Hydrogen sulfide (H₂S) is an important gasotransmitter expressed in various tissues of the organism, including the eye. It is known that H₂S is localized especially in the retina and corneal layers in bovine eye. The enzymes that mediate H₂S synthesis are 3-mercaptopyruvate sulfurtransferase (3-MST), cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE). Herein, we aimed to investigate the concentration levels and distribution profiles of these enzymes in bovine retina and retinal artery. Enzyme levels were measured by ELISA and distribution were determined by immunofluorescence microscopic analysis. Much higher concentrations of CBS and CSE have been detected in the retinal artery compared to the retina. In both tissues, particulary 3-MST was found at the lowest level while, CSE was determined to be the most abundant enzyme among the others. CBS distribution was shown in both endothelial and smooth muscle layers, while CSE was seen especially in the endothelial layer of the retinal artery. In the retina, CBS and CSE were expressed in cone-basil cells and retinal ganglion cells, while CSE was also present in bipolar cells. Our results indicated that H₂S is synthesized endogenously in ocular tissues. The widespread expression of H₂S synthesizing enzymes in the retina and retinal artery of the bovine eye, which has anatomical similarities with the human eye, may suggest a protective role for H₂S against retinal vascular diseases as well as a regulatory role in the retinal vascular tone.

硫化氢 (H ₂ S) 是一种重要的气体递质，在生物体的各种组织中表达，包括眼睛。已知H ₂ S尤其定位于牛眼的视网膜和角膜层中。介导 H ₂的酶S 合成是 3-巯基丙酮酸硫转移酶 (3-MST)、胱硫醚 β-合酶 (CBS) 和胱硫醚 γ-裂解酶 (CSE)。在此，我们旨在研究这些酶在牛视网膜和视网膜动脉中的浓度水平和分布特征。酶水平通过ELISA测量，分布通过免疫荧光显微镜分析确定。与视网膜相比，在视网膜动脉中检测到更高浓度的 CBS 和 CSE。在这两种组织中，特别是 3-MST 的含量最低，而 CSE 被确定为最丰富的酶。CBS 分布在内皮层和平滑肌层中均可见，而 CSE 尤其在视网膜动脉的内皮层中可见。在视网膜中，CBS 和 CSE 在锥形罗勒细胞和视网膜神经节细胞中表达，而 CSE 也存在于双极细胞中。我们的结果表明，H₂ S 在眼组织中内源性合成。H ₂ S 合成酶在牛眼视网膜和视网膜动脉中的广泛表达，与人眼具有解剖学相似性，可能表明 H ₂ S 对视网膜血管疾病具有保护作用，以及在视网膜血管疾病中的调节作用。视网膜血管张力。