Kaluresis Independent K Homeostasis in Dogs: Activity after Ureter Ligation and Pancreatectomy

Summary

In ureter ligated dogs intravenous administration of KCI stimulates both insulin secretion and activity of a kaluresis independent K homeostatic mechanism (K transfer capacity) that retards the development of hyperkalemia by transferring K to intracellular fluid. If the preparation is K loaded by infusion with 2 mEq KCI/kg/hr until prelethal ECG changes of hyperkalemic cardiotoxicity appear, about 50% of administered K is transferred. An increased proportion - 70% - is transferred if the animal is K loaded 70 minutes after pancreatectomy - when serum immunoreactive insulin is fixed at < 4 uU/ml. That proportion (70%) is unchanged by simultaneous adrenalectomy, but is reduced to less than 40% by propranolol blockade of B receptors. Increased post pancreatectomy K transfer capacity apparently involves K transfer mediated by B receptors that are activated by an extra-adrenomedullary B agonist(s). Findings also indicate that residual post pancreatectomy insulin biological activity mediates K transfer.

Key-Words

Hyperkalemia - B Receptor Blockade - K Transfer Capacity - Insulin Biological Activity - Adrenalectomy - Extra-Adrenal B Agonist