RT Journal A1 FRIED PH, RAKOFF AE T1 THe one hour rat ovary hyperemia pregnancy test with synergist JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1949 FD September 3 VO 141 IS 1 SP 25 OP 25 DO 10.1001/jama.1949.62910010005005c UL http://dx.doi.org/10.1001/jama.1949.62910010005005c AB Investigations by us to overcome certain disadvantages of the rat ovary hyperemia pregnancy tests led to our use of a pituitary synergist to improve the three hour test as a routine laboratory procedure1 and to our present consideration of a one hour rapid rat pregnancy test for urgent cases. The one hour test is based on the augmentation by a pituitary extract of the rat ovary hyperemia response to chorionic gonadotropin; the latter is the basis of the rat ovary hyperemia reaction. In preliminary experiments it was found that the addition of the pituitary extract to a subminimal effective dosage2 (0.7 international unit) of chorionic gonadotropin increased the percentage of positive reactions from 12.5 to 100 when tested at one hour.PROCEDURE  The one hour rat ovary hyperemia pregnancy test with the addition of a pituitary extract was performed on each of 163 specimens sent to the Endocrine