Central and peripheral integration of interrenal and thyroid axes signals in common carp (Cyprinus carpio L.)

Author:

Geven Edwin J W,Flik Gert,Klaren Peter H M

Abstract

In teleostean fishes the hypothalamic–pituitary–thyroid axis (HPT axis) and the hypothalamic–pituitary–interrenal axis (HPI axis) regulate the release of thyroid hormones (THs) and cortisol respectively. Since many actions of both hormones are involved in the regulation of metabolic processes, communication between both signal pathways can be anticipated. In this study, we describe central and peripheral sites for direct interaction between mediators of both neuroendocrine axes in the common carp (Cyprinuscarpio). Despite suggestions in the literature that CRH is thyrotropic in some fish; we were not able to establish stimulatory effects of CRH on the expression of the pituitary TSHβ subunit gene. In preoptic area tissue incubated with 10−7 M thyroxine (T4) a 2.9-fold increase in the expression of CRH-binding protein (CRHBP) was observed. Thus, T4could reduce the bioavailable hypothalamic crh via the up regulation of crhbp expression and hence down regulate the HPI axis. At the peripheral level, cortisol (10−6 M), ACTH (10−7 M), and α-MSH (10−7 M) stimulate the release of T4from kidney and head kidney fragments, which contain all functional thyroid follicles in carp, by two- to fourfold. The substantiation of three pituitary thyrotropic factors, viz. TSH, ACTH, and α-MSH, in common carp, allows for an integration of central thyrotropic signals. Clearly, two sites for interaction between the HPT axis, the HPI axis, and α-MSH are present in common carp. These interactions may be key to the proper regulation of general metabolism in this fish.

Publisher

Bioscientifica

Subject

Endocrinology,Endocrinology, Diabetes and Metabolism

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3