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It is shown, that the value of Km for maltase, alkaline phosphatase, aminopeptidase M and glycyl-L-leucinedipeptidase, prepared from the jejunum and ileum of 10-day rat litter in membrane and soluble forms in most cases differed but a little in control animals and the rat litter whose mothers in the period of lactation had a diet with 2.5-fold reduced content of protein, and did not change under action of injected thyroxin and dexamethasone. It may be assumed that in the given experimental conditions each of the investigated digestive hydrolases in membrane and soluble forms represents the same enzyme. In conditions of the protein insufficiency in lactating females diet and under action of exogene hormones, apparently, no significant changes occur in structure of synthesised enzymes.

It has been found for the first time that protein deficit in female's nutrition during prenatal development of the offspring is accompanied by considerable changes in the activity of intestinal digestive enzymes and of the same hydrolases in the colon, liver and kidneys both in early and in late ontogenesis. It seems possible that changes of the small intestine enzyme functions and hydrolytic functions of other digestive and non-digestive organs in result of an unfavorable early "metabolic/nutritional programming" may be crucial in disorders of metabolic processes leading to development of diseases of risk in adult life.

In the colon mucous membrane, activity of a wide range of membrane and mainly intracellular enzymes was studied in the organism at different conditions. The data obtained suggest participation of digestive hydrolases in the colon not only on postdigestive processes but, in certain states of the organism, in digestive processes too.

Protein deficiency in female rats diet during pregnancy and lactation resulted in deceleration of induction of sucrase both forms in the jejunum and ileum; in acceleration of induction of the maltase membrane from in the jejunum; and in suppression of the lactase membrane form in the ileum; in earlier forming of the adult-type distribution of activity of the membrane form of intestinal alkaline phosphatase and in a decrease in activity of the enzyme soluble form. The findings are corroborated by a suppression of activities of the membrane and soluble forms of the small intestine digestive enzymes in 30-day old rat pups fed with a control (adequate) ration starting 21 days after the birth.

With ageing the membrane/soluble form ratio of membrane-boundenzymes increases especially in the ileum and that of peptidases changes rather insignificantly in both portions of the rat small intestine. The soluble forms are supposed to take part in assimilation of food substrates penetrating enterocytes in an unsplit form due to an enhanced permeability of the membranes, particularly those of the ileum.