降钙素基因相关肽控制性降压对大鼠肝血流及氧供氧耗的影响

Effecsts of human a-calcitonin gene-related peptide and sodium nitroprusside on hepatic blood flow, oxygen supply and consumption in rats

目的:研究α-hCGRP控制性降压对肝血流和肝氧耗的影响。方法:20只SD大鼠随机分为α-h CGRP组(C组)和硝普钠组(S组)。C组和S组动物分别静注α-h CGRP和硝普钠使大鼠平均动脉压降至6.7kPa并维持1小时。采用放射性同位素技术测定肝动脉、门脉和全肝血流量,并根据血气分析结果计算肝氧供和氧耗。结果:C组动物在控制性降压中肝动脉、全肝血流量及肝氧供显著增加;S组动物在降压中上述指标均显著下降,而肝氧耗显著增加。停用降压药物后C组动物无反跳性高血压出现,而S组动物出现明显的反跳性高血压。结论:α-h CGRP应用于控制性降压可维持肝脏正常的血供和氧供;硝普钠降压则导致肝血供和氧供不足。因此,α-h CGRP应用于控制性降压较硝普钠安全。

To evaluate the influence of human α-caleitonin gene related peptide (α-hCGRP) used in the controlled hypotension on hepatic blood flow, oxygen supply and oxygen consumption in rats. Method: Alpha-hCGRP and sodium nitroprusside were administered intravenously to reduce the blood pressure of rats to 6.7 kPa maintained for 1 h. Radiomierospheres were employd to measure hepatic arterial blood flow (HABF), portal venous blood flow (PVBF), and total hepatic blood flow (TABF). The arterial0portal,and hepatic venous blood gases were analyzed. The hepatic oxygen supply and oxygen consumption were calculated according to values of blood flow and gases. Result: HABF, TABF, and hepatic oxygen supply increased significantly, and PVBF decreased slightly during α-hCGRPinduced hypotension. HABF, TABF and hepatic oxygen consumption increased significantly, and hepatic oxygen supply decreased significantly during sodium nitroprusside hypotension. Rebound hypertension occurred after the discontinua tion of sodium nitroprusside rather than α-hCGRP. Conclusion: Alpha-hCGRP does not cause hepatic hypoxia during controlled hypotension, while sodium nitroprusside may result in hepatic hypoxia. Alpha hCGRP is more adequate to be used to controlled hypotension than sodium nitroprusside. No rebound hypotension is another advantage of α-hCGRP.