[Pregnancy-induced changes in adrenergic receptors].

In the 24th and 26th week of pregnancy and also 6 weeks post partum, n = 32 pregnant women were evaluated for the concentration of adrenergic receptors on blood cells by radioligand binding assay and an isoprenaline stimulation of the beta-receptors. The concentrations of estradiol and progesterone in serum were also determined and nephrosonography was carried out. The stimulation and concentration of the beta-receptors were significantly higher during pregnancy than post partum. The alpha-receptors displayed contrary alterations: Here, the concentration evaluated during pregnancy was considerably lower. No connection was determined between the progesterone level in serum and the extent of the receptor alterations. However, one was found with the estrogen level and the dilatation of the upper urinary tract: Pregnant women with pronounced alterations above the median showed a distinct decrease of estradiol and a marked dilatation of the kidney collecting system. Alterations in the adrenergic receptors can therefore be determined during pregnancy. The extent of the receptor fluctuation is connected to the estradiol concentration in serum and the dilatation of smooth muscle hollow organs.