Intraluminal capsaicin does not affect fluid and electrolyte absorption in the human jejunum but does cause pain.
BACKGROUND
Stimulation of sensory nerves with capsaicin regulates ion transport in the small intestine in animal experiments.


OBJECTIVE
To investigate whether sensory nerves that are stimulated by capsaicin administration influence fluid and electrolyte absorption in the human jejunum in vivo.


METHODS
Intestinal perfusion studies were performed in 12 healthy subjects using a four lumen tube with a proximal occlusion balloon and a plasma-like electrolyte solution. After an initial control period, 5 (n = 3), 10 (n = 8), or 50 (n = 1) micrograms/ml capsaicin was added to the perfusate, and this was followed by a final control period. Rates of absorption of water, sodium, potassium, chloride, and bicarbonate were determined in a 30 cm segment of jejunum using a non-absorbable volume marker.


RESULTS
At all three concentrations of capsaicin there were no significant changes in water and electrolyte absorption as compared with control periods. Two subjects who received 10 micrograms/ml and the subject receiving 50 micrograms/ml experienced crampy abdominal pain.


CONCLUSIONS
The results do not support the hypothesis that capsaicin sensitive afferent nerves are involved in the physiological regulation of net absorption or secretion across the human jejunal mucosa. Chemical stimulation of these nerves, however, gives rise to abdominal pain.
Hammer
J
J
Department of Internal Medicine, University of Graz, Austria.
Hammer
H F
HF
Eherer
A J
AJ
Petritsch
W
W
Holzer
P
P
Krejs
G J
GJ
D000328:Adult; D002211:Capsaicin / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004573:Electrolytes / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007583:Jejunum / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects*; D010146:Pain / Q000139:chemically induced; D014867:Water / Q000378:metabolism
D004573:Electrolytes; D014867:Water; D002211:Capsaicin