Comparative effects of diverse vertebrate gonadotropins on androgen formation in vitro from testes of roosters and mice.

A study was carried out to compare the androgen formation activity of gonadotropins from diverse vertebrate species by rooster and mouse testes in vitro. The dispersed testicular interstitial cells from 6- to 7-wk-old mice or testicular slices from 3- to 4-mo-old roosters were incubated with varying doses of luteinizing hormones (LHs)/gonadotropins (GTHs) in Medium 199 containing isobutyl-methyl-xanthine and N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid buffer (pH 7.4) at 34 degrees C (mice) or 37 degrees C (roosters) for 4 hr under continuous aeration of 95% O2-5% CO2 in a Dubnoff incubator shaken at 100 cycles/min. Androgen in the medium was measured by radioimmunoassay. The results revealed that dose-related androgen formations were obtained both in rooster and mouse systems in response to stimulations of all LHs/GTHs tested. The mouse system was more responsive to mammalian LHs and placental GTHs, less responsive to LHs from chickens, frogs, and turtles, and extremely unresponsive to piscine GTHs. In contrast, the rooster system was highly responsive to LHs from both mammals and chickens in androgen formation; it was also responsive to LHs from turtles and frogs as well as to piscine GTHs, although with relatively lower sensitivity. The rooster testis system is thus suitable for in vitro bioassay of LHs/GTHs from virtually all vertebrate classes, whereas the mouse testis system is more suitable for bioassay of mammalian LHs and placental GTHs. The differential androgen formation potencies of the diverse vertebrate GTHs in testis systems between roosters and mice indicate that a divergence exists in the testicular receptors between the two animal species.(ABSTRACT TRUNCATED AT 250 WORDS)