In vivo effects of peroxovanadium compounds in BB rats.

Peroxovanadium compounds, each containing an oxo ligand, one or two peroxo anions, and an ancillary ligand in the inner coordination sphere of vanadium, were synthesized, crystallized and characterized by 51V NMR as > 95% pure. They markedly decreased plasma glucose in insulin-deprived diabetic BB rats, with a nadir occurring between 60 and 100 min after intravenous, intraperitoneal or subcutaneous administration. Plasma glucose was reduced after oral administration in insulin-treated and in insulin-deprived BB rats.

Hypoglycemic effects of peroxovanadium compounds in Sprague-Dawley and diabetic BB rats.

Highly purified peroxovanadium (pV) compounds, each containing an oxo ligand, one or two peroxo anions, and an ancillary ligand in the inner coordination sphere of vanadium, were shown to decrease plasma glucose markedly in both normal Sprague-Dawley and insulin-deprived diabetic BB rats. Maximal decreases in plasma glucose were at 60-100 min after intravenous, intraperitoneal, or subcutaneous administration. Synergism between these compounds and insulin was observed.

Predictive value of lymphocyte antibodies for the appearance of diabetes in BB rats.

Lymphocyte antibodies have been described in autoimmune disorders, including insulin-dependent diabetes mellitus (IDDM). We have developed a quantitative method to measure autoantibodies directed against T-lymphocytes, based on two-color fluorescence labeling of Wistar mononuclear cells and analysis of fluorescence by flow cytometry. The lymphocyte antibody levels were determined retrospectively in the serum of 73 BB and 18 Wistar rats.

Prevention of adoptive transfer in BB rats by prophylactic insulin treatment.

Prophylactic insulin can prevent diabetes in the BB rat. We evaluated its use to prevent adoptive transfer of diabetes by activated splenocytes. ConA-activated spleen cells from acutely diabetic BB rats were divided into two equal aliquots and injected intravenously in paired diabetes-prone BB rat littermates.

Metabolic time course and immunologic concomitants of adoptive transfer of type I diabetes in the BB rat.

The metabolic and cellular immune changes during adoptive transfer of type I diabetes mellitus in the BB rat were examined. Concanavalin A (Sigma Chemical Co, St Louis) stimulation of acutely diabetic BB rat splenocytes increased the Ia-positive cells, but no other lymphocyte subset. Each spleen cell preparation was divided into two and injected into two separate recipients.