Does oxytocin play a role in the onset of maternal behaviour in the rat?

1984 ◽  
Vol 101 (3) ◽  
pp. 353-357 ◽  
Author(s):  
E. L. M. Bolwerk ◽  
H. H. Swanson

ABSTRACT Oxytocin is released during parturition and may also play a role in maternal behaviour. Oxytocin, injected in the cerebral ventricles, has been reported to accelerate the onset of maternal behaviour in oestrogen-pretreated virgin Sprague—Dawley rats within 2 h of injection. This study was an attempt to replicate and extend these findings in Wistar rats. In the first experiment, 16 virgin females were ovariectomized and a cannula was placed into the cerebral ventricle. Forty-eight hours after a single injection of 24 μg oestradiol benzoate (OB), 400 ng oxytocin or saline were injected into the ventricle. In the second experiment three groups were observed: an untreated control group plus two ovariectomized and cannulated groups treated with OB in a regimen designed to mimic pregnancy. After 10 days of OB administration they received an injection of either saline or oxytocin (400 ng) into the ventricle. Immediately after this injection they were exposed to the pups and observations started. In both experiments no rat became maternal in the first 1·5 h after the intracerebroventricular injection. Oxytocin therefore did not induce a rapid onset of maternal responsiveness in oestrogen-pretreated Wistar rats. J. Endocr. (1984) 101, 353–357

Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.


Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.


Author(s):  
Xiangyu Liu ◽  
Xiong Xue ◽  
Junsheng Tian ◽  
Xuemei Qin ◽  
Shi Zhou ◽  
...  

The objectives of this study were to compare the antidepressant effects between endurance and resistance exercise for optimizing interventions and examine the metabolomic changes in different types of skeletal muscles in response to the exercise, using a rat model of chronic unpredictable mild stress (CUMS)-induced depression. There were 32 male Sprague-Dawley rats randomly divided into a control group (C) and 3 experimental groups: CUMS control (D), endurance exercise (E), and resistance exercise (R). Group E underwent 30 min treadmill running, and group R performed 8 rounds of ladder climbing, 5 sessions per week for 4 weeks. Body weight, sucrose preference, and open field tests were performed pre and post the intervention period for changes in depressant symptoms, and the gastrocnemius and soleus muscles were sampled after the intervention for metabolomic analysis using the 1H-NMR technique. The results showed that both types of exercise effectively improved the depression-like symptoms, and the endurance exercise appeared to have a better effect. The levels of 10 metabolites from the gastrocnemius and 13 metabolites from the soleus of group D were found to be significantly different from that of group C, and both types of exercise had a callback effect on these metabolites, indicating that a number of metabolic pathways were involved in the depression and responded to the exercise interventions.


2009 ◽  
Vol 29 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Amal A El-Bakary ◽  
Sahar A El-Dakrory ◽  
Sohayla M Attalla ◽  
Nawal A Hasanein ◽  
Hala A Malek

Methanol poisoning is a hazardous intoxication characterized by visual impairment and formic acidemia. The therapy for methanol poisoning is alcohol dehydrogenase (ADH) inhibitors to prevent formate accumulation. Ranitidine has been considered to be an inhibitor of both gastric alcohol and hepatic aldehyde dehydrogenase enzymes. This study aimed at testing ranitidine as an antidote for methanol acute toxicity and comparing it with ethanol and 4-methyl pyrazole (4-MP). This study was conducted on 48 Sprague-Dawley rats, divided into 6 groups, with 8 rats in each group (one negative control group [C1], two positive control groups [C2, C3] and three test groups [1, 2 and 3]). C2, C3 and all test groups were exposed to nitrous oxide by inhalation, then, C3 group was given methanol (3 g/kg orally). The three test groups 1, 2 and 3 were given ethanol (0.5 g/kg orally), 4-MP (15 mg/kg intraperitoneally) and ranitidine (30 mg/kg intraperitoneally), respectively, 4 hours after giving methanol. Rats were sacrificed and heparinized, cardiac blood samples were collected for blood pH and bicarbonate. Non-heparinized blood samples were collected for formate levels by high performance liquid chromatography. Eye balls were enucleated for histological examination of the retina. Ranitidine corrected metabolic acidosis (p = .025), decreased formate levels (p = .014) and improved the histological findings in the retina induced by acute methanol toxicity.


1987 ◽  
Vol 112 (2) ◽  
pp. 275-282 ◽  
Author(s):  
E. van Leengoed ◽  
E. Kerker ◽  
H. H. Swanson

ABSTRACT Endogenous oxytocin released into the brain at parturition may stimulate the onset of maternal behaviour. In this study an attempt was made to block spontaneous maternal behaviour following natural delivery in Wistar rats by the injection of an antagonist of oxytocin into the cerebral ventricles. The analogue antagonist, d(CH2)5-8-ornithine-vasotocin, was administered by injection into a chronically implanted cannula in the right lateral ventricle at hourly intervals, beginning immediately after the expulsion of the first pup. The antagonist did not interfere with the normal progress of parturition or birth-related behaviours. After delivery of the last pup, mothers rested for 40 min in the test cage with the pups having been removed. Four pups and standard nesting material were then presented. Latency to pup carrying and duration of pup manipulation, nest building, and time spent on the nest with the pups, as well as duration of autogrooming and general activity were determined. Saline-injected controls started gathering the pups immediately and usually showed all elements of maternal behaviour within 10 min. Antagonist-treated mothers showed a marked delay in the onset of pup grouping and other maternal behaviours. At the end of 1 h, two out of six mothers had not yet picked up a single infant. Pups left overnight with their mothers were gathered into the nest and suckled, and no long-term effects of the antagonist were evident on retesting. The effectiveness of oxytocin antagonist in suppressing the rapid onset of post-partum maternal behaviour supports the hypothesis that centrally released oxytocin is involved in this process. It is noteworthy that these effects were obtained in Wistar rats, a strain in which oxytocin has failed to accelerate responsiveness to pups in virgin females. J. Endocr. (1987) 112, 275–282


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 723-723
Author(s):  
Qing-Feng Tao ◽  
Diego Martinez vasquez ◽  
Ricardo Rocha ◽  
Gordon H Williams ◽  
Gail K Adler

P165 Aldosterone through its interaction with the mineralocorticoid receptor (MR) plays a critical role in the development of hypertension and cardiovascular injury (CVI). Normally, MR is protected by 11β-hydroxysteroid dehydrogenase (11β-HSD) which inactivates glucocorticoids preventing their binding to MR. We hypothesis that if activation of MR by either aldosterone or glucocorticoids induces hypertension and CVI, then the inhibition of 11β-HSD with glycyrrhizin (GA), a natural inhibitor of 11β-HSD, should induce damage similar to that observed with aldosterone. Sprague-Dawley rats were uninephrectomized, and treated for 4 weeks with 1% NaCl (in drinking water) for the control group, 1% NaCl + aldosterone infusion (0.75 μg/h), or 1% NaCl + GA (3.5 g/l in drinking water). After 4 weeks, aldosterone and GA caused significant increases in blood pressure compared to control rats ([mean ± SEM] 211± 9, 205 ± 12, 120 ± 9 mmHg, respectively, p<0.001). Both aldosterone- and GA-treated rats had a significant increase in proteinuria (152.2 ± 8.7 and 107.7 ± 19.5 mg/d, respectively) versus controls (51.2 ± 9.5 mg/d). There was a significant increase (p<0.001) in heart to body weight ratio in the rats treated with aldosterone or GA compared with control (3.92 ± 0.10, 3.98 ± 0.88, and 3.24 ± 0.92 mg/g, respectively). Hearts of GA and aldosterone treated rats showed similar histological changes consisting of biventricular myocardial necrosis and fibrinoid necrosis of small coronary arteries and arterioles. These data suggests that in rodents activation of MR by either aldosterone or corticosterone leads to severe hypertension, vascular injury, proteinuria and myocardial infarction. Thus, 11β-HSD plays an important role in protecting the organism from injury.


2012 ◽  
Vol 27 (5) ◽  
pp. 301-305 ◽  
Author(s):  
Baohua Zhu ◽  
Chuanming Tong ◽  
Weitao Guo ◽  
Rong Pu ◽  
Guoping Zhang ◽  
...  

PURPOSE: To investigate synergistic suppression of donor liver pre-perfusion with recipient serum (RS) and cobra venom factor (CVF) treatment on hyperacute rejection (HAR) following liver xenotransplantation. METHODS: Guinea-pigs (GP, n=24) and Sprague-Dawley rats (SD, n=24) were recruited. Before transplantation, serum was collected from SD rats and used for preparation of inactivated complements. GP and SD rats were randomly assigned into four groups (n=6), respectively: RS group, CVF group, RS+CVF group and control group. Orthotopic liver xenotransplantation was performed with modified two-cuff technique. The survival time and liver function of recipients, morphological and pathological changes in rat livers were investigated. RESULTS: There was no piebald like change in the recipient livers in all experiment groups. The survival time of recipients in all experiment groups was longer than that in control group (p<0.05). Moreover, the survival time in the RS+CVF group was markedly longer than that in the RS group (p<0.01) and CVF group (p<0.05). The serum ALT level in all experiment groups were lower than that in the control group (p<0.05). Furthermore, the ALT level in the RS+CVF group was significantly lower than that in the CVF group (p<0.05) and RS group (p<0.01). The histological damages were significantly improved when compared with the control group, and the histological damages in the RS+CVF group were milder than those in the remaining groups (p<0.05) CONCLUSION: Pre-perfusion of donor liver with recipient serum and cobra venom factor treatment can exert synergistic suppressive effects on the hyperacute rejection following liver xenotransplantation.


Author(s):  
Min Hu ◽  
Fan Du ◽  
Shi Liu

The purpose of this study was to investigate the effects of electroacupuncture at Zusanli acupoint on the enteric neuropathy in diabetic rats. Sprague–Dawley rats were divided into different groups depending on the total electroacupuncture span and frequency. The expression of nitric oxide synthase (nNOS), choline acetyltransferase (CHAT), protein gene product 9.5 (PGP9.5), and doublecortin was significantly decreased in the diabetic group compared with the control group. Long-term electroacupuncture at Zusanli with either high frequency or low frequency could increase the expression levels of nNOS, CHAT, PGP9.5, and doublecortin, and the increase was greater in the high-frequency group. But no obvious changes were seen in the short-term electroacupuncture groups. These results suggest that electroacupuncture at Zusanli can restore the deficiency of enteric neurons in diabetes partly but a comparative long duration of stimuli (6 weeks) is required. The increase of doublecortin may be involved in this positive process.


2019 ◽  
Vol 26 (02) ◽  
Author(s):  
Sidra Hamid ◽  
Qaiser Aziz ◽  
Aneela Jamil ◽  
Lubna Meraj ◽  
Shazia Muazam ◽  
...  

Background: The most potent and effective drugs used for the management of blood pressure in hypertensive patients are Calcium channel blockers (CCBs). Nifedipine, a CCB, acts by blocking entry of calcium ions all the way through the voltage gated calcium channels (VGCCs) of L-type present in the smooth muscle cells of blood vesselsand reducing the blood pressure by decreasing the peripheral vascular resistance. Objectives: The study objective was to determine the effect of nifedipine on serum luteinizing hormone (LH) and serum testosterone in male Sprague Dawley rats. Study Design: Animal experimental study. Setting: All experiments were conducted at the Research laboratory of Shifa College of Medicine, Islamabad along with National Institute of Health (NIH), Islamabad. Period: October, 2012 to April, 2014. Methods: The study was done on adult male Sprague-Dawley rats (N= 60) aged 90-120 days old and their body weights varied between 200 + 50 grams. Rats were divided intotwo groups (n=30). Group A was administered0.5 ml distilled water/rat daily orally, group B was administered orally with nifedipine 50 mg/kg/rat dissolved in 1ml of DMSO. All the doses were given to rats for 8 weeks. After 8 weeks, serum luteinizing hormone and serum testosterone were measured in both groups. Results: In Nifedipine treated group, serum testosterone was significantly decreasedand serum LH was unaffected as compared to the control group. Conclusion: Nifedipine has adverse effects on male fertility as it decreases serum testosterone level.


2020 ◽  
Vol 14 (03) ◽  
pp. 124-127
Author(s):  
Somia Iqbal ◽  
Noman Sadiq ◽  
Saad Siddiqui ◽  
Hira Iqbal

Background: Obesity is a prevailing metabolic disorder that affects the functioning of the male reproductive system. Excessive adipose tissue enhances reactive oxygen species generation and is linked with male infertility. Spinach has demonstrated antioxidant effects. The present study was conducted to determine the antioxidant effects of spinach on sperm parameters in obese Sprague Dawley rats. Subjects and methods: This randomized control study was conducted at the animal house of the National Institute of Health Islamabad, Islamic International Medical College, Cosmesurge International Hospital, Rawalpindi, and Apollo lab, Islamabad, Pakistan from April 2016 to March 2017. Forty male Sprague Dawley rats having an age of 8 weeks and weight 160-200g were tagged from number 1 to 40. Every third rat was randomly allocated to control Group A (n=13) and remaining into the Experimental group (n=27). Rats of control Group A was given a standard diet while a high-fat diet was given to Experimental group rats to induce obesity for the duration of six weeks. Weight (g) was measured weekly and obesity was confirmed when rats attain more than 20% weight when compared with that of rats of control Group A. Then, after obesity induction, the experimental group was alienated into the obesity control group (Group B) and spinach treated group (Group C). For sample, rats of Group A and Group B were sacrificed, and the cauda epididymis of each rat was placed in a Petri dish containing normal saline and cut into pieces to allow the release of sperm and then sperm parameters (sperms concentration, motility, and morphology) were recorded under the microscope. Then, spinach (5% hot water extract) along with the persistence of fat diet was administered to Group C for 4 weeks and finally, sperm parameters were measured in this group. Results: Sperm concentration/ml, motility (%), and normal morphology (%) of Group B rats were significantly decreased as compared to Group A rats. However, sperm concentration/ml, motility (%), and normal morphology (%) of Group C (spinach treated group) rats was significantly increased (p<0.001) as compared to Group B (obesity control group) rats after administering spinach. Conclusion: The addition of Spinach in a normal diet regimen restores normal sperm morphology, improves sperm motility and concentration.


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