Intravital microscopy was used in a preparation of rat cremaster muscle that was isolated from its normal blood supply and externally perfused with a physiological solution, thus allowing exclusion of circulating converting enzyme, renin, and angiotensinogen. The arterioles studied were classified as second-, third-, and fourth-order arterioles with mean diameters of 60.5, 29.9, and 14.8 micron...

The cremaster skeletal muscle of anesthetized rats was denervated and extended with intact circulation into a tissue bath. Intravital microscopy was used to measure microvessel diameter at three different anatomical levels within the microcirculation: large distributing arterioles (x control diameter = 100 ± 7 /nn), large capacitance venules (147 ± 8 /tin), and small terminal arterioles (17 ± 1...

Magnetic nanoparticles (MNPs) have been proposed for targeted or embolization therapeutics. How MNP retention occurs in circulation may critically determine local hemodynamics, tissue distribution of MNPs, and the therapeutic effects. We attempted to establish a microcirculation model to study the magnetic capture of MNPs in small vessels and to determine the factors affecting MNP retention. Tw...

Obesity is a risk factor for hypertension and other vascular disease. The aim of this study was to examine the effect of diet-induced obesity on endothelium-dependent dilation of rat cremaster muscle arterioles. Male Sprague-Dawley rats (213 ± 1 g) were fed a cafeteria-style high-fat or control diet for 16-20 wk. Control rats weighed 558 ± 7 g compared with obese rats 762 ± 12 g (n = 52-56; P <...

Indomethacin or glibenclamide treatments attenuate functional dilation of larger-diameter "feed" arterioles paired with venules in hamster cremaster muscle. We tested the hypothesis that release of cyclooxygenase products from venules is important for functional dilation of third- and fourth-order arterioles. We also tested whether ATP-sensitive potassium channels are important during functiona...