obstacle to development of methods to quantify (β-cell turnover from pancreas tissue is the lack of conversion factors for the frequency of (β-cell replication or apoptosis detected by immunohistochemistry to rates of replication or apoptosis. We addressed this obstacle in islets from 1-mo-old rats by quantifying the relationship between the rate of (β-cell replication observed directly by time-lapse video microscopy (TLVM) and the frequency of (β-cell replication in the same islets detected by immunohistochemistry using antibodies against Ki67 and insulin in the same islets fixed immediately after TLVM. Similarly, we quantified the rate of (β-cell apoptosis by TLVM and then the frequency of apoptosis in the same islets using TdT-mediated dUTP nick-end labeling and insulin. Conversion factors were developed by regression analysis. The conversion factor from Ki67 labeling frequency (%) to actual replication rate (%events/h) is 0.025 ± 0.003 h-1. The conversion factor from TdT-mediated dUTP nick-end labeling frequency (%) to actual apoptosis rate (%events/h) is 0.41 ± 0.05 h -1. These conversion factors will permit development of models to evaluate (β-cell turnover in fixed pancreas tissue.
|American Journal of Physiology - Endocrinology and Metabolism
|Published - 2009 Jan
- Conversion factor
- TdT-mediated dUTP nick-end labeling
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Physiology (medical)