Anti-kidney antibody teratogenesis: evidence for a direct action on the rat conceptus by a mechanism involving the yolk sac.

IgG from anti-rat kidney antiserum (anti-K) was added to 48-h cultures of 9.5-day whole rat conceptuses. At concentrations of 25 micrograms/ml and above, dysmorphogenesis of embryos (optic vesicle defects) was observed. Significant embryonic growth retardation was apparent at 75 micrograms/ml and above. Other abnormalities (neural tube defects, deficits in axial rotation, reduced somite numbers) were seen at 100 and 150 micrograms/ml. In separate experiments, anti-K inhibited pinocytosis of 125I-polyvinylpyrrolidone by isolated yolk sacs. All of these effects of anti-K are similar to those produced by anti-visceral yolk sac antiserum suggesting a similar mechanism of teratogenic action, namely interference with yolk-sac-mediated embryotrophic nutrition.