Hyperkalemia, hyperglycemia, and plasma levels of cyclic AMP and cyclic GMP induced by portal vein injection of cyclic nucleotides and their butyryl derivatives into dogs

Abstract

The levels of serum potassium, blood glucose, and plasma adenosine cyclic 3′:5′-monophosphate (cAMP) and guanosine cyclic 3′:5′-monophosphate (cGMP) were studied after the portal vein injection of cyclic nucleotides and their derivatives, (cAMP, cGMP, N6, O2′,-dibutyryl adenosine 3′:5′-monophosphate (DBcAMP), N6-monobutyryl adenosine cyclic 3′:5′-monophosphate (NMBcAMP), and O2′-monobutyryl adenosine cyclic 3′:5′-monophosphate (OMBcAMP)), into dogs. Dose-related hyperglycemic responses were observed after the injection of DBcAMP (1–8 mg/kg). Transient and prominent hyperkalemia and hyperglycemia were caused by the injection of DBcAMP, NMBcAMP, and OMBcAMP (4 mg/kg). The hyperkalemic response was highest with NMBcAMP (1.22 mequiv./L), followed by OMBcAMP (0.64), DBcAMP (0.54), cGMP (0.47), and cAMP (0.41), whereas the hyperglycemic response was highest with NMBcAMP (146 mg/100 mL), followed by DBcAMP (93.6), OMBcAMP (77.1), and cAMP (56.0), and there was only a slight change with cGMP (28.4) compared with the control. The plasma level of cAMP was maximal with DBcAMP (1.92 nmol/mL), followed by NMBcAMP (1.28) and OMBcAMP (0.76), whereas the plasma levels of cGMP showed no evident change, except that caused by DBcAMP (0.27). Of the cyclic nucleotides tested, NMBcAMP was found to be most potent in causing both hyperkalemia and hyperglycemia. Based on these results, possible correlations between hyperkalemia, hyperglycemia, and plasma levels of cAMP and cGMP are discussed.