Plasma Osmolality and Plasma Vasopressin (2)	

Using visual analogue scales to assess thirst, a similar linear relationship exists between plasma osmolality (pOS) and thirst (Th), defined by the function:

Th=0.30 (pOS-281), r=0.91, P<0.001.

The functional analysis of osmotically mediated vasopressin release is helpful in defining disorders of vasopressin secretion. Abnormalities in the sensitivity of the vasopressin-releasing unit and in the threshold of vasopressin secretion have been defined.