Protasoni G, Castoldi G, Busca G, Panzacchi G, Genovesi S, Golin R, Stella A
Istituto di Clinica Medica Generale e Terapia Medica, Milan, Italy.
J Hypertens. 1995 Dec;13(12 Pt 2):1753-7.
To investigate the effects of the interaction between adenosine receptors and renal nerves on renin release.
The effects on renin secretion of A1 (2-chloro-N6-cyclopentiladenosine) and A2 (2-hexynil-5'-N-ethyl-carboxamido-adenosine) adenosine-receptor agonists were studied in two groups of anaesthetized rats, each with one kidney surgically denervated. Arterial blood pressure and the renal blood flow of innervated and denervated kidneys were continuously recorded. Cannulae were inserted into both renal veins through femoral veins. After 1h of rest, A1 and A2 agonists were intravenously infused for 30 min in the two groups of rats. Plasma renin activity was measured by radioimmunoassay in blood samples drawn simultaneously from both renal veins and the femoral artery before and after the drug infusion.
Infusions of A1 and A2 agonists produced comparable hypotensive effects. During A1 agonist administration, the heart rate decreased significantly, but it did not change after A2 agonist treatment. Renal blood flow was reduced by administration of the A1 agonist in both kidneys, while A2 agonist administration significantly reduced the renal blood flow of the innervated kidney only. The veno-arterial difference in plasma renin activity decreased after the A1 agonist infusion in both kidneys, but after the A2 agonist infusion it increased significantly in the innervated kidney only.
Renal nerves do not influence the inhibition of renin release mediated by A1 adenosine receptors. In vivo, A2-receptor agonist administration can stimulate renin release only in the presence of intact renal nerves.
研究腺苷受体与肾神经之间的相互作用对肾素释放的影响。
在两组麻醉大鼠中研究A1（2-氯-N6-环戊基腺苷）和A2（2-己炔基-5'-N-乙基-羧酰胺基腺苷）腺苷受体激动剂对肾素分泌的影响，每组中有一侧肾脏经手术去神经支配。连续记录支配侧和去神经支配侧肾脏的动脉血压和肾血流量。通过股静脉将套管插入双侧肾静脉。休息1小时后，在两组大鼠中静脉输注A1和A2激动剂30分钟。在药物输注前后，通过放射免疫分析法测定同时从双侧肾静脉和股动脉采集的血样中的血浆肾素活性。
输注A1和A2激动剂产生了相当的降压效果。在给予A1激动剂期间，心率显著降低，但在给予A2激动剂后心率未改变。给予A1激动剂后，双侧肾脏的肾血流量均减少，而给予A2激动剂仅使支配侧肾脏的肾血流量显著减少。输注A1激动剂后，双侧肾脏血浆肾素活性的静脉-动脉差值均降低，但输注A2激动剂后，仅支配侧肾脏的该差值显著增加。
肾神经不影响由A1腺苷受体介导的肾素释放抑制作用。在体内，仅在肾神经完整的情况下，给予A2受体激动剂才能刺激肾素释放。
