EFFECT OF TESTOSTERONE PROPIONATE ON THE RELEASE OF FSH FROM THE PITUITARY GLAND

1968 ◽  
Vol 57 (2) ◽  
pp. 289-295 ◽  
Author(s):  
E. Steinberger ◽  
G. Duckett

ABSTRACT On the basis of a study of changes in follicle stimulating hormone (FSH) levels in rat pituitary glands, obtained at various times after orchiectomy, it has been previously suggested that the Leydig cell secretions may regulate the release of FSH from the pituitary gland (Steinberger & Duckett 1966). This hypothesis was put to test in the present study. FSH levels have been determined in the pituitary gland and plasma of normal, testosterone-treated, orchiectomized, and orchiectomized testosteronetreated rats. A marked drop of pituitary FSH levels, associated with an elevation of plasma FSH levels, was observed in orchiectomized rats. Administration of testosterone to orchiectomized rats prevented the drop in pituitary FSH levels and rendered the blood levels undetectable. These results are interpreted as supporting the hypothesis that testosterone has an inhibitory effect on the release of FSH from the pituitary gland.

1972 ◽  
Vol 50 (8) ◽  
pp. 768-773 ◽  
Author(s):  
E. A. Ibrahim ◽  
B. E. Howland

The concentration of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in serum and pituitary glands was studied in intact female rats and rats that were ovariectomized on day 0 of the experiment and then starved or fed for 2, 4, 7, or 9 days. Ovariectomy resulted in enhanced rates of synthesis and release of FSH and LH as indicated by the significant (P < 0.01) rises in the concentration of both hormones in the pituitary gland and serum.Starvation resulted in a decrease in body and pituitary weight. The concentration of FSH and LH in pituitary glands of starved rats was higher (P < 0.05) than that in fed rats on days 7 and 9. The concentration of FSH and LH in serum of starved rats was increased after ovariectomy but the levels on days 7 and 9 were lower than those of fed rats.These results suggest that the synthesis of FSH and LH was enhanced in both starved and fed rats following ovariectomy while the rate of release of both hormones was decreased at 7 and 9 days of starvation in comparison with rats fed ad libitum.


1968 ◽  
Vol 40 (2) ◽  
pp. 165-173 ◽  
Author(s):  
M. R. SAIRAM ◽  
H. G. MADHWA RAJ ◽  
N. R. MOUDGAL

SUMMARY The follicle-stimulating hormone (FSH) inhibitor in monkey urine was purified by selective extraction of the crude extract with acetate buffer, ammonium sulphate precipitation and DEAE-cellulose chromatography. The purified inhibitor was free of luteinizing hormone activity. It behaved as an apparently homogeneous protein. The inhibitor contained about 20% carbohydrate (hexoses, hexosamines, fucose and sialic acid). Thin-layer gel filtration indicated a molecular weight of about 65,000. The inhibitor was labile to heat treatment, exposure to extremes of pH and denaturing agents. The inhibitor effectively neutralized the biological activity of FSH preparations from human, monkey, horse, pig, sheep and rat pituitary glands, pregnant mare serum gonadotrophin and human pituitary urinary gonadotrophin.


1978 ◽  
Vol 78 (1) ◽  
pp. 1-6 ◽  
Author(s):  
ADRIANA VIVAS ◽  
MARÍA ESTER CELIS

The release of melanocyte-stimulating hormone (MSH) into the medium during incubation and the pituitary tissue content of MSH were measured separately using pituitary glands collected from rats at various stages of the oestrous cycle. The MSH was measured by a biological assay using a synthetic α-MSH as standard. The release of MSH was maximal during the pro-oestrous phase and MSH content of the pituitary gland was highest during dioestrus. The influences of the tripeptide Pro-Leu-Gly-NH2, which inhibits MSH secretion in vivo, and of progesterone on the release of MSH in vitro were studied with tissue collected at various phases of the oestrous cycle. Pro-Leu-Gly-NH2 was effective in inhibiting MSH release both at pro-oestrus and oestrus but not at dioestrus. Progesterone overcame this inhibition.


1969 ◽  
Vol 44 (3) ◽  
pp. 349-356 ◽  
Author(s):  
B. M. BINDON

SUMMARY The method of Lamond & Bindon (1966) was used to measure follicle-stimulating hormone (FSH) in the pituitary glands of mice and rats killed at different times on each of days 1–6 of pregnancy. The sensitivity of the method allowed detection of FSH fluctuations not previously described in these species. A significant fall in pituitary FSH occurred in both species on day 3, although it was earlier in the mouse than in the rat. This transient decline in FSH activity, interpreted as a release of the hormone, was followed in both species by a gradual increase on days 4 and 5. Ovarian weight, measured only in the mouse, increased significantly late on day 3 and is believed to reflect changes in pituitary FSH. The results indicate that implantation in the mouse and rat is initiated by altered activity of the pituitary gland during the first 3 days of pregnancy. It appears that this pituitary mechanism differs from that responsible for the events of the oestrous cycle.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 558
Author(s):  
ZeWen Yu ◽  
WenZhi Ren ◽  
Tian Wang ◽  
WeiDi Zhang ◽  
ChangJiang Wang ◽  
...  

CircRNAs have been identified to be expressed differently and stably in numerous species and tissues, but their functions in growth hormone (GH) secretion are still largely unknown. In summary, we have revealed a circRNA-miRNA-mRNA network that may play a biological role in the rat pituitary gland. First, we verified the chromosome location information of circAgtpbp1 according to sequencing analysis. The circAgtpbp1 characteristics were authenticated through PCR, qRT–PCR, treating with RNase and fluorescent in situ hybridization (FISH). Second, we detected the expression pattern of circAgtpbp1 in the rat anterior pituitary by qRT–PCR. We also designed circAgtpbp1 siRNA and constructed overexpression plasmid to evaluate the effect of circAgtpbp1 function on GH secretion by qRT–PCR, ELISA and Western blot. CircAgtpbp1 is a stable, truly circular molecule. We found that circAgtpbp1 interacted with miR-543-5p and can regulate GH secretion in pituitary cells through a circAgtpbp1-miR-543-5p-GH axis. Overall, the evidence generated by our study suggests that circAgtpbp1 can act as a sponge of miR-543-5p to reduce the inhibitory effect of miR-543-5p on Gh1 and further promote GH secretion. These findings expand our existing knowledge on the mechanisms of hormone regulation in the pituitary gland.


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