Guanidino compound levels in the serum of healthy adults and epileptic patients.

Some guanidino compounds are known to be convulsants and to change in the brain during seizures. In this study, we examined the serum levels of guanidino compounds in healthy adults (controls), non-epileptic neurological patients (NENP) and epileptic neurological patients (ENP). In healthy adults, serum levels of guanidinoacetic acid (GAA), creatinine (CRN) and homoarginine (HArg) were significantly lower in women than in men. Serum levels of GAA in ENP and NENP were significantly lower than in controls, with the exception of female NENP. In the male patients, CRN levels were significantly lower in ENP and NENP compared to the controls. Significantly higher arginine (Arg) levels were observed in both male and female ENP and NENP. HArg levels in the male patients were significantly lower in ENP compared with both controls and NENP. With regard to serum levels of guanidino compounds in ENP with symptomatic generalized epilepsy and with symptomatic partial epilepsy, significantly lower levels of HArg were observed in male ENP with symptomatic generalized epilepsy than in NENP. Serum levels of GAA and HArg in uncontrolled female ENP were significantly lower than those in controlled ENP. Furthermore, Arg and HArg levels in uncontrolled male ENP were significantly lower than in controlled ENP. Serum levels of Arg in male ENP and HArg in both sexes of ENP taking valproic acid were significantly lower than those in ENP not taking valproic acid. These results suggest that some metabolic disorder of guanidino compounds may exist in ENP and NENP and that guanidino compounds may be affected by seizure types, seizure severity and anticonvulsants.