Jin Ying, Zhong Yong-Mei, Yang Xiong-Li
Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, PR China.
Neurosci Lett. 2007 Jun 27;421(2):106-9. doi: 10.1016/j.neulet.2007.05.037. Epub 2007 May 26.
Natriuretic peptides (NPs) may act as neuromodulators through activation of three specific receptor subtypes (NPRs). In the present study we examined the expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) on different subtypes of retinal amacrine cells (ACs) in rat by immunofluorescence double labeling. All three NPs were moderately expressed in dopaminergic and cholinergic ACs, stained by tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT), respectively. The immunostaining appeared on the membrane, cytoplasm and somatodendritic compartments of these ACs. In AII glycinergic ACs, labeled by parvalbumin (PV), however, only faint punctate staining, if any, was seen. These results suggest that NPs could be produced in ACs and play a neuromodulatory role in the inner retina. Together with a previous immunocytochemical study, showing that NPR-B is present in cultured rat GABAergic ACs, our results further suggest that NPs produced in ACs may also modulate their own activity.
利钠肽（NPs）可通过激活三种特定受体亚型（NPRs）发挥神经调节作用。在本研究中，我们通过免疫荧光双标法检测了大鼠视网膜无长突细胞（ACs）不同亚型上心房利钠肽（ANP）、脑利钠肽（BNP）和C型利钠肽（CNP）的表达。所有三种利钠肽在分别由酪氨酸羟化酶（TH）和胆碱乙酰转移酶（ChAT）染色的多巴胺能和胆碱能无长突细胞中呈中度表达。免疫染色出现在这些无长突细胞的细胞膜、细胞质和树突-胞体区室。然而，在由小白蛋白（PV）标记的AII甘氨酸能无长突细胞中，仅可见微弱的点状染色（若有的话）。这些结果表明，利钠肽可在无长突细胞中产生，并在内层视网膜中发挥神经调节作用。结合先前一项免疫细胞化学研究显示NPR-B存在于培养的大鼠GABA能无长突细胞中，我们的结果进一步表明，无长突细胞中产生的利钠肽也可能调节其自身活性。
