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Chloroquine, an Activator of Bitter Taste Receptors, Relaxed Male Guinea Pig Gallbladder Strips
Author(s) -
Kline Loren
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.763.3
Subject(s) - chelerythrine , chemistry , medicine , endocrinology , activator (genetics) , receptor , nifedipine , dantrolene , bisindolylmaleimide , pharmacology , calcium , protein kinase c , biochemistry , enzyme
Taste receptor cells are present in several extra‐oral locations such as the gut, human airway smooth muscle, vascular smooth muscle, and myometrial smooth muscle. A pharmacologic approach was used. The purpose of this study was to determine if the motility of the gallbladder was affected by a bitter tastant such as chloroquine (ChQ). ChQ relaxed both cholecystokinin octapeptide (CCK)‐ and KCl‐induced tension in a concentration dependent manner. There was no significant difference in the amount of ChQ‐induced relaxation of either CCK (1.0 nM) ‐ or KCl (40 mM)‐induced tension at any concentration of ChQ used (50, 100, 150, and 200 mM). In some strips ChQ induced a transient tension (0.4 g lasting 1.4min). To determine if ChQ inhibited extracellular Ca 2+ entry, ChQ was added to the chambers prior to the CCK a significant decrease in the amount of CCK‐induced tension was observed (1.12±0.08 vs. 0.9±0.06 g, n=4, p<0.001). A similar result was observed when KCl was used (1.12±0.1 vs. 0.7±0.1 g, n=4, p<0.001). Penitrem A, a blocker of high conductance Ca 2+ activated K + channels, decreased the amount of ChQ‐induced relaxation (34.5±4.3 vs. 27.0±3.2%, n=3, p<0.02). Bisindolylmaleimide IV (BIM) and chelerythrine Cl − were used together to block PKC. They significantly decreased the amount of ChQ‐induced relaxation (23.8±3.2 vs. 18.9±3.0%, n=3, p<0.03). Neither PKA‐IM, a PKA blocker, nor KT5823, a PKG blocker, had a significant effect on the amount of ChQ‐induced relaxation. ChQ relaxed guinea pig gallbladder strips by blocking extracellular Ca 2+ entry and blocked the actions of PKC. Support or Funding Information This research did not receive any specific grant from funding agencies in the public, commercial, or not‐for‐profit sectors. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .