TABLE 1.
Lower PC enzyme activity in pancreatic islets than rat islets or INS-1 832/13 cells
Enzyme activities in whole-cell homogenates of human islets were compared with activities in homogenates of either rat islets or INS-1 832/13 cells measured in the same assay batch. PC was also measured in islets of older rats as a control for aging. Results are the mean ± S.E. with the number of observations in parentheses. The activity of propionyl-CoA carboxylase (PCC), an enzyme that catalyzes a reaction similar to PC, is shown as an additional control. The mean ± S.E. BMI and age of the human islet donors whose islets were used for these measurements were 28.9 ± 1.9 kg/m2 and 51.3 ± 2.6 years.
| Islet source | PC activity | PCC activity |
|---|---|---|
| nmol of CO2 fixed per min/mg of protein | nmol of CO2 fixed per min/mg of protein | |
| Human islets | 6.3 ± 0.8 (23)a | 25.3 ± 4.1 (6) |
| Same assay control, rat (age 2 months) islets | 45.5 ± 4.4 (7) | 29.0 ± 1.6 (7) |
| Same assay control, INS-1 832/13 cells | 44.8 ± 2.5 (15) | 1.6 ± 0.2 (9) |
| Rat (age 11 months) islets | 59.8 ± 3.3 (6) |
a p < 0.001 versus rat islet or INS-1 832/12 cell PC values.