Glomerulopressin activity in peripheral blood of newly diagnosed type I (insulin-dependent) diabetic patients and in normal subjects treated with glucagon.

The glomerulopressin activity of the ultrafiltrate obtained from the peripheral blood of normal subjects, newly diagnosed Type I (insulin-dependent) diabetic patients (IDD), and in normal subjects treated with glucagon was studied in two bioassays: tonic tension contraction of the rat stomach fundus (TTC) and increase in the ureteral pressure of the toad, which was considered as a glomerular pressure index (delta GPI). The ultrafiltrate of four normal volunteers had a low activity in the TTC assay, and in two subjects no activity was observed. The ultrafiltrate of five of these subjects had no activity in delta GPI. In IDD patients the ultrafiltrates were active in the TTC assay and in the toad assay. In glucagon treated normal volunteers three of the ultrafiltrates were very active in the TTC assay and other three had a low activity. In the toad assay five of them were active and no response was observed in one subject. These observations suggest that glomerulopressin activity is increased in peripheral venous blood of untreated newly diagnosed IDD patients and in normal subjects treated with glucagon.