Absence of pathological changes following intravenous methamphetamine and intra-arterial iothalamate meglumine

Eleven Rhesus monkeys received injections of intravenous methamphetamine hydrochloride (Desoxyn) and/or intra-arterial 60% iothalamate meglumine (Conray) according to a schedule previously reported to produce marked radiological and pathological changes in the cerebral vasculature of the Rhesus monkey. While radiological changes consistent with impaired cerebral circulation were observed, they could not be correlated directly with the administration of intravenous methamphetamine because of the trauma and variability of the technique utilized. Moreover, significant pathological changes could not be found in animals given intravenous methamphetamine alone, intra-arterial iothalamate meglumine alone, or both drugs together. This was true for both drug naive and drug experienced monkeys. These results suggest: (1) radiological changes consistent with decreased cerebral blood flow are not necessarily pathognomonic for reported morphological lesions, and (2) further investigation is required to determine the specific factors necessary to cause the previously reported changes.