No abstract

Blunted growth hormone responses to clonidine have been reported in most studies of humans with panic disorder but have been an inconsistent finding in the study of other anxiety syndromes. The growth hormone response to oral clonidine (100 micrograms/kg) was investigated in the adult nervous pointer dog, a genetic animal model of anxiety. Compared with placebo, clonidine produced significant increases in plasma levels of growth hormone; however, there were no differences in the growth hormone (GH) responses to clonidine in the nervous compared with the normal pointer dogs. Findings in this animal model are discussed within the context of noradrenergic-hypothalamic-GH dysfunction reported in some but not all types of anxiety disorders in humans.