| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Biology of Reproduction, Vol 23, 29-39, Copyright © 1980 by Society for the Study of Reproduction
1 Worcester Foundation for Experimental Biology,
Shrewsbury, Massachusetts 01545 Androgen levels were measured in fluids obtained from conscious adult rams through catheters
in the rete testis, testicular lymphatic ducts, and internal spermatic vein. Comparisons were made
between serial samples of rete testis fluid (RTF) and testicular lymph (TL) or spermatic venous
blood plasma (SV), or between TL and SV. It was found that pre-injection levels of testosterone (T), as measured by radioimmunoassay,
were similar in RTF and TL, but approximately two times higher in SV. Following i.v. injection of
1 or 2 mg/ram of LH or LH plus 5 mg FSH, the distribution of androgens among testicular compartments changed drastically. There was a pronounced elevation in the concentration of T in TL
and SV, but a much smaller increase in 5
2 The Population Council,
Rockefeller University,
New York, New York 10021
-dihydrotestosterone (DHT). In contrast, the concentration in RTF of T, DHT and androgen-binding protein (ABP), as determined by polyacrylamide
gel electrophoresis, changed little. The concentration of T in peripheral blood plasma (PB) was
always correlated with T levels in TL or SV. Injection of FSH alone apparently did not affect
androgen concentrations peripherally or the distribution of androgens between testicular compartments. Nor did FSH appear to potentiate the steroidogenic effect of LH in PB, TL or RTF.
Little change in T concentrations in RTF was observed during naturally occurring episodic changes
in T levels in TL or SV. These results clearly demonstrate the very stable androgen milieu in the
seminiferous tubules in the face of widely fluctuating T levels in adjacent testicular compartments
and point to the existence in the seminiferous tubules of a regulatory mechanism that limits access
of T to the tubular lumen.
Note:
ACKNOWLEDGMENTS
We thank Jehbco, Pty. Ltd., Brookvale, N.S.W.,
Australia, for providing samples of silicone-rubber
tubing used for collection of RTF. We are grateful to
Dr. Andrzej Bartke for helpful criticism of the manuscript. This work was supported by USPHS grant NIH
HD 09356.
This article has been cited by other articles:
|
|
 |
|
  P. Y. Liu, P. Y. Takahashi, P. D. Roebuck, A. Iranmanesh, and J. D. Veldhuis Age-specific changes in the regulation of LH-dependent testosterone secretion: assessing responsiveness to varying endogenous gonadotropin output in normal men Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2005; 289(3): R721 - R728. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
