Volume 116, Issue 4, Pages 884-892 (April 1999) Inflammatory modulation of calcium-activated potassium channels in canine colonic circular smooth muscle cells  Gang Lu, Bruno Mazet, Chengwen Sun, Xiaohua Qian, Christoper P. Johnson, Mark B. Adams, Richard J. Roman, Sushil K. Sarna  Gastroenterology  Volume 116, Issue 4, Pages 884-892 (April 1999) DOI: 10.1016/S0016-5085(99)70071-5 Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 1 KCa currents in the cell-attached patch configuration in colonic circular muscle cells from (A) normal and (B) inflamed colon. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 2 (A) The NPo of BK channels increased with membrane potential in both normal (○; n = 8) and inflamed (●; n = 7) colon cells in the cell-attached patch configuration. The NPo in inflamed colon cells was less than that in normal cells at all membrane potentials. *P < 0.05 vs. normal colon. (B) The NPo of BK channels also increased voltage dependently in both normal (○; n = 8) and inflamed (●; n = 7) colon cells in the excised inside-out patch configuration. In this configuration, the NPo in cells from inflamed colon also was significantly less than that in cells from normal colon at all positive membrane potentials. *P < 0.05 vs. normal colon. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 3 KCa currents in canine colonic circular smooth muscle cells in the inside-out patch configuration in (A) normal and (B) inflamed colon cells. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 4 Normalized product parameter (NPo/NPomax) plotted as a function of membrane potential. NPomax is the value of NPo at +40 mV in normal and inflamed colon cells. Normalized NPo was 1 for both normal and inflamed tissues at +40 mV (⊚). The solid line represents the Boltzmann function fit to data from normal colon cells (n = 4), and the broken line represents the fit to data from inflamed colon cells (n = 4). Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 5 (A) Single-channel KCa currents in a normal colon cell. (B) All-points histogram of the tracing in A. (C) Single-channel KCa currents in an inflamed colon cell. (D) All-points histogram of the tracing in C. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 5 (A) Single-channel KCa currents in a normal colon cell. (B) All-points histogram of the tracing in A. (C) Single-channel KCa currents in an inflamed colon cell. (D) All-points histogram of the tracing in C. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 6 The mean maximum number of simultaneous channel openings in inflamed colon cells was significantly less than that in normal colon cells at membrane potential +40 mV. However, when the membrane potential was increased to +80 mV in inflamed colon cells, the mean maximum number of channel openings in cells from inflamed colon was not different than that in cells from the normal colon at +40 mV. *P < 0.05 vs. normal colon. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 7 The NPo increased significantly at all membrane potentials when the patch was excised into the inside-out configuration in (A) normal and (B) inflamed colon cells. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions

Fig. 8 NPo vs. membrane voltage at free Ca2+ concentrations of 0.1, 1.0, and 10.0 μmol/L in (A) normal and (B) inflamed colon cells. Gastroenterology 1999 116, 884-892DOI: (10.1016/S0016-5085(99)70071-5) Copyright © 1999 American Gastroenterological Association Terms and Conditions