Vasopressin has three main effects: 1  Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis.
It can be caused by damage to the vagus nerve, which regulates the digestive system. A damaged vagus nerve prevents the muscles in the stomach and intestine from functioning, preventing food from moving through the digestive system properly. Often, the cause of gastroparesis is unknown.
Basically in gastroparesis, the stomach motility disappears and food remains stagnant in the stomach. The most common cause of gastroparesis is diabetes but it can also occur from a blockage at the distal end of stomach, a cancer or a stroke.