Insulin immunoreactive

One of the remarkable autoimmune phenomena that penicillamine can cause is the induction of anti-insulin antibodies, with resultant hypoglycemia (autoimmune hypoglycemia) (924,925). In these patients, there are high concentrations of immunoreactive insulin, despite undetectable free insulin. When penicillamine is withdrawn antibody titers fall sharply. The occurrence of hypoglycemia rather than hyperglycemia is not fully understood (926). 

Figure 25-13 Response of plasma insulin to glucose stimulation. A 20-g glucose pulse is given intravenously at time 0. A, Healthy subjects. B, Patients with type 2 diabetes mellitus (NIDDM). C, Patients with type I diabetes mellitus (IDDM). IRf, Immunoreactive insulin. Values before time 0 represent baseline. (From Pfeifer MA, Halter JB, Porte D Jr. Insulin secretion in diabetes mellitus. Am J Med 1981 70.-579-88.)...

The term immunoreactive insulin is used in reference to assays that may recognize, in addition to insulin, substrates that share antigenic epitopes with insulin. Examples include proinsulin, proinsuHn conversion intermediates, and insulin derivatives, produced by gly-cation or dimerization. 

FIGURE 40.11 Seram levels of immunoreactive insulin (IRI) and glucose after nasal administration of insulin... 

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... 

D-GIucose (mg/100 ml) D-Fructose (mg/100 ml) Triglyceride (/xmol/100 ml) Free fatty acid (/xmol/100 ml) Immunoreactive insulin (/xunits/ml) ... 

Fig. 38.10 Serum levels of immunoreactive insulin (IRI) and glucose after nasal administration of insulin (21 U/body) with HPE-101 (1% w/v) and/or HP-p-CyD (10% w/v) to ratsvt Insulin alone A, with HP-p-CyD A, with HPE-101 , with HPE-101 and HP-p-CyD. Each point represents the mean SE of four rats.

The effects of FAG and 4P-GLC-FAG on immunoreactive insulin (IRI) release from the perfused pancreas of normal rats have been examined [160]. Glucose (8.3 mM)-induced IRI release is increased in the presence of FAG. (0.1-1 mM), but neither GAL-DNJ, DMDP nor 4P-GLC-FAG. FAG increase both of ist and 2nd phase. FAG has no effect on IRI release in perfusate containing 2.8 mM glucose. The lack of any potentiating effect of 4P-GLC-FAG on insulin release seems to support the hypothesis that the compound is hydrolyzed over time to the active FAG. A-Containing sugars with both P-glucosidase inhibitory activity and... 

Syvalahti E, Pihlajamaki K, lisalo E. Effect of tuberculostatic agents on the re onse of serum growth hormone and immunoreactive insulin to intravenous tolbutamide, andonthehalf-life of tolbutamide, IntJ Clin Pharmacol Biopharm ( 916) 13, 83-9. 

Since in vitro studies with perfused rat pancreas (Fig. 1) have shown that immunoreactive insulin (IRI) is released rather instantaneously when glucose or glucagon are added to the perfusate (Grodsky and Bennett, 1966), an attempt was made to investigate in man the very early phase of insulin release during the first 5 minutes after stimulation (Simpson et al., 1967). We characterized the early insulin response to intravenous glucose in normal human subjects, in subjects with diabetic heritage, lean noninsulin dependent diabetics (Simpson et al., 1966), and nondiabetic obese patients (Bendetti et al, 1967). 

Fig.. 2, Effect of glucagon on serum immunoreactive insulin (IRI), free fatty acid (FFA) and glucose in normal dogs.

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