Mondal M S, Nakazato M, Date Y, Murakami N, Yanagisawa M, Matsukura S
Third Department of Internal Medicine, Miyazaki Medical College, Kiyotake, Miyazaki, 889-1692, Japan.
Biochem Biophys Res Commun. 1999 Mar 24;256(3):495-9. doi: 10.1006/bbrc.1999.0362.
Orexins A and B, novel hypothalamic peptides encoded by a single mRNA transcript, stimulate food intake. Two antisera specific for the individual rat orexins were prepared and sensitive RIAs developed. Orexin-A and -B are abundant in the rat hypothalamus, medulla-pons, and midbrain-thalamus, and moderately abundant in the cerebral cortex. No orexins were found in the adipose tissues or visceral organs studied. The major endogenous molecule of orexin-A is a 33-amino-acid peptide, and that of orexin-B a 28-amino-acid peptide. After a 48 h fast, the orexin-A and -B contents of the lateral hypothalamus exhibited a trend to increase, but the contents of other brain tissues significantly decreased as compared with the fed control rats. No circadian variations in the orexin contents were found in the brain. The extensive and abundant distribution of orexins in the brain and changes in their contents upon fasting suggest that they serve as neuromodulators and/or neurotransmitters that regulate feeding behavior through interaction with diverse neural networks.
食欲素A和B是由单一mRNA转录本编码的新型下丘脑肽，可刺激食物摄入。制备了两种对大鼠个体食欲素具有特异性的抗血清，并开发了灵敏的放射免疫分析法。食欲素A和B在大鼠下丘脑、延髓-脑桥和中脑-丘脑含量丰富，在大脑皮层含量中等。在所研究的脂肪组织或内脏器官中未发现食欲素。食欲素A的主要内源性分子是一种33个氨基酸的肽，食欲素B的主要内源性分子是一种28个氨基酸的肽。禁食48小时后，下丘脑外侧区的食欲素A和B含量呈增加趋势，但与喂食的对照大鼠相比，其他脑组织的含量显著降低。在大脑中未发现食欲素含量的昼夜变化。食欲素在大脑中广泛而丰富的分布以及禁食时其含量的变化表明，它们作为神经调节剂和/或神经递质，通过与多种神经网络相互作用来调节摄食行为。
