PHYSICAL ACTIVITY, PANCREATIC FUNCTION AND OBESITY

  • Stern, Judith S, (PI)

Project: Research project

Description

The underlying causes of obesity in man are still not known. Therefore it
is extremely difficult to prevent or permanently cure obesity. It is
unlikely that obesity in man is a single entiry. In experimental animals
evidence separately implicates pancreatic and adrenal function, decreased
sympathetic tone, physical inactivity, diet composition and, of course,
adipose tissue development. We plan to study these factors in two
different animals models of obesity: genetically obese Zucker rats and in
Osborne-Mendel rats made obese on palatable diets. The specific
experiments include: 1. Examining the influence of the central nervous system (CNS) on
pancreatic insulin hypersecretion in obesity using a perfused rat
pancreatic preparation in which the CNS innervation is left intact;
Evaluating the effects of phentolamine (an alpha adrenergic blocker),
propranolol (a beta adrenergic blocker) and atropine (an inhibitor of the
parasympathetic nervous system). 2. Studying insulin release in preobese rats in isolated perfused
pancreata. 3. Studying the effects of adrenalectomy (ADX) on development of adiposity
(using osmium fixation technique) and protein turnover in Zucker obese
rats; Studying glucose metabolism and insulin sensitivity in skeletal
muscle using a hind limb perfusion system in ADX obese and lean Zucker rats
fed a high fat diet; Studying possible alterations in taste, preference
and/or caloric regulation with ADX. 4. Evaluating the contribution of various tissues to the thermic effect of
a high carbohydrate or high fat meal (as measured by blood flow) in
genetically obese rats, in rats made obese on high fat diets and in obesity
resistant rats. 5. Studying how exercise termination effects norephineprine turnover and
activity of catecholamine synthesizing enzymes--tyrosine hyroxylase and
dopamine beta hydroxylase; Investigating effects of exercise termination
and high fat diets on adipocyte proliferation by measuring 3H-thymidine
incorporation into adipocyte DNA. 6. Exploring the effects of treadmill exercise of different intensity and
duration in male and female rats on food intake and metabolic responses to
exercise termination including body composition, adipose cellularity,
lipoprotein lipase activity in white and brown adipose tissues well as
citrate synthase activity in muscle.
StatusFinished
Effective start/end date4/1/773/31/88

Funding

  • National Institutes of Health

Fingerprint

Obesity
Exercise
High Fat Diet
Adipocytes
Central Nervous System
Insulin
Diet
Adrenergic alpha-Antagonists
Osmium
Zucker Rats
White Adipose Tissue
Adrenergic beta-Antagonists
Brown Adipose Tissue
Lipoprotein Lipase
Phentolamine
Adrenalectomy
Adiposity
Mixed Function Oxygenases
Body Composition
Atropine

ASJC

  • Medicine(all)