Small Intestinal Dipeptidases and Disaccharidases in Experimental Uremia in Rats

Abstract

Rats were made severely uremic with partial nephrectomy (24-hour creatinine clearance 10% of normal). Jejunal dipeptidase activities (substrates: glycyl-L-leucine, L-alanyl-L-proline, and L-methionyl-L-methionine), disaccharidase activities (maltase, sucrase, trehalase, and lactase) and morphology were studied. A highly significant increase in glycyl-L-leucine and L-methionyl-L-methionine dipeptidases was found in uremic rats compared with controls. Proline dipeptidase activities were unaltered. Disaccharidase activities showed a slight increase in sucrase in uremic rats; otherwise no change was found.

Small Intestinal Dipeptidases and Disaccharidases in Uraemic Rats on a Low Protein Diet

“…We found that glycyl-L-leucine and L-methionyl-L-methionine dipeptidase activities were increased, but that the L-alanyl-L-proline dipeptidase activity was un changed in uraemic rats given a normal diet (24% protein) [1]. Our results presented in this paper indicate that glycyl-L-leucine and L-methionyl-L-methionine dipeptidase ac tivities decrease when low (6%) protein feeding is insti tuted, whereas the L-alanyl-L-proline dipeptidase activity increases.…”

“…Uraemic rats given a diet with normal protein content exhibit increased activities of some dipeptidases in homo genate of mucosa and in brush border preparations [1,[17][18][19]. We found that glycyl-L-leucine and L-methionyl-L-methionine dipeptidase activities were increased, but that the L-alanyl-L-proline dipeptidase activity was un changed in uraemic rats given a normal diet (24% protein) [1].…”

“…We recently reported that severely uraemic rats showed significant increase in the activity of two intestinal dipepti dases [1], In patients with chronic renal failure the activities of some small intestinal dipeptidases and disaccharidases were decreased [2]. The reason for this discrepancy is un known.…”

Circadian Rhythms of Intestinal Disaccharidases in Experimental Uremia in Rats

“…Grimmer et al [5,6] showed a drecrease of sucrase and maltase activities of the intestinal mucosa, whereas Wizemann et al [19] found an increase of maltase and no change in lactase and sucrase, and Sterner et al [18] observed a slight increase of sucrase and no change in maltase, trehalase and lactase.…”

“…Although morphological dis orders of the gastrointestinal tract in chronic renal failure are well documented [1,3,8,9], conflicting data have been reported concerning intestinal enzyme activities [3,5,6,9,18,19],…”