The femoral artery (FA) is the largest vessel in the hindlimb circulation and its proper tone regulation ensures adequate blood supply to muscle tissue. We investigated whether an alanine mutation of the targeting subunit of myosin-light-chain-phosphatase (MLCP), MYPT1, at threonine 696 (MYPT1-T696A/+), decisive for enzyme acivity, affects the responsiveness of young and old FAs (y-FAs and o-FAs) to activation of nitric-oxide/soluble-guanylate-cyclase/protein-kinase-G cascade (NO/sGC/PKG). Contractile responses of the vessels were measured by wire myography.
View Article and Find Full Text PDFObjective: Small arteries from different organs vary with regard to the mechanisms that regulate vasoconstriction. This study investigated the impact of advanced age on the regulation of vasoconstriction in isolated human small arteries from kidney cortex and periintestinal mesenteric tissue.
Methods: Renal and mesenteric tissues were obtained from patients (mean age 71 ± 9 years) undergoing elective surgery.
Stretch-induced vascular tone is an important element of autoregulatory adaptation of cerebral vasculature to maintain cerebral flow constant despite changes in perfusion pressure. Little is known as to the regulation of tone in senescent basilar arteries. We tested the hypothesis, that thin filament mechanisms in addition to smooth muscle myosin-II regulatory-light-chain-(MLC)-phosphorylation and non-muscle-myosin-II, contribute to regulation of stretch-induced tone.
View Article and Find Full Text PDFAnimal models and clinical studies suggest an influence of angiotensin II (AngII) on the pathogenesis of liver diseases via the renin-angiotensin system. AngII application increases portal blood pressure, reduces bile flow, and increases permeability of liver tight junctions. Establishing the subcellular localization of angiotensin II receptor type 1 (AT1R), the main AngII receptor, helps to understand the effects of AngII on the liver.
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