The capability of androgen aromatization by bank vole Leydig cells in vitro: the effect of aromatase inhibitor.
The effect of increasing concentrations of aromatase inhibitor CGS 16949A on LH- and testosterone-supplemented estradiol secretion by Leydig cells was studied. Leydig cells were obtained from immature and mature bank voles, which were reared in a long or a short photoperiod conditions. They were either incubated for 6 hrs with LH and/or testosterone (LH/testosterone-supplemented cultures), or as the control cultures. Aromatase inhibitor was added for further 18 h. After 24-h incubation period testosterone and estradiol secretion were radioimmunologically examined. This study revealed that in bank voles, Leydig cells' aromatase activity appeared to be photoperiod- and age-dependent. However, the differences in its activity were seen only in case of mature tissue. In immature bank voles, reared in both regimes of light aromatase activity was low, while in mature animals a 50% increase was observed. Thus, aromatase activity and estradiol biosynthesis were much lower in the Leydig cell culture from a short day than in the analogus culture fom a long one. The present study also showed different sensitivity to the stimulation of LH between young and adult bank voles kept in different regimes of light, which could be connected with the number of Leydig cells' LH receptors.
Kmicikiewicz
I
I
Laboratory of Animal Endocrinology and Tissue Culture, Jagiellonian University, Cracow, Poland.
Bilińska
B
B
D000367:Age Factors; D000818:Animals; D047072:Aromatase Inhibitors; D003411:Arvicolinae; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D017316:Fadrozole / Q000494:pharmacology*; D007985:Leydig Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D017440:Photoperiod; D013739:Testosterone / Q000378:metabolism*
D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors; D013739:Testosterone; D017316:Fadrozole