Abstract
The acute changes in the canine bowel wall during and after superior mesenteric arterial (SMA) occlusion were studied. Mitochondrial damage was indicated in histochemical analyses by diminished succinyl dehydrogenase activity before any changes appeared in lysosomal acid phosphatase. These findings were corroborated in thoracic duct lymph, where glutamic acid dehydrogenase activity rose before that of acid phosphatase. The appearance of high lactic acid dehydrogenase (LDH) activities in lymph as early as after 15 minutes of occlusion suggested that besides mitochondria the cellular membranes were damaged early during ischemia. During oxygen breathing, changes in succinyl dehydrogenase activity occurred later than during room air breathing. LDH activity in the lymph also rose later. More radioactive triolein was absorbed when the animals were ventilated with 100% oxygen. Oxygen consumption in vitro was reduced after 1 hour's SMA occlusion, both in animals ventilated with air or with oxygen. After 100% oxygen ventilation, the cells preserved better the capacity to produce energy through anaerobic glycolysis, when tested in vitro.
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