On the characteristical selective absorption by the cat's intestine

Abstract

Cats of from 2 to 5 kg. of weight were anestetized with subcutaneous «Sommi-Lefa» and prepared according to SOLS and PONZ's technique for successive absorptions (5) «in vivo». The volume of isotonic solution of sugar to be absorbed was 15 ml., the repletion pressure was 12 cm. of water, the absorption time 30 minutes, the residual solution was washed away with 130 ml. of normal saline solution.

The absorption of glucose (5.4 % ) by the cat' s intestine remains relatively constant from 8 to 10 succesive absorptions in the same jejunal loop «in vivo» (Table 1).

Succesive alternated absorptions of glucose and xylose show very clearly that xylose is absorbed much more slowly than glucose. In the first jejunal portion the average absorption of glucose is around 38 micromoles per centimeter of intestine and that of xylose is around 25 (Table II). In the last portion of ileum, the absorption is 24 and 18 respectively (Table III). The absorption rate of xylose in the proximal loop is 66 % that of glucose and in the distal loop it is 75 % and one and the other decrease all along the intestine (Figure 1).

The results are contrary to the believe usually accepted that in the cat xylose was absorbed at the same rate as glucose, differently from other animals. DAVIDSON and GARRY, which first set forth this exception, used the distal portion of the small intestine, in which the differences are smaller, and the absorption technique of VERZAR with only one absorption by each animal and consequently a great individual variability which would mask such differences. While the absorption of glucose is almost equal in the cat and the rat, xylose's is from 2 to 3 times greater in the cat.