Tv. Busygina et Av. Osadchuk, The effects of the genotype and social stress on cAMP- and substrate-dependent mechanism regulating the hormone-producing function of mouse testes, RUSS J GEN, 37(5), 2001, pp. 528-534
Several steps of cAMP- and substrate-dependent testosterone production in t
he testes were studied with laboratory mouse micropopulations of six inbred
strains (A/He, CBA/Lac, C57B1/6J, DD, YT, PP). The strains differed in bas
al testosterone production in the gonads and in its response to activation
of the adenylate cyclase signal transduction pathway at various steps by hu
man chorionic gonadotropin (hCG), the cholera toxin, forskolin, and dibutyr
yl-cAMP and in the presence of pregnenolone, an early precursor of testoste
rone. Establishment of dominant-subordinate relationships in mouse populati
ons substantially affected testosterone production in response to all activ
ators of testicular steroidogenesis. The secretory activity of the testes d
ecreased at the early establishment of social hierarchy in experimental mic
ropopulations, then returned to the initial level, and again decreased in t
he case of activation with hCG, dibutyryl-cAMP, and pregnenolone. With all
activators of steroidogenesis, basal and activated testosterone production
changed in the same direction during the establishment and maintenance of s
ocial hierarchy, suggesting coordinated changes in all examined steps of te
stosterone biosynthesis in the testes. The among-strain differences in resp
onse to all activators of steroidogenesis remained much the same at various
stages of the establishment of social hierarchy. The parameters of cAMP- a
nd substrate-dependent testosterone production averaged over individual sta
ges of the establishment of social hierarchy proved associated. Their genot
ypic correlations were positive and, in many cases, significant. Subsequent
component analysis showed that one principal component accounted for more
than 80% of the total among-strain variation, suggesting a coordinated gene
tic control of the endocrine function of the testes.