PHI在正常大鼠组织中优先与VIP受体结合。

PHI preferentially binds to VIP receptors in normal rat tissues.

作者信息

Huang M, Rorstad O P

机构信息

Department of Medicine, University of Calgary, Alberta, Canada.

出版信息

Peptides. 1990 Sep-Oct;11(5):1015-20. doi: 10.1016/0196-9781(90)90026-2.

DOI:10.1016/0196-9781(90)90026-2

PMID:2178244

Abstract

Vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI) are homologous neuropeptides with parallel biological actions. These similarities raise the question whether VIP and PHI have common or distinct mechanisms of action, including receptors. The present study attempted to distinguish specific binding sites for VIP and PHI in normal rat tissues using the homologous radioligands [Tyr(125I)10]VIP and [Tyr(125I)10]rat PHI. In rat brain, anterior pituitary, and liver membranes both radioligands identified a VIP-preferring receptor. Rat PHI had less than 10% the binding potency of VIP in these tissues irrespective of which radioligand was used. In rat uterine membranes [Tyr(125I)10]VIP bound to a receptor with approximately 100 times greater affinity for VIP over PHI. No specific binding of [Tyr(125I)10]rat PHI to rat uterus could be demonstrated. In conclusion, these results support the predominance of VIP-preferring receptors as opposed to PHI-preferring receptors in normal rat brain, anterior pituitary, liver and uterus.

摘要

血管活性肠肽（VIP）和肽组氨酸异亮氨酸（PHI）是具有相似生物学作用的同源神经肽。这些相似性引发了一个问题，即VIP和PHI是否具有共同或不同的作用机制，包括受体。本研究试图使用同源放射性配体[酪氨酸（125I）10]VIP和[酪氨酸（125I）10]大鼠PHI来区分正常大鼠组织中VIP和PHI的特异性结合位点。在大鼠脑、垂体前叶和肝细胞膜中，两种放射性配体均鉴定出一种对VIP更具亲和力的受体。无论使用哪种放射性配体，大鼠PHI在这些组织中的结合能力均不到VIP的10%。在大鼠子宫膜中，[酪氨酸（125I）10]VIP与一种对VIP的亲和力比对PHI高约100倍的受体结合。未证实[酪氨酸（125I）10]大鼠PHI与大鼠子宫有特异性结合。总之，这些结果支持在正常大鼠脑、垂体前叶、肝脏和子宫中，以对VIP更具亲和力的受体为主，而非对PHI更具亲和力的受体。