Increased susceptibility to seizures and decreased catecholamine turnover in spontaneously hypertensive rats

Spontaneously hypertensive rats (SHR) were compared with normotensive Wistar rats for their sensitivity to tonic extensor seizures. SHR were more sensitive to seizures and did not respond to the anticonvulsant effects of L-DOPA. SHR had a slower turnover rate of norepinephrine in brain stem and cortex and of dopamine in striatum. Steady-state levels of catecholamines were similar in both groups. These findings are consistent with earlier ones that reported an inverse relationship between central catecholamine activity and sensitivity to electroconvulsive seizures.