Beta 2-adrenoceptors mediate adrenaline's facilitation of neurogenic vasoconstriction.
Acute bilateral adrenal demedullation significantly reduced pressor responses in pithed spontaneously hypertensive rats. The subsequent infusion of adrenaline (50 ng/min i.v.) significantly enhanced neurogenic pressor responses without affecting those induced by noradrenaline. The adrenaline-induced enhancement of neurogenic pressor responses was unaffected by pretreatment with the beta 1-selective adrenoceptor antagonist atenolol (0.3 mg/kg i.v.), but was completely abolished by pretreatment with the beta 2-selective antagonist ICI 118551 (0.01 mg/kg i.v.). Pressor responses to noradrenaline remained unaltered.
D000313:Adrenal Medulla / Q000502:physiology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D011412:Propanolamines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects*; D014666:Vasomotor System / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; C026777:ICI 118551; D001262:Atenolol; D004837:Epinephrine