The spontaneously diabetic Wistar rat (the "BB" rat): the significance of transient glycosuria.

A longitudinal study of thirteen rats with transient and intermittent episodes of glycosuria was undertaken, to further characterize the "BB" diabetic syndrome. "Chemical diabetes" (normal fasting glycemia, abnormal GTT) was observed in five rats, accompanied by the same dramatic insulitis previously reported in this syndrome, in two of the three pancreases examined. Progression from "chemical" to overt diabetes occurred in one of these rats. Two other patterns of presentation were observed. Periods of complete remission occurred in four rats with diabetes considered sufficiently severe to warrant previous treatment with insulin. Four additional rats with previous glycosuria (untreated) showed no abnormalities on followup. It is not known whether hyperglycemia accompanied the glycosuria in these rats, and renal glycosuria has not been excluded. Thus, the "BB" diabetic syndrome exists in not only the overt and "chemical" forms, but may also present with transient glycosuria, followed by a variety of subsequent progressions.