Somatostatin-like immunoreactivity and somatostatin receptor binding in rat brain in pentylenetetrazol-induced kindling.

Kindling was induced in Sprague-Dawley rats by repeated injection of pentylenetetrazol (PTZ, 30 mg/kg, IP). Somatostatin-like immunoreactivity (SLI) and 125I-Tyr-somatostatin binding were measured in different areas of the brain in saline-injected controls, rats receiving PTZ but not kindled (prekindled rats), and kindled rats. Compared to SLI levels in controls, SLI increased (p < 0.01) in the frontal cortex, striatum (p < 0.05 in kindled rats), and hippocampus of both prekindled and kindled animals. Hypothalamic levels of SLI remained unchanged. Compared with the controls, no change was found in somatostatin receptor binding in the frontal cortex, striatum or hippocampus in prekindled or kindled animals. These results suggest that an increased level of somatostatin may be connected to the development and maintenance of kindling.