Esvaziamento gastrico de liquidos em ratos submetidos a desidratação por privação de agua

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

The aim of the present report was to study a model of dehydration caused by water deprivation and the gastric emptying of liquids in dehydrated rats. Wistar rats (n=380) were used: 80 for the first study and 300 for the second one. In the first group, animals were prived of water for periods of 24 (n=10), 48 (n=10) and 72 hours (n=10) and compared to the controls (n=15) which received water. Subsequently, in the study of recovery from dehydration (n=15), the period of 72 hours deprivation was used and 67 hours after deprivation, water was supplied for 60 (n=15) and 120 minutes (n=15), and controls (n=5) had no access to water. Weight loss, hematocrit and plasmatic density were the parameters established in each animal. In the study of gastric emptying, three proof meals, saline (n-30), water (n=30) and WHO rehydrating solution (n=30), were studied in the deprivation periods of 24, 48 and 72 hours. Control groups had the same number of animals. Then, in the period of 72 hours deprivation, gastric emptying of rehydrating solution (n=10) and of water (n=10) was determined, and water was offered for 60 minutes after 67 hours deprivation. The same procedure was used for rehydrating (n=10) and gluco-saline (n=10) solutions and water was offered for 120 minutes. The same number of control animals was used in both studies. In the model of dehydration, the three parameters showed a statistically significant difference between the animals from study and control groups at privation periods of 48 and 72 hours and the difference was more evident in the latter (p<0,05). In the recovery of dehydration, after 67 hours of deprivation, water was supplied for 60 minutes and the values of weight loss, hematocrit and plasmatic density decreased progressively when evaluated 72 hours after the beginning of the study. The values tended toward normalization when water was offered for 120 minutes. The values of gastric retention of saline and of water were lower than those of rehydrating solution in the three periods. As for the measurement of gastric retention , there was no difference between the controls and the groups of study, with water deprivation, except for the proof meals of water and rehydrating solution, at the period of 72 hours deprivation, which showed a retard of gastric emptying (p<0,05). In the group of animals with partial supply of water for 60 minutes, at the period of 67 hours deprivation, there was a recovery of the pattern of water gastric emptying concerning the control group, and the retard of the rehydrating solution was maintained (p<0,02). In the gastric emptying of rehydrating and gluco-saline solutions, with partial supply of water for 120 minutes, at the period of 67 hours deprivation, proof meals had a tendency to retard when evaluated 72 hours after the beginning of the study (p=0.04). When dehydration was caused by water deprivation, with no change or with little alterations of body electrolytic content, rehydrating solution showed a retard of gastric emptying, after rehydration with water. However, in the rehydrated animal, water showed a gastric emptying similar to that of the control group. In our study, evidences show that the mechanisms of control, in which receptors of duodenal mucosa take part, and which modify gastric motility, are altered in the dehydration caused by water deprivation

ASSUNTO(S)

hidratação gastroenterologia

ACESSO AO ARTIGO

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