Estimation of First-phase Insulin Secretion in the Zucker Fatty Rat

摘要

The present study was designed to test the efficacy of the popular index AIRG (i.e. acute insulin response after glucose bolus) in the characterization of the first-phase insulin secretion in the Zucker Fatty Rat. The reliability of the AIRG was evaluated by direct comparison with the first-phase β-cell responsiveness index (Φ1) provided by C-peptide minimal model. To this aim, AIRG and Φ1 were simultaneously computed from IVGTT data, measured in six Zucker fatty rats (ZFR), 7-to-9week-old, and seven age-matched Zucker lean rats (ZLR). In the whole 13 rats population, the AIRG showed a significant linear correlation with Φ1 (r = 0.89, P < 0.0001). Moreover, both Φ1 (P < 0.05) and AIRG (p<0.001) showed a significant increase, in the ZFRs, compared to control group (ZLR). These findings suggest that the AIRG index is able to provide similar information of Φ1, in the evaluation of the alteration of the first-phase insulin secretion in Zucker Fatty Rats. Thus, the present study proposes the AIRG, as a suitable empiric index for a simple, reliable and low-cost quantification of the first-phase insulin secretion in Zucker Fatty Rats.