Improvement of the rat ovary hyperemia test for pregnancy, by adding a pituitary synergist.

Abstract

THE rat ovary hyperemia reaction has been used as the basis of a rapid pregnancy test, since it is the earliest demonstrable reaction to chorionic gonadotropin (1). The accuracy of the two-hour rat ovary hyperemia pregnancy test has varied greatly, however, being 99.5, 95.0, 84.5 and 68.8 per cent respectively in the hands of four different observers (2–5). Objections have been raised particularly to the false negative reactions in individual animals and to the lack of a sharp positive end point (4, 5, 6, 7). In a recent study (8) in our laboratory, approximately 90 per cent of the false negative reactions were attributed to the failure of an adequate response by the animals, and the remainder were thought to be due to poor urine absorption or other factors. Modifications in technic improved results slightly. A further attempt to overcome the false negative reactions by enhancing the ovarian hyperemia response to chorionic gonadotropin led to our use of an anterior pituitary extract for this purpose (9). ...