Lack of contribution of P2X receptors to neurally mediated vasoconstriction in the rabbit kidney in vivo
Lack of contribution of P2X receptors to neurally mediated vasoconstriction in the rabbit kidney in vivo
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DOI：
10.1111/j.1748-1716.2006.01526.x
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发表时间：
2006-03-01
影响因子：
6.3
通讯作者：
Evans, R. G.
中科院分区：
文献类型：
--
作者：
Eppel, G. A.;Ventura, S.;Evans, R. G.
目的：三磷酸腺苷（ATP）在体内对局部肾灌注神经控制的作用尚不清楚。方法：在肾动脉灌注α，β-亚甲基ATP（α，β-mATP，7-56 μ g kg（-1）min（-1））使P2 X（1）受体脱敏之前和期间，检测对RNS的反应。结果：3分钟的RNS训练使肾血流量（RBF）、皮质激光多普勒流量（CLDF）和髓质LDF（MLDF）在4 Hz时分别减少-90 +/-3%、-89 +/-3%和-31 +/-11%。MLDF的降低程度小于CLDF或RBF。在短训练RNS期间，RBF、CLDF和MLDF分别减少-22 +/-2%、-15 +/- 2%和-12 +/-2%，在1 Hz下持续32 s。CLDF和MLDF的降低程度相似。输注α，β-mATP诱导RBF、CLDF和MLDF一过性降低，但在5分钟内这些变量恢复至对照水平。血管反应RNS没有显着改变α，β-mATP treatment.Conclusions：在兔肾在体内，α，β-mATP敏感受体介导血管收缩，减少灌注在皮质和髓质血管床。然而，这些受体不介导神经诱导的肾灌注减少。
Aim: The contribution of adenosine triphosphate (ATP) to the neural control of regional renal perfusion in vivo remains unknown. We therefore examined whether P2X receptors mediate renal vascular responses to electrical stimulation of the renal nerves (RNS) in pentobarbitone anaesthetized rabbits.Methods: Responses to RNS were tested before and during renal arterial infusion of alpha,beta-methylene ATP (alpha,beta-mATP, 7-56 mu g kg(-1) min(-1)) to desensitize P2X(1) receptors. RNS consisted of 3 min trains at graded frequencies and short trains of RNS (4-32 pulses).Results: Three-minute trains of RNS reduced renal blood flow (RBF), cortical laser Doppler flux (CLDF), and medullary LDF (MLDF) by -90 +/- 3%, -89 +/- 3% and -31 +/- 11%, respectively, at 4 Hz. MLDF was reduced less than CLDF or RBF. During short train RNS, RBF, CLDF and MLDF were reduced by -22 +/- 2%, -15 +/- 2% and -12 +/- 2%, respectively, for 32 s at 1 Hz. CLDF and MLDF were reduced to a similar extent. Infusion of alpha,beta-mATP induced transient reductions in RBF, CLDF and MLDF, but within 5 min these variables had recovered to control levels. Vascular responses to RNS were not significantly altered by alpha,beta-mATP treatment.Conclusions: In the rabbit kidney in vivo, alpha,beta-mATP-sensitive receptors mediate vasoconstriction and reduce perfusion in both cortical and medullary vascular beds. However, these receptors do not mediate neurally induced reductions in renal perfusion.