Infection of hypophysectomized mice with Newcastle disease virus caused a time-dependent increase in corticosterone and interferon production. Prior treatment with dexamethasone completely inhibited the virus-induced elevation in corticosterone concentration, but did not significantly alter the interferon response. Lymphocytes appear to be the most likely source of an adrenocorticotropin-like substance that is responsible for the increased corticosterone, since spleen cells from the virus-infected, but not from control or dexamethasone-treated, hypophysectomized mice showed positive immunofluorescence with antibody to adrenocorticotropin-(1-13 amide). Thus the adrenocorticotropin-like material and interferon appear to be coordinately induced and differentially controlled products of different genes. These findings strongly suggest the existence of a lymphoid-adrenal axis. Copyright © 1982 AAAS.