The effect of mepyramine and ranitidine on the oestrogen and anti-oestrogen stimulated rat uterus.

The aims of this study were to elucidate further the role of histamine in the rat uterotrophic response and to investigate the differences between the oestrogen and the anti-oestrogen induced uterine responses. The parameters examined were uterine blood flow (measured by the microsphere technique), uterine wet and dry weights. 17 beta-Oestradiol and the anti-oestrogen, tamoxifen, were used to stimulate the ovariectomised rat uterus and the antihistamines mepyramine (H1) and ranitidine (H2) were employed to modify these responses. The uterine changes evoked by oestradiol proved to be more susceptible to modification by the antihistamines than the tamoxifen-stimulated responses. The results suggest that histamine is involved in the early uterine response to oestradiol but histamine does not appear to play a major role in the uterine response to tamoxifen.