CENTRAL β-ADRENERGIC RECEPTORS FOR BLOOD PRESSURE REGULATION IN SPONTANEOUSLY HYPERTENSIVE RATS

Abstract

The intraventricular injection of a .beta.-agonist, isoproterenol, in rats caused a central depressor effect, which was neither blocked by a .beta.-blocker, propranolol, nor by a .beta.1-blocker, practolol, but was blocked by an .alpha.-blocker, phentolamine. .beta.2-Agonists, salbutamol and orciprenaline, caused a central pressor response which was blocked by the .beta.-blocker, propranolol. As the central depressor responses to an .alpha.-agonist and pressor responses to a .beta.2-agonist were significantly increased in SHR [spontaneously hypertensive rats], the possible involvement of not only central .alpha.-, but also .beta.(.beta.2)-receptors in the hypertensive state is indicated.