Biological effects of cysteamine: relationship to somatostatin depletion.

Cysteamine given subcutaneously to rats decreases brain concentrations of somatostatin-like immunoactivity (SLI) but does not affect vasopressin-like immunoactivity as determined by radioimmunoassay and immunocytochemistry. Since somatostatin-related peptides act within the central nervous system (CNS) to increase body temperature and decrease adrenal epinephrine secretion, changes in these parameters were assessed following cysteamine administration. Cysteamine administration lowers oxygen consumption and body temperature, and elevates plasma concentrations of epinephrine, glucose, insulin and glucagon. The lowering of body temperature and elevation of plasma epinephrine is prevented by CNS administration of the CNS-selective somatostatin analog desAA1,2,4,5,12,13[D-Trp8 ))somatostatin. The CNS actions of somatostatin-related peptides are opposite to the effects of cysteamine. The observations are consistent with the possibility that brain somatostatin-related peptides are involved in regulation of body temperature and adrenal epinephrine secretion.