Plasma cyclic nucleotide levels in juvenile-onset diabetes.

In patients with juvenile-onset diabetes, plasma concentrations of 3',5'-adenosine cyclic monophosphate (cAMP) were significantly lower than those of norman subjects [16 +/- 4 and 24 +/- 7 pmol per milliliter (p less than 0.025), respectively] as determined in this laboratory; whereas there were essentially no differences in plasma levels of 3',5'-guanosine cyclic monophosphate (cGMP). Because cAMP inhibits cell growth and cGMP stimulates it, these findings may represent an important factor in the atherosclerotic and obliterative angiopathies of diabetic individuals. We observed that cyclic nucleotide values were the same whether or not the subjects were receiving insulin. Those given insulin plus enough glucose to maintain hyperglycemia revealed modest elevations in cyclic nucleotide levels. Thus, the ratio of cAMP to cGMP, abnormally low in juvenile-onset diabetes, is relatively independent of short-term variations in plasma levels of either glucose of insulin.