R. C. Graham, R. Noble
Mar 1, 1955
Citations
0
Influential Citations
14
Citations
Journal
Endocrinology
Abstract
AMONG the various actions ascribed to the plant Lithospermum is the the ability of extracts to inactivate certain pituitary hormones when mixed with them (Noble, Plunkett and Graham, 1954). The present paper records the antigonadotrophic activity of various species of Lithospermum, the seasonal variation in activity and tests for comparable activity in various other plants. laboratory methods The in vitro inactivation of Pregnant Mares’ Serum (P.M.S.) Gonadotrophin has been used exclusively in these tests. A standard procedure was adopted as follows. The P.M.S. (300 i.u./mg.1) was dissolved in water in a concentration of 100 i.u. per 0.1 cc. The extract to be tested was added in a volume of 0.4 cc./100 i.u./rat dose. The pH was adjusted to 7.5 with the addition of NaOH or HC1 and the mixture incubated at 37° C. for 2 hours. Immature female rats (45–75 gm. of Sprague-Dawley strain) received a single subcutaneous injection of 0.5 cc. of the mixture containing the equivalent of 100 i.u. of P.M.S.