NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Experimental Biology (IJEB) >
IJEB Vol.45 [2007] >
IJEB Vol.45(02) [February 2007] >

Title: Effect of KATP channel openers on myogenic and neurogenic responses in goat urinary bladder
Authors: Vijayakumar, C
Kathirvel, K
Sardar, K K
Parija, S C
Keywords: Electrical field stimulation
Goat urinary bladder
KATP channels openers
Issue Date: Feb-2007
Publisher: CSIR
Abstract: Isolated goat detrusor muscle exhibited spontaneous contractility with an irregular amplitude and frequency. The spontaneity of detrusor muscle exhibited a mean amplitude as 11.99 ± 0.83 mm and frequency as 1.37 ± 0.16/min. KATP-channel openers namely, cromakalim or pinacidil (10-7-10-4 M) added cumulatively, elicited a concentration-related inhibition of both amplitude and rate of spontaneous contractions. The mean IC50 values for both amplitude and frequency for cromakalim were 3.3 × 10-6 M and 2.9 × 10-6 M, respectively; and for pinacidil were 2.0 × 10-5 M and 1.5 × 10-5 M, respectively. Glibenclamide, a KATP-channel blocker inhibited the cromakalim-induced concentration-related relaxation of spontaneous contractions with a significant increase in its mean IC50. ACh -induced concentration-related contractile response was inhibited in the presence of either cromakalim (10-4 M) or pinacidil (10-4 M). The mean EC50 value of ACh, in the presence of cromakalim (2.5 × 10-3 M) was significantly increased as compared to the control (1.2 × 10-6 M). In the presence of glibenclamide (10-5 M) the inhibitory effect of cromakalim was significantly reduced with consequent decrease in the EC50 value (1.9 × 10-5 M). Application of EFS (30 V and 5 ms) on goat urinary bladder strips at 1, 2, 5, 10, 20 and 30 Hz elicited frequency-related contractile responses. Both cromakalim and pinacidil caused a rightward shift in the frequency-related contractile response curve with significant increase in the mean EF25 and EF50 values, respectively. In the presence of glibenclamide (10-4M), the frequency-related inhibitory response curve was shifted to left with significant (P <0.001) increase in the mean EF25, EF50 and EF75. The present results suggest that in the goat detrusor muscle, agonist and EFS-induced contractile responses were more potently inhibited by cromakalim than pinacidil with activation of glibenclamide sensitive KATP channels.
Page(s): 185-193
ISSN: 0975-1009 (Online); 0019-5189 (Print)
Source:IJEB Vol.45(02) [February 2007]

Files in This Item:

File Description SizeFormat
IJEB 45(2) 185-193.pdf246.86 kBAdobe PDFView/Open
 Current Page Visits: 28 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 163641 since 01-Sep-2015  Last updated on 21-Jun-2016Webmaster: