Helen T. Parsons

The lack of correlation between hypersensitivity to egg white and symptoms of injury

Abstract Attempts to induce anaphylaxis in rats by the intraperitoneal injection of egg white were unsuccessful. Attempts to bring about anaphylactic shock by the intracardiac injection of egg white in rats in various stages of injury due to dietary egg white were unsuccessful. Attempts to induce passive hypersensitivity in guinea pigs by the intraperitoneal injection of blood from severely affected rats were unsuccessful. The intraperitoneal injection of egg white over a protracted period in rats on a complete stock ration or in those fed on a ration containing subinjurious amounts of egg white did not bring about the appearance of characteristic symptoms of injury. Precipitins for egg white were demonstrable in the serums of some of the rabbits showing specific symptoms of injury, but not in all of them. The serums of monkeys showing specific symptoms of injury were devoid of precipitins for egg white. Guinea pigs could regularly be rendered anaphylactic to egg white by the alimentary route; but specific symptoms of injury in these animals have not been conclusively demonstrated. The inclusion in the diet of guinea pigs of substances known to protect other animals from injury did not prevent the sensitization of the guinea pigs. Intradermal tests for sensitivity to egg white in rats showing marked symptoms and in guinea pigs which had been fed for some time on diets containing egg white produced no reactions. It is concluded that the experimental evidence does not support the hypothesis of the allergic cause of the lesions in question.

Influence of pteroylglutamic acid administration upon fecal riboflavin values in human subjects.

Summary As a part of long-time experiments in this laboratory on riboflavin metabolism in human subjects on weighed diets of known riboflavin content, it was noted that with the daily administration of 10 mg of synthetic pteroylglutamic acid for 25 to 40 days there was a striking decrease in fecal riboflavin values as compared to basal periods.

Ineffectiveness of parenteral pyridoxine in relieving or preventing the egg white syndrome in the rat.

Summary Parenteral doses of pyridoxine failed to cure or to delay the onset of the egg white syndrome in rats on a ration which included the essential fatty acids. The assumption by others, therefore, that “pyridoxine and essential fatty acids act mutually to enhance or replace biotin,” is not supported by these experiments with the rat.

Response of [i.e. to] high protein diets and unilateral nephrectomy during reproduction in the rat

This study was undertaken to determine the extent to which the task of excretion of nitrogenous katabolites could be intensified in the organism by simultaneous reduction of kidney tissue, reproduction with lactation and high protein intake and to observe the physiological adjustments made to these conditions. Unilateral nephrectomy was performed on adult female rats which were placed immediately on the experimental rations and, as soon as the regular oestrous cycle was reestablished, were mated. The weight of the litters at birth and at weaning were compared and lactation closely observed during this time. Some of the mother rats were killed after the first litter was weaned and others were bred one or more times further, and then killed. Reproduction on the protein diets was fairly successful but lactation was definitely deficient until certain changes were made in the experimental food. In Table I is given a summary of the high protein rations and control low protein rations fed. Renal enlargement calculated on the basis of increase in weight of the remaining (left) kidney over the “normal” kidney weight corresponding to the actual heart weight ranged from 219 to 29% in the animals on the protein-rich rations and from 58 to 7% in those on the low-protein control food. The degree of renal enlargement appeared to be due largely to 2 factors, namely, to the concentration of dietary protein and to the extent to which the maternal organism was called upon to satisfy the nutritional demands of the suckling young. The length of time on the ration after nephrectomy, the age of the animal, and gestation unaccompanied by lactation, were comparatively negligible factors in the renal enlargement under the conditions of these experiments.