Effects of cold exposure on blood pressure, heart rate and forearm blood flow in normotensives during selective and non-selective beta-adrenoceptor blockade.
Haemodynamic effects of a cold pressor test (foot immersion for 6 min in water at 5 degrees C) without medication and after the non-selective beta-adrenoceptor blocker propranolol and the selective beta-adrenoceptor blocker metoprolol were studied in 17 volunteers. In the control study as well as in the study with the beta-adrenoceptor blockers cold exposure caused comparable changes, namely a blood pressure rise and a reduction of forearm blood flow. The increase in heart rate during cold exposure was clearly and equally reduced by both beta-adrenoceptor blockers. Plasma noradrenaline rose significantly by 47%, plasma adrenaline did not change. It is concluded, that as to this kind of stress, beta 1-selective-adrenoceptor blockade confers no important advantage over non-selective beta-adrenoceptor blockade.
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D001262:Atenolol / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D003080:Cold Temperature; D005260:Female; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects*
D000319:Adrenergic beta-Antagonists; D001262:Atenolol; D011433:Propranolol; D008790:Metoprolol