Chinese J Physiol
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The present study was designed to determine whether arterial pressure or blood flow contributes to the reduction in tissue bleeding (TB) during sodium nitroprusside (SNP) induced hypotension. We performed the experiment in dogs with sinus denervation and vagotomy to minimize reflex intervention. The Group 1 of Series I experiment consisted of 6 dogs with the measurements of systemic arterial pressure (SAP) and femoral arterial flow (Q). ⋯ The amount of TB at this condition was greatly increased to 48.6 +/- 2.9 ml/20 min (P less than 0.001). The results indicate that SNP decreases SAP, hindlimb Q, vascular resistance and TB in dogs with baroreceptor denervation. The data obtained from the studies of the constant Q perfusion with and without SNP suggest that the major determinant of tissue bleeding is blood pressure instead of blood flow.