Vasoactive intestinal peptide as a neural mediator of gastric relaxation
| Autor: | John R. Grider, S.I. Said, Gabriel M. Makhlouf, M. B. Cable |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
medicine.medical_specialty
Physiology Muscle Relaxation Vasoactive intestinal peptide Guinea Pigs Stimulation Antigen-Antibody Complex Peptide hormone Biology In Vitro Techniques Inhibitory postsynaptic potential chemistry.chemical_compound Adenosine deaminase Adenosine Triphosphate Physiology (medical) Internal medicine medicine Animals Neurotransmitter Hepatology Immune Sera Purinergic receptor Stomach Gastroenterology Affinity Labels Muscle Smooth Adenosine Electric Stimulation Kinetics Endocrinology chemistry Biophysics biology.protein hormones hormone substitutes and hormone antagonists medicine.drug Muscle Contraction Vasoactive Intestinal Peptide |
| Zdroj: | The American journal of physiology. 248(1 Pt 1) |
| ISSN: | 0002-9513 |
| Popis: | Two main candidates, adenosine 5'-triphosphate (ATP) and vasoactive intestinal peptide (VIP), have been proposed as inhibitory transmitters at neuromuscular junctions in the gut. We have used a photoaffinity analogue of ATP, 3'-O-(4-benzoyl)benzoyl ATP or BzATP, that binds covalently to ATP receptors and inactivates them in the presence of light and a specific high-affinity VIP antiserum in order to examine the contributions of ATP and VIP to neurally induced relaxation in circular smooth muscle of the gastric fundus of the guinea pig. VIP and ATP caused dose-dependent relaxation; the effect of ATP was equal to that of its stable isostere, alpha, beta-methylene ATP, and was resistant to degradation by adenosine deaminase, indicating interaction of ATP with purinergic P2-receptors. Relaxation induced by VIP was selectively inhibited by VIP antiserum (final dilution 1:120), while that induced by ATP was selectively inhibited by photoactivated BzATP. Relaxation induced by electrical field (i.e., neural) stimulation was inhibited by VIP antiserum only; photoactivated BzATP had no effect. Inhibition of neurally induced relaxation ranged from 86% (P less than 0.01) at the lowest frequencies to 34% (P less than 0.01) at the highest frequencies. Maximal field stimulation caused an 11-fold increase in VIP release from intramural neurons. The results strongly favor VIP as the neural mediator of gastric relaxation. |
| Databáze: | OpenAIRE |
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