Water deprivation for 24 hours increases selectively blood flow in posterior pituitary of conscious rats.

Blood flow was measured by means of 125I-Antipyrin distribution and was found to be increased in the posterior pituitary of conscious rats following water deprivation for 24 h as compared to either normohydrated control or to force hydrated rats (2.86 ml min-1 g-1 vs. 2.36 ml or 2.08 ml, respectively). Other parameters of systemic haemodynamics, blood flow in the brain or in the hypothalamus and in anterior pituitary did not differ in three experimental groups of rats subjected to various water intake. The increased blood flow in the posterior pituitary in dehydrated rats presumably parallels the locally intensified metabolic rats due to the enchanged stimulation of the antidiuretic hormone release.