The Morphology of Immunologically Induced Hydrocephalus in the Newborn Rat

Abstract

Anti-rat-kidney serum injected into a pregnant rat on the 9th day of gestation, before the appearance of the neural plate, resulted in megalocephalic hydrocephalus in the offspring. The present study shows that there is no obstruction to the flow of the CSF from the ventricles to the venous sinuses, seen with tracer studies and light microscopy, and that there is evidence of an increase in CSF pressure within the ventricular system. Although it is known that these teratogenic antisera localize in the yolk sac and produce yolk sac dysfunction, the mechanism of induction of hydrocephalus is yet to be clarified. Hydrocephalus has been induced immunologically in fetal rats with heterologous nephrotoxic antiserum (rabbit or sheep anti-rat kidney serum [RARKS or SARKS]) (8), anti-rat placental serum (6), and anti-rat yolk serum (3). Prenatally induced immunological hydrocephalus has not been recorded as a human disease. We report here the first morphological study of ARKS-induced hydrocephalus in the brain of newborn rats. ARKS injected into pregnant rats results in the birth of offspring presenting with a wide variety of anomalies, the most common being hydrocephalus (4). The highest incidence of hydrocephalus was produced by an intravenous (I.V.) or intraperitoneal (I.P.) injection of ARKS on the 9th day of gestation (5).