Effects of blood flow reduction and lymphatic ligation on coronary transport in dogs.

We studied the effects of reduced-flow coronary ischemia and coronary lymphatic ligation on transcapillary movement of albumin. We infused 125I-albumin intravenously into four groups of five anesthetized, open-chest dogs in which external carotid-to-coronary arterial cannulas had been placed. One group was subjected to both lymphatic ligation and ischemia; a second group to lymphatic ligation only; a third group ischemia only; and the fourth was a control group. After 1 hr, 85Sr-microspheres were injected into the cannula. After 2 hr, the animals were sacrificed. Extravascular albumin activities in heart sections that were perfused from the cannula were normalized to extravascular albumin in normal-flow regions. This variable was greater in the lymph-ligated and ischemic groups than in the control, and greater in the combined lymph-ligated and ischemic group than any other group. Relative increase in coronary vascular resistance over the protocol interval correlated significantly with normalized albumin content in the cannulated sections. Although both ischemia and lymph ligation lead to increased extravascular albumin accumulation, their mechanisms are different. Increased extravascular albumin after ischemia may be due to increased capillary permeability.