Juxtamedullary microvascular responses to arginine vasopressin in rat kidney.
Juxtamedullary microvascular responses to arginine vasopressin in rat kidney.
复制标题
大鼠肾脏中近髓微血管对精氨酸加压素的反应。
DOI：
10.1152/ajprenal.1994.267.2.f249
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Carmines,PK
中科院分区：
文献类型：
--
作者：
Harrison-Bernard,LM;Carmines,PK
通过实验确定精氨酸抗利尿激素（AVP）诱导的血管阻力调节导致乳头状血流量减少的部位。同时测量管腔直径和中心线红细胞速度，可以估计体外血液灌注的髓旁肾单位的单血管血流。AVP （0.1-1,000 pM）引起外髓降血管直肠（OMDVR）血流（10 pM）的浓度依赖性降低，但未改变OMDVR直径。AVP浓度为1 pM时，传入动脉直径明显减小，AVP浓度为100 pM时，弓形动脉直径明显减小。AVP浓度增加至1000 pM，导致小叶间动脉、远端传入小动脉和传出小动脉的血管直径显著减小。AVP降低传入动脉直径和血流的作用在V1受体拮抗剂存在下被阻断。这些数据表明，传入小动脉对AVP的血管收缩作用表现出最大的敏感性，而OMDVR则表现出不敏感。我们得出结论，AVP引起的OMDVR血流变化不是由于肽对该血管段的直接作用，而是由于其对上游血管的作用。
Experiments were performed to determine the site of arginine vasopressin (AVP)-induced vascular resistance adjustments that result in decreases in papillary blood flow. Simultaneous measurements of luminal diameter and centerline erythrocyte velocity allowed estimation of single-vessel blood flow in in vitro blood-perfused juxtamedullary nephrons. AVP (0.1-1,000 pM) caused concentration-dependent reductions in outer medullary descending vasa recta (OMDVR) blood flow (10 pM) without altering OMDVR diameter. Afferent arteriolar diameter was significantly decreased by 1 pM AVP, whereas arcuate artery diameter was decreased by 100 pM AVP. Increasing the concentration of AVP to 1,000 pM resulted in significant reductions of vessel diameter in interlobular arteries, distal afferent arterioles, and efferent arterioles. The effects of AVP to decrease afferent arteriolar diameter and blood flow were blocked in the presence of V1 receptor antagonist. These data indicate that afferent arterioles exhibit the greatest sensitivity to the vasoconstrictor effects of AVP, whereas OMDVR appear insensitive. We conclude that the change in OMDVR blood flow produced by AVP is not due to a direct effect of the peptide on this vascular segment but to its effect on upstream vessels.