Wildey G M, Glembotski C C
J Neurosci. 1986 Dec;6(12):3767-76. doi: 10.1523/JNEUROSCI.06-12-03767.1986.
Binding sites for 125I-atrial natriuretic peptide (ANP)2 in rat olfactory bulb membranes have been studied using pharmacological and biochemical methods. Various unlabeled ANP-related peptides were tested for the ability to inhibit the binding of the radioligand in membrane binding assays. ANP(92-126) and ANP(99-126) were the most potent inhibitors tested, both exhibiting an IC50 value of 0.40 nM. ANP(103-126) and ANP(103-123) were 3 and 70 times less potent, respectively. ANP(111-126) was unable to inhibit the binding of the radioligand at a concentration of 1 microM. Several peptides unrelated to ANP were unable to inhibit the binding of the radioligand to rat olfactory bulb membranes. Membranes labeled with 125I-ANP were incubated with cross-linking agents and subjected to SDS-PAGE followed by autoradiography. A band possessing an apparent molecular mass of 116 kDa was identified. The labeling of this band was progressively decreased by increasing concentrations of unlabeled ANP(99-126) (IC50 = 0.6 nM) and by several other ANP-related peptides at nanomolar concentrations. For comparison purposes, ANP binding sites in rat aorta membranes were labeled with 125I-ANP and cross-linked using identical techniques. Three bands possessing molecular masses of 120, 72, and 62 kDa were identified. These results indicate that the ANP binding site in rat olfactory bulb membranes displays pharmacological and biochemical properties similar to peripheral ANP receptors.
已使用药理学和生物化学方法研究了大鼠嗅球膜中125I-心房利钠肽（ANP）2的结合位点。在膜结合试验中测试了各种未标记的ANP相关肽抑制放射性配体结合的能力。ANP(92 - 126)和ANP(99 - 126)是测试的最有效抑制剂，两者的IC50值均为0.40 nM。ANP(103 - 126)和ANP(103 - 123)的效力分别低3倍和70倍。ANP(111 - 126)在1 microM浓度下无法抑制放射性配体的结合。几种与ANP无关的肽无法抑制放射性配体与大鼠嗅球膜的结合。用125I-ANP标记的膜与交联剂孵育，然后进行SDS-PAGE和放射自显影。鉴定出一条表观分子量为116 kDa的条带。随着未标记ANP(99 - 126)浓度的增加（IC50 = 0.6 nM）以及其他几种纳摩尔浓度的ANP相关肽的存在，该条带的标记逐渐减少。为作比较，用125I-ANP标记大鼠主动脉膜中的ANP结合位点，并使用相同技术进行交联。鉴定出三条分子量分别为120、72和62 kDa的条带。这些结果表明，大鼠嗅球膜中的ANP结合位点表现出与外周ANP受体相似的药理学和生物化学特性。
