TY - JOUR
T1 - Hyperventilation alters colonic motor and sensory function
T2 - Effects and mechanisms in humans
AU - Bharucha, A. E.
AU - Camilleri, M.
AU - Ford, M. J.
AU - O'Connor, M. K.
AU - Hanson, R. B.
AU - Thomforde, G. M.
PY - 1996
Y1 - 1996
N2 - Background and Aims: Hyperventilation-induced hypocapnia affects hemodynamic function and enhances colonic motility. The aims of this study were to determine the effects of hypocapnic hyperventilation on colonic motility and sensation in health and to explore the putative neurohumoral mechanisms. Methods: In experiment 1, colonic tone, sensation, plasma levels of cortisol, β-endorphin, selected gut neuropeptides, norepinephrine, epinephrine, and splanchnic blood volume were measured during two sequences of hypocapnic hyperventilation. In experiment 2, colonic tone and sensation were assessed during eucapnic hyperventilation and abdominal compression. Results: Hypocapnic hyperventilation, but not eucapnic hyperventilation or abdominal compression, significantly increased colonic tone and sensitivity to balloon distention (P = 0.017) without altering humoral mediators or splanchnic blood volume. Plasma norepinephrine level increased (P = 0.017) and splanchnic blood volume decreased (P = 0.028) during 5 minutes after hyperventilation, consistent with homeostatic responses. Conclusions: Increased colonic tone and sensation during hypocapnic hyperventilation are not caused by colonic compression. These effects of hyperventilation are not mediated humorally but may result from direct metabolic effects of hypocapnia on colonic muscle or from changes in central autonomic control of colonic smooth muscle.
AB - Background and Aims: Hyperventilation-induced hypocapnia affects hemodynamic function and enhances colonic motility. The aims of this study were to determine the effects of hypocapnic hyperventilation on colonic motility and sensation in health and to explore the putative neurohumoral mechanisms. Methods: In experiment 1, colonic tone, sensation, plasma levels of cortisol, β-endorphin, selected gut neuropeptides, norepinephrine, epinephrine, and splanchnic blood volume were measured during two sequences of hypocapnic hyperventilation. In experiment 2, colonic tone and sensation were assessed during eucapnic hyperventilation and abdominal compression. Results: Hypocapnic hyperventilation, but not eucapnic hyperventilation or abdominal compression, significantly increased colonic tone and sensitivity to balloon distention (P = 0.017) without altering humoral mediators or splanchnic blood volume. Plasma norepinephrine level increased (P = 0.017) and splanchnic blood volume decreased (P = 0.028) during 5 minutes after hyperventilation, consistent with homeostatic responses. Conclusions: Increased colonic tone and sensation during hypocapnic hyperventilation are not caused by colonic compression. These effects of hyperventilation are not mediated humorally but may result from direct metabolic effects of hypocapnia on colonic muscle or from changes in central autonomic control of colonic smooth muscle.
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U2 - 10.1053/gast.1996.v111.pm8690201
DO - 10.1053/gast.1996.v111.pm8690201
M3 - Article
C2 - 8690201
AN - SCOPUS:0030017455
SN - 0016-5085
VL - 111
SP - 368
EP - 377
JO - Gastroenterology
JF - Gastroenterology
IS - 2
ER -