In-vivo administration of CLC-K kidney chloride channels inhibitors increases water diuresis in rats: a new drug target for hypertension?
J Hypertens
; 30(1): 153-67, 2012 Jan.
Article
in En
| MEDLINE
| ID: mdl-22080226
ABSTRACT
OBJECTIVE:
The human kidney-specific chloride channels ClC-Ka (rodent ClC-K1) and ClC-Kb (rodent ClC-K2) are important determinants of renal function, participating to urine concentration and blood pressure regulation mechanisms. Here we tested the hypothesis that these chloride channels could represent new drug targets for inducing diuretic and antihypertensive effects.METHODS:
To this purpose, the CLC-K blockers benzofuran derivatives MT-189 and RT-93 (10, 50, 100âmg/kg), were acutely administered by gavage in Wistar rats, and pharmacodynamic and pharmacokinetic parameters determined by functional, bioanalytical, biochemical and molecular biology assays.RESULTS:
Plasma concentration values for MT-189 and RT-93 were indicative of good bioavailability. Both MT-189 and RT-93 dose-dependently increased urine volume without affecting electrolyte balance. A comparable reduction of SBP was observed in rats after MT-189, RT-93 or furosemide administration. Benzofuran derivatives treatment did not affect kidney CLC-K mRNA level or inner medulla osmolality, whereas a significant vasopressin-independent down-regulation of aquaporin water channel type 2 was observed at protein and transcriptional levels. In rats treated with benzofuran derivatives, the observed polyuria was mainly water diuresis; this finding indirectly supports a cross-talk between chloride and water transport in nephron. Moreover, preliminary in-vitro evaluation of the drugs capability to cross the blood-inner ear barrier suggests that these compounds have a limited ability to induce potential auditory side effects.CONCLUSION:
CLC-K blockers may represent a new class of drugs for the treatment of conditions associated with expanded extracellular volume, with a hopeful high therapeutic potential for hypertensive patients carrying ClC-K gain-of-function polymorphisms.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chloride Channels
/
Diuresis
/
Hypertension
Limits:
Animals
Language:
En
Journal:
J Hypertens
Year:
2012
Document type:
Article
Affiliation country: