Multihormonal Control of Pre-Pro-Somatostatin mRNA Levels in the Periventricular Nucleus of the Male and Female Rat Hypothalamus

1990 ◽  
Vol 52 (5) ◽  
pp. 527-536 ◽  
Author(s):  
Ricardo Zorrilla ◽  
Jacques Simard ◽  
Eric Rhéaume ◽  
Fernand Labrie ◽  
Georges Pelletier
1993 ◽  
Vol 58 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Karen S.L. Lam ◽  
Gopesh Srivastava ◽  
Sau-Ping Tam ◽  
Lap-Ping Chung ◽  
Sau-Fong Chan ◽  
...  

Endocrinology ◽  
2014 ◽  
Vol 155 (9) ◽  
pp. 3597-3609 ◽  
Author(s):  
Bailey A. Kermath ◽  
Penny D. Riha ◽  
Michael J. Woller ◽  
Andrew Wolfe ◽  
Andrea C. Gore

Abstract The role of the hypothalamus in female reproductive senescence is unclear. Here we identified novel molecular neuroendocrine changes during the natural progression from regular reproductive cycles to acyclicity in middle-aged female rats, comparable with the perimenopausal progression in women. Expression of 48 neuroendocrine genes was quantified within three hypothalamic regions: the anteroventral periventricular nucleus, the site of steroid positive feedback onto GnRH neurons; the arcuate nucleus (ARC), the site of negative feedback and pulsatile GnRH release; and the median eminence (ME), the site of GnRH secretion. Surprisingly, the majority of changes occurred in the ARC and ME, with few effects in anteroventral periventricular nucleus. The overall pattern was increased mRNA levels with chronological age and decreases with reproductive cycle status in middle-aged rats. Affected genes included transcription factors (Stat5b, Arnt, Ahr), sex steroid hormone receptors (Esr1, Esr2, Pgr, Ar), steroidogenic enzymes (Sts, Hsd17b8), growth factors (Igf1, Tgfa), and neuropeptides (Kiss1, Tac2, Gnrh1). Bionetwork analysis revealed region-specific correlations between genes and hormones. Immunohistochemical analyses of kisspeptin and estrogen receptor-α in the ARC demonstrated age-related decreases in kisspeptin cell numbers as well as kisspeptin-estrogen receptor-α dual-labeled cells. Taken together, these results identify unexpectedly strong roles for the ME and ARC during reproductive decline and highlight fundamental differences between middle-aged rats with regular cycles and all other groups. Our data provide evidence of decreased excitatory stimulation and altered hormone feedback with aging and suggest novel neuroendocrine pathways that warrant future study. Furthermore, these changes may impact other neuroendocrine systems that undergo functional declines with age.


1996 ◽  
Vol 91 (2) ◽  
pp. 300-303 ◽  
Author(s):  
R.Jeroen Pasterkamp ◽  
Kazunari Yuri ◽  
David T.M. Visser ◽  
Shinji Hayashi ◽  
Mitsuhiro Kawata

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.


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.


2011 ◽  
Vol 209 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Karine Bibeau ◽  
Mélissa Otis ◽  
Jean St-Louis ◽  
Nicole Gallo-Payet ◽  
Michèle Brochu

In low sodium-induced intrauterine growth restricted (IUGR) rat, foetal adrenal steroidogenesis as well as the adult renin–angiotensin–aldosterone system (RAAS) is altered. The aim of the present study was to determine the expression of cytochrome P450 aldosterone synthase (P450aldo) and of angiotensin II receptor subtypes 1 (AT1R) and 2 (AT2R) in adult adrenal glands and whether this expression could be influenced by IUGR and by high-salt intake in a sex-specific manner. After 6 weeks of 0.9% NaCl supplementation, plasma renin activity, P450aldo expression and serum aldosterone levels were decreased in all groups. In males, IUGR induced an increase in AT1R, AT2R, and P450aldo levels, without changes in morphological appearance of the zona glomerulosa (ZG). By contrast, in females, IUGR had no effect on the expression of AT1R, but increased AT2R mRNA while decreasing protein expression of AT2R and P450aldo. In males, salt intake in IUGR rats reduced both AT1R mRNA and protein, while for AT2R, mRNA levels decreased whereas protein expression increased. In females, salt intake reduced ZG size in IUGR but had no affect on AT1R or AT2R expression in either group. These results indicate that, in response to IUGR and subsequently to salt intake, P450aldo, AT1R, and AT2R levels are differentially expressed in males and females. However, despite these adrenal changes, adult IUGR rats display adequate physiological and adrenal responses to high-salt intake, via RAAS inhibition, thus suggesting that extra-adrenal factors likely compensate for ZG alterations induced by IUGR.


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