[Effect of vasopressin, aldosterone and angiotensin on the permeability of the choroid plexus to water]. / Vliianie vazopressina, al'dosterona i angiotenzina na pronitsaemost' khoroidal'nogo spleteniia dlia vody.

In anesthetized dogs with cannulae implanted in the lateral cerebral ventricle, the water transfer from the CSF to the blood was studied using determination of drainage of tritiated water injected into the ventricle. Vasopressin and aldosterone accelerated the transfer of tritiated water into veins whereas angiotensin decelerated it. The data obtained suggest that the above hormones regulate volume and osmolality of the CSF.

[Reflex regulation of potassium excretion in the postnatal ontogeny of the dog]. / Reflektornaia reguliatsii ékskretsii kaliia v postnatal'nom ontogeneze sobaki

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. Intravenous injections of pituitrin P reproduce the reactions which were observed in reflex potassium regulation in puppies up to 4 months, this finding indicating possible participation of neurohypophysial hormones in these reactions. In acute experiments it was shown that in puppies of the first month, the liver is not capable of potassium retention. This may be one of the causes of absence of reflex potassium excretion in animals of this age.

[Natriuretic component of the osmoregulating reflex during postnatal dog ontogenesis]. / Natriureticheskii komponent osmoreguliruiushchego refleksa v postnatal'nom ontogeneze sobak

In experiments on puppies ageing from 3 days up to 8 months, as well as on adult dogs, studies have been made of mechanisms of excretion of water and sodium during the increase of osmotic concentration in the blood circulation of the liver and spleen. It was found that in contrast to adult dogs, in which the osmotic shift decreases diuresis and increases sodium excretion, the decrease of diuresis in 1-month puppies is accompanied by a decrease of sodium excretion. Two-component osmoregulatory reaction is developed only to the 2nd month of life. Pituitrin P, injected intravenously, evoked the same reactions which were observed in osmoregulatory reflexes at various stages of ontogenesis. Studies on papillary-cortical osmotic and sodium gradients implies that kidney reactions to osmotic shifts are realized via neurohypophysial hormones; maturation of mechanisms realizing the osmotic papillary-cortical gradient takes place previously to those which realize sodium concentration gradient.