Development of malnutrition in rats

Abstract
Male weanling rats were fed either a low protein diet of 0.5% casein, supplemented with methionine, a control diet of 21% casein fed ad libitum, or the 21% casein diet pair-fed to the low protein group for 5 weeks. On the 5th week of the experiment, five animals from the low protein group were rehabilitated onto the 21% casein diet and were continued with the control and pair-fed groups for another 7 weeks. During the first 4 weeks of the experiment, the low protein animals lost 20% of their initial body weight. At the 5th week, two of the four animals killed and three of the five animals rehabilitated showed edema. Body weights of the low protein animals rehabilitated to the 21 % casein diet were still lower than those of the pair-fed and control animals by the 12th week of the experiment. The malnourished rats also exhibited an abnormal accumulation of liver glycogen, which was evident by the 2nd week, and a disturbed electrophoretic pattern of the serum proteins. Transferrin bands were decreased by the 2nd week and remained about the same throughout the rest of the experiment. The prealbumin band was essentially gone by the 2nd week and the albumin was unaffected until the end of the 3rd week, but clearly reduced by the 5th week. The ratios of total concentration of serum free glycine, serine, glutamic acid, glutamine and taurine to leucine, isoleucine, valine and methionine and the ratios of serum free phenylalanine to tyrosine were elevated in low protein rats in agreement with the behavior of these ratios in human kwashiorkor patients.