A new animal model of non-insulin-dependent diabetes mellitus induced by the NDK25 variant of encephalomyocarditis virus.

Intraperitoneal inoculation with NDK25, a variant of Encephalomyocarditis (EMC) virus which has been newly cloned from the M variant of EMC virus (EMC-M), caused DBA/2 mice to develop noninsulin-dependent diabetes mellitus. The NDK25-infected mice demonstrated abnormal glucose tolerance from 1 to 3 weeks after inoculation. The infection resulted in mild insulitis and the destruction of pancreatic beta cells at 1 week after inoculation and led to a significant reduction in the insulin content of the pancreas, but there was no ketonuria. The insulin content of the pancreas was recovered considerably from 15 +/- 3 at 1 week to 95 +/- 16 micrograms/g pancreas at 12 weeks, although the latter value was still significantly lower than that of the control mice (P < 0.05). Under microscopy, mild and partial infiltration of mononuclear cells was observed in about half the pancreatic islets only 1 week after inoculation, and then disappeared. Thus, we believe we have established a new model of noninsulin-dependent diabetes mellitus using the NDK25 variant of EMC virus.