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.
Just after the food enters the stomach, a band of muscle (the lower esophageal sphincter, or LES) closes off the esophagus. If the muscle does not close tightly enough or gets weak over time, stomach contents can back up into the esophagus, causing heartburn and other symptoms.