Multiple Congenital Abnormalities in the Rat Resulting from Acute Maternal Niacin Deficiency During Pregnancy. ∗

Abstract

Summary

Pregnant rats were given a purified niacin-deficient diet containing the niacinamide antimetabolite, 6-aminonicotinamide (100 mg/kg of diet), on days 7–9, 8–10, 9–11 or 10–13 of pregnancy. Days 8–10 appeared to be the period of greatest sensitivity as 80% embryonic mortality or abnormality was observed at autopsy on day 21 of pregnancy. A high incidence of embryonic mortality with resorption and a low incidence of abnormal young were observed, regardless of when the diet was first instituted. Malformations in 21-day fetuses from mothers consuming 1–2 mg of 6-AN included defects of the skeleton, central nervous system and eye, urinary system, trunk, thyroid and thymus glands.