Korean J Physiol Pharmacol.
2000 Apr;4(2):91-97.
Combined trial of fish oil and exercise training prevents impairment in
insulin action on glucose transport of skeletal muscle induced by
high-fat diet in rats
- Affiliations
-
- 1Department of Physiology, Yeungnam University College of Medicine,
Taegu, South Korea.
- 2Department of Internal Medicine, School of Medicine, Catholic University
of Taegu-Hyosung, Taegu 705-503, Korea.
Abstract
- The purpose of the present study was to determine the preventive
effects of combined interventional trial of fish oil treatment and
exercise training on insulin resistance of skeletal muscle in high-fat
fed rats. Male Wistar rats were randomly divided into chow diet (CD),
high-fat diet (HF), high-fat diet with fish oil (FO), high-fat diet
with exercise training (EX), and FO+EX groups. The rats in control
group were fed chow diet containing, as percents of calories, 58.9%
carbohydrate, 12.4% fat, and 28.7% protein. High-fat diet provided 32%
energy as lard, 18% as corn oil, 27% as carbohydrate and 23% as casein.
The fish oil diet had the same composition as the high fat diet except
that 100 g menhaden oil was substituted for corn oil. Insulin
sensitivity was assessed by in vitro glucose transport in the soleus
muscle after diet treatment and treadmill running for 4 weeks. While
the FO or EX only partially prevented insulin resistance on glucose
transport and visceral obesity induced by high-fat diet, these
interventions completely corrected hyperinsulinemia and hyperglycemia
from the high-fat diet. The rats in the FO+EX showed normalized insulin
action on glucose transport, plasma chemicals and visceral fat mass.
Insulin-mediated glucose transport was negatively associated with total
visceral fat mass (r=-0.734; p<0.000), plasma triglyceride (r=-0.403;
p<0.05) and lepin (r=-0.583; p<0.001) concentrations with significance.
Multiple stepwise regression analysis showed that only total visceral
fat mass was independently associated with insulin-mediated glucose
transport (r=-0.668; p<0.000). In conclusion, combined interventional
trial of FO+EX recovered insulin resistance on glucose transport of
skeletal muscle induced by high-fat diet. Visceral fat mass might be
more important factor than plasma TG and leptin to induce insulin
resistance on glucose transport of skeletal muscle in high-fat fed
rats.