Ca2+ channel blockade inhibits gallbladder ion transport
| Autor: | Mohammad Z. Abedin, Saunders Kd, Robert Kleinman, Joe A. Cates, Joel J. Roslyn |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty Epithelium Theophylline Internal medicine medicine Animals Ion transporter Transepithelial potential difference Ussing chamber Chemistry Gallbladder Electric Conductivity Sciuridae Biological Transport Anatomy Calcium Channel Blockers Blockade Electrophysiology Microscopy Electron Endocrinology medicine.anatomical_structure Verapamil Surgery Calcium Channels Intracellular medicine.drug |
| Zdroj: | Journal of Surgical Research. 49:306-310 |
| ISSN: | 0022-4804 |
| DOI: | 10.1016/0022-4804(90)90026-x |
| Popis: | Recent studies suggest that cholesterol gallstone (GS) formation is characterized by altered gallbladder epithelial ion transport and increased gallbladder (GB) luminal Ca2+. Moreover, intracellular Ca2+ has been reported to be an important modulator of intestinal ion transport. The aim of the present study was to determine the effects of Ca2+ channel inhibition on GB ion transport. Prairie dog GBs were mounted in a Ussing chamber and bathed in warm oxygenated Ringer's solution, and short-circuit current (Isc), transepithelial potential difference (Vms), and tissue resistance (Rt) were recorded. Following stabilization, the mucosal surfaces of the GBs were exposed to 1 or 0.1 mM verapamil (VER). Effects on Isc were apparent within 10 sec with nadir values reached in 5 +/- 1 min. Profound (76%) inhibition of Isc was seen with 1 mM verapamil exposure (26 +/- 6 microA.cm-2) as compared to baseline values (170 +/- 6 microA.cm-2) (P less than 0.001). Verapamil exposure (1 mM) also led to a marked inhibition of Vms (P less than 0.001, vs baseline) and a significant increase in Rt (P less than 0.05 vs baseline). Similar trends were seen using 0.1 mM verapamil (Isc nadir 133 +/- 13 microA.cm-2). Verapamil-induced effects on gallbladder electrophysiology were largely reversible (75-90% recovery of baseline Isc after tissue washing). These data suggest that (1) verapamil induces rapid but reversible inhibition of ion transport and (2) Ca2+ channel blockade inhibits ion transport in a dose-dependent fashion. We would propose that intracellular Ca2+ may be a regulator of GB ion transport. |
| Databáze: | OpenAIRE |
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