Insulin like activity

Hydrogen peroxide (H202) exhibits insulin-like activity in isolated cells. Like that of vanadate, this effect is thought to be mediated by inhibition of protein-tyrosine phosphatases. 

Haratake, M., M. Fukunaga, M. Ono, and M. Nakayama. 2005. Synthesis of vana-dium(IV,V) hydroxamic acid complexes and in vivo assessment of their insulin-like activity. J. Biol. Inorg. Chem. 10 250-258. 

Gray, A.M. and Flatt, P.R. (1999) Insulin releasing and insulin like activity of the traditional anti diabetic plant Coriandrum sativum (coriander). British journal of Nutrition 81 (3), 203-209. 

Processing of GH could go further, with production of relatively small peptides which retain substantial or even enhanced activity, and it has been suggested that this may be important in the actions of the hormone in vivo [131]. In particular, fragments which retain the diabetogenic or insulin-like activities of GH have been reported [95,131]. What role these play in the normal physiological actions of the hormone is unclear. 

In summary, the participation of the GPI/IPG system in cell activation by insulin is supported by the following evidences First, insulin induces tlie hydrolysis of GPI and the release of IPG second, impaired GPI metabolism or treatment with anti-IPG antibodies neutralize insulin actions and, third, natural and synthetic IPG have insulin-like activity. Several other diffusible factors activate GPI hydrolysis with the concomitant release of IPG. The next question is at which points IPG second messengers cross talk with the established signal transduction pathways. 

Zapata, A., Leon, Y, Mato, J. M., Varela-Nieto, L, Penades, S., and Martin-Lomas, M. Synthesis and investigation of the possible insulin-like activity of lD-4-O- and lD-6-0-(2-amino-2-deoxy-a-D-glu-copyranosyl)-myo-inositol 1-phosphate and 1 D-6-0-(2-amino-2-deoxy-a-D-gluco-pyranosyl)-myo-inositol l,2-(cyclic phosphate). Carhohydr. Res., 1994, 264, 21—31. 

Plasma Factors that Influence Insulin Action. Berson and Yalow argue persuasively that there is no evidence that insulin of pancreatic origin ever becomes bound to a plasma protein, from which it can subsequently be released in recognizable form. 2 Newer evidence, based on an examination of the insulin-like activity of plasma, from which all immunoreactive insulin had been precipitated with anti-insulin serum, confirms this conclusion. 3 Nevertheless, there is ample evidence that there exist in plasma, substances that have insulin-like activity or that can modify the... 

There may, however, be other related peptides which are as yet uncharacterized. For example, forms of rat IGF-II have been described with molecular masses of8700 and 16300 (M25) these are immunologically related to the characterized peptide of molecular mass 7500 (M5). A big IGF-II has also been reported in human spinal fluid and serum (H9). It is conceivable that these species are incompletely processed precursor firrms of IGF-II. In addition to such variants of known IGFs, variants of different charge have also been described. One, an acidic peptide (pi 4.8) first detected by its insulin-like activity, cross-reacts in two radioimmunoassays for SM-C/IGF-I, but not in an assay for IGF-II (H13). Finally, the existence of a fetal somatomedin has been postulated (H2), but whether this differs from IGF-II remains to be established. 

C21. Cornell, H. J., and Herington, A. C., Evidence for a biologically active, carrier-bound form of non-suppressible insulin-like activity (NSILA) in human serum. Int. J. Biochem. 15, 553-558 (1983). 

D20. Drop, S. L. S., Valiquette, G., Guyda, H. J., Corvol, M. T., and Posner, B. I., Partial purification and characterization of a binding protein for insulin-like activity in human amniotic fluid A possible inhibitor of insuhn-like activity. Acta Endocrinol. (Copenhagen) 90, 505-518 (1979). 

Franklin, R. C., Rennie, C. C., and Cameron, D. P., Serum levels of the acid-ethanol soluble component of non-suppressible insulin-like activity in untreated and treated streptozotocin-diabetic rats. J. Endocrinol. 81, 331-337 (1979). 

H12. Herington, A. C., and Kuffer, A. D., Identification of a specific inhibitor of nonsup-pressible insulin-like activity in a partially purified hmnan serum fi action. Etulocrinology (Baltimore) 109, 1634-1640 (1981). 

H13. Herington, A.C., and Kuffer, A. D., IGF-like diaracteristics of an acidic non-suppressi-ble insulin-like activity. In "Insulin-like Growth Factors/Somatomedins (E. M. Spencer, ed.), pp. 121-125. De Gruyter, Berlin, 1983. 

Oelz, O., Jakob, A., and Froesch, E. R., Nonsuppressible insulin-like activity (NSILA) of human serum. Eur. J. Clin. Invest. I, 48-53 (1970). 

PIO. Pierson, R. W., andTemin, H. M., The partial puiificsition from calf serum a fraction with multiplication-stimulating activity fr>r chidcen fibroblasts in cell culture and with non-suf ressible insulin-like activity. /. Cdl. FhysioL 79, 319-330 (1972). 

---