Synergism of atrial pressure and adrenergic stimulation for ANF release in the rat.
The effect of adrenergic stimulation on atrial natriuretic factor (ANF) release was studied in conscious rats. 60 min i.v. infusion of 15 micrograms/kg/min phenylephrine produced an elevation in mean arterial pressure of about 50 mmHg that was associated with an immediate, transitory increase in both central venous (CVP) and left ventricular end-diastolic (LVEDP) pressures. Heart rate was not changed. The elevation in CVP, but not LVEDP, persisted until 5 min, together with a 50-fold increase in plasma C-terminal ANF concentrations (from 19 +/- 5 to 1010 +/- 339 fmol/ml); at 30 min, in the absence of any increases in CVP or LVEDP, plasma ANF was still elevated by 5-fold (114 +/- 35 fmol/ml). It is suggested that adrenergic stimulation 'per se' can induce ANF release, independently of atrial pressure. Furthermore, combined adrenergic stimulation and increased atrial wall tension could result in a potentiation of the ANF secretory response 'in vivo', in the case where both stimuli are present concomitantly.
Lachance
D
D
Clinical Research Institute of Montreal, Quebec, Canada.
Garcia
R
R
D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D004357:Drug Synergism; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007260:Infusion Pumps; D008297:Male; D010656:Phenylephrine / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains; D013566:Sympathomimetics / Q000008:administration & dosage*
D013566:Sympathomimetics; D010656:Phenylephrine; D009320:Atrial Natriuretic Factor