[Endogenous nitrogen losses in rats fed by intravenous and enteral routes].

Endogenous losses of nitrogen were studied under the feeding with isocaloric mixtures containing glucose, polycose, mineral substances, and vitamins. At the end of the first week endogenous losses of nitrogen with urine and feces under both routes of feeding were higher than at the end of the second week of nitrogen-free feeding. Upon intravenous feeding the nitrogen-saving action of the mixture containing glucose was more remarkable at the end of the second week than that of the mixture containing glucose and fatty emulsion. Endogenous losses of nitrogen upon intravenous feeding with a mixture containing fatty emulsion and glucose and losses upon intragastric feeding with a mixture of fatty emulsion and polycose were similar at the end of the second week.