Abstract
In view of the reports of Smith 1 and of Evans and Simpson 2 on the prevention of the peripheral action of the gonad-stimulating complex of the anterior pituitary by the simultaneous administration of anterior pituitary growth-promoting extracts, it was thought that the latter might have some influence on the increase in gonad-stimulating potency of the anterior pituitary which has been shown to follow castration. 3
A growth-promoting extract was prepared from bovine anterior lobe tissue according to the method of Bugbee, Simond, and Grimes. 4 The extract contained also a slight amount of gonad-stimulating substance since a single intravenous injection of 7 cc. produced ovulation in the rabbit, and 0.5 cc. daily for 6 days caused a slight increase in weight of the ovaries and uteri of immature female rats.
The work of Evans and Simpson was confirmed on a group of 12 immature female rats, 4 litters of 3 littermate sisters each. Two females from each litter received 3 glands apiece from littermate male donors daily for 4 days; and to one of these females was administered simultaneously 0.5 cc. of the growth-promoting extract twice daily, subcutaneously, for the 4 days. The females were killed 48 hours after the last implantation, the ovaries and uteri were removed and weighed. The largest ovaries and uteri were found in the group receiving the implantations alone; in the group receiving the implantations plus the extract, the organs were definitely smaller than in the preceding group, indicating a nullification of the action of the implants; yet the organs were definitely larger than in the case of the untreated control group, hence the nullification of the action of the implants was not complete, as reported by Evans and Simpson. This difference can, of course, be explained on the basis of relative dosage.
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