Protective effects of ethynylestradiol on the hemodynamic changes induced by lipopolysaccharide in anesthetized rats.
J Cardiovasc Pharmacol
; 31(4): 479-83, 1998 Apr.
Article
in En
| MEDLINE
| ID: mdl-9554792
ABSTRACT
Estrogen pretreatment has been reported to protect rats from death induced by endotoxin. We investigated the effects of posttreatment with a synthetic estrogen, ethynylestradiol, on arterial pressure and hemodynamics in thiobutabarbitone-anesthetized rats challenged with Escherichia coli lipopolysaccharide. Rats were i.v. injected with lipopolysaccharide (1 mg/kg) followed by vehicle or a single dose of ethynylestradiol (0.25, 0.5, or 1 mg/kg) 1 h later. Another group (time-matched control) was given the vehicle. In the time-control group, there was a slight decrease in mean arterial pressure (-10 +/- 3 mm Hg) but no significant changes in cardiac output, total peripheral resistance, or heart rate over the 6-h study period. Lipopolysaccharide progressively reduced mean arterial pressure and cardiac output (-27 +/- 8 mm Hg and -52 +/- 6 ml/min, after 6 h) and increased total peripheral resistance and heart rate (+0.33 +/- 0.10 mm Hg/min/ml and +21 +/- 13 beats/min, after 6 h). None of the time-control rats died, but 36% of the rats treated with lipopolysaccharide died between 3 and 6 h after endotoxin challenge. Ethynylestradiol, at 0.25 and 0.5 completely, and at 1 mg/kg partially, restored mean arterial pressure and cardiac output at 6 h after injection of lipopolysaccharide. Ethynylestradiol at 0.5 and 1 mg/kg, but not 0.25 mg/kg, completely reversed the increase in total peripheral resistance at 6 h after injection of lipopolysaccharide. Mortality was 14% in each of the three groups of rats given ethynylestradiol 1 h after lipopolysaccharide. Therefore posttreatment with ethynylestradiol attenuated hemodynamic changes in endotoxic shock.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Shock, Septic
/
Estradiol Congeners
/
Ethinyl Estradiol
/
Hemodynamics
Type of study:
Etiology_studies
/
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
J Cardiovasc Pharmacol
Year:
1998
Type:
Article
Affiliation country:
Canada