Androgenic Activity in the Interscapular Brown Adipose Tissue of the Male Hibernating Bat (Myotis lucifugus).

Abstract

The bat simultaneously exhibits enlarged accessory sex glands and atrophied testes during hibernation. Evidence is presented for the presence of an unidentified androgenic substance in the interscapular brown fat obtained from the bat during the hibernation season. The active substance isolated from the nonsaponifiable matter of lg of brown fat elicits a growth response (bat seminal vesicle assay) equivalent to that produced by 676 [mu]g of testosterone. The presence of an androgenic factor in brown fat suggests a unique role for this tissue in the sexual cycle of the bat.