EFFECTS OF DIABETES ON CALCIUM UPTAKE BY RAT BRUSH BORDER MEMBRANE VESICLES

1. We investigated the mechanism of decreased transmucosal calcium transport in the gut of the diabetic rat by comparing calcium uptake by brush border membrane vesicles from control and streptozotocin diabetic rats at 5 days. Brush border calcium uptake consists of saturable and non‐saturable components. Saturable uptake is mediated by a specific mobile carrier mechanism and is defined by Vmax (saturable uptake of calcium at infinite medium calcium concentration) and KT (calcium concentration at Vmax/2). Non‐saturable uptake is defined by kD (rate constant for non‐saturable uptake per unit calcium concentration), and comprises both diffusive and surface binding components of calcium uptake.

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