Gastrointestinal motor inhibition by exogenous human, salmon, and eel calcitonin in conscious dogs.
Effects of synthetic eel (E-), salmon (S-), and human (H-) calcitonin (CT) on gastrointestinal motility were studied in conscious beagle dogs, which had been implanted with strain gauge force transducers. Intramuscular administration of E-, S-, or H-CT interrupted gastric migrating motor complexes, digestive pattern, and gastric emptying. The order of potency was E-CT = S-CT > H-CT. Motor inhibition induced by CT occurred independently of plasma immunoreactive motilin levels or hypocalcemia. In addition, E-CT and S-CT induced vomiting without a retrograde giant contraction (RGC) during the postprandial state. Apomorphine or CuSO4 initiated RGC prior to vomiting. RGC induced by apomorphine was inhibited by pretreatment with E-CT as well as hexamethonium, atropine, or surgical vagotomy. E-CT showed no inhibitory effect on nicotine stimulated contraction of isolated guinea-pig ileum. These results suggest that peripherally administered CT inhibits canine gastrointestinal motility at the central nervous system level by lowering vagal activity.
Nakamura
H
H
Toxicology Research Laboratories, Chugai Pharmaceutical Co. Ltd., Nagano, Japan.
Asano
T
T
Haruta
K
K
Takeda
K
K
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D002116:Calcitonin / Q000494:pharmacology*; D002118:Calcium / Q000097:blood; D004285:Dogs; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D008297:Male; D009037:Motilin / Q000097:blood; D009119:Muscle Contraction / Q000187:drug effects; D010275:Parasympathetic Nervous System / Q000187:drug effects; D013270:Stomach / Q000294:innervation; D009435:Synaptic Transmission / Q000187:drug effects; D014160:Transducers, Pressure; D014628:Vagotomy; D014839:Vomiting / Q000139:chemically induced / Q000503:physiopathology
D000700:Analgesics; D009037:Motilin; C028815:salmon calcitonin; D002116:Calcitonin; D002118:Calcium