ETHANOL DOSAGE REGIMES IN STUDIES OF ETHANOL TOXICITY - INFLUENCE OF NUTRITION AND SURGICAL INTERVENTIONS

In this review we consider some of the practical facets of acute and c hronic drug regimes. In particular, we illustrate our arguments with s pecific reference to alcohol and-draw attention to methodological cons traints that might alter biochemical or physiological processes. These includes the imposition of nutritional abnormalities and surgical pro cedures. These two areas are highlighted because there is evidence to show that they have marked influences on metabolic parameters, exempli fied by tissue protein synthesis. In general, there is no controversy as to methods for acute studies with alcohol, although some reports ha ve failed to investigate whether intravenous, intragastric or intraper itoneal regimes move accurately mimic the clinical situation. With reg ard to chronic feeding regimes, evidence is provided to support the ar gument that, currently, the most appropriate feeding protocol ensures that both control and treated groups receive identical amounts of nutr ients albeit with differences in the calories apportioned to ethanol, which is substituted by isocaloric glucose or other carbohydrates in c ontrols. However, there are still other methods being employed: these are subject to misinterpretation as the principle of ensuring that con trol and ethanol-fed rats receive identical amounts of nutrients, is i gnored. In this review we also draw attention to the fact that surgica l procedures, which are often employed to facilitate the measurement o f body parameters (for example, implantation of cannulae), themselves alter tissue metabolism. The importance of this relates to the concept of metabolic superimposition, which implicates interacting responses when two or more stresses (i.e. surgery and drug administration) are s uperimposed.