Plasma hyperosmolality delays the response in skin blood flow to heat stress by elevating the internal temperature threshold for cutaneous vasodilation. This elevation could be because of a delayed onset of cutaneous active vasodilation and/or to persistent cutaneous active vasoconstriction. Seven healthy men were infused with either hypertonic (3% NaCl) or isotonic (0.9% NaCl) saline and passi...

BACKGROUND We previously reported that σ1-receptor (σ1R) expression in the thoracic aorta decreased after pressure overload (PO) induced by abdominal aortic banding in ovariectomized (OVX) rats. Here, we asked whether stimulation of σ1R with the selective agonist SA4503 elicits functional recovery of aortic vasodilation and constriction following vascular injury in OVX rats with PO. METHODS A...

Microvascular recruitment in muscle is a determinant of insulin sensitivity. Whether perivascular adipose tissue (PVAT) is involved in disturbed insulin-induced vasoreactivity is unknown, as are the underlying mechanisms. This study investigates whether PVAT regulates insulin-induced vasodilation in muscle, the underlying mechanisms, and how obesity disturbs this vasodilation. Insulin-induced v...

Spaceflight and prolonged bed rest induce deconditioning of the cardiovascular system and bone loss. Previous research has shown declines in femoral bone and marrow perfusion during unloading and with subsequent reloading in hindlimb-unloaded (HU) rats, an animal model of chronic disuse. We hypothesized that the attenuated bone and marrow perfusion may result from altered vasomotor properties o...

BACKGROUND Inflammation is fundamental to the development of atherosclerosis. We examined the effect of anti-inflammatory doses of salicylate on endothelium-dependent vasodilation, a biomarker of cardiovascular risk, in a broad range of subjects. METHODS AND RESULTS We performed a randomized, double-blind, placebo-controlled crossover trial evaluating the effects of 4 weeks of high-dose salsa...

A novel histamine receptor subtype, histamine H(3) receptor, mediates inhibition of peripheral autonomic neurotransmission. The present study was designed to examine vascular effects of histamine H(3) receptor by using a selective histamine H(3) receptor agonist, R-(-)-alpha methylhistamine (alpha-methylhistamine), in rat mesenteric resistance arteries. The isolated mesenteric vascular beds wer...

Mitochondria affect cerebrovascular tone by activation of mitochondrial ATP-sensitive K+ (K ATP) channels and generation of reactive oxygen species (ROS). Insulin resistance accompanying obesity causes mitochondrial dysfunction, but the consequences on the cerebral circulation have not been fully identified. We evaluated the mitochondrial effects of diazoxide, a putative mitochondrial K ATP cha...

Isolated rabbit spinal resistance-sized arteries (∼100 μm in diameter and ∼3 mm long) were cannulated at both ends with glass micropipettes and perfused at constant pressure (60 mmHg). An increase of flow rate corresponding to a change of pressure gradient (ΔP) ranging from 0 to 20 mmHg produced a flow-dependent vasodilation. Treatment with 50 μM aspirin or 10 μM indomethacin produced a signifi...

Nicotine stimulates presynaptic nicotinic acetylcholine receptors in perivascular adrenergic nerves and releases unknown transmitter(s) that activate transient receptor potential vanilloid-1 (TRPV1) located on calcitonin gene-related peptide (CGRP)-containing (CGRPergic) nerves, resulting in vasodilation. The present study investigated a potential transmitter transmitting between perivascular a...

In septic shock (SS), cardiovascular collapse is caused by the release of inflammatory mediators. We previously found that lysozyme-c (Lzm-S), released from leukocytes, contributed to systemic vasodilation in a canine model of SS. We then delineated the pathway by which this occurs in a canine carotid artery organ bath preparation (CAP). We showed that Lzm-S could intrinsically generate hydroge...