Abstract
Insulin-deficient rats are characterized by multiple defects in the pathway of glycogen synthesis and breakdown in both liver and skeletal muscle. The aim of this study was to clarify whether islet transplantation under the kidney capsule, which is associated with delivery of insulin into the peripheral circulation, is able to normalize glycogen metabolism in liver and muscle of streptozotocin-diabetic rats. Three groups of male Lewis rats were studied under fasting condition: controls, untreated diabetics, and islet transplanted diabetics. Glycogen content, glucose-6-phosphate concentration, and glycogen synthase activity were measured in both liver and skeletal muscle. Untreated diabetic rats were characterized by an increase in glycogen content of 178% and a reduction of glucose-6-phosphate level of 50%. Both glycogen and glucose-6-phosphate contents were restored to normal in transplanted diabetic rats. Active glycogen synthase (0.35 ± 0.1 nmol/min/mg) and activity ratio (0.22 ± 0.04) were significantly impaired compared with controls (0.99 ± 0.2 nmol/min/mg and 0.43 ± 0.06, respectively) and were normalized by islet transplantation. In the skeletal muscle, glycogen content was similar in the three groups of animals, whereas muscle glucose-6-phosphate level was reduced by 28% and glycogen synthase was in a less active state in the untreated diabetic rats. Both the glucose-6-phosphate concentration and the kinetic profile of glycogen synthase were normalized by islet transplantation. In conclusion, islet transplantation under the kidney capsule corrects the diabetes-induced abnormalities in glycogen and glucose-6-phosphate content and glycogen synthase activity in both liver and skeletal muscle.
| Original language | English |
|---|---|
| Pages (from-to) | 103-112 |
| Number of pages | 10 |
| Journal | Cell Transplantation |
| Volume | 11 |
| Issue number | 2 |
| Publication status | Published - 2002 |
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Keywords
- Glucose-6-phosphate
- Glycogen
- Glycogen synthase
- Islet transplantation
- Liver
- Muscle
ASJC Scopus subject areas
- Cell Biology
- Transplantation
Cite this
Islet transplantation under the kidney capsule corrects the defects in glycogen metabolism in both liver and muscle of streptozocin-diabetic rats. / Matarazzo, Margherita; Giardina, Maria Grazia; Guardasole, Vincenzo; Davalli, Alberto M.; Horton, Edward S.; Weir, Gordon C.; Saccà, Luigi; Napoli, Raffaele.
In: Cell Transplantation, Vol. 11, No. 2, 2002, p. 103-112.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Islet transplantation under the kidney capsule corrects the defects in glycogen metabolism in both liver and muscle of streptozocin-diabetic rats
AU - Matarazzo, Margherita
AU - Giardina, Maria Grazia
AU - Guardasole, Vincenzo
AU - Davalli, Alberto M.
AU - Horton, Edward S.
AU - Weir, Gordon C.
AU - Saccà, Luigi
AU - Napoli, Raffaele
PY - 2002
Y1 - 2002
N2 - Insulin-deficient rats are characterized by multiple defects in the pathway of glycogen synthesis and breakdown in both liver and skeletal muscle. The aim of this study was to clarify whether islet transplantation under the kidney capsule, which is associated with delivery of insulin into the peripheral circulation, is able to normalize glycogen metabolism in liver and muscle of streptozotocin-diabetic rats. Three groups of male Lewis rats were studied under fasting condition: controls, untreated diabetics, and islet transplanted diabetics. Glycogen content, glucose-6-phosphate concentration, and glycogen synthase activity were measured in both liver and skeletal muscle. Untreated diabetic rats were characterized by an increase in glycogen content of 178% and a reduction of glucose-6-phosphate level of 50%. Both glycogen and glucose-6-phosphate contents were restored to normal in transplanted diabetic rats. Active glycogen synthase (0.35 ± 0.1 nmol/min/mg) and activity ratio (0.22 ± 0.04) were significantly impaired compared with controls (0.99 ± 0.2 nmol/min/mg and 0.43 ± 0.06, respectively) and were normalized by islet transplantation. In the skeletal muscle, glycogen content was similar in the three groups of animals, whereas muscle glucose-6-phosphate level was reduced by 28% and glycogen synthase was in a less active state in the untreated diabetic rats. Both the glucose-6-phosphate concentration and the kinetic profile of glycogen synthase were normalized by islet transplantation. In conclusion, islet transplantation under the kidney capsule corrects the diabetes-induced abnormalities in glycogen and glucose-6-phosphate content and glycogen synthase activity in both liver and skeletal muscle.
AB - Insulin-deficient rats are characterized by multiple defects in the pathway of glycogen synthesis and breakdown in both liver and skeletal muscle. The aim of this study was to clarify whether islet transplantation under the kidney capsule, which is associated with delivery of insulin into the peripheral circulation, is able to normalize glycogen metabolism in liver and muscle of streptozotocin-diabetic rats. Three groups of male Lewis rats were studied under fasting condition: controls, untreated diabetics, and islet transplanted diabetics. Glycogen content, glucose-6-phosphate concentration, and glycogen synthase activity were measured in both liver and skeletal muscle. Untreated diabetic rats were characterized by an increase in glycogen content of 178% and a reduction of glucose-6-phosphate level of 50%. Both glycogen and glucose-6-phosphate contents were restored to normal in transplanted diabetic rats. Active glycogen synthase (0.35 ± 0.1 nmol/min/mg) and activity ratio (0.22 ± 0.04) were significantly impaired compared with controls (0.99 ± 0.2 nmol/min/mg and 0.43 ± 0.06, respectively) and were normalized by islet transplantation. In the skeletal muscle, glycogen content was similar in the three groups of animals, whereas muscle glucose-6-phosphate level was reduced by 28% and glycogen synthase was in a less active state in the untreated diabetic rats. Both the glucose-6-phosphate concentration and the kinetic profile of glycogen synthase were normalized by islet transplantation. In conclusion, islet transplantation under the kidney capsule corrects the diabetes-induced abnormalities in glycogen and glucose-6-phosphate content and glycogen synthase activity in both liver and skeletal muscle.
KW - Glucose-6-phosphate
KW - Glycogen
KW - Glycogen synthase
KW - Islet transplantation
KW - Liver
KW - Muscle
UR - http://www.scopus.com/inward/record.url?scp=0035987936&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035987936&partnerID=8YFLogxK
M3 - Article
VL - 11
SP - 103
EP - 112
JO - Cell Transplantation
JF - Cell Transplantation
SN - 0963-6897
IS - 2
ER -