Peripheral vasoconstriction associated with hyperpotassemia.

• Experimental conditions have been described in which constriction of the small blood vessels in the cheek pouch of the golden hamster was found in association with increased serum potassium levels. The arterioles of adrenalectomized hamsters became progressively constricted, starting three to four days after operation until death. An increase in serum potassium occurred during the same period of time. Severe vasoconstriction in the cheek pouch preparation also accompanied hyperpotassemia during the terminal stages following total body x-irradiation with 1,000 r. A direct vasoconstrictor action of potassium has been postulated, but supportive evidence has not been consistent. Katz and Lindner reported constriction of perfused coronary arteries in dogs when the potassium levels in the perfusate were greatly increased. Driscol and Berne, using a similar preparation, were unable to confirm these results. Vasoconstriction associated with experimental hyperpotassemia has been reported to occur in perfused hiud limbs of dogs and cats. Emanuel et al. have demonstrated that potassium excess has a direct vasodilator action on arterioles in perfused fore limbs of dogs.