Hattori Y, Kasai M, Uesugi S, Kawata M, Yamashita H
Department of Physiology, Okayama University, Medical School, Japan.
Brain Res. 1988 Mar 8;443(1-2):355-9. doi: 10.1016/0006-8993(88)91633-2.
The effects of atrial natriuretic polypeptide (ANP) on the extracellularly recorded activity of neurons in the subfornical organ (SFO) were investigated in rat brain slice preparations by adding the peptide to the perfusion medium. Eight (14%) of 56 SFO neurons were inhibited and none of the cells were excited by ANP at 10(-7) M. Of 42 SFO neurons tested with both ANP and angiotensin II (AII) at 10(-7) M, 4 (10%) cells were inhibited by ANP and excited by AII, the remainder responded to either one or other of the peptides but not both or were unresponsive. In 13 (87%) of 15 SFO neurons, ANP at 10(-7) M depressed by more than 40% the excitation induced by AII at 10(-7) M, while ANP did not always depress the excitation induced by raising the extracellular potassium concentrations in 6 SFO cells tested. We conclude that ANP strongly depresses AII-induced excitation in all SFO neurons, although it has very weak inhibitory effects on spontaneous activity, thus ANP may act as a neuromodulator in the SFO.
通过将心房利钠多肽（ANP）添加到灌注培养基中，在大鼠脑片制备物中研究了其对穹窿下器（SFO）中细胞外记录的神经元活动的影响。在56个SFO神经元中，有8个（14%）受到抑制，在10⁻⁷M浓度下，没有细胞被ANP兴奋。在用10⁻⁷M的ANP和血管紧张素II（AII）共同测试的42个SFO神经元中，有4个（10%）细胞被ANP抑制而被AII兴奋，其余细胞对其中一种肽有反应但对另一种无反应或均无反应。在15个SFO神经元中的13个（87%）中，10⁻⁷M的ANP使10⁻⁷M的AII诱导的兴奋降低了40%以上，而在测试的6个SFO细胞中，ANP并不总是能抑制由细胞外钾浓度升高所诱导的兴奋。我们得出结论，尽管ANP对自发活动的抑制作用非常微弱，但它能强烈抑制所有SFO神经元中AII诱导的兴奋，因此ANP可能在SFO中充当神经调节剂。
