Serum ACTH and adrenal histology in reproductively inhibited male prairie deermice (Peromyscus maniculatus bairdi).

Exogenous ACTH will cause adrenal hypertrophy and gonad dysfunction in reproductively capable male deermice. The ultrastructure of the zona fasciculata of inhibited animals is substantially different from ACTH stimulated animals which suggests that ACTH alone does not produce the inhibition. Although ACTH concentrations were variable, there was no clear demonstration that any differences existed between reproductively capable vs inhibited animals at the time when corticosterone is known to be elevated in the inhibited animals. A contributory role for ACTH in promoting inhibition is not ruled out, but neither is it likely that elevated ACTH alone accounts for the observed reproductive inhibition in animals taken from populations.