Hemodynamic Effects of Uranyl Acetate in Pregnant Rats

Veronika Morvai1, Éva Szakmáry2, and György Ungváry3

1 Department of Occupational and Environmental Health, Semmelweis University, Faculty of Medicine, Budapest, Hungary
2 National Institute of Occupational Health, József Fodor National Center for Public Health, Budapest, Hungary
3 József Fodor National Center for Public Health, Budapest, Hungary

Corresponding author: Veronika Morvai, MD., PhD., DSc.
    Department of Occupational and Environmental Health
    Semmelweis University
    P.O.B. 22
    H-1096 Budapest, Hungary
    Telephone: (+36) 1-476-1346
    Fax number: (+36) 1-476-1346
    E-mail: morvai@fjokk.hu

CEJOEM 2004, Vol.10. No.3.: 259–268

Key words:
Uranyl acetate, pregnant rat, ECG changes, hemodynamic changes

Abstract:
The authors sought answer to the question, whether the alteration of the maternal circulation played a role in the mechanism of the offspring damaging effect of low-radiation uranyl acetate that had been proved to have specific embryotoxic and teratogenic effects in a true rodent (rat) and in a non-true rodent (rabbit). Pregnant Sprague-Dawley rats were treated by gavage on days 6–15 of gestation with 0 or 75 mg/kg uranyl acetate dissolved in water. At the end of the treatment the animals were anesthetized with pentobarbital and ECG was recorded. The changes of hemodynamics were studied using the 57Co-labelled microsphere method of McDewitt and Nies (1976). Cardiac output and its organ fractions (brain, lungs, liver, kidney, skull, femur, ovaries, uterus, and placenta) were determined. The total peripheral resistance, the nutritive blood flow, and the vascular resistance of the organs were calculated. It was found that uranyl acetate significantly increased the cardiac index and the duration of the QRS complex, at the same time it decreased the heart rate. The treatment did not change the hemodynamic parameters of the brain, lungs, liver, skull, and femur, but it decreased the nutritive blood flow of the kidneys and increased the renal vascular resistance. As for the reproductive organs, the nutritive blood flow of the uterus significantly decreased, while the vascular resistance of the placenta increased. It was concluded that in pregnant rats the uranyl acetate-induced systemic hypoxia significantly aggravated the local relative hypoxia due to the reduced blood flow of the reproductive organs and thereby considerably amplified the offspring damaging effect of the uranium salt.

Received: 18 February 2004
Accepted: 26 February 2004
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