Effect of Anabolic Androgens on Tissue Replacement in the Ear of the Rabbit

Abstract

IT was recently reported that, when tissue of 1 cm² area was excised through the full thickness of the pinna of the rabbit's ear, regeneration occurred. Furthermore, the rate of regeneration was significantly greater in males than in females^1,2. It was suggested that the rate of regeneration might be influenced by male sex hormones. If this were so, then treatment of females with androgens should increase the rate of regeneration. Two androgens were used in experiments to test this hypothesis: (a) androst-4-en-17β-3-one-phenyl-propionate (testosterone phenyl-propionate—TPP)—a steroid with highly androgenic and some anabolic activities, closely allied to the naturally occurring steroid testosterone; (b) 19-nor-androst-4-en-17β-3-one-phenyl-propionate (nandrolone phenylpropionate, NPP, or ‘Durabolin’)—a steroid with less androgenic but more anabolic activity than testosterone phenyl-propionate, and therefore more suitable for the treatment of females.