Abstract

The effect of cyanate on the central nervous system was examined. Since clinical signs manifested in acute cyanate toxicity are similar to those observed due to excessive levels of blood ammonia and, since hydrolysis of cyanate results in ammonia production, the concentration of blood ammonia was determined in rats at various time intervals after the i.p. injection of sodium cyanate. No increase in this parameter was observed. After ¹⁴C-sodium cyanate injection (i.p.) the cerebrospinal fluid (CSF) of rats was analyzed for both cyanate and carbamylated protein. A very rapid equilibrium was established between blood and CSF cyanate yet little if any carbamylation of CSF proteins occurred in contrast to hemoglobin which was extensively carbamylated. Twenty-four hours after injection virtually all unbound ¹⁴C radioactivity had disappeared from both the CSF and the blood. The interaction between sodium cyanate and morphine was investigated to determine if the combination could lead to substantial respiratory depression and thuscause death. No such interaction was observed. Following a recent report that cyanate-treated rats suffered a learning deficit, three behavioral tests were performed so as to evaluate the possibility of brain dysfunction.