Prolonged inhibition of nitric oxide synthesis in pregnant rats: effects on blood pressure, fetal growth and litter size.

Methods: In order to investigate the effect of chronic inhibition of nitric oxide synthesis along pregnancy, pregnant rats were given drinking water alone (control group) or drinking water containing nonselective nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME; 15 mg/day/rat equivalent to 50 mg/kg/day; treated group), from postmating days 1 to 18 of pregnancy. On days 1 to 17 of pregnancy, urinary volume, urinary sodium and potassium excretion, and urine protein concentration were measured. Systolic blood pressure (SBP) was recorded daily.

Intrauterine growth restriction in spontaneously hypertensive rats.

We examined the test profile of changes in systolic blood pressure (SBP), urinary volume, urinary sodium, and protein excretion in normotensive (Sprague Dawley) and spontaneously hypertensive rats (SHR) up to the 18th day of pregnancy. On days 6, 11, and 18 of pregnancy, the number of implantation sites, number of embryos, litter size, placenta, and litter weight were determined. In SHR, SBP (mmHg) increased significantly from the start of the test and remained high throughout the experiment.

IGF-I, 17beta-estradiol and progesterone in SHR and in rats treated with L-NAME: fetal-placental development.

Methods: The relationship between progesterone (P4), 17beta-estradiol, insulin-like growth factor (IGF-I) and embryonic and fetal development, were examined. Female Sprague Dawley rats were divided into two groups: control untreated (n=60) and treated (n=63) with L-NAME (N(omega)-nitro-L-arginine methyl ester), 15 mg/day in drinking water from the first day after mating to day 18 of gestation. A further group was formed (n=63) of spontaneously hypertensive rats (SHR).