EFFECT OF GENDER ON DEVELOPMENT AND DIURNAL RHYTHM OF PROSTAGLANDIN RECEPTORS IN RAT AORTA

Abstract

The prostaglandin endoperoxide H2 analogue, U‐46619 (15‐hydroxyll, 9‐epoxymethano‐prosta‐5Z, 13E‐enoic acid), was used to determine the effect of gender on the isotonic contractile response of the superfused rat aorta preparation over a 24 h period and at 10 and 16 weeks of age. The maximal responses of the male aortae were 20 ± 3% and 36 ± 4% (P< 0.001) greater than the female at 10 and 16 weeks, respectively. Similarly, sensitivity of the male aorta to the PGH2 analogue increased with age. The male but not the female exhibited a diurnal rhythm in which both the maximum contractile response and sensitivity were significantly decreased at night. We conclude that these gender differences may be related to the secretion of androgen, since reported peak serum testosterone over a 24 h period and testosterone changes with maturation are coincident with the maximum response of male aortae to the PGH2 analogue. 1981 British Pharmacological Society