Hypertrophy and Changes in Cholinesterase Activities of the Intestine, Erythrocytes and Plasma After ‘Partial’ Resection of the Small Intestine of the Rat

Abstract

‘Partial’ resection of the small intestine in rats resulted in a disproportionately great impairment of absorption of vitamin A and several lasting anatomical and enzymatic changes. Anatomical changes consisted of a true hypertrophy of the remaining intestine, indicated by an increase in its wet and dry weight. Simple transection produced some increase in the weight of the intestine, and sham operation resulted in loss of intestinal tissue. Our interpretation of these data is that the stress of the abdominal operation results in loss of intestinal tissue, whereas actual removal of a section of the intestine releases a mechanism for restoration of lost tissue. Enzymatic changes after resection consisted of an increase in cholinesterase activity of the intestine and erythrocytes, which was not observed after simple transection or sham operation. All three groups of rats showed an increase in cholinesterase activity of the plasma. Our tentative conclusions from these data are: a) Regenerated intestinal tissue is capable of synthesizing cholinesterase. b) Disproportionately greater impairment of intestinal absorption of vitamin A after resection may be caused in part by a disequilibrium in the acetylcholine-cholinesterase system in favor of cholinesterase. c) Increase in the specific cholinesterase activity of the erythrocytes may be related to the mechanism responsible for the intestinal hypertrophy. d) Increase in the cholinesterase activity of the plasma is caused by the abdominal operation per se.