Effects of Nitroglycerine on Erythrocyte Rheology:A Novel Mechanism to Explain the Enhancement of Nutrient Blood Flow to Ischemic Zones

Objectives Nitroglycerine (NTG) enhances coronary blood flow to compromised myocardium is important in relieving ischemia. However, the mechanism for this increase in myocardial blood flow (MBF) is not well defined. In small vessels and capillaries, relative blood viscosity plays a very important role in determining myocardial vascular resistance (MVR). MVR reduce is due partly to the increase in negative charge of erythrocyte surface. We therefore hypothesized that the enhancement of nutrient blood flow to zones of myocardial ischemia during NTG is partly secondary to reduced MVR and blood flow viscosity. The latter is affected by the negative charge of erythrocyte surface. Methods 6 dogs with LAD flow-limiting stenosis (group 1) and 6 dogs with LAD flow-limiting stenosis and LCx occmusion (group 2) were studied. At baseline and during intracoronary infusions of NTG (0.3-0.6 μg·kg-1·min-1), hemodynamics, MBF (mL·min-1·g-1), whole blood viscosity (WBη, mPa. S), elongation index (EI), eletrophoretic mobility of erythocytes (EME, [μ.s-1)/(V.cm-1)]) and percent wall thickening (%WT) were determined. MVR was calculated using driving pressure/MBF. Results As compared to baseline, no changes in hemodynamics were seen during NTG. MBF increased and MVR decreased significantly in normal bed, the central 25% and the entire of stenosed bed (P<0.05), with a decrease in WBη in both group 1 and group 2 dogs (18.6±9.7 % and 19.2±14.5 %, respectively). However, the % decrease in WBη was proportioned to the % increase in MBF or the % decrease in MVR only in the central 25% of stenosed bed (r=0.87, P<0.001), but not in the entire stenosed bed and normal bed. EI did not show statistically significant differences between during NTG and at baseline, but EME did increase. And the % decrease in WBη during NTG was related to the % increase in EME (r=0.83, P=0.01). Conclusions NTG reduced myocardial vascular resistance and blood viscosity due to the change of negative charge of erythrocyte surface may, in part, be the mechanism of the enhancement of nutrient blood flow to zones of myocardial ischemia. These results provide additional insights into the complex anti-ischemic effects of NTG.

Effects of Xianzhen Tablet（仙贞片）on Na^+-K^+-ATPase and Ca^(2+)-Mg^(2+)-ATPase in Erythrocytic Membranes and Viscosity of Whole Blood in Non-Insulin-Dependent Diabetes Patients with Qi-Yin Deficiency, Kidney Deficiency and Blood Stasis

Objective: To assess the effects of Xianzhen tablet (XZT) on Na+-K+ -ATPase and Ca2+ Mg2+-ATPase on erythrocytic membranes, viscosity of whole blood, plasma glucose and clinical manifestations.Methods: Seventy-two cases of non-insulin-dependent diabetes mellitus (NIDDM) patients with deficiency of both Qi and Yin, deficiency of the Kidney and blood stasis were selected, and the effects of treatment on Na+ K + -ATPase, Ca2+-Mg2+ -ATPase, whole blood viscosity, blood sugar and clinical Symptoms were observed.Results: In XZT group (test group), activities of Na+ -K+ -ATPase and Ca2+ -Mg2+ -ATPase rose significantly(P< 0. 01, P< 0. 05) after treatment. Viscosity of whole blood and clinical manifestations also improved obviously. The total effective rate in lowering plasma glucose was 77. 8 % with fasting blood glucose (FBG) and 69.4 % with 2 hours postprandial plasma blood glucose (2°PBG). In the control group, viscosity of whole blood andclinical manifestations had no significant improvement. Its total effective rate in lowering plasma glucose was41. 7% with FBG and 38. 9% with 2°PBG. Conclusions: XZT played a certain role in increasing activities ofNa+ -K + -ATPase and Ca2+-Mg2+ -ATPase, decreasing viscosity of whole blood and plasma glucose and improving clinical manifestations. Therefore, XZT was experimentally manifested as an effective drug in treating NIDDM patients with Qi-Yin deficiency, renal deficiency and blood stasis.

Effects of L.F04,the Active Fraction of Lycopus lucidus, on Erythrocytes Rheological Property

Objective: To study the effects of L.F04, the active fraction of Lycopus lucidus, on erythrocytes rheological property so as to investigate its mechanism in promoting blood circulation and removing blood stasis. Method: The effects of L.F04 (used for treatment for 10 days in different dosages) on deformability, aggregation and membrane liquidity of erythrocytes (MLE) as well as whole blood apparent viscosity (η_b) were examined on the basis of rat model of blood-stasis syndrome induced by venous injection of high molecular weight dextran. Result: As compared with the normal control group, the model group's RBC deformability and MLE were lower, and the aggregation of erythrocytes and η_b were higher. Compared with the model group, both L.F04 0.612g/kg and 0.306g/kg showed significant effect in improving deformability and inhibiting aggregation of red blood cells (RBC) and reducing blood viscosity. The trend of improving MLE was also shown. Conclusion: L.F04 could significantly improve the abnormal rheological property of erythrocytes.