Showing 2 results for Regular Insulin
Ali Reza Esteghamati, Mehrshad Abbasi, Abbas Yousefizadeh,
Volume 5, Issue 1 (8-2005)
Abstract
Background: The aim of this study was to compare time action profile of regular human Insulin produced by Exir pharmaceutical Co. and Actrapid® HM produced by Novo Nordisk with euglycemic clamp technique for the first time in Iran.
Methods: Euglycemic glucose clamps were performed with two Insulin brands in a single-center, randomized, double-blind, and crossover study on 6 healthy male volunteers. Glucose disposal kinetics including metabolic clearance rate of glucose (MCRg) and metabolic clearance rate of insulin (MCRi) were determined during a 2-h predetermined intravenous Insulin infusion while blood glucose levels were maintained steady using variable continues intravenous glucose infusions based on method of De Fronzo.
Results: There were no differences in glucose kinetics or time action profile with respect to glucose infusion rates (688.4 vs. 664.6 mg/kg per 120min), MCRg (0.63±0.19 vs. 0.62±0.25 ml/kg), and MCRi(110 % vs110%) between Exir and Novo Nordisk regular human Insulin preparations. Serum insulin levels increased and serum C-peptide levels decreased with both exogenous Insulin infusions which were statistically the same for both preparations.
Conclusion: Time action profile and bioavailability of regular human insulin produced by Exir Pharmaceutical Corporation is comparable with commonly used Novo Nordisk preparation demonstrated by 2 hour euglycemic clamp study.
Maryam Chinisaz, Azadeh Ebrahim-Habibi, Parichehreh Yaghmaei, Kazem Parivar, Ahmad- Reza Dehpour,
Volume 13, Issue 4 (5-2014)
Abstract
Background: The flexible structure of proteins is one important factor in the formation of ordered aggregates (amyloid fibril). This is a major problem for therapeutic proteins such as insulin. Study on the induction and inhibition of insulin fibrillation process with specific compounds such as aromatic derivatives may provide useful information about means of stabilization of protein structures.
Methods: To induce fibrillation, regular insulin was incubated in phosphate buffer (pH=7.4) during 24 hours. Amyloid formation was investigated by using Congo red absorbance and transmission electron microscopy (TEM). Then nodular amyloidosis was observed in mice upon amyloid fibril injection, after which the excised nodule was studied by Congo red staining and polarized light microscopy. Then, some aromatic compounds effect was investigated on the fibrillation process.
Results: Regular insulin form mature amyloid fibrils at pH=7.4, 37°C after 24 hours. Silibinin had the highest inhibitory effect on that process. Furthermore, Amyloid fibril injection in mice caused nodular amyloidosis.
Conclusion: Regular insulin has a high potential to undergo amyloid aggregation. Nodular amyloidosis confirms fibril formation by insulin under in vitro condition. Silibinin could be considered as a potential compound capable to increase protein structure stability.
