[Elevated immunoreactive-somatostatin levels in the brain of ataxic mutant mice]. 
Immunoreactive-somatostatin (IR-SRIF) levels were investigated in the brain of 4 types of ataxic mice (Rolling Mouse Nagoya, Weaver, PCD, Staggerer) with different cerebellar pathologies.  IR-SRIF concentrations (ng/mg) were found to be significantly elevated in both cerebellum and cerebrum of all ataxic mutant mice, IR-SRIF (ng/organ) was found to be increased in the cerebellum and cerebrum in Rolling Mouse Nagoya and PCD compared with control mice.  The gel-filtration profile (Sephadex G-50) in the cerebellar extracts of Rolling Mouse Nagoya proved to be identical to that of control mice.  Three peaks of IR-SRIF were found to be uniformly elevated in Rolling Mouse Nagoya, with the highest peak coinciding with authentic somatostatin-14.  The present results suggest that elevated levels of IR-SRIF in the brain may play a role in the mechanism underlying the manifestation of ataxia in ataxic mutant mice, especially in Rolling Mouse Nagoya and PCD.