title: Atrial natriuretic factor release by angiotensin II in the conscious rat.
abstract: Since it was previously reported that atrial natriuretic factor (ANF) may exert an inhibitory effect on renin release, the existence of an Angiotensin II (Ang II)-ANF feedback mechanism was investigated. Male rats were infused intraperitoneally for 7 days with either saline, a nonpressor dose of Ang II (200 ng/kg/min), or a pressor dose (800 ng/kg/min) of Ang II. Systolic blood pressure, plasma ANF, 24-hour urinary sodium excretion, urine volume, and water intake were measured. A significant increase in plasma ANF was observed in the group with a pressor response (blood pressure rose from 89.0 +/- 3.9 to 136.7 +/- 11.4 mm Hg; ANF rose from 36.8 +/- 4.9 to 92.7 +/- 17.7 pg/ml). There was no significant time effect on 24-hour sodium excretion, urine volume, and water intake in both Ang II-infused groups. In a second set of experiments, male rats were infused intravenously for 60 minutes with either saline, a nonpressor dose of Ang II (16 ng/kg/min), or a pressor dose (800 ng/kg/min) of Ang II. Left ventricular end-diastolic pressure, right atrial pressure, and mean arterial pressure were monitored. There was a significant increase in plasma ANF and left ventricular end-diastolic pressure only with the pressor dose (blood pressure rose from 85.0 +/- 6.1 to 140.0 +/- 5.5 mm Hg; ANF rose from 22.6 +/- 6.0 to 108.3 +/- 47.7 pg/ml; left ventricular end-diastolic pressure rose from 5.3 +/- 5.7 to 20.8 +/- 7.9 mm Hg). No significant modification of right atrial pressure was recorded.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratory of Experimental Hypertension and Vasoactive Peptides, Clinical Research Institute of Montreal, Quebec, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Lachance
authors.forename: R
authors.initials: R
authors.lastname: Garcia
mesh_terms: D000450:Aldosterone / Q000097:blood; D000704:Analysis of Variance; D000804:Angiotensin II / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D003243:Consciousness; D006325:Heart Atria / Q000032:analysis / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D066298:In Vitro Techniques; D007260:Infusion Pumps; D007262:Infusions, Intravenous; D007263:Infusions, Parenteral; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood; D013997:Time Factors
chemical_list: C472610:atrial natriuretic peptide, rat; D000804:Angiotensin II; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012083:Renin