Studies on LH modulated 8kDa peptide involved regulation of testosterone production in rat Leydig cells.
OBJECTIVE
To demonstrate the role of the 8 kDa peptide in regulation of testosterone production by rat Leydig cells.


METHODS
A peptide similar to 8 kDa peptide purified from immature rat Leydig cells was isolated and purified from rat lung cytosol. Immunological and structural similarity between the peptides purified from lung and Leydig cells was established by Western blot and tryptic map comparison respectively.


RESULTS
Addition of the 8 kDa peptide 10, 50, 100, and 150 microg decreased the production of testosterone in Leydig cells dose-dependently. But the addition of the peptide 150 microg along with hCG had no effect on hCG-stimulated increase in testosterone production.


CONCLUSIONS
In vitro addition of the peptide purified from lung cytosol to adult rat Leydig cells resulted in a concentration-dependent decrease in basal testosterone production although it had no effect on hCG-stimulated testosterone production.
Ramaraj
P
P
Department of Diabetes, Endocrinology & Metabolism, The University of Hope National Medical Centre, Duarte, CA 91007, USA.
Rao
A J
AJ
D000818:Animals; D007985:Leydig Cells / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000502:physiology*; D008297:Male; D008970:Molecular Weight; D010455:Peptides / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013739:Testosterone / Q000096:biosynthesis*
D010455:Peptides; D013739:Testosterone; D007986:Luteinizing Hormone