NEONATAL TREATMENT OF BB RATS WITH SULFATIDE DELAYS DEVELOPMENT OF DIABETES BUT DOES NOT CHANGE INCIDENCE

Sulphatide is a newly described autoantigen in insulin-dependent diabe tes mellitus; it is present in the islets of Langerhans, and anti-sulp hatide antibodies are found in diabetic patients and in spontaneously diabetic BB rats. The aim of the study was to treat neonatal BB rats w ith sulphatide in order to induce tolerance and thereby possibly influ ence later diabetes development. One hundred and twelve newborn BB rat s, divided into three groups, were treated once daily during the first 6 days of life with intrathymic injections of sulphatide, galactosyl- ceramide (which is similar to sulphatide but without sulphate) or phos phate buffer alone. Although the results showed no difference in diabe tes incidence among the three groups, there was a delayed onset of dia betes in the sulphatide-treated group, which developed diabetes on ave rage at 77 +/- 1 days of age, compared to 70 +/- 2 days (p < 0.02) for the galactosyl-ceramide-treated group and 70 +/- 1 days (p < 0.01) fo r the buffer-treated group. The degree of insulitis and the size of is lets of Langerhans were studied histologically for the diabetic animal s in all three groups; there were no significant differences although the sulphatide-treated group tended to have a more normal histology. T he blood glucose levels for the diabetic BE rats were similar in all t hree groups. Thus, neonatal treatment with the diabetic autoantigen su lphatide at the chosen dosage does not influence the incidence of diab etes, but delays the onset of disease.