Increase of renal sympathetic nerve activity by metoprolol or propranolol in conscious spontaneously hypertensive rats.
1 Mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded in conscious spontaneously hypertensive rats (SHR). 2 Infusion of metoprolol (4 mumol kg-1 h-1) or propranolol (1.5 mumol kg-1 h-1) reduced HR and significantly increased RSNA. 3 Administration of metoprolol caused a sustained decrease of MAP starting in the third hour of infusion. In contrast, administration of propranolol induced a biphasic response in MAP. It is suggested that the increase of RSNA after both beta-adrenoceptor blocking drugs is due to a decrease in arterial baroreceptor activity.
Majcherczyk
S
S
Department of Pharmacology and Biochemistry, Hässle Cardiovascular Research Laboratories, Mölndal, Sweden.
Mikulski
A
A
Sjölander
M
M
Thorén
P
P
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology*; D007668:Kidney / Q000294:innervation; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D011311:Pressoreceptors / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D013564:Sympathetic Nervous System / Q000187:drug effects*
D011433:Propranolol; D008790:Metoprolol