No apparent role for T-type Ca2+ channels in renal autoregulation
| Autor: | Thomas Hartig Braunstein, Lars Juhl Jensen, Max Salomonsson, Rasmus Hassing Frandsen, Pernille B. Lærkegaard Hansen, Charlotte Mehlin Sorensen, Niels-Henrik Holstein-Rathlou |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Mibefradil medicine.medical_specialty Kidney Renal circulation Voltage-dependent calcium channel Physiology business.industry Calcium channel Clinical Biochemistry 030204 cardiovascular system & hematology 03 medical and health sciences 030104 developmental biology 0302 clinical medicine medicine.anatomical_structure Endocrinology Nifedipine Physiology (medical) Internal medicine Renal blood flow medicine Autoregulation business medicine.drug |
| Zdroj: | Pflügers Archiv - European Journal of Physiology. 468:541-550 |
| ISSN: | 1432-2013 0031-6768 |
| Popis: | Renal autoregulation protects glomerular capillaries against increases in renal perfusion pressure (RPP). In the mesentery, both L- and T-type calcium channels are involved in autoregulation. L-type calcium channels participate in renal autoregulation, but the role of T-type channels is not fully elucidated due to lack of selective pharmacological inhibitors. The role of T- and L-type calcium channels in the response to acute increases in RPP in T-type channel knockout mice (CaV3.1) and normo- and hypertensive rats was examined. Changes in afferent arteriolar diameter in the kidneys from wild-type and CaV3.1 knockout mice were assessed. Autoregulation of renal blood flow was examined during acute increases in RPP in normo- and hypertensive rats under pharmacological blockade of T- and L-type calcium channels using mibefradil (0.1 μM) and nifedipine (1 μM). In contrast to the results from previous pharmacological studies, genetic deletion of T-type channels CaV3.1 did not affect renal autoregulation. Pharmacological blockade of T-type channels using concentrations of mibefradil which specifically blocks T-type channels also had no effect in wild-type or knockout mice. Blockade of L-type channels significantly attenuated renal autoregulation in both strains. These findings are supported by in vivo studies where blockade of T-type channels had no effect on changes in the renal vascular resistance after acute increases in RPP in normo- and hypertensive rats. These findings show that genetic deletion of T-type channels CaV3.1 or treatment with low concentrations of mibefradil does not affect renal autoregulation. Thus, T-type calcium channels are not involved in renal autoregulation in response to acute increases in RPP. |
| Databáze: | OpenAIRE |
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