title: Induction of adrenocortical special zone in the male possum (Trichosurus vulpecula).
abstract: The induction of adrenocortical special zone (S.Z.) by gonadotrophin administration was studied in male brush tailed possums. Castrated males injected with porcine FSH (NIH-FSH-P2) formed well developed S.Z.s, varying in sizes from 5-20% of the gland's volume. Pregnant mare serum gonadotrophin (PMSG) was ineffective. From adrenal homogenates of FSH treated possums incubated with [3H]-progesterone the major conversion products were 5 beta-reduced steroid metabolites (72%) and cortisol (4%). The conversion products from adrenals of saline and PMSG treated males were cortisol and corticosterone (65%). Of the ten untreated castrates, one had a well developed S.Z. and two had S.Z.s at an early stage of development. Significant 5 beta-reduction of [3H]progesterone was only found in one animal. The plasma FSH concentrations were in intact males 317 +/- 41 ng rat FSH ml-1 (mean +/- SEM) and in castrates 769 +/- 64. The possible reasons for the lack of spontaneous S.Z. formation in intact males are discussed.
mesh_terms: D000302:Adrenal Cortex / Q000033:anatomy & histology* / Q000187:drug effects / Q000378:metabolism; D000305:Adrenal Cortex Hormones / Q000378:metabolism*; D000818:Animals; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D007774:Lactation; D008297:Male; D009893:Opossums / Q000502:physiology*; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D006064:Gonadotropins, Equine; D011374:Progesterone; D005640:Follicle Stimulating Hormone