Free amino‐acids in liver and blood after partial hepatectomy in normal and adrenalectomized rats

Abstract

It is well known that, after removal of part of the liver of the rat, the remainder grows rapidly to reach the normal size in 2-3 weeks (Higgins & Anderson, 1931). Though many aspects of this growth process have been investigated, little attention has been paid to changes in amino-acid metabolism. Since the liver plays a prominent part in the metabolism of these substances, one would expect that there might be changes in their concentration, both in the liver and in the blood, after partial hepatectomy, and that these changes might even be related causally to the subsequent regeneration. Christensen, Rothwell, Sears & Streicher (1948) have reported a considerable rise in the concentration of free amino-acids of rat liver cells 1-3 days after partial hepatectomy, though they found no significant change in the blood plasma; Des Marais & Dugal (1948), on the other hand, found a rise in free amino-acids of plasma in the first day after partial hepatectomy. Christensen et al. (1948) give some data on glycine and glutamine, and the peptide glutathione, but this appears to be the only information available at present. Thus although there is some information about a change in total concentration of amino-acids in liver and blood, of the individual compounds little is known. The work described here was undertaken with the object of filling this gap. For this purpose the technique of filter-paper chromatography was chosen. It was felt that, in a preliminary investigation of this sort, the disadvantages of this method on the quantitative side were outweighed by its simplicity and wide application, and that it would be more useful to have information about a wide range of substances within fairly wide limits of accuracy, than more exact information about a few. This method has been used in conjunction with estimation of total free carboxyl-amino nitrogent (Hamilton & Van Slyke, 1943) in liver and plasma.The investigation was confined to the first 24 hr after partial hepatectomy. t This term will be shortened to amino-nitrogen in the rest of this paper.

Variation of acid-soluble sulphydryl groups during liver regeneration.

“…Such an increase in -SH level has been reported by several groups of workers, who are in general agreement that a rise of between 20% and 100% occurs by 24 hours after partial hepatectomy (Christiansen et al, 1948;Ferrari and Harkness, 1954;Bahr, 1957;Hopsu and Harkonnen, 1960; Millard Smith, 1962).…”

Internal redistribution of tissue protein synthesis in uremia

“…Lysine is a major constituent of nuclear histones and cellular ribonucleoproteins (14), which are important regulators of tissue protein synthesis. Soon after partial hepatectomy, when the rate of hepatic protein synthesis accelerates, lysine content of liver tissue increases (15,16). One might speculate that the present changes in uremia were analogous.…”

The effects of pregnancy and parturition on phosphorus metabolites in rat uterus studied by 31P nuclear magnetic resonance.

“…The results of the present study show that changes in PME-peak size cannot serve as a universal index of tissue growth rate: in the uterus, the size of the PME peak increases during rapid involution. Attention was first drawn to a possible relation between tissue growth and the presence of a high concentration of phosphoethanolamine by Ferrari & Harkness (1954). Interestingly these authors also caution 'high concentration of this substance appears to be associated with growing tissue, though this is not a universal rule'.…”