The production of congenital malformations using tissue antisera. II. The spectrum and incidence of malformations following the administration of kidney antiserum to pregnant rats

Abstract

Abstract Rabbit anti‐rat‐kidney antiserum, when injected into rats seven, eight, nine and ten days pregnant, results in embryonic death, growth retardation and malformations. The spectrum of malformations is different for each day of gestation studied. The kidney malformations produced are related to its qualities as a potent general teratogenic agent and not to any specific effect on the developing urinary system. The utilization of low doses of kidney antiserum can result in a significant increase in the incidence of malformations without interfering with either the survival or growth of the exposed fetuses. It is not known whether the teratogenicity of this antiserum is due to (a) induced maternal biochemical or physiological pathology, (b) direct toxicity to the embryo or (c) interference with the deciduo‐trophoblast. Although some other antisera have not been found to be teratogenic, rabbit anti‐rat‐placental serum has also been found to be a potent teratogenic agent having similar properties to kidney antiserum. The relevance of potent teratogenic proteins to the problem of human malformations is purely hypothetical and further investigation may reveal that no relationship exists between teratogenic proteins and human malformations. In spite of this, the findings reported herein should prove to be both stimulating and provocative.