A cyclic GMP‐dependent housekeeping Cl⁻ channel in rabbit gastric parietal cells activated by a vasodilator ecabapide

Abstract

1 The membrane potential of rabbit gastric parietal cells is dominated by a Cl-channel with a subpicosiemens single channel conductance in the basolateral membrane. The effects of 3- [[[2-(3,4-dimethoxyphenyl)

Is Rabbit CLCA1 Related to the Basolateral Ca2+-Dependent Cl- Channel of Gastric Parietal Cells?

“…We first recorded whole-cell Cl Ϫ currents of rabbit parietal cells continuously at a holding potential of 0 mV, the zero-current potential for K ϩ and nonselective cation channels [7]. The whole-cell Cl Ϫ current was previously confirmed to be generated by an opening of the basolateral housekeeping Cl Ϫ channel (0.3 pS) activated via Ca 2ϩ /NO/cGMP pathway [1].…”

“…In whole-cell voltage-clamp experiments of rabbit parietal cells, A23187 ( tion of an overdose of urethane (Ͼ2 g/kg), and the trachea, lung, heart, kidney, pancreas, stomach, and colon were obtained. Isolated gastric glands and the parietal cell-rich suspension (88 to 89% of parietal cells) were prepared from the stomach as previously described [7,8].…”

“…Whole-cell currents were recorded from rabbit parietal cells in isolated gastric glands by using an EPC-7 patch-clamp system (List Electronic, Darmstadt, Germany) as previously described [7]. The extracellular bathing solution contained (in mM) 133 KCl, 7 NaCl, 1 sodium aspartate, 1 MgCl 2 , 1 CaSO 4 , 0.1 ouabain, and 10 HEPES (pH 7.3).…”

Pharmacology of the Gastric Pro-kinetic Drug Ecabapide (DQ-2511)

“…Intracellular electrophysiological recording methods were used to investigate the effects of ecabapide on electrical and Reproduced with permission from Sakai et al (1996). synaptic behaviour of neurons in the enteric nervous system of the guinea-pig small intestine (Wood 1993(Wood , 1994a.…”

Possible Mechanisms Underlying the Suppression of Gastric Vagal Afferents Due to Ecabapide (DQ-2511), a Gastroprokinetic Agent, in Rats.

“…On the ba sis of the above studies, ecabapide was considered to exert its action via suppression of activation of afferents in the sensory component of gastric inhibitory vago-vagal reflex pathways (3,4). More recently, ecabapide was reported to stimulate the intracellular production of guanosine 3",5' cyclic monophosphate (cGMP) content (5,6) at a con centration as low as 10-' M when rabbit gastric parietal cells were used (7). To date, stimulation of guanylate cy clase and accumulation of intracellular cGMP have been proposed to induce smooth muscle relaxation related to nitric oxide (NO), which plays a pivotal role as a key mediator in these events (8,9).…”