Tachykinins potently stimulate human small bowel blood flow: a laser Doppler flowmetry study in humans
| Autor: | Per M. Hellström, Gazelius B, Mikael Lördal, Peter T. Schmidt |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male medicine.medical_specialty Adolescent Manometry medicine.medical_treatment Neurokinin A Substance P Blood Pressure Statistics Nonparametric chemistry.chemical_compound Diastole Internal medicine Intestine Small medicine Laser-Doppler Flowmetry Humans Intestinal Mucosa Infusions Intravenous Pulse Saline Migrating motor complex Skin Myoelectric Complex Migrating Dose-Response Relationship Drug business.industry musculoskeletal neural and ocular physiology Gastroenterology Blood flow Laser Doppler velocimetry respiratory system Small intestine biological factors Stimulation Chemical Blood pressure Endocrinology medicine.anatomical_structure chemistry nervous system Regional Blood Flow Small Intestine Female business circulatory and respiratory physiology |
| Zdroj: | Gut. 52(1) |
| ISSN: | 0017-5749 |
| Popis: | Background: The two tachykinins substance P and neurokinin A are abundantly present in the gastrointestinal tract. Substance P preferring neurokinin 1 receptors are mainly found in submucosal blood vessels while neurokinin A preferring neurokinin 2 receptors seem to be confined to smooth muscle cells. Tachykinin effects on intestinal mucosal blood flow in humans are not known. Aim: To study the effects of substance P and neurokinin A on small bowel mucosal blood flow in humans. Methods: A manometry tube supplied with single fibre microprobes recorded mucosal blood flow in the proximal small bowel using laser Doppler flowmetry, concomitant with luminal manometry, defining phases I, II, and III of the migrating motor complex. Simultaneously, flowmetry of temporal skin was performed. Under fasting conditions saline was infused intravenously over four hours followed by infusion of substance P, neurokinin A, or saline. Results: During phase I, substance 1–6 pmol/kg/min increased mucosal blood flow dose dependently by a maximum of 158%. Blood flow of the temporal skin increased in parallel. Neurokinin A 6–50 pmol/kg/min increased mucosal blood flow maximally by 86% at 25 pmol/kg/min while blood flow of temporal skin increased at all doses. Substance P at all doses and neurokinin A at the highest dose only, increased pulse rate. Systolic blood pressure was unchanged by either peptide while substance P at the highest dose decreased diastolic pressure. Conclusion: Tachykinins increase blood flow of the small bowel and temporal skin. With substance P being more potent than neurokinin A, these effects are probably mediated through neurokinin 1 receptors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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