Effects of morphine sulphate on capillary filtration and thoracic duct lymph formation in the rat.

Abstract

SUMMARYRats with chronic experimental fistulae of the thoracic duct were maintained post‐operatively on regimes of saline infusion given either intravenously or intragastrically. A narcotizing dose of morphine sulphate reduced lymph flow during intravenous infusion but not during intragastric infusion. This could be interpreted as due to reduction of capillary filtration rather than reduction of fluid absorption from the gut or diminished lymph propulsion. Morphia initiated a moderate hypotension of at least seven hours' duration. This hypotension was sustained well beyond the time during which lymph flow was reduced. Portal pressure and flow appeared to be unaffected by morphia. The reduced filtration following morphia has been tentatively attributed to a reduction in filtering area of the abdominal capillary bed rather than to lowered capillary filtering pressure.