Source : WordNet®

Pitressin
     n : hormone secreted by the posterior pituitary gland (trade
         name Pitressin) and also by nerve endings in the
         hypothalamus; affects blood pressure by stimulating
         capillary muscles and reduces urine flow by affecting
         reabsorption of water by kidney tubules [syn: {vasopressin},
          {antidiuretic hormone}, {ADH}]