Acetylcholine-induced vasodilation in the uterine vascular bed of pregnant rats with adriamycin-induced nephrosis.
OBJECTIVE
This project was designed to study endothelium-dependent vasodilation in the uterine vascular bed during experimentally induced preeclampsia in rats.


METHODS
Uterine vascular beds were isolated from non-pregnant and pregnant rats with or without treatment with adriamycin (ADR) and perfused with physiological solution. Thereafter, vasodilator responses to acetylcholine were recorded. RECORDS: Pregnant ADR-treated rats displayed symptoms of preeclampsia including hypertension and proteinuria. Blood pressure was 110.0 +/- 4.7 mm Hg (n = 5) in control pregnant rats and 136.0 +/- 5.3 mm Hg (n = 5) in ADR-treated pregnant rats, and urinary protein concentrations were 0.35 mg/ml (n = 5) and 13.2 +/- 3.6 mg/ml (n = 9), respectively. Both blood pressure and proteinuria values were significantly (p < 0.05) different between controls and ADR-treated rats. However, acetylcholine-induced dose-dependent vasodilator responses in the vascular beds were not significantly different between the pregnant and nonpregnant rats. Although acetylcholine-induced vasodilation was significantly reduced by N omega-nitro-L-arginine methyl ester hydrochloride (L-NAME) in both groups, the residual response to acetylcholine was not affected by indomethacin, suggesting that prostanoids were not involved in this response. The L-NAME-resistant component, endothelium-derived hyperpolarizing factor (EDHF), was greater in ADR-treated uterine beds than in those of the controls, indicating a significant contribution from EDHF in these vessels. In the presence of an elevated external potassium ion concentration, acetylcholine produced similar vasodilator responses, indicating that the release of nitric oxide was not impaired.


CONCLUSIONS
These results indicate that endothelium-dependent vasodilation was not impaired in this model of preeclampsia.
Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Kuwait.
Mariam H
MH
Yousif
Ayotunde S
AS
Adeagbo
Elizabeth A
EA
Kadavil
Bindu
B
Chandrasekhar
Mabayoje A
MA
Oriowo
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001685:Biological Factors / Q000502:physiology; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D009401:Nephrosis / Q000139:chemically induced; D009569:Nitric Oxide / Q000502:physiology; D011225:Pre-Eclampsia / Q000139:chemically induced / Q000503:physiopathology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D014599:Uterus / Q000098:blood supply*; D014664:Vasodilation / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology*
D001685:Biological Factors; D014665:Vasodilator Agents; C067410:endothelium-dependent hyperpolarization factor; D009569:Nitric Oxide; D000109:Acetylcholine