Influence of sex‐steroid hormones on the regulation of lymphocyte beta 2‐adrenoceptors during the menstrual cycle.

Abstract

1. Up to 40% of female asthmatic subjects suffer a premenstrual deterioration in their condition which may be ameliorated by progesterone supplementation, although the mechanism responsible for this phenomenon is not understood. In vitro studies have shown that female sex‐steroid hormones potentiate the bronchorelaxant effect of isoprenaline, whilst in vivo it has been shown that females exhibit greater sensitivity of systemic beta 2‐adrenoceptor responses. 2. The aim of the present study was to determine whether cyclical alterations in beta 2‐adrenoceptor expression, occurring under the influence of ovarian sex‐steroid hormones, may offer an explanation for these findings. In vitro parameters of lymphocyte beta 2‐adrenoceptor function were investigated in nine normal female subjects (aged 24 +/‐ 2 years) during the follicular (day 2‐4) and luteal (day 21‐23) phases of their menstrual cycle, and results were compared with those of nine age‐matched healthy male controls studied at the same time intervals. 3. In female subjects there were significant increases in serum concentrations of oestradiol (3.3‐fold) and progesterone (10.6‐fold) between the follicular and luteal phases of the menstrual cycle, whereas no changes occurred in males. 4. In females during the luteal phase, the increase in sex‐steroid hormones was mirrored by an increase in lymphocyte beta 2‐adrenoceptor density (Bmax) and in maximal cyclic AMP response to isoprenaline (Emax), which were significantly higher than in male subjects. Mean differences (95% CI) between male and female subjects on visit 2 were 1.09 (0.49 to 1.69) fmol/10(6) cells (P = 0.001) for Bmax, and 3.42 (0.80 to 6.04) pmol/10(6) cells (P = 0.02) for Emax.(ABSTRACT TRUNCATED AT 250 WORDS) 1994 The British Pharmacological Society