OBJECTIVE By heme degradation, heme oxygenase-1 (HO-1) provides endogenous carbon monoxide and bilirubin, both of which play major roles in vascular biology. The current study aimed to examine whether induction of HO-1 and its byproducts modulate the process of microvascular thrombus formation in vivo. METHODS AND RESULTS In individual microvessels of mouse cremaster muscle preparations, ferr...

The events responsible for cell injury after a tissue stimulation are only incompletely understood. The purpose of this study was to examine mechanisms of cell injury in two tissues, rat mesentery and cremaster muscle, after tissue stimulation with N-formylmethionyl-leucyl-phenylalanine (FMLP) and platelet-activating factor (PAF). The response was studied in the same animal in random order usin...

Activation of pulmonary C-fibers can reflexively decrease heart rate, blood pressure, and peripheral vascular resistance. However, the effects of these afferents on microvascular tone remain incompletely understood. In this study, we examined the effects of these afferents on microvascular tone in a striated muscle vascular bed. The right cremaster muscle in pentobarbital-anesthetized rats with...

Microvascular reactions to increases in intravascular pressure were studied in the cremaster muscle of the anesthetized rat by enclosing the animal in an airtight box with the muscle exteriorized for observation of the microcirculation. Since the cremaster was exposed to atmospheric pressure, increasing pressure within the box produced equal increases in arterial and venous pressures. Thus, int...

Several systematic reviews have reported that flow mediated dilatation (FMD) was significantly increased in subjects after ingestion of chocolate that contains flavan-3-ols; however, the mechanisms responsible for this effect are not clear. In this study, we evaluated the effects of a single oral dose of flavan-3-ols on the systemic circulation and microcirculation in the cremaster muscle using...

Objective—Tumor necrosis factor(TNF) has been linked to obesity-related insulin resistance and impaired endothelium-dependent vasodilatation, but the mechanisms have not been elucidated. To investigate whether TNFdirectly impairs insulin-mediated vasoreactivity in skeletal muscle resistance arteries and the role of c-Jun N-terminal kinase (JNK) in this interference. Methods and Results—Insulin-...

The role of arachidonic acid metabolism and nitric oxide (NO) in hypoxia-induced changes of vascular tone was investigated in first-order cannulated rat cremaster muscle resistance arteries. Spontaneous tone reduced arterial diameter from 179 ± 2 μm (fully dilated) to 98 ± 3 μm under normoxia ([Formula: see text] = 150 mmHg). Hypoxia ([Formula: see text] 5-10 mmHg) had no significant effect on ...