Central adrenoceptors concerned in the release of adrenocorticotrophic hormone

The effect of injecting the alpha-adrenoceptor stimulating drugs adrenaline, noradrenaline and phenylephrine and the beta-adrenoceptor stimulating drug, isoprenaline into the lateral ventricles (i.c.v.) of the brains of dogs on the plasma cortisol concentration was investigated. Adrenaline, noradrenaline and phenylephrine produced a significant rise in the plasma cortisol concentration. Isoprenaline had no effect on the plasma cortisol concentration. The effect of noradrenaline and phenylephrine on the plasma cortisol concentration was completely blocked by yohimbine (i.c.v.). This indicates that the stimulation of central alpha-adrenoceptors can cause the release of adrenocorticotrophic hormone.