Autoregulation of testicular LH receptors in Ames dwarf (df/df) and pigmy (pg/pg) mice.

The autoregulation of testicular LH receptors was studied in mutant mice with congenital PRL and GH deficiency (df/df) and in mutant mice with congenital resistance to GH (pg/pg). Low dose of hCG produced an increase in LH receptors in df/df mice, but not in normal mice of the same strain. Intermediate doses of hCG did not affect LH receptors in df/df mice, while decreasing them in normal mice. In pg/pg mice, hCG caused changes in LH receptors which were identical to those observed in their normal siblings. Comparison of these two mutations suggests a lack of involvement of GH in the regulation of testicular LH receptors. Moreover, results obtained from df/df mice could indicate the presence of direct effects of the df mutation on testicular LH receptors.