The microvascular anatomy of the canine stomach. A comparison between the body and the antrum.

To investigate whether there is a difference in the microvascular architecture between the body and the antrum of the canine stomach, these two locations were compared with respect to microsphere entrapment and the microvascular architecture and diameter in relation to histology by corrosion casting and by intraarterial injection of india ink. There was 63% shunting of 9-micron microspheres in the antrum, but none in the body. Corrosion cast and Indian ink studies showed that in the body there was a single microvascular network of capillaries that appeared to originate from the arterioles in the submucosa and were in close apposition to the epithelial cells of the gastric glands. The diameter of these capillaries was 8.6 +/- 0.2 microns. In contrast, there were two distinct capillary networks in the antrum: a basal and a superficial. The capillaries of the basal network of the antrum originated from the arterioles at the level of the muscularis mucosa and drained into the capillaries of the superficial mucosa. The capillaries of the superficial network had a significantly larger diameter (10.8 +/- 0.4 microns) than those of the basal network (7.3 +/- 0.2 microns). In many instances the capillaries of the superficial network originated directly from the ascending arterioles passing through the basal network. These direct arteriocapillary connections may have permitted the shunting of 9-microns spheres in the antrum.