Effects of rosiglitazone on intramyocellular lipid accumulation in Psammomys obesus.
OBJECTIVE
To examine the effects of rosiglitazone in intramyocellular lipid (IMCL) content in diabetic Psammomys obesus using novel electron microscopy technologies.


BACKGROUND
P. obesus is an unique polygenic model of obesity and type 2 diabetes. Male diabetic P. obesus were treated daily with 5 mg/Kg Rosiglitazone by oral gavage for 14 days. Data were compared with a group of age-matched diabetic P. obesus treated with saline vehicle.


METHODS
Assessment of insulin resistance and adiposity were determine before and after the treatment period by oral glucose tolerance test (oGTT) and dual energy X-ray absorptiometry (DEXA) analysis. We used a new scanning electron microscopy technology, (WETSEM) to investigate the effects of rosiglitazone administration on IMCL content, size and distribution in red gastrocnemius muscle.


RESULTS
Rosiglitazone treatment improved glucose tolerance in P. obesus with no difference in the overall body fat content although a significant reduction in subscapular fat mass was observed. Rosiglitazone changed the distribution of lipid droplet size in skeletal muscle. Treated animals tended to have smaller lipid droplets compared with saline-treated controls.


CONCLUSIONS
Since smaller IMCL droplets are associated with improvements in insulin sensitivity, we propose that this may be an important mechanism by which rosiglitazone affects glucose tolerance.
Molero
Juan Carlos
JC
Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Australia.
Lee
Scott
S
Leizerman
Ilit
I
Chajut
Ayelet
A
Cooper
Adrian
A
Walder
Ken
K
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000494:pharmacology; D005849:Gerbillinae; D005951:Glucose Tolerance Test; D006943:Hyperglycemia / Q000139:chemically induced / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000097:blood; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D008055:Lipids / Q000502:physiology*; D008297:Male; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007004:Hypoglycemic Agents; D007328:Insulin; D008055:Lipids; D045162:Thiazolidinediones; D000077154:Rosiglitazone