[Reflex regulation of potassium excretion in the postnatal ontogeny of the dog].

In experiments on puppies ageing from 7 days to 8 months, as well as on adult dogs, studies have been made on reflex mechanisms of potassium excretion after injection of 135 mM KCl solution (0.7 ml/kg) to the portal vein. It was found that reflex regulation of potassium extrusion undergoes 3 developmental stages: in puppies up to 1 month potassium excretion is absent; from 1 to 4 months ionuresis is not differentiated, since injection of KCl increases excretion of both K and Na; after 4 months of postnatal life potassium excretion attains its final form.