Influence of hypoxia and hyperoxia on the cardiovascular and lethal effects of ethanol

Citation
O. Strubelt et M. Younes, Influence of hypoxia and hyperoxia on the cardiovascular and lethal effects of ethanol, PHARM TOX, 84(3), 1999, pp. 101-106
Citations number
43
Categorie Soggetti
Pharmacology & Toxicology
Journal title
PHARMACOLOGY & TOXICOLOGY
ISSN journal
09019928 → ACNP
Volume
84
Issue
3
Year of publication
1999
Pages
101 - 106
Database
ISI
SICI code
0901-9928(199903)84:3<101:IOHAHO>2.0.ZU;2-N
Abstract
The mutual potentiation of the hepatotoxic effects of ethanol and hypoxia r aised the question of whether such an interaction also occurs in the cardio vascular system. Therefore, anaesthetized rats were infused intravenously w ith ethanol (25 mg/kgxmin.) over 90 min. to reach blood ethanol concentrati ons between 2.2 and 2.6 g/l and were ventilated artificially either with ro om air, 10% O-2/90% N-2 or 100% O-2. Under normoxic conditions, ethanol pro duced a slow decrease of mean arterial blood pressure from 130 to 100 mmHg due to the decline in cardiac output and stroke volume (-20%) while heart r ate and peripheral resistance remained unchanged. Hypoxia (arterial oxygen tension 35-38 mmHg) without ethanol produced immediate hypotension (-60 mmH g) without decreasing the cardiac output, i.e. by reducing peripheral resis tance. In combination with ethanol, hypoxia produced an even stronger hypot ension (-90 mmHg) due to reduction in both cardiac output and peripheral re sistance. On the other hand, respiration with 100% O-2 (arterial oxygen ten sion about 500 mmHg) elevated peripheral resistance, attenuated ethanol-ind uced cardiodepression and prevented ethanol-induced hypotension. The lethal doses of ethanol evaluated by infusing 75 mg/kgxmin. ethanol until death a mounted to 4.1 g/kg with 10% O-2, to 5.5 g/kg with 20% O-2 (room air) arid to 6.9 g/kg with 100% O-2. Thus decrease in vascular contractility induced by hypoxia combined with ethanol-induced cardiodepression may result in let hal cardiovascular failure. Hyperoxia, on the other hand, counteracts ethan ol-induced cardiodepression and its acute toxicity by raising the vascular contractility.