RESUMO
Vasoactive intestinal polypeptide (VIP) is one of the main neurotransmitters implicated in the relaxation of the lower esophageal sphincter (LES). The effect of exogenous VIP on LES motor activity was determined by esophageal manometry. LES pressure (LESP) and LES relaxation were compared in four healthy volunteers and in six patients with achalasia. The effects of intravenous doses of 1.5, 3, and 5 pmol.kg-1.min-1 of VIP were compared with placebo. Neither placebo nor 3 and 5 pmol.kg-1.min-1 of VIP produced any effect on esophageal motility in healthy volunteers. In achalasia the three doses of VIP caused a dose-dependent decrease in LESP with a significant improvement in LES relaxation. A dose of 5 pmol.kg-1.min-1 produced a maximal decrease of 51% in LESP. A beta-adrenergic agonist, isoproterenol, caused a decrease in LESP both in healthy volunteers and in patients with achalasia without improving LES relaxation. In summary, intravenous VIP improved LES relaxation and caused a decrease in LESP in patients with achalasia without affecting LESP in healthy volunteers, indicating that the LES muscle in achalasia is supersensitive to VIP. The current study suggests that a selective damage in the noncholinergic nonadrenergic innervation of the esophagus is in part responsible for the motor alteration seen in these patients. The findings and the inability of isoproterenol to improve LES relaxation despite decreasing LESP support a role in VIP as a indicator of LES relaxation.
Assuntos
Acalasia Esofágica/fisiopatologia , Junção Esofagogástrica/efeitos dos fármacos , Peptídeo Intestinal Vasoativo/farmacologia , Adolescente , Adulto , Junção Esofagogástrica/fisiopatologia , Feminino , Humanos , Isoproterenol/farmacologia , Masculino , Pessoa de Meia-Idade , Relaxamento Muscular , Pressão , Peptídeo Intestinal Vasoativo/efeitos adversos , Peptídeo Intestinal Vasoativo/sangueRESUMO
The effect of local instillation of alcohol on sphincter of Oddi motor activity was determined by endoscopic manometry. Sphincter of Oddi pressures and motor function were compared in eight cholecystectomized subjects with normal sphincter of Oddi motor function and in four patients with chronic alcoholic pancreatitis. The effect of local instillation of 3 ml of 40% alcohol was compared with water instillation. In cholecystectomized subjects, alcohol produced a significant increase of basal sphincter of Oddi pressure from 21.0 +/- 2.8 mm Hg to 95.8 +/- 83 mm Hg (p less than 0.01) without significant changes in the amplitude, duration, and frequency of phasic contractions. In patients with alcoholic chronic pancreatitis, alcohol instillation resulted in a significant increase of basal sphincter of Oddi pressure from 32.5 +/- 4.8 mm Hg to 225.1 +/- 105 mm Hg without changes in amplitude, duration, and frequency of phasic contractions. Two patients with chronic alcoholic pancreatitis had a tonic contraction of the sphincter of Oddi with transitory and mild epigastric pain. Local instillation of alcohol increases sphincter of Oddi motor activity which may play a role in the pathogenesis of alcoholic pancreatitis.
Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Etanol/farmacologia , Manometria , Esfíncter da Ampola Hepatopancreática/fisiologia , Adulto , Alcoolismo/complicações , Colecistectomia , Doença Crônica , Etanol/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/efeitos dos fármacos , Pancreatite/etiologia , Pancreatite/fisiopatologia , Pressão , Esfíncter da Ampola Hepatopancreática/efeitos dos fármacos , Esfíncter da Ampola Hepatopancreática/fisiopatologiaRESUMO
In this study we describe in detail the characteristics of sphincter of Oddi motor function in a large group of healthy subjects. Studies were obtained in 50 healthy volunteers. The findings showed a sphincter of Oddi segment that had a basal pressure of 14.8 +/- 6.3 mm Hg (X +/- SD). Phasic contractions were superimposed on the basal pressure. They had an amplitude of 119.7 +/- 32 mm Hg, a duration of 4.7 +/- 1 sec, and a frequency of 5.7 +/- 1.2 contractions/min. In 40 subjects the propagation sequence of phasic contractions could be evaluated and were simultaneous in 53%, antegrade in 35%, and retrograde in 11% of the waves. In 20 subjects, pressure measurements done at the common bile duct sphincter waves. In 20 subjects, pressure measurements done at the common bile duct sphincter were similar to those obtained at the pancreatic duct sphincter. In 10 subjects, pressure values obtained at the common bile duct sphincter within a week were similar. Our study should help to establish standards for normal manometric values of the sphincter of Oddi and emphasizes the importance of having a healthy volunteer group from which to obtain the normal values of sphincter of Oddi motor function.
Assuntos
Ampola Hepatopancreática/fisiologia , Esfíncter da Ampola Hepatopancreática/fisiologia , Adulto , Colangiopancreatografia Retrógrada Endoscópica , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Peristaltismo , Pressão , Valores de ReferênciaRESUMO
The effect of nifedipine on sphincter of Oddi (SO) motor activity was determined by endoscopic manometry. Sphincter of Oddi pressures and motor function were compared in 21 healthy volunteers and in 9 patients with SO dyskinesia. The effects of sublingual doses of 10 or 20 mg of nifedipine were compared with placebo. Neither placebo nor 10 mg of nifedipine produced any effect on SO motor activity. In healthy volunteers 20 mg of nifedipine produced a moderate but significant decrease in basal SO pressure from 12.0 to 6.7 mmHg as well as in the amplitude, duration, and frequency of phasic contractions. In patients with SO dyskinesia 20 mg of nifedipine also resulted in a significant but more profound decrease of the basal SO pressure from 47.1 to 17.3 mmHg as well as in a decrease of amplitude, duration, and frequency of the phasic contractions. Neither placebo nor 10 or 20 mg of nifedipine has any effect on the sequence of phasic contractions. In summary, nifedipine may have a possible therapeutic role in the treatment of SO dyskinesia.