Karel Tyml

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Sepsis is associated with oxidative stress and impaired glutamatergic transmission in brain. We investigated whether sepsis impairs accumulation of the antioxidant, ascorbate, and uptake of glutamate by astrocytes. Bacterial endotoxin (Escherichia coli lipopolysaccharide, LPS) and the inflammatory cytokine, interferon-gamma (IFNgamma), were applied to(More)
OBJECTIVE Increased nitric oxide (NO) production in sepsis precipitates microcirculatory dysfunction. We aimed (i) to determine if NO is the key water-soluble factor in the recently discovered sepsis-induced deficit in arteriolar conducted vasoconstriction, (ii) to identify which nitric oxide synthase (NOS) isoforms account for this deficit, and (iii) to(More)
The aim of the study was to address discrepant findings in the literature regarding coupling between decreased functional demand during disuse and reduced capillarity. We previously reported [K. Tyml, O. Mathieu-Costello, and E. Noble. Microvasc. Res. 49: 17-32, 1995] that severe disuse of rat extensor digitorum longus (EDL) muscle caused by a 2-wk(More)
The aim of this study was to explore the phenomenon first described by Dietrich (Microvasc. Res. 38: 125-135, 1989) in which a local application of norepinephrine (NE) on a capillary can temporarily reduce flow via constriction of the feeding arteriole. Our objectives were to show that this phenomenon of remote response is not limited to vasoconstriction,(More)
Atrial fibrillation (AF), the most common cardiac arrhythmia seen in general practice, can be promoted by conduction slowing. Cardiac impulse conduction depends on gap junction channels, which are composed of connexins (Cxs). While atrial Cx40 and Cx43 are equally expressed, AF studies have primarily focused on Cx40 reductions. The G60S Cx43 mutant(More)
The preceding study (Dietrich and Tyml, 1992. Microvasc. Res. 43) demonstrated that a local application of norepinephrine (NE) on a capillary in a skeletal muscle produces a temporary reduction in blood flow within this capillary. The reduction is mediated via constriction of the supplying arteriole. The objective of the present study was to address the(More)
Recently, Dietrich (1989, Microvasc. Res. 38, 125-135) demonstrated that a local application of a minute amount of norepinephrine (NE, 5.5 mM, 0.01-88 pmole) on a capillary in rat mesentery can elicit constriction of the feeding arteriole 0.5-1.0 mm away. This constriction can reduce or even stop blood flow in capillaries supplied by the arteriole. The main(More)
Although electrical coupling along the arteriolar endothelium is central in arteriolar conducted response and in control of vascular resistance, little is known about the pathophysiological effect of hypoxia and reoxygenation (H/R) on this coupling. We examined this effect in a monolayer of cultured microvascular endothelial cells (ECs) derived from(More)
Objective—To determine the roles of nitric oxide synthase (NOS) and NADPH oxidase in the impairment of capillary blood flow in sepsis and in the reversal of this impairment by ascorbate. Design—Prospective, controlled laboratory study. Interventions—Sepsis was induced by feces injection into peritoneum (FIP). A bolus of ascorbate or NADPH oxidase inhibitor(More)
The phenomenon of "capillary contractility" was first described more than 100 years ago. Recent reports on this phenomenon in the frog mesentery have been based on the observation of dramatic reductions of luminal diameter and blood flow during electrical stimulation of the capillary wall. The aim of this study was to establish the presence and the(More)
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