Vasopressin and oxytocin in genetically hypertensive rats of the Lyon strain.
To investigate the role of arginine vasopressin (AVP) in genetic hypertension, we measured 24-h urinary volume, osmolality, and 24-h AVP excretion, as well as pituitary and pineal AVP and oxytocin levels, in genetically hypertensive (LH), normotensive (LN), and low blood pressure (LL) 5-and 45-week-old female rats of the Lyon strains. We also determined vascular sensitivity to AVP, norepinephrine, and angiotensin II in 6- and 21-week-old rats. AVP secretion was increased in both LH and LL rats compared with LN controls. Previous reports of increased AVP secretion in spontaneously hypertensive rats have suggested that AVP might play a role in high blood pressure. The existence of a similar increase in LL rats indicates that genetic hypertension of LH rats is not related directly to their increased AVP secretion. Furthermore, the vascular sensitivity to AVP was not specifically enhanced in 21-week-old LH rats compared with LN and LL controls. This study provides evidence against a major role of vasopressin in the genesis and maintenance of high blood pressure in this model of experimental hypertension, and emphasizes that the choice of controls in such investigations is of crucial importance.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006973:Hypertension / Q000235:genetics* / Q000378:metabolism; D009994:Osmolar Concentration; D010121:Oxytocin / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D011922:Rats, Mutant Strains
D000804:Angiotensin II; D001127:Arginine Vasopressin; D010121:Oxytocin; D004837:Epinephrine