Abstract
The current study was designed to examine calcium transport across the basolateral membrane of the enterocyte of control and diabetic rats. The slope of initial rate of ATP-dependent calcium uptake was significantly greater in controls than in diabetic rats (P < 0.001). Kinetic analysis of ATP-dependent calcium uptake showed a maximum velocity (Vmax) of 0.19 ± 0.02 and 0.37 ± 0.01 μmol · g protein-1 · s-1 in diabetic and control rats, respectively (P < 0.01). Km values were similar. Insulin therapy and calmodulin added to freeze-thawed basolateral membranes vesicles stimulated Vmax of ATP-dependent calcium uptake in diabetic membranes to values close to those of controls without a change in Km values. In contrast, the Ca++-Na+ exchange process was similar in both control and diabetic rats. These results suggest that the ATP-dependent calcium uptake process is decreased in diabetic animals. This decrease is stimulated by calmodulin or insulin therapy, implying a causal relationship between insulin deficiency and calmodulin activity in diabetes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 209-214 |
| Number of pages | 6 |
| Journal | American Journal of Clinical Nutrition |
| Volume | 58 |
| Issue number | 2 |
| State | Published - 1993 |
| Externally published | Yes |
Keywords
- Calcium
- Calmodulin
- Diabetes
- Insulin
- Intestine
ASJC Scopus subject areas
- Nutrition and Dietetics
- Medicine (miscellaneous)