scholarly journals Hyponatremia induced by vasopressin or desmopressin in female and male rats.

1993 ◽  
Vol 3 (9) ◽  
pp. 1600-1606
Author(s):  
J G Verbalis

Previous studies have demonstrated that hyponatremia induced by continuous sc infusion of desmopressin (dDAVP) in combination with a liquid diet allows brain volume adaptation with negligible morbidity and mortality in rats. In contrast, some studies of hyponatremia induced by injections of long-acting preparations of arginine vasopressin (AVP) have reported mortality rates as high as 20 to 80%. To evaluate the possibility that the use of AVP to produce antidiuresis may cause greater mortality as a result of increased brain edema, this study examined brain water and electrolyte contents of male and female rats after varying periods of hyponatremia induced by continuous sc infusions of either dDAVP (5 ng/h) or AVP (100 ng/h). Rats infused with AVP had AVP levels in plasma elevated into ranges reported in patients with the syndrome of inappropriate antidiuretic hormone secretion (17.5 +/- 2.0 pg/mL); however, despite the production of comparably severe degrees of hyponatremia with both AVP and dDAVP infusions (105 to 115 mmol/L), no mortality occurred in any of the rats (N = 40 AVP infused and N = 40 dDAVP infused). AVP- and dDAVP-induced hyponatremia both caused transient brain edema in female and male rats, but brain water content returned to the levels of normonatremic controls after 5 days in the females and 10 days in the males. However, at no time during the 10-day study period did brain water content differ significantly between rats infused with AVP or dDAVP, either in females or males. Decreases in brain electrolytes were also equivalent in the AVP- and dDAVP-infused male and female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

1989 ◽  
Vol 121 (2) ◽  
pp. 343-349 ◽  
Author(s):  
E. Saridaki ◽  
D. A. Carter ◽  
S. L. Lightman

ABSTRACT The role of γ-aminobutyric acid (GABA) in the control of oxytocin and arginine vasopressin (AVP) release from the posterior pituitary was investigated using the GABA agonist muscimol and the GABA antagonists bicuculline and picrotoxin. Two perifusion model systems were studied using (a) intact isolated posterior pituitaries (IPP) and (b) neurosecretosomes from both male and female rats. In experiments on tissue from male rats, the stimulated release of oxytocin and AVP in both models was inhibited by muscimol, an effect which was reversed in the presence of bicuculline. Bicuculline alone increased the release of oxytocin only. Although similar responses to muscimol or bicuculline were seen in neurosecretosomes from female animals, neither agent affected oxytocin and AVP release from the intact IPP. Picrotoxin had a similar effect to bicuculline on oxytocin in isolated posterior pituitaries from male as well as female rats, although at the neurosecretosome level a paradoxical inhibition was observed. These results provide evidence for an endogenous GABA receptor mechanism at the level of the neurosecretory terminals in both male and female rats. The sexually dimorphic IPP response suggests a second more complex mechanism involving either pituicytenerve terminal interactions and/or a secondary role of other neurotransmitters in the GABA regulation of neurohypophysial hormones. Journal of Endocrinology (1989) 121, 343–349


2021 ◽  
Author(s):  
Heather M Minchew ◽  
Sarah K Christian ◽  
Paul Keselman ◽  
Jinxiang Hu ◽  
Brian T Andrews ◽  
...  

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. Cerebral edema following TBI is known to play a critical role in injury severity and prognosis. In the current study we used multimodal magnetic resonance imaging (MRI) to assess cerebral edema 24 hours after unilateral contusive TBI in male and female rats. We then directly quantified brain water content in the same subjects ex vivo. We found that in male rats, the injured cortex had higher brain water content and lower apparent diffusion coefficient (ADC) values compared with the contralateral side. Females did not show hemispheric differences for these measures. However, both males and females had similarly elevated T2 values in the injured cortex compared with the contralateral side. A strong correlation was observed between brain water content and T2 values in the injured cortex in male rats, but not in females. These findings raise questions about the clinical interpretation of radiological findings pertinent to edema in female TBI patients. A more mechanistic understanding of sex differences and similarities in TBI pathophysiology will help improve patient management and the development of effective treatment strategies for TBI in men and women.


1978 ◽  
Vol 78 (3) ◽  
pp. 399-406 ◽  
Author(s):  
J. TH. J. UILENBROEK ◽  
R. TILLER ◽  
F. H. DE JONG ◽  
F. VELS

Adult male and female rats received an ovarian homotransplant under the kidney capsule or in the spleen 14 days after gonadectomy. After transplantation under the kidney capsule, the high levels of both LH and FSH normally observed after gonadectomy decreased to the levels found in intact male and female rats. After transplantation into the spleen, however, the serum levels of LH increased still further, although a decrease was observed in the level of FSH. In male rats, the concentrations of oestradiol-17β in the plasma increased from 17 to 56 pg/ml after transplantation of an ovary under the kidney capsule; the concentration was not increased after intrasplenic ovarian transplantation. In female rats with an intrasplenic transplant, the uterine weight did not increase and vaginal smears were not cornified. Administration of oestrogen and progesterone to produce approximately the concentrations found in rats with an intrasplenic transplant did not result in decreased concentrations of FSH. These results suggest that the ovary secretes a substance with specific FSH-suppressing activity, which is not inactivated by the liver.


2020 ◽  
Author(s):  
Fariba Azarkish ◽  
Ali Atash Ab Parvar ◽  
Mehdi Nematbakhsh ◽  
aghdas dehghani ◽  
Ali Atash Ab Parvar

Abstract Background Renal ischemia/reperfusion injury (IRI) may influence distance organ such as lung. The severity of IRI induced - lung injury can be affected by gender. The aim of this study was to determine the role of gender in IRI induced- lung injury in different of renal reperfusion time. Methods 80 male and female Wistar rats were assigned into 8 groups; 4 groups in each gender including sham, renal ischemia (ISC) for 45 min by clamping renal vessels followed by 3 hr, 24 hr or 48 hr reperfusion.blood samples were obtained for measuring the serum level of blood urea nitrogen (BUN), creatinine (Cr), nitrite, and malondialdehyde (MDA). The kidneys and lung tissues were removed and used for MDA and nitrite measurements and the histological changes evaluation.the percentage of lung water content was calculated. Results In both genders, the rise in Cr and BUN reached the peak at 24 h reperfusion. In 3 h reperfusion female rats, lead to significant increase in serum level of nitrite compared with males. In male rats subjected to 3 h reperfusion, the renal MDA level increased but not seen in females. The enhanced lung tissues damages were depended to reperfusion time in both genders. The water content of lung was reduced in 3 h of reperfusion groups. Conclusions IRI caused kidney and lung dysfunction depends on reperfusion time. Considering gender difference, female gender may be more sensitive to alteration of nitrite level compared with males. It seems that the effect of IRI is more rapid in males than females.


1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.


2020 ◽  
Vol 12 (1) ◽  
pp. 001-008
Author(s):  
Ting Liu ◽  
Xing-Zhi Liao ◽  
Mai-Tao Zhou

Abstract Background Brain edema is one of the major causes of fatality and disability associated with injury and neurosurgical procedures. The goal of this study was to evaluate the effect of ulinastatin (UTI), a protease inhibitor, on astrocytes in a rat model of traumatic brain injury (TBI). Methodology A rat model of TBI was established. Animals were randomly divided into 2 groups – one group was treated with normal saline and the second group was treated with UTI (50,000 U/kg). The brain water content and permeability of the blood–brain barrier were assessed in the two groups along with a sham group (no TBI). Expression of the glial fibrillary acidic protein, endthelin-1 (ET-1), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) were measured by immunohistochemistry and western blot. Effect of UTI on ERK and PI3K/AKT signaling pathways was measured by western blot. Results UTI significantly decreased the brain water content and extravasation of the Evans blue dye. This attenuation was associated with decreased activation of the astrocytes and ET-1. UTI treatment decreased ERK and Akt activation and inhibited the expression of pro-inflammatory VEGF and MMP-9. Conclusion UTI can alleviate brain edema resulting from TBI by inhibiting astrocyte activation and ET-1 production.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.


2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maryam Malek ◽  
Mehdi Nematbakhsh

Background. Angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor (ACE2/Ang-1-7/MasR) appears to counteract most of the deleterious actions of angiotensin-converting enzyme/angiotensin II/angiotensin II receptor 1 (ACE/Ang II/AT1R) in renal ischemia/reperfusion (I/R) injury but ACE2 activity and its levels are sexually dimorphic in the kidney. This study was designed to evaluate the effects of activation endogenous ACE2 using the diminazene aceturate (DIZE) in renal I/R injury in male and female rats.Methods. 36 Wistar rats were divided into two groups of male and female and each group distinct to three subgroups (n=6). I/R group was subjected to 45 min of bilateral ischemia and 24 h of reperfusion, while treatment group received DIZE (15 mg/kg/day) for three days before the induction of I/R. The other group was assigned as the sham-operated group.Results. DIZE treatment in male rats caused a significant decrease in blood urea nitrogen (BUN), creatinine, liver functional indices, serum malondialdehyde (MDA), and increase kidney nitrite levels (P<0.05), and in female rats a significant increase in creatinine and decrease serum nitrite levels compared to the I/R group (P<0.05).Conclusions. DIZE may protect the male kidney from renal I/RI through antioxidant activity and elevation of circulating nitrite level.


2012 ◽  
Vol 7 (6) ◽  
pp. 980-986 ◽  
Author(s):  
Milan Marounek ◽  
Zdeněk Volek ◽  
Eva Skřivanová ◽  
Marian Czauderna

AbstractMale and female rats were fed diets supplemented with cholesterol and palm fat at 10 and 50 g/kg, respectively; serum, hepatic tissue and faeces were analysed. Cholesterol supplementation significantly increased serum and hepatic cholesterol both in male and female rats. Male and female rats fed the cholesterol-containing diet differed significantly in serum cholesterol concentration (2.48 µmol/mL vs 2.92 µmol/mL), concentration of serum triacylglycerols, but not in hepatic cholesterol concentration. The serum and hepatic cholesterol concentrations correlated non-significantly in male rats (r=0.491; P=0.063) and significantly in female rats (r=0.818; P<0.001). Cholesterol supplementation non-significantly decreased relative expression of the hepatic LDL receptor gene and significantly increased relative expression of the hepatic cholesterol 7α-hydroxylase gene in rats of both genders. The faeces of control rats contained similar amounts of cholesterol and bile acids. Cholesterol supplementation increased cholesterol concentration 10 times in the faeces of male rats and 12 times in faeces of female rats. The corresponding increases of bile acid concentration were much lower (83% in male rats and 108% in female rats). It can be concluded that the effects of cholesterol supplementation were more pronounced in female than in male rats.


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