Experimental Neurolathyrism in Monkeys

Abstract

UNTIL now the cause of the relation between Lathyrus sativus and the spastic paraplegia, known as neurolathyrism, has been inferred purely on epidemiological grounds and neurotoxic manifestations with or without histopathological verification have not so far been obtained^1–4. The isolation and characterization of β-N-oxalyl-L-α,β-diaminopropionic acid (OX-Dapro), an unusual amino-acid, which was “neurotoxic” to 1 day old chicks have, however, been reported^5,6. We have found that intraperitoneal injection of this compound in adult chicks required a proportionately much larger dose to produce similar effects. An intraperitoneal or intravenous administration of this compound to adult rats at a level of 1 mg/g body weight or intraperitoneally in mice did not produce any symptoms, while administration of 25 µg intracisternally was seen to produce convulsions. It was felt that this might be caused by an effective “blood–brain barrier”⁷ and thus we decided to investigate the effect of this compound when intrathecally injected into adult monkeys (Macaca radiata).