Journal of Stress Physiology & Biochemistry, Vol. 6 No. 3
2010, pp. 44-55 ISSN 1997-0838
Original Text Copyright (cc) 2010 by Nirupama, Devaki and Yajurvedi
ORIGINAL
ARTICLE
Data source : Google Scholar
QueryDate : 2016-12-24
Cites : 12
REPEATED ACUTE STRESS INDUCED ALTERATIONS IN
CARBOHYDRATE METABOLISM IN RAT
Nirupama, R., Devaki, M. and Yajurvedi, H. N.*
Department of Zoology, University of
Mysore, Mysore-570 006, India *Telephone no. : 0821 2419778 (O) 09740970928 (Mob)
*Email- hnyajurvedi@rediffmail.com
Received May 6, 2010
Acute stress induced alterations in the activity levels of
rate limiting enzymes and concentration of intermediates of different
pathways of carbohydrate metabolism have been studied. Adult male
Wistar rats were restrained (RS) for 1 h and after an interval of 4 h
they were subjected to forced swimming (FS) exercise and appropriate
controls were maintained. Five rats were killed before the commencement
of the experiment (initial controls), 5 control and equal number of
stressed rats were killed 2 h after RS and remaining 5 rats in each
group were killed 4 h after FS. There was a significant increase in the
adrenal 3β- hydroxy steroid dehydrogenase activity following RS, which
showed further increase after FS compared to controls and thereby
indicated stress response of rats. There was a significant increase in
the blood glucose levels following RS which showed further increase and
reached hyperglycemic condition after FS. The hyperglycemic condition
due to stress was accompanied by significant increases in the
activities of glutamate- pyruvate transaminase, glutamate- oxaloacetate
transaminase, glucose -6- phosphatase and lactate dehydrogenase and
significant decrease in the glucose -6- phosphate dehydrogenase and
pyruvate dehydrogenase activities, whereas pyruvate kinase activity did
not show any alteration compared to controls. Further, the glycogen and
total protein contents of the liver were decreased whereas those of
pyruvate and lactate showed significant increase compared to controls
after RS as well as FS.
The results put together indicate that acute stress induced
hyperglycemia results due to increased gluconeogenesis and
glycogenolysis without alteration in glycolysis. The study first time
reveals that after first acute stress exposure, the subsequent
stressful experience augments metabolic stress response leading to
hyperglycemia. The results have relevance to human health as human
beings are exposed to several stressors in a day and such an experience
might lead to insulin resistance because prolonged hyperglycemic
condition is known to cause insulin resistance.
