Experimental Hypertonicity: Alterations in the Distribution of Body Water, and the Cause of Death 1

Abstract

In dogs deprived of food and water, water is lost out of proportion to the loss of salt. Concentrations of sodium and of chloride in serum therefore rise progressively for many days, until, just before death, concentrations as high as 186 m.Eq. of sodium and 133 m.Eq. of chloride per liter of serum have been found (1). It was not, however, clear whether death was due to the hypertonicity of the body fluids or to the concomitant dehydration. In certain of the present experiments, a comparable degree of hypertonicity has been produced acutely, without reducing the total body water. In others, hypertonic solutions were administered to animals already dehydrated. The reactions of the animals have been compared with those of the animals in which hypertonicity resulted from water loss alone. MATERIALS AND METHODSTwelve dogs in all were used. Chemical data relating to the fluid and salt exchanges of 8 of them are presented in the preceding paper (2). Two received 5 per cent saline intravenously, the rest intraperitoneally. Four of the animals had their ureters ligated just before the experiment. Dial anesthesia was used in 9 of the acute experiments, morphine in 1 acute experiment, and no anesthetic in the 2 chronic experiments.After the anesthetic had taken effect, the animal was weighed, and a preliminary blood sample and electrocardiogram were obtained. Sodium chloride in 5 per cent solution was then injected intravenously or intraperitoneally. In some experiments, peritoneal fluid was removed after 30 or 40 minutes, in amounts approximating or somewhat exceeding the volume of saline injected.This fluid always contained salt in a concentration much lower than 5 per cent. Serial electrocardiograms were obtained from time to time.

Transfers of Intracellular Potassium in Experimental Dehydration 1

“…Our experiments reported here and elsewhere (1,18,19) give some negative and some positive clues to the factors common to all the diverse states in which there may be a loss of excess potassium. It cannot simply be the result of a temporary increase of plasma volume, since it is absent following intravenous injections of isotonic and hypotonic solutions (Table I, Experiments llC, 13A, 14) and since it appears as readily after intraperitoneal as after intravenous injections of hypertonic salt solutions (Tables II and III).…”

The changes in water and chloride distribution during heavy sweating

“…Nadal et al showed in 1941 that the peripheral circulatory failure seen in salt deficiency was due to the reduction in the extracellular fluid volume, and that in water deficiency water is lost from both compartments; Marriott (1947) also explained the clinical picture of dehydration, from whatever cause, on the basis of loss of extracellular fluid. But Gamble (1944) and Winkler, Elkinton, Hopper & Hoff (1944) The intracellular over-hydration that occurs when salt is not replaced and water losses are either replaced or not very high is analogous to that described by Danowski, Winkler & Elkinton (1946) in over-hydrated dogs. These animals developed convulsions, the so-called water intoxication; it is possible that 'heat cramps' in man may be the same condition; in the long series of tests, of which the thirty here described are a small proportion only, the conditions for intracellular over-hydration were frequently fulfilled and 'heat cramps', fully developed or incipient, were a regular complaint.…”

Simultaneous Measurements of the Blood Volume in Man and Dog by Means of Evans Blue Dye, T1824, and by Means of Carbon Monoxide. Ii. Under Abnormal Conditions, Including Secondary Shock 1

“…Finally, 2 dogs (25B, 29), initially dehydrated by prolonged withdrawal of food and water, subsequently received repeated intraperitoneal injections of a 5 per cent sodium chloride solution. Certain data from these last 2 experiments have been published elsewhere (11).…”