Effect of nitric oxide on basal and stretch-induced release of atrial natriuretic factor (ANF) from isolated perfused rat atria.
We investigated the effect of the NO donor SNAP (6.7 nM) on basal and stretch-induced ANF release from isolated perfused rat atria. There was no significant difference in basal ANF secretion between the vehicle- and SNAP-infused atria (SNAP: 388+/-63 pg. 100 microl(-1), n = 13 vs. vehicle: 349+/-26 pg. 100 microl(-1), n = 5). Atrial distention caused an increase in ANF secretion in both the buffer- and SNAP-treated groups. SNAP greatly attenuated the stretch-induced increase in ANF (SNAP: 225+/-7 pg. 100 microl(-1), n = 5 vs. vehicle: 448+/-72 pg. 100 microl(-1), n = 13, P < 0.05). The compliance of atria treated with SNAP was lower than that of the vehicle-perfused atria (P < 0.05). Thus, although SNAP appeared to attenuate stretch-induced ANF secretion, there was in fact no significant difference in the ratio of Delta[ANF] to Deltaintraluminal volume (SNAP: 5.8+/-1.3 pg. 100 microl(-1). microl(-1) vs. vehicle: 8.2+/-1.4 pg. 100 microl(-1). microl(-1).). In conclusion, we found no evidence that NO alters the control of basal or stretch-induced ANF secretion. NO can however reduce ANF release by shifting the pressure-volume curve, so that a given increase in atrial pressure is associated with a smaller increase in intraluminal volume and reduced atrial distention.
Departments of Physiology and Medicine, 475 Heritage Medical Research Centre, University of Alberta, Alberta, T6G 2S2, Edmonton, Canada. susan.jacobs@ualberta.ca
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D000818:Animals; D009320:Atrial Natriuretic Factor / Q000187:drug effects / Q000378:metabolism*; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009470:Muscle Spindles / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D010477:Perfusion; D011863:Radioimmunoassay; D051381:Rats; D020318:Rats, Long-Evans
D020030:Nitric Oxide Donors; C110881:S-nitro-N-acetylpenicillamine; C472610:atrial natriuretic peptide, rat; D009569:Nitric Oxide; D009320:Atrial Natriuretic Factor; D010396:Penicillamine