Blood levels of PMS after a single injection into mice.

A comparision of the effects of intraperitoneal and subcutaneous injections of PMS as an ovulatory gonadotropin was made by using the induced ovulatory response in immature mice pretreated with 2.5 IU of PMS. The intraperitoneal injection increased the sensitivity of the assay by 2.3-fold, as compared to the subcutaneous administration. The blood levels of PMS after a single intravenous or subcutaneous injection into adult ovariectomized mice were examined. The half-life of PMS after an intravenous injection was shown to be 6 hr in the mouse. After a subcutaneous injection, the plateau period of PMS in the blood lasted 9 hr from 9 to 18 hr after administration, but the level was 25 %, as compared with the initial one after an intravenous injection of the same amount. Either by an intravenous or a subcutaneous injection, the blood level of PMS 24 hr after administration was the same, that is, 12.5%, as compared with the initial one after the intravenous injection. These results were discussed in relation to various responses to PMS.