Regulation of Testosterone Rhythmicity by Gonadotropins in Bonnet Monkeys (Macaca radiata)

Mukku, VR and Murty, GSRC and Srinath, BR and Ramasharma, K and Kotagi, SG and Moudgal, NR (1981) Regulation of Testosterone Rhythmicity by Gonadotropins in Bonnet Monkeys (Macaca radiata). In: Biology Of Reproduction, 24 (4). pp. 814-819.

PDF full_text_7.pdf - Published Version Restricted to Registered users only Download (651kB) | Request a copy

Abstract

In an attempt to study the factor(s) that regulates production of nychthemeral testosterone surges in adult male bonnet monkeys (Macaca radiata), serum levels of testosterone, LH, FSH, and prolactin were monitored during a 24 h period. Only prolactin showed a significant increment in its levels coincident with that of the testosterone surge. The relationship between LH and testosterone production was studied by 1) observing the responsiveness of testes, in terms of testosterone production, to one or two injections of oLH (1 mg/injection) given 12 h apart at 0900 and 2100 h; and 2) monitoring the effect on testicular testosterone production of LH antiserum injection given at 1000, 1700, and 2100 h. That each LH injection brought about an increment in testosterone level of equal magnitude suggests that the difference in responsiveness of the testes to unchanging levels of LH at morning and night hours is not due to any alteration in substrate availability at the two time intervals. The LH antiserum experiments indicate that irrespective of the time of its administration the nocturnal surge of testosterone, which normally occurs at 2200 h, is blocked. While the antiserum prevents a rise in testosterone level, it appears not to influence basal testosterone production. The results further show that even at 2100 h, when surge testosterone production is already initiated, the testis is still highly sensitive to lack of LH, antiserum injection bringing about within 2 h a significant reduction in testosterone levels (by 69% in experimentals vs 11% in controls).

Item Type:	Journal Article
Publication:	Biology Of Reproduction
Publisher:	Society for the Study of Reproduction
Additional Information:	Copyright of this article belongs to Society for the Study of Reproduction.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	04 Jan 2010 07:35
Last Modified:	19 Sep 2010 05:46
URI:	http://eprints.iisc.ac.in/id/eprint/23690

Actions (login required)

View Item