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 mul(-1) n=13 vs. vehicle: 349+/-26 pg. 100 mul(-1) n = 5). Atrial distention caused an increase in ANF secretion in both the buffer- and SNAP-treated groups: SNAP greatly attenuated me stretch-induced Increase in ANF (SNAP: 225+/-7 pg. 100 mul(-1). n = 5 vs. vehicle: 448+/-72 pg. 100 mul(-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 Delta intraluminal volume (SNAP: 5.8+/-1.3 pg. 100 mul-1. mul(-1) vs. vehicle: 8.2+/-1.4 pg. 100 mul(-1). mul(-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. (C) 2001 Elsevier Science B.V. All rights reserved.