QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ismahan, G. Articles by Parvez, S. Search for Related Content PubMed PubMed Citation Articles by Ismahan, G. Articles by Parvez, S.

Effect of Starvation and Pattern of Feeding upon Activities of Enzymes Catechol-O-methyltransferase and Monoamine Oxidase in Heart and Liver of Developing Rats^1,2,

Neuropharmacology Unit, Laboratory of General Physiology, University of Paris XI, Bat. 440-PC-013, 91405 Orsay, France

Due to the well known effects of monoamines on glycogen turnover the activities of monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) were determined in heart and liver of young rats starved for up to 60 hours or subjected to perturbed pattern of feeding for 3 weeks. The hepatic and cardiac glycogen and blood glucose levels were also determined to estimate the metabolic status of the animal and to determine if there was any link between the activities of monoamine degrading enzymes and glycogen turnover. Cardiac COMT activity was markedly decreased by 24 and 48 hours of starvation but the activity returned to normal after 60 hours of starvation. Liver COMT increased progressively up to 60 hours of starvation. Refeeding rats for 24 hours following 60 hours of starvation reversed to some extent the effect of starvation for liver MAO. A perturbed pattern of feeding for 3 weeks decreased COMT activity in heart and increased this activity in liver on both per mg tissue and per mg protein basis. MAO activity increased in heart and liver when the results were expressed in cpm/mg of organ as well as cpm/mg protein. Liver glycogen nearly disappeared following 24, 48, and 60 hours of starvation but heart glycogen reached its maximum value by 48 hours of starvation. Refeeding the rats for 24 hours following 60 hours of starvation brought heart glycogen to normal level while live glycogen remained far below the control value. The effects of a perturbed pattern of feeding are more severe than starvation for glycogen storage. The simultaneous estimations of the variations in glycogen and the activities of MAO and COMT suggest the existence of a possible correlation between the processes of monoamine metabolism and glycogen breakdown.

KEY WORDS: • heart • liver • MAO • COMT • monoamines • rhythm • developing-rats • carbohydrate-metabolism

¹ Supported by a grant from INSERM, Paris, France (ATP-77-87).

² Dedicated to Dr. Alexander Psychoyos at the occasion of his 50th anniversary.

³ Gul Ismahan is a Ph.D. fellow of Paris University.

⁴ Author to whom proof should be addressed.

Manuscript received 15 March 1977.