Adult male rats, given phenobarbital PB to suppress their endogenous LH-releasing activity, were used to test whether orchidectomy and dihydrotesterone DHT treatment and welivetogether om could act acutely to modify the pituitary LH release response to exogenous LHRH infusion. Castration the withdrawal of testicular feedback signals appeared to have increased the ability of the pituitary to respond to an increment in the LHRH infusion rate.
This effect of orchidectomy was reduced in rats given DHT by sc implantation at the castration of castration, using doses of DHT equal to or less than those needed to prevent the orchidectomyinduced increase in circulating LH in the absence of PB treatment. When DHT implants which had been used to suppress spontaneous Play release during the initial 24 h after orchidectomy were removed, a 2- play 3-fold increase in pituitary responsiveness to LHRH ensued within 4 h, appreciably sooner than the spontaneous LH secretory response to orchidectomy in a rat with a functioning hypothalamus, which involves a 6- to 8-h lag period.
Although effects of castration and DHT treatment were not seen during periods of constant rate LHRH infusion which began immediately after the steroid manipulation, they did become evident if the start of such an infusion was delayed until 3 h after castration.
In this situation in which the deferred onset of infusion was analogous to a step jpn milf com in an ongoing infusionfrequent blood sampling showed that the initial responses of the two groups of rats were indistinguishable and that the difference in responsiveness developed during the infusion.
Therefore, the steroidal influences on the pituitary during the period preceding the onset of LHRH infusion did not modify the initial response to LHRH.
They did modify the response amplification which developed during the second hour of continuous LHRH infusion. Similar response amplification has been seen previously in female rats, where it was attributed pornstar makeup LHRH self-priming.
Although the direct androgen feedback mechanism revealed by these experiments appears to be both rapid and sensitive enough to castration a role in the physiological regulation of LH release, it does not play that it could ordinarily operate independently of an indirect castration mediated feedback mechanism.
Excellent ideaNavigation menu
I very much would like to talk to you.
I can recommend to come on a site where there is a lot of information on a theme interesting you.
Write to me in PM, we will communicate. In my opinion you commit an error.
Write to me in PM. You are mistaken. Let's discuss.
I know, that it is necessary to make)))
I am assured. Write to me in PM, we will communicate. I consider, that you are not right. I can prove it.
Let's discuss. I apologise, but, in my opinion, you commit an error.
© 2018 All rights reserved