Coronary interarterial anastomoses in young pigs and mongrel dogs.

Interarterial anastomoses in .young pigs have been compared with those in mongrel dogs by direct flow measurements during life and by injections after death. Results indicate that pigs have minimal functional collaterals in comparison with dogs and that injection studies roughly predict the degree of collateral function. The data indicate that the extent of collateral development in dogs is independent of clog or heart weight and hence offers more protection against the effects of coronary occlusion in small hearts than in large hearts. Other studies indicate that coronary flow, myoeardial oxygen consumption and coronary vasomotor responses in pigs are similar to those in dogs.