Effect of vincristine on gastric motility in conscious rats.
We investigated the possible involvement of the upper alimentary tract in vincristine (VCR)-induced dysmotility. Gastric contractions were recorded by a strain-gauge force transducer in conscious rats. Rats were injected with various doses of VCR followed by continuous recording for 12 hr. Additionally, 3-hr recordings to study the later effects were performed one and three days after injection. Gastric motility was dose-dependently increased by VCR. Post- versus preinjection motility index (MI; area under contraction waves) ratios were 0.78+/-0.12 for saline and 1.95+/-0.21 for VCR at 0.75 mg/kg. This increase in MI was completely inhibited by atropine and hexamethonium. MI one day after injection of VCR (0.75 mg/kg) was significantly less than in control (0.32+/-0.10 vs 0.92+/-0.24, respectively). The decrease was reversed by acetylcholine. In conclusion, VCR first increased gastric motility, and this was followed by a gradual decrease in conscious rats. These alterations may involve a presynaptic cholinergic pathway.
Kaneko
H
H
Department of Pediatrics, Gunma University School of Medicine, Maebashi, Japan.
Tomomasa
T
T
Watanabe
T
T
Takahashi
A
A
Tabata
M
M
Hussein
S
S
Morikawa
A
A
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects*; D018738:Hexamethonium / Q000494:pharmacology; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D014750:Vincristine / Q000494:pharmacology*
D000972:Antineoplastic Agents, Phytogenic; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D018738:Hexamethonium; D014750:Vincristine; D001285:Atropine; D000109:Acetylcholine