The effect of Escherichia coli STa enterotoxin and other secretagogues on mucosal surface pH of rat small intestine in vivo

G T McEwan, H Daniel, C Fett, M N Burgess, M L Lucas

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Abstract

The mucosal surface pH of rat small intestine was measured in vivo. The surface pH in the normal jejunum was 6.20 +/- 0.02 (67) and 7.00 +/- 0.05 (5) in the ileum. Escherichia coli STa toxin induced a rapid and reversible alkalinization of both jejunal and ileal mucosae to a pH of 6.91 +/- 0.08 (10) and 7.67 +/- 0.06 (5) respectively. The synthetic ST analogue, STh-(6-19), had an effect identical to native STa toxin on jejunal surface pH. Theophylline (20 mM) maintained the STa-elevated jejunal surface pH after toxin removal but had no effect on untreated tissue. 8-Bromo cyclic GMP resembled STa by causing similar mucosal alkalinization in the jejunum; 8-bromo cyclic AMP, forskolin and cholera toxin individually had considerably smaller effects on surface pH, although combining forskolin or cholera toxin with theophylline resulted in alkalinization of the jejunal mucosa to a pH of 6.92 +/- 0.03 (5) and 6.76 +/- 0.04 (4). These results indicate that cyclic-GMP-dependent secretory processes are more capable of inducing surface pH changes than those dependent on cyclic AMP. The ability of STa to alter mucosal surface pH makes it a useful tool to investigate the microclimate hypothesis for weak electrolyte absorption.
Original languageEnglish
Pages (from-to)219-37
Number of pages19
JournalProceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)
Volume234
Issue number1275
Publication statusPublished - 22 Jul 1988

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Small Intestine
Escherichia coli
Cholera Toxin
Colforsin
Jejunum
Theophylline
Mucous Membrane
Microclimate
8-Bromo Cyclic Adenosine Monophosphate
heat stable toxin (E coli)
Secretory Pathway
Cyclic GMP
Ileum
Cyclic AMP
Electrolytes

Keywords

  • Animals
  • Bacterial Toxins
  • Cholera Toxin
  • Colforsin
  • Cyclic GMP
  • Enterotoxins
  • Escherichia coli Proteins
  • Hydrogen-Ion Concentration
  • Ileum
  • Intestinal Mucosa
  • Jejunum
  • Kinetics
  • Male
  • Microelectrodes
  • Perfusion
  • Rats
  • Rats, Inbred Strains
  • Reference Values
  • Theophylline

Cite this

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title = "The effect of Escherichia coli STa enterotoxin and other secretagogues on mucosal surface pH of rat small intestine in vivo",
abstract = "The mucosal surface pH of rat small intestine was measured in vivo. The surface pH in the normal jejunum was 6.20 +/- 0.02 (67) and 7.00 +/- 0.05 (5) in the ileum. Escherichia coli STa toxin induced a rapid and reversible alkalinization of both jejunal and ileal mucosae to a pH of 6.91 +/- 0.08 (10) and 7.67 +/- 0.06 (5) respectively. The synthetic ST analogue, STh-(6-19), had an effect identical to native STa toxin on jejunal surface pH. Theophylline (20 mM) maintained the STa-elevated jejunal surface pH after toxin removal but had no effect on untreated tissue. 8-Bromo cyclic GMP resembled STa by causing similar mucosal alkalinization in the jejunum; 8-bromo cyclic AMP, forskolin and cholera toxin individually had considerably smaller effects on surface pH, although combining forskolin or cholera toxin with theophylline resulted in alkalinization of the jejunal mucosa to a pH of 6.92 +/- 0.03 (5) and 6.76 +/- 0.04 (4). These results indicate that cyclic-GMP-dependent secretory processes are more capable of inducing surface pH changes than those dependent on cyclic AMP. The ability of STa to alter mucosal surface pH makes it a useful tool to investigate the microclimate hypothesis for weak electrolyte absorption.",
keywords = "Animals, Bacterial Toxins, Cholera Toxin, Colforsin, Cyclic GMP, Enterotoxins, Escherichia coli Proteins, Hydrogen-Ion Concentration, Ileum, Intestinal Mucosa, Jejunum, Kinetics, Male, Microelectrodes, Perfusion, Rats, Rats, Inbred Strains, Reference Values, Theophylline",
author = "McEwan, {G T} and H Daniel and C Fett and Burgess, {M N} and Lucas, {M L}",
year = "1988",
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journal = "Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)",
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TY - JOUR

T1 - The effect of Escherichia coli STa enterotoxin and other secretagogues on mucosal surface pH of rat small intestine in vivo

AU - McEwan, G T

AU - Daniel, H

AU - Fett, C

AU - Burgess, M N

AU - Lucas, M L

PY - 1988/7/22

Y1 - 1988/7/22

N2 - The mucosal surface pH of rat small intestine was measured in vivo. The surface pH in the normal jejunum was 6.20 +/- 0.02 (67) and 7.00 +/- 0.05 (5) in the ileum. Escherichia coli STa toxin induced a rapid and reversible alkalinization of both jejunal and ileal mucosae to a pH of 6.91 +/- 0.08 (10) and 7.67 +/- 0.06 (5) respectively. The synthetic ST analogue, STh-(6-19), had an effect identical to native STa toxin on jejunal surface pH. Theophylline (20 mM) maintained the STa-elevated jejunal surface pH after toxin removal but had no effect on untreated tissue. 8-Bromo cyclic GMP resembled STa by causing similar mucosal alkalinization in the jejunum; 8-bromo cyclic AMP, forskolin and cholera toxin individually had considerably smaller effects on surface pH, although combining forskolin or cholera toxin with theophylline resulted in alkalinization of the jejunal mucosa to a pH of 6.92 +/- 0.03 (5) and 6.76 +/- 0.04 (4). These results indicate that cyclic-GMP-dependent secretory processes are more capable of inducing surface pH changes than those dependent on cyclic AMP. The ability of STa to alter mucosal surface pH makes it a useful tool to investigate the microclimate hypothesis for weak electrolyte absorption.

AB - The mucosal surface pH of rat small intestine was measured in vivo. The surface pH in the normal jejunum was 6.20 +/- 0.02 (67) and 7.00 +/- 0.05 (5) in the ileum. Escherichia coli STa toxin induced a rapid and reversible alkalinization of both jejunal and ileal mucosae to a pH of 6.91 +/- 0.08 (10) and 7.67 +/- 0.06 (5) respectively. The synthetic ST analogue, STh-(6-19), had an effect identical to native STa toxin on jejunal surface pH. Theophylline (20 mM) maintained the STa-elevated jejunal surface pH after toxin removal but had no effect on untreated tissue. 8-Bromo cyclic GMP resembled STa by causing similar mucosal alkalinization in the jejunum; 8-bromo cyclic AMP, forskolin and cholera toxin individually had considerably smaller effects on surface pH, although combining forskolin or cholera toxin with theophylline resulted in alkalinization of the jejunal mucosa to a pH of 6.92 +/- 0.03 (5) and 6.76 +/- 0.04 (4). These results indicate that cyclic-GMP-dependent secretory processes are more capable of inducing surface pH changes than those dependent on cyclic AMP. The ability of STa to alter mucosal surface pH makes it a useful tool to investigate the microclimate hypothesis for weak electrolyte absorption.

KW - Animals

KW - Bacterial Toxins

KW - Cholera Toxin

KW - Colforsin

KW - Cyclic GMP

KW - Enterotoxins

KW - Escherichia coli Proteins

KW - Hydrogen-Ion Concentration

KW - Ileum

KW - Intestinal Mucosa

KW - Jejunum

KW - Kinetics

KW - Male

KW - Microelectrodes

KW - Perfusion

KW - Rats

KW - Rats, Inbred Strains

KW - Reference Values

KW - Theophylline

M3 - Article

C2 - 2905462

VL - 234

SP - 219

EP - 237

JO - Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)

JF - Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)

SN - 0080-4649

IS - 1275

ER -