Sympathetic supraspinal control of venous membrane potential in spontaneous hypertension in vivo. Am J Physiol 1982 Sep;243(3):C101-6
Date
09/01/1982Pubmed ID
7114244DOI
10.1152/ajpcell.1982.243.3.C101Scopus ID
2-s2.0-0020189433 (requires institutional sign-in at Scopus site) 13 CitationsAbstract
To clarify the mechanisms controlling mesenteric venous membrane potential (Em) in spontaneously hypertensive rats (SHR) and Wistar-Kyoto normotensive rats (WKY), Em was measured in vivo using flexibly mounted glass microelectrodes. Venous diameters were also measured. Ems under control conditions were significantly less in SHR. alpha-Adrenergic blockade with phenoxybenzamine (PBZ) significantly dilated and hyperpolarized SHR small veins but failed to alter the membrane potential of WKY small veins. After blockade with PBZ, membrane potentials were similar in both strains. Propranolol suffusion failed to alter the SHR membrane potential but depolarized WKY small veins. During blockade with PBZ, propranolol depolarized venous membranes equally in both strains. Membrane potentials after spinal section were similar in both strains and equal to the Ems during total adrenergic blockade. The data indicate that, in SHR, the relatively depolarized Em derives from altered alpha-adrenergic input. In SHR, alpha-adrenergic input appears to exert its depolarizing effect, at least in party, by interfering with the expression of endogenous, beta-adrenergic hyperpolarization. The beta-adrenergic influence, like the alpha-adrenergic input in SHR, is dependent on intact supraspinal pathways.
Author List
Willems WJ, Harder DR, Contney SJ, McCubbin JW, Stekiel WJMESH terms used to index this publication - Major topics in bold
AnimalsBlood Pressure
Hypertension
Male
Membrane Potentials
Microelectrodes
Norepinephrine
Phenoxybenzamine
Phentolamine
Propranolol
Rats
Rats, Inbred Strains
Spinal Cord
Sympathetic Nervous System
Veins
