Coordinated pattern of expression and localization of insulin-like growth factor-II (IGF-II) and IGF-binding protein-2 in the adult rat brain.

Endocrinology ◽  
1994 ◽  
Vol 135 (5) ◽  
pp. 2255-2264 ◽  
Author(s):  
A Logan ◽  
A M Gonzalez ◽  
D J Hill ◽  
M Berry ◽  
N A Gregson ◽  
...  
Keyword(s):  
Growth Factor ◽  
Rat Brain ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Adult Rat ◽  
Factor Ii ◽  
Adult Rat Brain ◽  
Igf Binding ◽  
Igf Binding Protein

scholarly journals Significance of abnormal serum binding of insulin-like growth factor II in the development of hypoglycemia in patients with non-islet-cell tumors

1989 ◽  
Vol 86 (17) ◽  
pp. 6778-6782 ◽  
Author(s):  
W H Daughaday ◽  
M Kapadia
Keyword(s):  
Growth Factor ◽  
Islet Cell ◽  
Molecular Form ◽  
Binding Protein ◽  
Islet Cell Tumor ◽  
Target Cells ◽  
Insulin Like Growth Factor ◽  
Factor Ii ◽  
Igf Binding ◽  
Igf Binding Protein

We reported that serum and tumor from a hypoglycemic patient with a fibrosarcoma contained insulin-like growth factor II (IGF-II), mostly in a large molecular form designated "big IGF-II." We now describe two additional patients with non-islet-cell tumor with hypoglycemia (NICTH) whose sera contained big IGF-II. Removal of the tumor eliminated most of the big IGF-II from the sera of two patients. Because specific IGF-binding proteins modify the bioactivity of IGFs, the sizes of the endogenous IGF-binding protein complexes were determined after neutral gel filtration through Saphadex G-200. Normally about 75% of IGFs are carried as a ternary complex of 150 kDa consisting of IGF, a growth hormone (GH)-dependent IGF-binding protein, and an acid-labile complexing component. The three patients with NICTH completely lacked the 150-kDa complex. IGF-II was present as a 60-kDa complex with variable contributions of smaller complexes. In the immediate postoperative period, a 110-kDa complex appeared rather than the expected 150-kDa complex. Abnormal IGF-II binding may be important in NICTH because the 150-kDa complexes cross the capillary membrane poorly. The smaller complexes present in our patients' sera would be expected to enter interstitial fluid readily, and a 4- to 5-fold increase in the fraction of IGFs reaching the target cells would result.

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