Effects of Aging and Exercise Training on the Mechanisms of Angiotensin II-Induced Vasoconstriction in Rat Skeletal Muscle Arterioles. (December 2006) Yoonjung Park, B.A., Seoul National University; M.S., Seoul National University; M.A., The University of Texas at Austin Chair of Advisory Committee: Dr. Robert B. Armstrong Aging is associated with increases in regional and systemic vascular res...

Thromboxane A(2) (TxA(2)) preferentially constricts the renal afferent arteriole. Nitric oxide (NO) modulates vasoconstriction and is rapidly degraded by superoxide radical (O(2)(-)). We investigated the roles of NO and O(2)(-) in rabbit isolated, perfused renal afferent arteriole responses to the TxA(2)/prostaglandin H(2) (TP) receptor agonist U-46,619. U-46,619 (10(-10)-10(-6) M) dose-depende...

When a short segment of arteriole is stimulated, vasomotor responses spread bidirectionally along the vessel axis purportedly via gap junctions. We used connexin40 knockout (Cx40-/-) mice to study vasomotor responses induced by 10-second trains of electrical stimulation (30 Hz, 1 ms, 30 to 50 V) in 2nd or 3rd order arterioles of the cremaster muscle. Measurements were made at the stimulation si...

BACKGROUND There is evidence to indicate that peripheral glucocorticoid receptor (GR) function is reduced in major depression, and a possible molecular explanation for this is the impact of raised pro-inflammatory cytokines. The topical steroid vasoconstriction assay provides a convenient probe of peripheral GR function. The present study sought to assess the sensitivity of peripheral GRs in an...

Tryptamine is an endogenous and dietary indoleamine-based trace amine implicated in cardiovascular pathologies, including hypertension, migraine and myocardial infarction. This study aimed at identifying the signalling pathways for the vasoconstrictor response to tryptamine in rat isolated perfused mesenteric arterial beds and co-released vasodilator modulators of tryptamine-mediated vasoconstr...

The multifunctional Ca(2+)/calmodulin-dependent kinase II (CaMKII) is activated by vasoconstrictors in vascular smooth muscle cells (VSMC), but its impact on vasoconstriction remains unknown. We hypothesized that CaMKII inhibition in VSMC decreases vasoconstriction. Using novel transgenic mice that express the inhibitor peptide CaMKIIN in smooth muscle (TG SM-CaMKIIN), we investigated the effec...

Erythrocyte free hemoglobin (Hb) induces vasoconstriction due to nitric oxide (NO) scavenging, limiting the NO available for vascular smooth muscle. The central objective of this study was to restore NO bioavailability using long-lived circulating NO-releasing nanoparticles (NO-np) to reverse the vasoconstriction and hypertension induced by polymerized bovine Hb (PBH) NO scavenging. PBH (13 g/d...

BACKGROUND Reversible cerebral vasoconstriction syndrome (RCVS) could be complicated by cerebral ischemic events. Hypothetical mechanisms of RCVS involve endothelial dysfunction and sympathetic overactivity, both of which were reported to be related to brain-derived neurotrophic factor (BDNF). The study investigated the association between functional BDNF Val66Met polymorphism and RCVS. METHO...

This study investigated whether short-term exposure to Escherichia coli lipopolysaccharide (LPS) elicits vasomotor dysfunction in skeletal muscle in vivo and, if so, whether perivascular mast cell proteases partly modulate this response. With intravital microscopy, we found that suffusion of E. coli LPS on the in situ hamster spinotrapezius muscle for 60 min elicits immediate vasoconstriction f...

AIMS Inward remodelling of the resistance vasculature is predictive of hypertension and life-threatening cardiovascular events. We hypothesize that the contractile mechanisms responsible for maintaining a reduced diameter over time in response to prolonged stimulation with vasoconstrictor agonists are in part responsible for the initial stages of the remodelling process. Here we investigated th...