STUDIES OF EOSINOPHIL GRANULOCYTES

Abstract

ABSTRACT A cyclic variation in peroxidase activity, accounted for by the number of eosinophil granulocytes, occurs in the uterus. To investigate whether this variation could be a result of the variations in the secretion of oestrogens and progestogens the following experiments were performed. Castrated female mice were treated with various combinations of such hormones and it was found: (i) The peroxidase activity induced by 17β-oestradiol was almost entirely suppressed by the simultaneous administration of progesterone. (ii) The peroxidase activity induced by the longacting preparation 17β-oestradiol-p-propoxyphenylpropionate was substantially decreased by the long-acting progesterone capronate, given simultaneously. (iii) Simultaneous, single injections of the long-acting oestrogen and the short-acting progesterone produced peroxidase activities, initially lower but subsequently higher than those caused by this oestrogen alone. Previous investigators have found that 17β-oestradiol reduces the number of granulated mast cells in the uterus of spayed mice. In order to study the possible relation between mast cell degranulation and eosinophilia in the uterus, we treated spayed rats with some combinations of the histamine liberator 48/80 and the long-acting oestrogen. 48/80 alone did not induce eosinophilia in the uterus, whereas the eosinophilia in response to the oestrogen was enhanced by a previous mast cell degranulation. Cortisone, administered together with the oestrogen, suppressed the uterine peroxidase activity. Some effects of the three steroid hormones and of 48/80 on the weight of the uterus are described and discussed.