[Metabolism of insulin and immunoreactive insulin-like substances (proinsulin, HWIRI) in vivo in man].
Immunoreactive insulin (IRI) and its three constituents as determined by gel filtration: high molecular weight substances with insulin immunoreactivity (HWIRI), proinsulin (PI) and insulin (I), were measured hourly during 28 hours in the portal, hepatic and peripheral venous systems of a patient operated for a nesidioblastoma. The PI levels were constant from one system to the other (7.1 +/- 0.8 microU/ml; 7.3 +/- 0.8 microU/ml; 9.2 +/- 1.2 microU/ml). The I levels decreased from the portal (53.3 +/- 5.2 microU/ml) to the hepatic venous system (28.0 +/- 1.0 microU/ml) and from the latter to the peripheral venous system (19.8 +/- 2.0 microU/ml). The HWIRI levels were stable between the portal and the hepatic venous systems (4.7 +/- 0.7 microU/ml; 4.8 +/- 0.6 microU/ml) and higher in the peripheral system (8.2 +/- 1.2 microU/ml). Our results demonstrate that: --I is essentially degraded by the liver. --There is no variation of PI in the three compartments. --HWIRI is formed in the circulation. --Variations of IRI levels between venous systems acquire physiological significance only when accompanied by the variations of the levels of each constituent.
D007516:Adenoma, Islet Cell / Q000097:blood*; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D007340:Insulinoma / Q000097:blood* / Q000150:complications / Q000601:surgery; D008875:Middle Aged; D008970:Molecular Weight; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000150:complications / Q000601:surgery; D011384:Proinsulin / Q000097:blood*
D007328:Insulin; D011384:Proinsulin
Métabolisme de l'insuline et des substances à immunoréactivité insulinique (proinsuline, HWIRI) chez l'homme in vivo.