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.
1 The abnormal muscle contractions also cause pain.  Gastroparesis. This is what's called delayed gastric emptying â in other words, a stomach that's slow to empty itself. Your stomach muscles govern the movement of partly digested food through your stomach and into your small intestine.