To exit blood vessels, most (∼80%) of the lumenally adhered monocytes and neutrophils crawl toward locations that support transmigration. Using intravital confocal microscopy of anesthetized mouse cremaster muscle, we separately examined the crawling and emigration patterns of monocytes and neutrophils in blood-perfused unstimulated or TNF-α-activated venules. Most of the interacting cells in m...

In isolated cell systems, nitric oxide synthase (NOS) activity is regulated by caveolin (CAV), a resident caveolae coat protein. Because little is known of this interaction in vivo, we tested whether NOS and caveolin are distributed together in the intact organism. Using immunohistochemistry, we investigated the localization of constitutive neuronal (nNOS) and endothelial (eNOS) enzyme isoforms...

We studied in vivo interactions of nitric oxide (NO), oxidative stress, and prostanoids derived from the cyclooxygenase pathway in the arterioles studied by intravital microscopy in peripheral muscle. Topical administration of NO synthase (NOS) inhibitor Nomega-nitro-l-arginine (l-NNA) or cyclooxygenase inhibitor mefenamic acid (MA) alone leads to vasoconstriction. We found that l-NNA after MA ...

Arteriolar vasomotor responses can include a component that conducts along the vessel through gap junction channels. This study examined conducted vasomotor responses in arterioles of the hypertensive hamster. The cremaster muscle of normotensive (CHF-148) and spontaneously hypertensive (CHF-H4) hamsters was exteriorized. Micropipettes containing phenylephrine (0.1 M) or acetylcholine (ACh; 1.0...

Commonly used methods for assessing reductions in microvascular density (rarefaction) in hypertension detect only perfused microvessels. In the present study, samples of cremaster and spinotrapezius muscles were taken from rats with chronic (4-week) reduced renal mass hypertension and normotensive sham-operated control rats, as well as from 12-week-old spontaneously hypertensive rats and their ...

A smooth muscle hyperpolarization is essential for endothelium-dependent hyperpolarizing factor-mediated dilations. It is debated whether the hyperpolarization is induced by a factor (endothelium-derived hyperpolarizing factor) and/or is attributable to direct current transfer from the endothelium via myoendothelial gap junctions. Here, we measured membrane potential in endothelial cells (EC) a...

Objective—To investigate the effects of activation of the AMP-activated protein kinase (AMPK) on muscle perfusion and to elucidate the mechanisms involved. Methods and Results—In a combined approach, we studied the vasoactive actions of AMPK activator by 5-aminoimidazole4-carboxamide-1-D-ribofuranoside (AICAR) on rat cremaster muscle resistance arteries ( 100 m) ex vivo and on microvascular per...