantly different (p < 0.05) from the control values with an exception of AUCPLT for dose 2.4 μg/kg.Conclusions: RHuTPO exhibits nonlinear pharmacokinetics in rat. CL and Vss dependence on dose suggests receptor mediated drug disposition as a major reason of nonlinear PK. IV bolus doses 2.4, 4.8 and 9.6 μg/kg of rHuTPO moderately increase platelet count in rats that peaks on day 5–6 after drug administration. The observed lack of the PD marker increase with increased doses implicates that the applied doses are in a flat region of the dose-response curve. Compared to similar data reported for humans, rHuTPO is less efficacious in rats than in humans.

Fructose-induced hepatic gluconeogenesis: Effect of l-carnitine

High fructose feeding (60 g/100 g diet) in rodents induces alterations in both glucose and lipid metabolism. The present study was aimed to evaluate whether intraperitoneal carnitine (CA), a transporter of fatty acyl-CoA into the mitochondria, could attenuate derangements in carbohydrate metabolizing enzymes and glucose overproduction in high fructose-diet fed rats. Male Wistar rats of body weight 150–160 g were divided into 4 groups of 6 rats each. Groups 1 and 4 animals received control diet while the groups 2 and 3 rats received high fructose-diet. Groups 3 and 4 animals were treated with CA (300 mg/Kg body weight/day, i.p.) for 30 days. At the end of the experimental period, levels of carnitine, glucose, insulin, lactate, pyruvate, glycerol, triglycerides and free fatty acids in plasma were determined. The activities of carbohydrate metabolizing enzymes and glycogen content in liver and muscle were assayed. Hepatocytes isolated from liver were studied for the gluconeogenic activity in the presence of substrates such as pyruvate, lactate, glycerol, fructose and alanine. Fructose-diet fed animals showed alterations in glucose metabolizing enzymes, increased circulating levels of gluconeogenic substrates and depletion of glycogen in liver and muscle. There was increased glucose output from hepatocytes of animals fed fructose-diet alone with all the gluconeogenic substrates. The abnormalities associated with fructose feeding such as increased gluconeogenesis, reduced glycogen content and other parameters were brought back to near normal levels by CA. Hepatocytes from these animals showed significant inhibition of glucose production from pyruvate (74.3%), lactate (65.4%), glycerol (69.6%), fructose (56.2%) and alanine (63.6%) as compared to CA untreated fructose-fed animals. The benefits observed could be attributed to the effect of CA on fatty acyl-CoA transport.

Taurine modifies insulin signaling enzymes in the fructose-fed insulin resistant rats

High fructose feeding induces insulin resistance and hyperinsulinemia in rats. The present study was proposed to elucidate the derangements in the insulin signaling pathway in high fructose-fed rats and whether taurine, a sulphur-containing amino acid could improve insulin action by modulating the signal transduction pathway. Male Wistar rats of body weight 170-190 g were divided into 4 groups of 6 rats each. Control rats received control diet and water ad libitum. Fructose fed animals received high fructose diet (> 60% of total calories) and water ad libitum. Fructose + taurine rats received fructose diet and 2% taurine solution ad libitum. Control + taurine rats received control diet and 2% taurine solution ad libitum. After the experimental period of 30 days, the effects of taurine on certain parameters on glucose metabolism were determined. The activities of protein tyrosine kinase (PTK) and protein tyrosine phosphatase (PTP) were assayed in liver. The activities of the glycolytic enzymes were significantly lower while the activities of the gluconeogenic enzymes were higher in untreated fructose-fed rats as compared to control animals. Depletion of liver glycogen was observed in fructose-fed rats. Fructose-fed rats showed alterations in the activities of insulin signaling enzymes PTK and PTP. Taurine administration improved insulin sensitivity and controlled hyperglycemia and hyperinsulinemia in fructose-fed rats. Taurine treatment also restored the glucose metabolizing enzyme activities in fructose-fed rats. Taurine supplementation might have a beneficial effect in overcoming insulin resistance and its associated abnormalities by modifying the post-receptor events of insulin action.

Relationships between fetal body weight of Wistar rats at term and the extent of skeletal ossification

We investigated the relationship between fetal body weight at term (pregnancy day 21) and the extent of ossification of sternum, metacarpus, metatarsus, phalanges (proximal, medial and distal) of fore- and hindlimbs and cervical and coccygeal vertebrae in Wistar rats. The relationships between fetal body weight and sex, intrauterine position, uterine horn, horn size, and litter size were determined using historical control data (7594 fetuses; 769 litters) of untreated rats. Relationships between body weight and degree of ossification were examined in a subset of 1484 historical control fetuses (154 litters) which were subsequently cleared and stained with alizarin red S. Fetal weight was independent of horn size, uterine horn side (left or right) or intrauterine position. Males were heavier than females and fetal weight decreased with increasing litter size. Evaluation of the skeleton showed that ossification of sternum, metacarpus and metatarsus was extensively complete and independent of fetal weight on pregnancy day 21. In contrast, the extent of ossification of fore- and hindlimb phalanges and of cervical and sacrococcygeal vertebrae was dependent on fetal body weight. The strongest correlation between body weight and degree of ossification was found for hindlimb, medial and proximal phalanges. Our data therefore suggest that, in full-term rat fetuses (day 21), reduced ossification of sternum, metacarpus and metatarsus results from a localized impairment of bone calcification (i.e., a malformation or variation) rather than from general growth retardation and that ossification of hindlimb (medial and proximal) phalanges is a good indicator of treatment-induced fetal growth retardation.

Taurine restores ethanol-induced depletion of antioxidants and attenuates oxidative stress in rat tissues.

Ethanol by its property of generating free radicals during the course of its metabolism causes damage to cell structure and function. The study investigates the protective effects of the antioxidant aminoacid taurine on ethanol-induced lipid peroxidation and antioxidant status. Male Wistar rats of body weight 170-190 g were divided into 4 groups and maintained for 28 days as follows: a control group and taurine-supplemented control group, taurine supplemented and unsupplemented ethanol-fed group. Ethanol was administered to rats at a dosage of 3 g/kg body weight twice daily and taurine was provided in the diet (10 g/kg diet). Lipid peroxidation products and antioxidant potential were quantitated in plasma and in following tissues liver, brain, kidney and heart. Increased levels of thiobarbituric acid substances (TBARS) and lipid hydroperoxides (LHP) in plasma and tissues, decreased activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were observed in hemolysate and tissues of ethanol-fed rats. The contents of reduced glutathione (GSH), alpha-tocopherol and ascorbic acid in plasma and tissues were significantly reduced in these animals as compared to control animals. Simultaneous administration of taurine along with ethanol attenuated the lipid peroxidation process and restored the levels of enzymatic and non-enzymatic antioxidants. We propose that taurine may have a bioprotective effect on ethanol-induced oxidative stress.

Differences in localization of substantia nigra vs interaural line in Wistar and Sprague Dawley rats

The position of substantia nigra anterior to the interaural line has been correlated with body weight in Wistar rats. A regression line y=0.0050x+1.36 makes it possible to locate the substantia nigra in different sized rats ranging between 140 g and 460 g. This equation is not valid for Sprague Dawley rats. The position of bregma anterior to the interaural line has also been examined. A fairly good correlation was found for Sprague Dawley rats while the position of bregma in Wistar rats was much more variable.