Effect on peroxidase activity and specific binding of the hormone 17 beta-oestradiol and rat salivary glands.

The effect was studied on immature and adult female rats. Oestradiol, given either once (10 micrograms) or three times (3 X 10 micrograms) subcutaneously significantly retarded the total weight gain of immature rats whereas, at the same time, the weight of the uteri increased several fold. The weights of neither salivary nor lacrimal glands were dependent on oestradiol. The activity of the peroxidase enzyme, a marker of oestrogen-responsive tissues, increased significantly in the rat uteri but had no effect on lacrimal peroxidase. The levels of rat salivary peroxidase increased during oestradiol administration with considerable differences between various glands. The increase in peroxidase activities could not be explained by changes in the total protein content but seemed to be specific for this enzyme. Experiments using [3H]-oestradiol indicated specific binding to uterus, parotid and submandibular glands. It is concluded that rat salivary glands are oestrogen-responsive.