Hormonal control of femoral gland secretion in the lizard, Amphibolurus ornatus.

Castration of the male lizard Amphibolurus ornatus results in atrophy of the femoral glands. The amount of secretion collected from glands decreased from (mean +/- SE) 136.6 +/- 13.0 micrograms/g body wt prior to castration to 102.7 +/- 14.6 micrograms/g body wt 28 days after castration (P less than 0.001). Over the same period the secretion from a group of intact males increased. Biosynthesis of steroids by testicular tissue from A. ornatus was studied in vitro using [4-14C]progesterone as substrate. A single androgen, probably testosterone, was isolated. Daily injections for 28 days of 1 microgram/g body wt of testosterone propionate (TP) and 5 alpha-dihydrotestosterone (DHT) stimulated femoral gland secretion in castrated males (TP, 201.8 +/- 21.5 micrograms/g body wt; DHT, 142.8 +/- 16.0 micrograms/g body wt). The glands of animals receiving injection medium only remained atrophic. Identical regimes of TP and DHT also stimulated femoral gland secretion in intact females from which no exudate could initially be collected. These data are consistent with the hypothesis that lizard femoral glands are androgen-dependent secondary sex characters.