The effect of protein energy malnutrition on plasma renin and oedema in the pig.

Five litter-mate male pigs, aged 7 days and fed a standard Pig Industry Board diet containing 190 g/kg dry mass of digestible protein, were compared with 10 male pigs from two litters fed a protein-deficient diet (50 g/kg) for a period of 70 days. The 10 experimental animals developed oedema between the 42nd and 70th days of the study and 4 of them became lethargic. Although the 10 experimental animals showed the typical biochemical changes characteristic of protein energy malnutrition (PEM), including changes in muscle electrolytes, liver fat and plasma albumin, the 4 lethargic animals showed a significant increase in effective plasma renin activity (EPRA) only by the 70th day of the study. Since oedema preceded any increase in EPRA in some pigs and developed in others without any change in EPRA, it is suggested that the increased renin activity is not responsible for the initial fluid retention and oedema.