Related Experiment Videos
Regulation of growth factor mRNA levels in the eyes of diabetic rats
W L Lowe1, R Z Florkiewicz, M A Yorek
1Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, USA.
Abstract:
The underlying etiology of diabetic microvascular disease remains unknown. To examine the potential contribution of basic fibroblast growth factor (bFGF), which is an angiogenic factor, and insulin-like growth factor-I (IGF-I) to the development of diabetic microvascular disease, bFGF and IGF-I mRNA levels were measured in tissues of control, diabetic, and insulin-treated diabetic rats. Diabetes was induced in rats by intravenous injection of streptozotocin (STZ) 65 mg/kg, and the rats were maintained for 21 days. bFGF mRNA levels increased threefold in the eyes of diabetic versus control rats, whereas a consistent change in bFGF mRNA levels was not observed in other tissues. In contrast, IGF-I mRNA levels decreased in the eyes and other tissues, including kidney, lung, and skeletal muscle, of diabetic as compared with control rats. Insulin treatment prevented the diabetes-induced increase in bFGF and decrease in IGF-I mRNA levels. Acidic FGF (aFGF) mRNA levels were unchanged in eyes from diabetic versus control rats. In partially purified retinas, diabetes increased bFGF mRNA levels twofold as compared with levels in control retinas, whereas IGF-I mRNA levels decreased to 58% of control levels in retinas from diabetic rats. Insulin treatment again prevented the diabetes-induced increase in IGF-I mRNA levels in the retina but had no effect on the diabetes-induced increase in bFGF mRNA levels. bFGF peptide levels were minimally increased in diabetic versus control retinas.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I) play roles in diabetic microvascular disease. Insulin treatment impacts bFGF and IGF-I mRNA levels in diabetic rats.
Area of Science:
- Endocrinology
- Molecular Biology
- Ophthalmology
Background:
- The etiology of diabetic microvascular disease is not fully understood.
- Basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I) are implicated in angiogenic processes.
- Investigating their roles in diabetes complications is crucial.
Purpose of the Study:
- To examine the contribution of bFGF and IGF-I to diabetic microvascular disease.
- To measure bFGF and IGF-I mRNA levels in diabetic rat tissues.
- To assess the effect of insulin treatment on these factors.
Main Methods:
- Diabetes induced in rats using streptozotocin (STZ).
- Measurement of bFGF and IGF-I mRNA levels in various tissues (eyes, kidney, lung, skeletal muscle).
- Analysis of bFGF and IGF-I peptide levels in retinas.
Main Results:
- bFGF mRNA levels significantly increased in the eyes of diabetic rats.
- IGF-I mRNA levels decreased in the eyes and other tissues of diabetic rats.
- Insulin treatment normalized bFGF and IGF-I mRNA levels, except for bFGF in the retina.
Conclusions:
- bFGF and IGF-I mRNA levels are altered in diabetic rats, particularly in the eyes.
- Insulin therapy can modulate these changes, suggesting a therapeutic target.
- Further research is needed to elucidate the precise mechanisms in diabetic microvascular complications.