Somatostatin-like immunoreactivity (SLI) was measured in cerebrospinal fluid (CSF) of rats kindled by pentylenetetrazol (PTZ) (35 mg/kg, i.p., daily) and saline-injected controls. Interictally the levels of SLI did not differ between the groups. Five minutes after the PTZ-induced generalized convulsion the amount of SLI released into CSF was higher (173%, P = 0.006) in kindled rats than in controls, which agrees with previous findings about elevated brain levels of SLI in kindling.