THE PARTICIPATION OF THE NITRERGIC PATHWAY IN INCREASED RATE OF TRANSITORY RELAXATION OF LOWER ESOPHAGEAL SPHINCTER INDUCED BY RECTAL DISTENSION IN DOGS

Context The rectal distension in dogs increases the rate of transitory lower esophageal sphincter relaxation considered the main factor causing gastroesophageal reflux. Objectives The aim of this study was evaluate the participation of the nitrergic pathway in the increased transitory lower esophageal sphincter relaxation rate induced by rectal distension in anesthetized dogs. Methods Male mongrel dogs (n = 21), weighing 10-15 kg, were fasted for 12 hours, with water ad libitum. Thereafter, they were anesthetized (ketamine 10 mg.Kg-1 + xylazine 20 mg.Kg-1), so as to carry out the esophageal motility evaluation protocol during 120 min. After a 30-minute basal period, the animals were randomly intravenous treated whith: saline solution 0.15M (1ml.Kg-1), L-NAME (3 mg.Kg-1), L-NAME (3 mg.Kg-1) + L-Arginine (200 mg.Kg-1), glibenclamide (1 mg.Kg-1) or methylene blue (3 mg.Kg-1). Forty-five min after these pre-treatments, the rectum was distended (rectal distension, 5 mL.Kg-1) or not (control) with a latex balloon, with changes in the esophageal motility recorded over 45 min. Data were analyzed using ANOVA followed by Student Newman-Keuls test. Results In comparison to the respective control group, rectal distension induces an increase in transitory lower esophageal sphincter relaxation. Pre-treatment with L-NAME or methylene blue prevents (P<0.05) this phenomenon, which is reversible by L-Arginine plus L-NAME. However, pretreating with glibenclamide failed to abolish this process. Conclusions Therefore, these experiments suggested, that rectal distension increases transitory lower esophageal sphincter relaxation in dogs via through nitrergic pathways

1.8 cineole decreases gastric compliance in anesthetized rats 1.8 cineol diminui a complacência gástrica de ratos anestesiados

PURPOSE: To study the effect of 1,8 cineoleee components of the essencial oil of Croton nepetaefolius - plant of North-East of Brasil, used in the popular medicine for riots of the gastrointestinal tract - on the motor behavior of the gut of Wistar rats. METHODS: Used 16 male animals under jejun of 24h weighing 300-350g. The effect of 1.8 cineoleee (1 or 3mg/Kg) on gastric compliance had been lead in anaesthetized rats. The variations of the gastric volume (GV), had been measured by plethysmography, while AP, HR and CVP had been monitored continuously by a digital system of data acquisition. RESULTS: Observe reduction of the GV, which was significant on 30, 40, 50 and 60min after treatment (2.0&plusmn;0.1; 1.9&plusmn;0.1; 1.8&plusmn;0.1 and 1.7&plusmn;0.1mL, versus 2.1&plusmn;0.2mL). The AP presented significant fall after the administration of 1.8 cineoleee, remaining thus during 60min of monitorization (87.9&plusmn;7.7; 87.6&plusmn;7.1; 87.9&plusmn;6.4; 87.8&plusmn;5.7; 86.0&plusmn;5.5 and 87.7&plusmn;6.0mmHg, respectively versus 94.4&plusmn;6.2 mmHg), as well as the HR (366.3&plusmn;13.4; 361.7&plusmn;11.5; 357.3&plusmn;10.4; 353.0&plusmn;10.4; 348.3&plusmn;11.1 and 350.4&plusmn;13.7bpm, respectively versus 395.2&plusmn;11.1bpm). The CVP did not suffer significant variations after treatment. CONCLUSION: Observe the 1.8 cineoleee reduces the gastric compliance in anaesthetized rats besides presenting effect hipotensor and bradicardic; probably for direct action on the gastrointestinal and vascular smooth muscel and moduling the autonomic nervous system.<br>OBJETIVO: Estudar o efeito do 1.8 cineol, componente do Cróton nepetaefolius (planta do Nordeste) comumente usada na medicina popular para distúrbios do trato gastrintestinal (TGI), sobre o comportamento motor do TGI de ratos Wistar anestesiados. MÉTODOS: Utilizamos 16 animais machos, pesando entre 300 a 350g. Os estudos de complacência gástrica foram conduzidos em animais sob jejum de 24h. As variações do volume gástrico (VG), foram medidas por pletismografia, enquanto a PA, FC e PVC foram monitoradas continuamente por um sistema digital de aquisição de dados. RESULTADOS: Observamos diminuição do VG, o qual foi significativo aos 30, 40, 50 e 60min após o tratamento com 1.8 cineol quando comparado ao perído basal (2,0&plusmn;0,1; 1,9&plusmn;0,1; 1,8&plusmn;0,1 e 1,7&plusmn;0,1mL, vs 2,1&plusmn;0,2mL). A PA apresentou queda significativa após a administração de 1.8 cineol, mantendo-se assim durante os 60min de monitoração (87,9&plusmn;7,7; 87,6&plusmn;7,1; 87,9&plusmn;6,4; 87,8&plusmn;5,7; 86,0&plusmn;5,5 e 87,7&plusmn;6,0mmHg, respectivamente vs 94,4&plusmn;6,2; mmHg), bem como a FC (366,3&plusmn;13,4; 361,7&plusmn;11,5; 357,3&plusmn;10,4; 353,0&plusmn;10,4; 348,3&plusmn;11,1 e 350,4&plusmn;13,7bpm respectivamente vs 395,2&plusmn;11,1bpm). Já a PVC não sofreu variações significativas durante após o tratamento. CONCLUSÃO: O 1.8 cineol diminui a complacência gástrica em ratos anestesiados além de apresentar efeitos hipotensor e bradicárdico; provavelmente por ação direta sobre a musculatura lisa gastrintestinal e vascular e modulação do sistema nervoso autônomo