Effects of Biogenic Amines on the Formation of Adenosine 3′,5′-Monophosphate in Porcine Cerebral Cortex, Hypothalamus and Anterior Pituitary Slices

Abstract

The effects of various concentrations of biogenic amines and other substances on the formation of adenosine 3′,5′-monophosphate (cyclic AMP) were compared in porcine cerebral cortex, medial hypothalamus and anterior pituitary slices incubated in Krebs-Ringer bicarbonate (KRB) buffer containing theophylline (10−2M). Histamine, norepinephrine, serotonin and dopamine, which are known to exist in high concentrations specifically in the hypothalamus, could significantly elevate cyclic AMP levels in medial hypothalamic slices. Epinephrine, acetylcholine, L-isoproterenol and prostaglandin E2 were ineffective in elevating cyclic AMP in medial hypothalamic slices. Histamine, in particular, markedly elevated cyclic AMP levels in medial hypothalamic slices, whereas it was ineffective in cerebral cortex and pituitary slices. Therefore, it is suggested that these biogenic amines, histamine, in particular, might play an important role in serving as neurotransmitters in the medial hypothalamus, although it is not yet known that cyclic AMP is involved as a mediator in the regulation of releasing-hormone secretion from the hypothalamus. (Endocrinology94: 1311, 1974)