scholarly journals Effects of Sex Steroids on Secretory Granule Formation in Gonadotropes of Castrated Male Rats with Respect to Granin Expression*

Endocrinology ◽  
1998 ◽  
Vol 139 (6) ◽  
pp. 2765-2773 ◽  
Author(s):  
Tsuyoshi Watanabe ◽  
Tomohiro Banno ◽  
Thomas Jeziorowski ◽  
Yoshiyuki Ohsawa ◽  
Satoshi Waguri ◽  
...  
Keyword(s):  
Sex Steroids ◽  
Plasma Levels ◽  
Chromogranin A ◽  
Secretory Granules ◽  
Male Rats ◽  
Female Rat ◽  
Granule Formation ◽  
Male And Female ◽  
Immunocytochemical Studies ◽  
Circulating Levels

Abstract Pituitary gonadotropes show sex-related differences in their ultrastructure. Typical gonadotropes of male rats exhibit both large granules, which contain chromogranin A (CgA), and small granules, which contain secretogranin II (SgII). In contrast, typical female rat gonadotropes show only a very few large granules among the numerous small granules. To clarify the nature of the biogenesis of these secretory granules and the effects of sex steroids, the ultrastructural and immunocytochemical changes in gonadotropes were examined in castrated male rats supplied with a testosterone or estradiol implant. In castrated rats, pituitary expression and plasma levels of LH increased drastically, but the pituitary content of CgA decreased. The majority of gonadotropes then showed features of “castration cells” containing many small secretory granules. A testosterone implant to castrated rats remarkably suppressed the expression and circulating levels of LH and increased the CgA content in the pituitary to near-normal levels. In this situation, immunocytochemical studies demonstrated that gonadotropes again exhibited large and small secretory granules with the respective localization of CgA and SgII. On the contrary, in castrated rats supplied with an estradiol implant, the expression and content of CgA in the pituitary were remarkably suppressed, and large secretory granules disappeared from gonadotropes. These results suggest that the expression of CgA in gonadotropes is regulated differently by male and female sex steroids. These different effects of androgen and estrogen on the expression level of CgA are closely associated with the sex-related differences in the ultrastructure of secretory granules within gonadotropes.

SEX STEROIDS STIMULATE THE ACTIVITY OF HYPOTHALAMIC ARYLAMIDASES IN THE RAT

1974 ◽  
Vol 76 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Herbert Kuhl ◽  
Christian Rosniatowski ◽  
Siang-An Oen ◽  
Hans-Dieter Taubert
Keyword(s):  
Glutamic Acid ◽  
Sex Steroids ◽  
Specific Pattern ◽  
Steroid Treatment ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Experimental Conditions ◽  
Male And Female ◽  
Male And Female Rats

ABSTRACT The effect of steroid treatment on the activity of hypothalamic arylamidases in male and female rats was investigated. A new and improved method for the assay of arylamidase activity utilizing L-α-amino acid-p-nitroanilides as substrates is presented. The influence of varying experimental conditions on the activity of hypothalamic arylamidases hydrolyzing the p-nitroanilides of cystine, glutamic acid, alanine, tyrosine, leucine, and phenylalanine, such as changes of substrate and enzyme concentration, temperature, incubation time, and pH, were tested. There was a sex-dependent response in the activity of hypothalamic arylamidases to treatment of the rats with sex steroids. In female rats, the injection of 7 μg of ethinyloestradiol was followed 16 hours later by a significant rise of L-cystine and L-glutamic acid arylamidase activity. In male rats, the injection of testosterone and of ethinyloestradiol respectively brought about a general stimulation of all enzyme activities. This indicates that this enzyme system of the male and female rat hypothalamus responds to steroid treatment of the animals with a sex-specific pattern.

scholarly journals Glutathione Conjugates of Ochratoxin a as Biomarkers of Exposure / Glutationski Konjugati Okratoksina A Kao Biomarkeri Izloženosti

2012 ◽  
Vol 63 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Mariana Tozlovanu ◽  
Delphine Canadas ◽  
Annie Pfohl-Leszkowicz ◽  
Christine Frenette ◽  
Robert J. Paugh ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Rat Kidney ◽  
Female Rats ◽  
Amide Bond ◽  
Male Rats ◽  
Dark Agouti ◽  
Female Rat ◽  
Male And Female ◽  
Male And Female Rats ◽  
Liver And Kidney

AbstractIn the present study the photoreactivity of the fungal carcinogen ochratoxin A (OTA) has been utilised to generate authentic samples of reduced glutathione (GSH) and N-acetylcysteine (NAC) conjugates of the parent toxin. These conjugates, along with the nontoxic OTα, which is generated through hydrolysis of the amide bond of OTA by carboxypeptidase A, were utilised as biomarkers to study the metabolism of OTA in the liver and kidney of male and female Dark Agouti rats. Male rats are more susceptible than female rats to OTA carcinogenesis with the kidney being the target organ. Our studies show that the distribution of OTA in male and female rat kidney is not significantly different. However, the extent of OTA metabolism was greater in male than female rats. Much higher levels of OTα were detected in the liver compared to the kidney, and formation of OTα is a detoxification pathway for OTA. These findings suggest that differences in metabolism between male and female rats could provide an explanation for the higher sensitivity of male rats to OTA toxicity

Effects of acute administration of 2-hydroxylated metabolites of oestrogens on LH and prolactin secretion in male and female prepubertal rats

1984 ◽  
Vol 103 (3) ◽  
pp. 317-325
Author(s):  
A. K. Brar ◽  
G. Fink
Keyword(s):  
Plasma Concentration ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Female Rat ◽  
Uterine Weight ◽  
Immature Female ◽  
Male And Female ◽  
Immature Male ◽  
Lh Release

ABSTRACT The effects of catechol oestradiol and catechol oestrone on the release of LH and prolactin were investigated in immature male and female Wistar rats. In male rats both catechol oestradiol and catechol oestrone significantly increased the plasma concentration of LH, and catechol oestradiol but not catechol oestrone significantly increased the plasma concentration of prolactin and decreased the pituitary concentration of LH. The parent oestrogens, oestradiol-17β and oestrone, had no effect on plasma LH concentrations, but both increased significantly the plasma concentration of prolactin, and oestrone but not oestradiol-17β increased the pituitary concentration of LH. In immature female rats, catechol oestradiol inhibited the surge of LH and the increase in uterine weight induced by injecting pregnant mare serum gonadotrophin (PMSG). The injection of oestrone induced an increase in the plasma concentration of LH which was about nine times greater than that produced by oestradiol-17β. There were no significant differences in the effects of these steroids on plasma prolactin concentration. These results (i) confirm that in the immature male rat catechol oestrogens can stimulate LH release and show that catechol oestradiol can increase prolactin release, (ii) show that catechol oestradiol can inhibit the stimulatory effects of PMSG on LH release and uterine weight in the immature female rat, and (iii) demonstrate that oestrone can stimulate LH release in the immature female rat. J. Endocr. (1984) 103, 317-325

scholarly journals Functional implications of the sex differences in transporter abundance along the rat nephron: modeling and analysis

2019 ◽  
Vol 317 (6) ◽  
pp. F1462-F1474 ◽  
Author(s):  
Rui Hu ◽  
Alicia A. McDonough ◽  
Anita T. Layton
Keyword(s):  
Sex Differences ◽  
Computational Models ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Distal Nephron ◽  
Male And Female ◽  
Modeling And Analysis ◽  
Functional Implications ◽  
Rat Kidneys

The goal of the present study was to investigate the functional implications of sexual dimorphism in the pattern of transporters along the rodent nephron as reported by Veiras et al. ( J Am Soc Nephrol 28: 3504–3517, 2017). To do so, we developed sex-specific computational models of water and solute transport along the superficial nephrons from male and female rat kidneys. The models account for the sex differences in the abundance of apical and basolateral transporters, single nephron glomerular filtration rate, and tubular dimensions. Model simulations predict that ~70% and 60% of filtered Na+ is reabsorbed by the proximal tubule of male and female rat kidneys, respectively. The lower fractional Na+ reabsorption in female kidneys is due primarily to their smaller transport area, lower Na+/H+ exchanger activity, and lower claudin-2 abundance, culminating in significantly larger fractional delivery of water and Na+ to the downstream nephron segments in female kidneys. Conversely, the female distal nephron exhibits a higher abundance of key Na+ transporters, including Na+-K+-Cl− cotransporters, Na+-Cl− cotransporters, and epithelial Na+ channels. The higher abundance of transporters accounts for the enhanced water and Na+ transport along the female, relative to male, distal nephron, resulting in similar urine excretion between the sexes. Consequently, in response to a saline load, the Na+ load delivered distally is greater in female rats than male rats, overwhelming transport capacity and resulting in higher natriuresis in female rats.

834 EFFECT OF MATERNAL OBESITY INDUCED BY DIFFERENT DIET PROGRAM ON THE PLASMA LEVELS OF APPETITE HORMONES AND INTESTINAL EXPRESSION OF ADIPOKINES AND ADIPO RECEPTORS 1 AND 2 IN MALE AND FEMALE RAT OFFSPRING

2020 ◽  
Vol 158 (6) ◽  
pp. S-165-S-166
Author(s):  
Urszula Glowacka ◽  
Kinga Gawlinska ◽  
Dawid Gawlinski ◽  
Marcin Magierowski ◽  
Zbigniew Sliwowski ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Maternal Obesity ◽  
Female Rat ◽  
Male And Female ◽  
Rat Offspring

Change from beta- to alpha-adrenergic glycogenolysis induced by corticosteroids in female rat liver

1997 ◽  
Vol 273 (1) ◽  
pp. R153-R160
Author(s):  
M. Moriyama ◽  
Y. Nakanishi ◽  
S. Tsuyama ◽  
Y. Kannan ◽  
M. Ohta ◽  
...  
Keyword(s):  
Glucose Production ◽  
Plasma Corticosterone ◽  
Mature Female ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Circadian Variations ◽  
Male And Female ◽  
Male And Female Rats ◽  
The Difference

The conversion of beta- to alpha-adrenergic glycogenolysis by corticosteroids was studied in perfused livers of mature female rats. Isoproterenol stimulated glucose production more effectively in female rats than in male rats, but the difference in its stimulatory effect disappeared in adrenalectomized (ADX) rats, whereas it remained in adrenodemedulated rats. When ADX female rats were treated with dexamethasone sulfate, alpha-responses increased and beta-responses decreased, depending on the concentration of dexamethasone sulfate. The treatment of female rats with 1.5 mg/kg dexamethasone sulfate changed the levels of the alpha- and beta-responses to those observed in male rats, and the changes were associated with changes in the number of receptors. Although periodicity of changes in plasma corticosterone levels was observed in both male and female rats, the extent of circadian variations was significantly lower in female rats during the estrous cycle than in male rats. The variations in plasma corticosterone levels and in both alpha- and beta-responses after ovariectomy approached those in male rats. The results suggest that the level of plasma corticosterone might play an important role in the regulation of the relative levels of alpha- and beta-adrenergic responses in female rats.

DIFFERENCES OF THE EFFECTS OF TESTOSTERONE PROPIONATE ON THE PRODUCTION OF LH AND FSH

1976 ◽  
Vol 82 (3) ◽  
pp. 683-690 ◽  
Author(s):  
Mridula Chowdhury ◽  
Emil Steinberger
Keyword(s):  
Treatment Period ◽  
Plasma Levels ◽  
Differential Effect ◽  
Direct Evidence ◽  
Testosterone Propionate ◽  
De Novo ◽  
Male Rats ◽  
Slight Tendency ◽  
Circulating Levels

ABSTRACT The effects of testosterone propionate (1 mg/day) on the synthesis and circulating levels of FSH and LH were studied in normal adult male rats. The pituitary and serum gonadotrophins were measured by double antibody radioimmunoassay. The de novo synthesis of gonadotrophins was assessed by the rate of in vitro incorporation of [3H]leucine into the immunoprecipitable FSH and LH. After 4 days of treatment with testosterone propionate the circulating LH levels dropped significantly, while FSH remained unchanged. Pituitary LH content and concentration declined significantly after 1 day, and incorporation of [3H]leucine into the immunoprecipitable LH became undetectable 4 days after initiation of treatment. Pituitary FSH content and concentration showed a significant increase after the 4th day of treatment. A slight tendency towards increased incorporation of [3H]leucine into FSH was observed throughout the treatment period, although it was statistically not significant. The data provide direct evidence for a differential effect of TP on FSH and LH production by the pituitary and show that the decrease in the pituitary and plasma levels of LH in testosterone treated rats is due to the decrease in LH synthesis.

scholarly journals Sex-specific effects of sex steroids on alveolar epithelial Na+ transport

2017 ◽  
Vol 312 (3) ◽  
pp. L405-L414 ◽  
Author(s):  
Melanie Haase ◽  
Mandy Laube ◽  
Ulrich H. Thome
Keyword(s):  
Respiratory Distress ◽  
Sex Steroids ◽  
Ussing Chamber ◽  
Minor Effect ◽  
Female Rat ◽  
Male And Female ◽  
Female Sex ◽  
Specific Effects ◽  
Channel Expression ◽  
Male Sex

Alveolar fluid clearance mediates perinatal lung transition to air breathing in newborn infants, which is accomplished by epithelial Na+ channels (ENaC) and Na-K-ATPase. Male sex represents a major risk factor for developing respiratory distress, especially in preterm infants. We previously showed that male sex is associated with reduced epithelial Na+ transport, possibly contributing to the sexual dimorphism in newborn respiratory distress. This study aimed to determine sex-specific effects of sex steroids on epithelial Na+ transport. The effects of testosterone, 5α-dihydrotestosterone (DHT), estradiol, and progesterone on Na+ transport and Na+ channel expression were determined in fetal distal lung epithelial (FDLE) cells of male and female rat fetuses by Ussing chamber and mRNA expression analyses. DHT showed a minor effect only in male FDLE cells by decreasing epithelial Na+ transport. However, flutamide, an androgen receptor antagonist, did not abolish the gender imbalance, and testosterone lacked any effect on Na+ transport in male and female FDLE cells. In contrast, estradiol and progesterone increased Na+ transport and Na+ channel expression especially in females, and prevented the inhibiting effect of DHT in males. Estrogen receptor inhibition decreased Na+ channel expression and eliminated the sex differences. In conclusion, female sex steroids stimulate Na+ transport especially in females and prevent the inhibitory effect of DHT in males. The ineffectiveness of testosterone suggests that Na+ transport is largely unaffected by androgens. Thus, the higher responsiveness of female cells to female sex steroids explains the higher Na+ transport activity, possibly leading to a functional advantage in females.

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