Atrial natriuretic peptide in dehydrated Long-Evans rats and Brattleboro rats.
Atrial natriuretic peptide (ANP) was measured by radioimmunoassay in atrial and plasma extracts from normal Long-Evans (LE) rats and Brattleboro-strain diabetes insipidus (DI) rats. LE rats, dehydrated for 72 hours, had an increased plasma osmolality and plasma vasopressin. They also demonstrated a higher atrial immunoreactive ANP (IR-ANP) content than hydrated animals (72 hr dehydration: 178.2 +/- 30.4 micrograms/g wet weight atria, mean +/- SE, control: 60.4 +/- 8.2; P less than 0.001). Plasma IR-ANP in dehydrated LE rats tended to be lower than hydrated LE but this was not statistically significant [72 hr dehydration: 61.9 +/- 5.9 pg/ml, control: 82.4 +/- 8.2]. IR-ANP concentration in atrial extracts from DI rats, without detectable plasma vasopressin levels but with increased plasma osmolality, was not different from that in hydrated LE rats (DI: 100.6 +/- 13.2 micrograms/g). There was also no significant difference between plasma IR-ANP in DI and hydrated LE rats (DI: 100.2 +/- 11.9 pg/ml). The atrial IR-ANP concentration in DI rats was decreased by infusion with either arginine-vasopressin (AVP) or 1-deamino-8-arginine vasopressin (DDAVP), and plasma IR-ANP was increased significantly by both infusions (AVP: 171.3 +/- 18.1 pg/ml, DDAVP: 179.5 +/- 24.6). Thus, changes in atrial and plasma IR-ANP concentration appeared to be associated with changes in water balance but not with plasma AVP levels, indicating that the changes in volume may be a more important factor controlling ANP release in vivo than vasopressin itself.
D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood / Q000494:pharmacology; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001769:Blood; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D003681:Dehydration / Q000150:complications / Q000378:metabolism*; D003919:Diabetes Insipidus / Q000150:complications / Q000378:metabolism*; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009994:Osmolar Concentration; D051381:Rats; D011910:Rats, Brattleboro; D012083:Renin / Q000097:blood
D001127:Arginine Vasopressin; D009320:Atrial Natriuretic Factor; D012083:Renin; D003894:Deamino Arginine Vasopressin