麻醉大鼠体内一氧化氮（NO）含量实验性变化期间的肾组织NO及肾内血流动力学

Renal tissue NO and intrarenal haemodynamics during experimental variations of NO content in anaesthetised rats.

作者信息

Grzelec-Mojzesowicz M, Sadowski J

机构信息

Laboratory of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.

出版信息

J Physiol Pharmacol. 2007 Mar;58(1):149-63.

PMID:17440233

Abstract

Direct renal nitric oxide (NO) measurements were infrequent and no simultaneous measurements of renal cortical and medullary NO and local perfusion. Large-surface NO electrodes were placed in renal cortex and medulla of anaesthetised rats; simultaneously, renal blood flow (RBF, index of cortical perfusion) and medullary laser-Doppler flux (MBF) were determined. NO synthase inhibitors: nonselective (L-NAME) or selective for neuronal NOS (nNOS) (S-methyl-thiocitrulline, SMTC), and NO donor (SNAP), were used to manipulate tissue NO. Baseline tissue NO was significantly higher in medulla (703+/-49 NM) than in cortex (231+/-17 nM). Minimal cortical and medullary NO current measured after maximal L-NAME dose (2.4 mg kg(-1) i.v.) was taken as tissue NO zero kevel. This dose decreased RBF and MBF significantly (-43%). SMTC, 1.2 mg kg(-1) h(-1) i.v., significantly decreased tissue NO by 105+/-32 nM in cortex and 546+/-64 nM in medulla, RBF and MBF decreased 30% and 20%, respectively. Renal artery infusion of SNAP, 0.24 mg kg(-1) min(-1) significantly increased tissue NO by 139+/-18 nM in cortex and 948+/-110 nM in medulla. Since inhibition of nNOS decreased medullary NO by 80% and MBF by 20% only, this isoform has probably minor role in the maintenance of medullary perfusion.

摘要

直接测量肾脏一氧化氮（NO）的情况并不常见，而且没有同时测量肾皮质和髓质的NO以及局部灌注。将大表面NO电极置于麻醉大鼠的肾皮质和髓质中；同时，测定肾血流量（RBF，皮质灌注指标）和髓质激光多普勒血流（MBF）。使用NO合酶抑制剂：非选择性的（L-精氨酸甲酯，L-NAME）或对神经元型一氧化氮合酶（nNOS）有选择性的（S-甲基硫代瓜氨酸，SMTC），以及NO供体（硝普钠，SNAP）来调控组织中的NO。髓质中的基线组织NO（703±49 nM）显著高于皮质（231±17 nM）。在给予最大剂量的L-NAME（2.4 mg kg⁻¹静脉注射）后测得的最低皮质和髓质NO电流被视为组织NO零水平。该剂量显著降低了RBF和MBF（-43%）。静脉注射1.2 mg kg⁻¹ h⁻¹的SMTC，使皮质中的组织NO显著降低105±32 nM，髓质中降低546±64 nM，RBF和MBF分别降低30%和20%。以0.24 mg kg⁻¹ min⁻¹的速度向肾动脉输注SNAP，使皮质中的组织NO显著增加139±18 nM，髓质中增加948±110 nM。由于抑制nNOS仅使髓质NO降低80%，MBF降低20%，因此该同工型在维持髓质灌注中可能起次要作用。