1. Volume 117, Issue 6, Pages 1363-1369 (December 1999)
L-type calcium channels in enterochromaffin cells from guinea pig and human duodenal crypts: An in situ study 
Richard B. Lomax, Sonia Gallego, Jesús Novalbos, Antonio G. García, Geoffrey Warhurst 
Gastroenterology 
Volume 117, Issue 6, Pages (December 1999)
DOI: /S (99)
Copyright © 1999 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Photomicrographs of guinea pig crypt preparation obtained using collagenase/dispase (A) before and (B) after filtering through 200-μm steel mesh to enrich for crypts. Bar = 30 μm.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

3. Fig. 2
[Ca2+] calibration in an EC cell loaded with fluo-3 showing changes in fluorescence (arbitrary units) with time. Effect of the application of high K+ and of 10 μmol/L ionomycin in Ca2+-free solution (containing 10 mmol/L EGTA) and in the presence of Ca2+ (10 mmol/L)-containing solution.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

4. Fig. 3
Photomicrographs of the base of 2 guinea pig duodenal crypts showing visualization of an intracellular Ca2+ response to high K+ and FPL in a single EC cell. (A–C) Fluorescence of the Ca2+-sensitive dye fluo-3 represented as pseudocolored images, with changes from blue to red indicative of increases in [Ca2+]i. Fluo-3 fluorescence is shown in (A) control buffer and (B) the presence of high K+ and FPL (3 μmol/L), showing the response of the EC cell (arrow) on (C) washout of K+ and FPL (D) Phase-contrast image of the 2 crypts and (E and F) immunolocalization of the EC cell marker 5-HT and the enteroendocrine cell marker chromogranin A, respectively.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

5. Fig. 4
Effect of high K+, FPL 64176, and noradrenaline on [Ca2+]i in a guinea pig duodenal crypt EC cell in situ. To stimulate voltage-gated Ca2+ influx, a high K+ (70 mmol/L) solution (K+) was applied for 1 minute, as shown by the top bars. High K+ depolarization evoked a reversible and reproducible increase in [Ca2+]i. The Ca2+ agonist FPL (FPL, 3 μmol/L) had no effect in control medium but markedly potentiated the response to high K+. Noradrenaline (NA, 50 μmol/L) was applied in control buffer and evoked a large, oscillatory increase in [Ca2+]i.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

6. Fig. 5
Effects of noradrenaline (NA), high K+ (K+), and FPL (FPL) on [Ca2+]i in human duodenal crypt cells. Noradrenaline (50 μmol/L), high K+ (70 mmol/L), and FPL (3 μmol/L) evoked increases in [Ca2+]i in an EC cell (top trace) but not in a nonexcitable crypt cell (bottom trace).
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions

7. Fig. 6
Secretion of 5-HT from suspensions of guinea pig duodenal crypts. The amount of 5-HT released into the medium over 15 minutes at 37°C was measured in control buffer or buffer containing 35 mmol/L K+ (K+), 35 mmol/L K+ with FPL (K+/FPL; 3 μmol/L), or noradrenaline (NA; 50 μmol/L). Data are expressed as percentage of the total crypt content of 5-HT and are shown as mean ± SEM for 4–6 observations in each group. *P < 0.05, **P < 0.02 compared with control.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions