INFLUENCE OF TRYPAN BLUE ON RESORPTION OF RAT EMBRYOS.

Abstract

TERATOGENIC agents have been found to cause an increase in fœtal mortality as well as developmental malformations. In a series of 206 embryos between 10½ and 14½ days of gestation from Wistar rats injected with 1 ml. of a 1 per cent solution of trypan blue at 8½ days of pregnancy, 45 embryos, or 21.8 per cent, were found to be undergoing resorption. These resorption products were examined and eight of them were serially sectioned at 5µ for histological investigation. A number of sites of complete resorption were observed, but they were not counted, so that the total number of resorptions was considerably in excess of the 45 products examined. Even so, this proportion of resorptions (21.8 per cent) is considerably greater than the 6.0 per cent of resorptions recorded by Beck et al.1 for a control group of Wistar rats, although much lower than the total resorption rate (56.2 per cent) recorded for rats injected with 1 per cent trypan blue in the same experiment.