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Not only students can express alcohol dehydrogenase: goldfish can too!
MedLine Citation:
PMID:  21098391     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
This article describes a novel approach to study the metabolic regulation of the respiratory system in vertebrates that suits physiology lessons for undergraduate students. It consists of an experimental demonstration of the goldfish's (Carassius auratus) adaptations to anoxia. The goldfish is one of the few vertebrates showing strong enzymatic plasticity for the expression of alcohol dehydrogenase (ADH), which allows it to survive long periods of severe anoxia. Therefore, we propose two simple laboratory exercises in which students are first asked to characterize the distribution of ADH isozymes in the goldfish by performing cellulose acetate electrophoresis. The second part of this laboratory lesson is the determination of liver glycogen. To further student comprehension, an interspecies comparative component is integrated, in which the same subjects are studied in an anoxia-sensitive species, the brook charr (Salvelinus fontinalis). ADH in goldfish is restricted to skeletal muscles, where it catalyzes alcoholic fermentation, permitting ethanol excretion through the gills and therefore preventing lactate acidosis caused by sustained glycolysis during anoxia. Electrophoresis also reveals the occurrence of a liver isozyme in the brook charr, which ADH catalyzes in the opposite pathway, allowing the usual ethanol degradation. As for the liver glycogen assay, it shows largely superior content in the goldfish liver compared with the brook charr, providing goldfish with a sustained energy supply during anoxia. The results of this laboratory exercise clearly demonstrate several physiological strategies developed by goldfish to cope with such a crucial environmental challenge as oxygen depletion.
Authors:
Valérie Chamberland; Pierre Rioux
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Advances in physiology education     Volume:  34     ISSN:  1522-1229     ISO Abbreviation:  Adv Physiol Educ     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-11-24     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100913944     Medline TA:  Adv Physiol Educ     Country:  United States    
Other Details:
Languages:  eng     Pagination:  222-7     Citation Subset:  IM    
Affiliation:
Département de Biologie, de Chimie et de Géographie, Université du Québec à Rimouski, Rimouski, Quebec, Canada. chamberland_valerie@live.ca
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