Beta-adrenergic stimulation of growth hormone release from perifused rat anterior pituitary cells.

Perifusion of dispersed rat anterior pituitary cells with pulses of the beta-adrenergic agonists isoproterenol and epinephrine resulted in a prompt, but brief, rise in growth hormone release. This effect was blocked by propranolol, a beta-adrenergic antagonist, but not phentolamine, an alpha-adrenergic antagonist. These results, in conjunction with other recent reports, suggest that epinephrine may act directly at the anterior pituitary gland as a physiological growth hormone-releasing factor.