Mode of ethanol administration influences the severity of hemorrhage-induced lactic acidemia in conscious guinea pigs.

Mechanisms that limit metabolic acidemia during shock are limited by ethanol (EtOH). This may be due to (1) loss of respiratory compensation, (2) a greater fall in cardiac output, (3) altered removal of plasma lactate by the liver, and (4) alterations in central nervous system orchestration of compensatory responses. We have previously shown that loss of metabolic compensation during hemorrhage is correlated with plasma EtOH concentrations.

Knockout mice reveal that the angiotensin II type 1B receptor links to smooth muscle contraction.

Background: Rodents express two isoforms of the angiotensin II type 1 (AT(1)) receptor: AT(1A) and AT(1B). It is unclear which receptor subtype mediates contraction in response to angiotensin II in various arteries. We tested the hypothesis that the AT(1B) receptor is the predominant receptor that mediates contraction in the abdominal aorta in response to angiotensin II.

H2O2-induced redox-sensitive coronary vasodilation is mediated by 4-aminopyridine-sensitive K+ channels.

Hydrogen peroxide (H(2)O(2)) is a proposed endothelium-derived hyperpolarizing factor and metabolic vasodilator of the coronary circulation, but its mechanisms of action on vascular smooth muscle remain unclear. Voltage-dependent K(+) (K(V)) channels sensitive to 4-aminopyridine (4-AP) contain redox-sensitive thiol groups and may mediate coronary vasodilation to H(2)O(2). This hypothesis was tested by studying the effect of H(2)O(2) on coronary blood flow, isometric tension of arteries, and arteriolar diameter in the presence of K(+) channel antagonists.

Reduced functional expression of K(+) channels in vascular smooth muscle cells from rats made hypertensive with N{omega}-nitro-L-arginine.

Smooth muscle membrane potential is determined, in part, by K(+) channels. In the companion paper to this article, we demonstrated that superior mesenteric arteries from rats made hypertensive with N(omega)-nitro-l-arginine (l-NNA) are depolarized and express less K(+) channel protein compared with those from normotensive rats. In the present study, we used patch-clamp techniques to test the hypothesis that l-NNA-induced hypertension reduces the functional expression of K(+) channels in smooth muscle.

Leptin receptors are expressed in coronary arteries, and hyperleptinemia causes significant coronary endothelial dysfunction.

Obesity is associated with marked increases in plasma leptin concentration, and hyperleptinemia is an independent risk factor for coronary artery disease. As a result, the purpose of this investigation was to test the following hypotheses: 1) leptin receptors are expressed in coronary endothelial cells; and 2) hyperleptinemia induces coronary endothelial dysfunction. RT-PCR analysis revealed that the leptin receptor gene is expressed in canine coronary arteries and human coronary endothelium.

C-reactive protein does not relax vascular smooth muscle: effects mediated by sodium azide in commercially available preparations.

C-reactive protein (CRP), an acute-phase protein and newly recognized indicator of cardiovascular risk, may have direct actions on the vascular wall. Previous studies suggest that CRP is a vasodilator that activates smooth muscle K(+) channels. We examined the reported vasoactive properties of CRP and further explored its mechanisms of action.

Ethanol intoxication and lactated Ringer's resuscitation prolong hemorrhage-induced lactic acidosis.

Ethanol (EtOH) blunts the respiratory and metabolic compensation during hemorrhage, resulting in a more severe lactic acidemia. We hypothesized that lactated Ringer's (LR) resuscitation may exacerbate this lactic acidemia. Male guinea pigs were implanted with arterial and venous catheters.