VITAMIN A AND REPRODUCTION

这项提议的广泛的长期目标是理解 维生素A在男性生殖功能中的作用，寻求 了解人体内维生素A的必要运动和代谢 睾丸和附睾部。提出的具体研究试图澄清 几种特定的维生素A转运或结合蛋白的作用 在这些器官里。特别强调了前面的两个 未描述的维甲酸结合蛋白存在于日本血吸虫附睾体中 那只老鼠。建议对这些蛋白质进行提纯和鉴定。 包括序列、结合特异性和内源性的测定 莱兰德。蛋白质的分布和细胞位置将是 通过制备可用于敏感的抗血清来测定 放射免疫分析和免疫定位。其他物种将被检查 对于这些蛋白质的存在，蛋白质的功能将是 通过研究它们将维甲酸输送到发育中的能力进行检查 精子。 初步研究表明，原代培养的支持细胞将 从其与视黄醇结合蛋白的复合体中内化视黄醇， 维生素A的血浆转运蛋白，以受体介导的方式。 这一过程将被进一步描述。人的新陈代谢 将测定内化视黄醇，特别强调 酯化作用和一种新的酶活性的可能参与， 卵磷脂视黄醇酰基转移酶。Sertoli可能会释放 对细胞内化的维生素A到培养液中进行检测。这个 RBP的质膜受体将在无细胞系统中进行研究， 在视黄醇从RBP转移到CRBP之后。粗品的提纯 将尝试RBP受体以产生可用于 放射免疫分析和免疫定位。 最后，细胞视黄醇结合蛋白的细胞特异性定位 和维甲酸结合蛋白在人类生殖组织中的表达 将会被确定。应用人CRBP抗血清，对人CRBP进行定位研究 人类的睾丸和附睾会继续。这样的研究将是 延伸至卵巢和子宫，这两个组织中含有丰富的CRBP。人CRABP 将被提纯并获得CRABP抗血清，将用于 放射免疫分析和免疫定位研究类似于 CRBP。

The broad long-term goal of this proposal is to understand the essential role that vitamin A plays in male reproductive function, seeking to understand the necessary movements and metabolism of vitamin A in the testis and epididymis. The specific research proposed seeks to clarify the roles of several specific transport or binding proteins for vitamin A in these organs. Particular emphasis is given to two previously undescribed retinoic acid-binding proteins present in the epididymis of the rat. It is proposed to purify and characterize these proteins including determination of sequence, binding specificity, and endogenous ligand. The distribution and cellular location of the proteins will be determined by preparation of antiserum that can be used for sensitive radioimmunoassay and immunolocalization. Other species will be examined for the presence of these proteins., The function of the proteins will be examined by studying their ability to deliver retinoic acid to developing sperm. Preliminary work has shown that Sertoli cells in primary culture will internalize retinol from its complex with retinol-binding protein, the plasma transport protein for vitamin A, in a receptor-mediated fashion. This process will be further characterized. The metabolism of the internalized retinol will be determined, with particular emphasis on esterification and the possible involvement of a novel enzyme activity, lecithinretinol acyl transferase. The possible release by the Sertoli cell of the internalized vitamin A to the medium will be examined. The plasma membrane receptor for RBP will be studied in cell-free systems, following the transfer of retinol from RBP to CRBP. Purification of the RBP receptor will be attempted in order to produce antiserum usable for radioimmunoassay and immunolocalization. Finally, the cell-specific location of cellular retinol-binding protein and cellular retinoic acid-binding protein in human reproductive tissue will be determined. With antiserum to human CRBP, localization studies in human testis and epididymis will be continued. Such studies will be extended to ovary and uterus, two tissues with abundant CRBP. Human CRABP will be purified and antiserum to CRABP obtained that will be used for radioimmunoassay and immunolocalization studies similar to those for CRBP.