Molecular Aging and Phosphorylation of Erythrocyte Pyruvate Kinase

The effects of halothane and morphine anesthesia on autoregulation of cerebral blood flow under the conditions of normo-, hypo-, and hypercapinia were studied in eleven dogs. The cerebral blood flow (CFB) from the sagittal sinus was continuously measured by electromagnetic flowmeter. Induced hypertension and hypotension were obtained with intravenous infusion of phenylephrine and blood withdrawal, respectively. In 1.5-per cent endtidal halothane group at normocapnia (39 mmHg), the mean CBF did not change significantly within a range of mean cerebral perfusion pressure (CPP) from 100 to 138 mmHg, and at hypocapnia (25 mmHg), within mean CPP from 41 to 169 mmHg. At hypercapnia (65 mmHg), change in CPP from 43 to 142 mmHg was accompanied by similar directional change in CBF, resulting in complate loss of autoregulation. In 2-mg/kg morphine group at normocapnia (35 mmHg) and hypocapnia (24 mmHg) the mean CPP from 84 to 169 mmHg. These results suggest that cerebral autoregulation is better preserved during morphine anesthesia than halothane, and is ameliorated by hypocapnia and impaired by hypercapnia.

erythrocyte

pyruvate kinase

phosphorylation