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Biomedical subjects

V Mathew

Publications and source records attributed to V Mathew.

42 records · Page 3Linked to original sources
PubMed1997

Enhanced endothelin-B-receptor-mediated vasoconstriction of small porcine coronary arteries in diet-induced hypercholesterolemia.

The coronary vasoconstrictor effects of endothelins, mediated by both endothelin ETA and ETB receptors, may be differentially altered in pathophysiological states associated with endothelial dysfunction and elevated endothelin levels. Experimental hypercholesterolemia is associated with coronary endothelial dysfunction and increased circulating endothelin concentrations. These studies were designed to test the hypothesis that experimental hypercholesterolemia is characterized by a differentially altered coronary contractile response to ETA- and ETB-receptor stimulation, in vitro. Pigs were fed either a normal or a high-cholesterol diet for 10 to 13 weeks. Changes in the intraluminal diameter of pressurized small coronary arteries (< 481 +/- 25 microns in diameter) to cumulative concentrations (10(-10) to 10(-6) mol/L) of endothelin-1 (ET-1), and sarafotoxin 6c (S6c), a specific ETB-receptor agonist, were measured using a video dimension analyzer. The maximal contraction attained with ET-1 was greater than with S6c in both normal (86 +/- 7% versus 47 +/- 7%, P = .001) and hypercholesterolemic (77 +/- 6% versus 37 +/- 7%, P < .001) pigs. At 10(-10) mol/L, vessels from hypercholesterolemic pigs manifested greater contraction to both ET-1 (23 +/- 6% versus 8 +/- 3%, P = .02) and S6c (17 +/- 5% versus 4 +/- 2%, P = .02). Incubation of arteries from hypercholesterolemic pigs with BQ-788 (ETB-receptor antagonist), but not FR-139317 (ETA-receptor antagonist), altered the contractile response to ET-1 at 10(-10) mol/L. Removal of the endothelium abolished the difference in response to S6c between normal and hypercholesterolemic pigs. These studies demonstrate that experimental hypercholesterolemia is characterized by enhanced coronary vasoconstriction to endothelins in vitro, the mechanism of which is mediated mainly through the ETB receptor. Thus, the ETB receptor has a role in regulation of coronary artery tone in both the steady-state and pathophysiological states.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1996

Evaluation of patients with minimally obstructive coronary artery disease and angina.

Atherosclerotic coronary artery disease is a progressive process adversely affecting the integrity of the coronary vasculature. In past years, most studies have focused on the morphological changes leading to compromised coronary blood flow in atherosclerosis. However, in recent years it has become apparent that abnormal coronary vasomotor regulation may precede or accompany gross morphological changes in coronary atherosclerotic disease. In fact, the pathophysiology of angina pectoris in many patients with risk factors for atherosclerosis and minimally obstructive disease may involve abnormal coronary vasomotor tone regulation. The aim of the present article is to describe a clinical approach to patients with angina pectoris and minimally obstructive coronary artery disease based on current knowledge of coronary vasomotor regulation.

Acetylcholine↗
PubMed1996

The role of endothelin in coronary atherosclerosis.

During the evolution of coronary atherosclerosis, growth factors, cytokines, and other molecules are involved in cell recruitment, migration, and proliferation. Endothelin is an endothelial-derived vasoconstrictor peptide that possesses mitogenic properties. In this review, current evidence is provided that suggests that endothelin fulfills proposed criteria to be considered an atherogenic peptide because of its mitogenic and proliferative properties, as well as its inter-actions with known atherogenic factors. In addition, a proposed role of endothelin in the evolution of atherosclerosis is outlined.

Angioplasty, Balloon, Coronary↗
PubMed1984

Hypoglycemic hemiplegic syndrome.

Hypoglycemia must be considered in any patient with an acute change of mental status or in a patient who shows a focal neurological deficit. Treatment with high IV glucose concentrations can save the patient from grave irreversible neurological sequelae and death.

Female↗