THE EFFECT OF OCTREOTIDE ON KAINATE-INDUCED WET DOG SHAKES AND SEIZURE ACTIVITY IN MALE AND FEMALE RATS

Abstract

Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epileptic seizures. Although WDS are often associated with the occurrence of seizures, we have recently shown that following nitric oxide (NO) synthesis inhibition, the number of WDS decreased; subsequently the onset of seizure activity was shortened, and the number of convulsions was increased. Somatostatin (SS), whose release appears to be controlled by NO, inhibits seizure activity. There are sex differences in seizure susceptibility as well as in SS and NO activities in brain. The present study was undertaken to assess the effect of octreotide (OC), a stable SS analogue, on KA-induced WDS and seizures in rats, with emphasis on possible sex differences. WDS and seizures were induced by KA in male and female (proestrus) Sprague Dawley rats; OC or saline was injected 30 min before KA and the behavior was monitored for 120 min after KA. Octreotide increased the number of WDS and decreased the number of convulsions; this effect was more pronounced in males. Onset of KA-induced seizure ac tivity was earlier in females than males; however, there was no effect of OC on seizure latency. Seizure activity started after the termination of WDS. These results show OC has opposite effects on WDS and convulsions, in that it stimulates the former and inhibits the latter. These results support our previous findings that WDS and seizure activity involve separate mechanisms and suggest that WDS may have an inhibitory effect on limbic seizures.