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Mechanisms of hydrogen peroxide-induced vasoconstriction in the isolated perfused rat kidney

100%

Moreno J. M., Rodriguez Gomez I., Wangensteen R., Perez-Abud R., Duarte J., Osuna A., Vargas F.

Journal of Physiology and Pharmacology

2010

tom 61

nr 3

325-332

The vasoconstrictor effect of hydrogen peroxide (H2O2) on isolated perfused rat kidney was investigated. H2O2 induced vasoconstriction in the isolated rat kidney in a concentration-dependent manner. The vasoconstrictor effects of H2O2 were completely inhibited by 1200 U/ml catalase. Endothelium-removal potentiated the renal response to H2O2. The H2O2 dose-response curve was not significantly modified by administration of the NO inhibitor L-NAME (10-4 mol/l), whereas it was increased by the non-specific inhibitor of K+-channels, tetraethylammonium (3·10-3 mol/l). Separately, removal of extracellular Ca2+, administration of a mixture of calcium desensitizing agents (nitroprusside, papaverine, and diazoxide), and administration of a protein kinase C (PKC) inhibitor (chelerythrine, 10-5 mol/l) each significantly attenuated the vasoconstrictor response to H2O2, which was virtually suppressed when they were performed together. The pressor response to H2O2 was not affected by: dimethyl sulfoxide (7·10-3 mol/l) plus mannitol (3·10-3 mol/l); intracellular Ca2+ chelation using BAPTA (10-5 mol/l); calcium store depletion after repeated doses of phenylephrine (10-5 g/g kidney); or the presence of indomethacin (10-5 mol/l), ODYA (2·10-6 mol/l) or genistein (10-5 mol/l). We conclude that the vasoconstrictor response to H2O2 in the rat renal vasculature comprises the following components: 1) extracellular calcium influx, 2) activation of PKC, and 3) stimulation of pathways leading to sensitization of contractile elements to calcium. Moreover, a reduced pressor responsiveness to H2O2 in female kidneys was observed.

Effects of deoxycorticosterone on renal vascular reactivity and flow-pressure curve in spontaneously hypertensive rats

100%

Chamorro V., Moreno M. J., Wangensteen R., Sainz J., Rodriguez-Gomez I., Osuna A., Vargas F.

Journal of Physiology and Pharmacology

2004

tom 55

nr 1,1

The role of mineralocorticoids as sodium retaining hormones has been recently enlarged to include their function as modulators of cardiovascular function and injury. This study evaluated the contribution of possible functional changes in resistance vessels to the additional BP increase produced by the chronic administration of DOCA to SHR. The flow-pressure curve and renal responses to vasoconstrictors (phenylephrine [Phe] and angiotensin II [AII]) and vasodilators (acetylcholine [ACh] and nitroprusside [NP]) were characterized in isolated kidneys from Wistar Kyoto (WKY) and SHR treated or untreated with DOCA for nine weeks. DOCA increased BP in SHR but did not modify BP in WKY rats. Kidneys from SHR showed enhanced reactivity to Phe and AII that was not increased by DOCA. DOCA reduced sensitivity to AII in SHR. Responsiveness to ACh was increased in SHR and was not attenuated by DOCA in WKY or SHR. Vasodilator response to NP was not significantly affected by DOCA in WKY or SHR. The flow-pressure curve was markedly up-shifted in SHR when compared with kidneys from WKY rats. DOCA administration did not modify the flow-pressure curve in WKY but produced attenuation at low flow levels in SHR. Our results demonstrate that DOCA increases BP in SHR but does not increase the flow-pressure curve or renal vascular reactivity to vasoconstrictors, and does not reduce responsiveness to endothelium-dependent and independent vasodilators in SHR or WKY rats. Therefore, our data suggest that the BP increase produced by DOCA in SHR is not related to abnormalities in vascular function in resistance vessels.

Cystinyl and pyroglutamyl-beta-naphthylamide hydrolyzing activities are modified coordinately between hypothalamus, liver and plasma depending on the thyroid status of adult male rats

84%

Segarra A. B., Prieto I., Martinez-Canamero M., Vargas F., de Gasparo M., Vanderheyden P., Zorad S., Ramirez-Sanchez M.

Journal of Physiology and Pharmacology

2018

tom 69

nr 2

Ograniczanie wyników

3 Journal of Physiology and Pharmacology

3 Vargas F.

2 Osuna A.

2 Wangensteen R.

1 Chamorro V.

1 Duarte J.

1 Martinez-Canamero M.

1 Moreno J. M.

1 Moreno M. J.

1 Perez-Abud R.

1 Prieto I.

1 Ramirez-Sanchez M.

1 Rodriguez Gomez I.

1 Rodriguez-Gomez I.

1 Sainz J.

1 Segarra A. B.

1 Vanderheyden P.

1 Zorad S.

1 de Gasparo M.

1 2018

1 2010

1 2004

Wyniki wyszukiwania

Mechanisms of hydrogen peroxide-induced vasoconstriction in the isolated perfused rat kidney

Effects of deoxycorticosterone on renal vascular reactivity and flow-pressure curve in spontaneously hypertensive rats

Cystinyl and pyroglutamyl-beta-naphthylamide hydrolyzing activities are modified coordinately between hypothalamus, liver and plasma depending on the thyroid status of adult male rats