Responses of cremasteric arterioles of spontaneously hypertensive rats to changes in extracellular K+ concentration. Microcirculation 1995 Dec;2(4):355-62
Date
12/01/1995Pubmed ID
8714816DOI
10.3109/10739689509148279Scopus ID
2-s2.0-0029440405 (requires institutional sign-in at Scopus site) 13 CitationsAbstract
OBJECTIVE: The goal of this study was to determine the effect of changes in extracellular K+ concentration ([K+]o) on active tone in cremasteric arterioles of spontaneously hypertensive rats (SHR) and their normotensive Wistar-Kyoto (WKY) and Wistar controls.
METHODS: Diameters of third- and fourth-order arterioles were measured in the cremaster muscle of hypertensive and normotensive rats during abrupt changes in superfusate K+ concentration from 4.7 mM to 0 mM to 15 mM K+.
RESULTS: Arterioles constricted in response to superfusion with 0 mM K+ and exhibited a large, transient dilation in response to an abrupt change from 0 mM to 15 mM [K+]o. Arteriolar dilation in response to 15 mM K+ was significantly larger in 12-15-week-old SHR than in WKY or Wistar controls. Arteriolar responses to 15 mM K+ were not significantly different in 4-6-week-old SHR and WKY. Dilator responses to 15 mM K+ were generally inhibited by 1 mM ouabain, although ouabain was less effective in inhibiting 15 mM K(+)-induced dilation in arterioles of SHR and WKY than in Wistar rats.
CONCLUSIONS: Dilation of cremasteric arterioles in response to 15 mM [K+]o is mediated, at least in part, via stimulation of the electrogenic Na+/K+ pump, although Na+/K(+)-pump-independent components may also contribute to the response. Arterioles of SHR with established hypertension exhibit an altered response to elevated [K+]o which is not present in SHR in the early stage of hypertension.
Author List
Lombard JH, Stekiel WJMESH terms used to index this publication - Major topics in bold
AnimalsArterioles
Hypertension
Muscle, Skeletal
Ouabain
Potassium
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Sodium-Potassium-Exchanging ATPase
Vasomotor System