THE FROG TEST (XEHOPUS LAEVIS), AS A RAPID DIAGNOSTIC TEST FOR EARLY PREGNANCY1

Abstract

IN 1930, HOGBEN (1) published his report on the use of the South African clawed toad, Xenopus laevis Daud, showing that extracts of the anterior lobe of the pituitary caused spontaneous ovulation in the mature female Xenopus. Following this original observation Shapiro and Zwarenstein (2) and Bellerby (3) working independently, simultaneously suggested the use of the Xenopus as an excellent animal for testing for pregnancy. Since the first reports of these early investigators many other substantiating results have been added to the literature (4,5,6). These observers used extracts of urine of pregnancy, injected the animals with concentrates of the anterior pituitarylike hormone (APL) derived from the urines and within 6 to 18 hours could establish the diagnosis of pregnancy. From a series of approximately 600 tests, an accuracy in diagnosis when checked with the Aschheim-Zondek test of 99% was obtained. Crew has become so enthusiastic with his results that in his pregnancy diagnosis laboratories in Edinb...