Arterial networks are controlled by the consolidated output of stimuli that set "how much" (magnitude) and "where" (distribution) blood flow is delivered. While notable changes in magnitude are tied to network wide responses, altered distribution often arises from focal changes in tone, whose mechanistic foundation remains unclear. We propose herein a framework of focal vasomotor contractility being controlled by pharmacomechanical coupling and the generation of Ca waves via the sarcoplasmic reticulum.
View Article and Find Full Text PDFThe arterial myogenic response to intraluminal pressure elicits constriction to maintain tissue perfusion. Smooth muscle [Ca] is a key determinant of constriction, tied to L-type (Ca1.2) Ca channels.
View Article and Find Full Text PDFObjective: The myogenic response sets the foundation for blood flow control. Recent findings suggest a role for G protein-coupled receptors (GPCR) and signaling pathways tied to the generation of reactive oxygen species (ROS). In this regard, this study ascertained the impact of NADPH oxidase (Nox) on myogenic tone in rat cerebral resistance arteries.
View Article and Find Full Text PDFEndotoxic manifestations are diminished in female populations due to immune boosting actions of sex steroids. Considering that tobacco constituents including nicotine inhibit estrogen synthesis, we tested the hypothesis that nicotine exposure unveils cardiovascular anomalies of endotoxemia in female rats. Studies were undertaken in conscious female rats treated with i.
View Article and Find Full Text PDFThe female gender is protected against immunological complications of endotoxemia. Here we investigated whether gonadal hormone depletion by ovariectomy (OVX) uncovers inflammatory and cardiovascular effects of endotoxemia and whether these effects are reversed by hormone replacement therapies. Changes in inflammatory cytokines, blood pressure (BP), left ventricular (LV) function, and cardiac autonomic activity caused by lipopolysaccharide (LPS) in conscious female rats with different hormonal states were determined.
View Article and Find Full Text PDFThe cholinergic antiinflammatory pathway favorably influences end organ damage induced by inflammatory conditions. Here, we hypothesized that α7 and/or α4β2-nicotinic acetylcholine receptors (nAChRs) protect against cardiovascular and autonomic imbalances induced by endotoxemia in rats. We assessed dose-effect relationships of i.
View Article and Find Full Text PDFThe male gender is more vulnerable to immunological complications of sepsis. Here, we tested the hypotheses that female rats are protected against endotoxemia-evoked hypotension and cardiac autonomic dysfunction, and that gonadal hormone receptors account for such protection. Changes in blood pressure, heart rate, and cardiac sympathovagal balance caused by i.
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