Gastric juice and analysis of basal and stimulated secretion following treatment with rice-bran oil.

In determining whether rice-bran oil (RBO) has antisecretory activity, we induced stress ulcers in 20 Wistar rats (10 controls; 10 animals given 0.2 ml/day RBO orally for 4 days prior to ulcer induction). In turn, we analyzed gastric juice for histamine, pepsin, H+ concentration ([H+]) and output volume. A second, complementary study was made of basal and stimulated gastric secretion through continuous "in vivo" recording of output. Secretion was stimulated with increasing doses of histamine, betanechol and pentagastrin. Ninety-four rats were used (47 controls and 47 rats given 0.2 ml/day RBO orally for 4 days prior to gastric output evaluation). The results were evaluated by the Student t-test. Ulcer index in the RBO-treated rats was significantly lower than among the controls (p less than 0.01), as also reflected by a significantly greater decrease in [H+] among the RBO-treated rats (p less than 0.05). However, no significant differences were observed for the remaining parameters. Continuous recording of basal gastric output showed a significant decrease in [H+] among the RBO-treated rats (p less than 0.01). Following histamine stimulation, [H+] was likewise significantly lower among the RBO-treated rats than in the controls. However, no significant differences were observed following stimulation with either betanechol or pentagastrin. RBO contains a high percentage of unsaturated fats; the latter act as precursors in the synthesis of arachidonic acid, which in turn is the essential precursor of prostaglandins--established inhibitors of gastric secretion. RBO also contains antioxidants such as alpha-tocopherol, which may likewise stimulate the synthesis of prostaglandins. RBO likely acts by increasing prostaglandin output, thus interfering with gastric HCl production.

The influcence of ziznc sulphte on gastric blood flow in rats

A reduçäo do fluxo sanguíneo gástrico é apontada como um dos fatores responsáveis pelas lesöes ulcerativas observadas no estômago e no duodeno. Esta deficiência de irrigaçäo reduz o suprimento de energia, oxigênio e outros fatores responsáveis pela manutençäo da integridade tissular contra os efeitos autolesivos do HCl e da pepsina da secreçäo gástrica. É reconhecida a relaçäo entre fluxo sangüíneo da mucosa e a secreçäo cloridro-péptica. Em doentes com úlcera duodenal, o fluxo sangüíneo é mais lento e a secreçäo ácida mais elevada do que em voluntários säo. Na patologia digestiva há muitas doenças associadas à reduçäo considerável dos níveis séricos de zinco (acrodermatite enteropática, doença celíaca, doença de Crohn, úlcera gástrica, etc.). A maior parte delas apresenta lesöes ulcerativas em diferentes partes do organismo. Neste trabalho, estudou-se o efeito do sulfato de zinco no fluxo sangüíneo gástrico, em condiçöes experimentais de estresse induzido por noradrenalina. Utilizando-se o tritio marcado, estudou-se o fluxo sangüíneo da mucosa gástrica em ratos tratados com sulfato de zinco e num grupo controle. Nesses dois grupos, avaliou-se a m,odificaçäo do fluxo snagüíneo apósa adminsitraçäo intraperitoneal de noradrenalina. No grupo controle observou-se uma reduçäo significante (p < 0,05) do fluxo 20 minutos após a injeçäo de noradrenalina. No grupo tratado com sulfato de zinco, näo houve modificaçäo significante, indicando que o zinco iônico exerce um efeito protetor da mucosa gástrica do rato, preservando seu fluxo sangüíneo contra o estresse