| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4276523 | Urological Science | 2010 | 5 Pages |
ObjectiveThe specific aim of this investigation was to determine the effect of hydrogen peroxide on calcium ATPase of the rabbit urinary bladder smooth muscle and mucosa in the presence of varying concentrations of calcium. Hydrogen peroxide can inhibit enzyme activity via oxidation of the proteins and is often used as a model of free radical damage. The activity of calcium ATPase is increased by increasing the calcium concentration in the buffer. In addition, calcium can also increase the activation of hydrolytic enzymes such as calpain and phospholipase A2.Materials and MethodsThe effect of 0%, 0.045%, 0.9% and 0.18% hydrogen peroxide on calcium ATPase activity was quantitated in rabbit urinary bladder smooth muscle and mucosa in the presence of 3 mM, 10 mM or 30 mM of calcium chloride.ResultsThe results were as follows: (1) Calcium ATPase activity increased with increasing calcium. The muscle and mucosa had similar activities at 3 mM and 10 mM calcium, but the mucosal activity was significantly higher than the muscle at 30 mM. (2) Hydrogen peroxide inhibited enzyme activity of the smooth muscle and contractile activity in a dose-dependent manner to approximately the same extent. (3) Hydrogen peroxide inhibited enzyme activity for both muscle and mucosa. (4) The muscle was significantly more sensitive to hydrogen peroxide than was the mucosa. (5) The mucosa had a significantly higher total antioxidant activity than the muscle.ConclusionThe increased sensitivity of the muscle to hydrogen peroxide may be due in part to its lower total antioxidant activity.
