Graded effects of oxygen and respiratory inhibitors on cell metabolism and spontaneous contractions in smooth muscle of the rat portal vein.
Graded effects of oxygen and respiratory inhibitors on cell metabolism and spontaneous contractions in smooth muscle of the rat portal vein.
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氧气和呼吸抑制剂对大鼠门静脉平滑肌细胞代谢和自发收缩的分级影响。
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
P. Hellstrand
中科院分区：
文献类型：
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作者：
B. Lövgren;P. Hellstrand
通过比较对氧和呼吸链抑制剂异戊巴比妥和氰化物的反应，研究了大鼠门静脉自发活动低氧舒张的基础。使用抑制剂，整个细胞团的O2消耗（FO 2）均匀降低，从而避免组织中的O2梯度。因此，这些影响不能归因于缺氧区域的全或无抑制，这种可能性可能使对缺氧反应的解释复杂化。随着PO 2逐步减少（96%至0%，在N2 + 4%CO2）或增加浓度的抑制剂（0 -5 mmol），FO 2减少，伴随着平均收缩活动（P）的减少和乳酸产生（弗拉）的增加。在96%O2中，当P大于对照值的10%时，计算的ATP产生（FATP）与P线性相关，缺氧和两种抑制剂的斜率相同。在这个范围内，减少FATP与P可以在很大程度上归因于减少收缩的代谢需求，从与门静脉在名义上无钙介质中放松的缺氧反应的比较中可以明显看出。随着PO 2的减少或异戊巴比妥浓度的增加，磷酸肌酸的组织含量下降，而ATP保持不变的P大于10%的控制。对缺氧和呼吸抑制的类似反应表明对血管平滑肌细胞的代谢和收缩性的分级效应，与这些干预措施在体内的血管舒张效应相关。
The basis for the hypoxic relaxation of spontaneous activity in the rat portal vein was investigated by comparing responses to oxygen and the respiratory chain inhibitors amobarbital and cyanide. With the inhibitors, O2 consumption (FO2) is uniformly decreased throughout the cell mass, and thus O2 gradients in the tissue are avoided. Hence the effects are not to be attributed to all-or-none inhibition in anoxic regions, a possibility that might complicate the interpretation of responses to hypoxia. With stepwise reduction in PO2 (96 to o% in N2 + 4% CO2) or increasing concentration of inhibitor (o-5 mmol), FO2 decreased with a concomitant reduction in mean contractile activity (P) and increase in lactate production (FLA). The calculated ATP production (FATP) was linearly related to P for P greater than 10% of the control value in 96% O2, with the same slope for hypoxia and both inhibitors. In this range the reduced FATP with P can largely be attributed to decreased metabolic demand of contraction, as evident from a comparison with the responses to hypoxia of portal veins relaxed in nominally Ca2+-free medium. With reduced PO2 or increased amobarbital concentration the tissue content of phosphocreatine decreased, whereas ATP remained constant for P greater than 10% of control. Similar responses to hypoxia and respiratory inhibition demonstrate graded effects on metabolism and contractility in the vascular smooth muscle cells, correlating with reported vasodilatory effects of these interventions in vivo.