Article Number: PRJA97540518


Vol. 2 Issue 1, pp: (1-20), January 2017.
Article Number: PRJA97540518
Copyright ©2017
Author(s) retain the copyright of this article
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution 4.0 International License.


Review

Significance of Hypothalamic-Pituitary-Adrenal Axis to adapt to Climate Change in Livestock

T.K. Binsiya1, V. Sejian2, M.Bagath2, G.Krishnan2, Iqbal Hyder3, A. Manimaran4, A.M. Lees5, J.B.Gaughan5 and R.Bhatta2

1Academy of Climate Change Education and Research, Kerala Agricultural

University, Vellanikkara, Thrissur, Kerala, India.

2ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Bangalore.

3Department of Veterinary Physiology, NTR College of Veterinary Science, Gannavaram-521102, Andhra Pradesh, India.

4ICAR-National Dairy Research Institute, Southern Regional Station, Adugodi, Bangalore.

5School of Agriculture and Food Sciences, The University of Queensland, Gatton 4343 QLD, Australia.

*Corresponding Author. E-mail: drsejian@gmail.com

 Received: July 23, 2016  Accepted: November 9, 2016  Published: January 27, 2017

ABSTRACT

Climate, which includes many atmospheric parameters such as temperature, humidity, wind speed and solar radiation can affect in many ways any animal’s ability to survive and produce. Adaptation involves the technique to adapt a species to its environment. Biological adaptation to thermal stress is accompanied by changes in protein, membrane lipid, and metabolic rate. Production of heat shock protein (HSP) is a cellular and tissue defense response to thermal stress. Hypothalamus, blood, thyroid, liver, lungs, heart, skin, cell and different axis play an important role in the process of attaining homeostasis by the animal. Hypothalamic-pituitary-adrenal (HPA) axis, somatotrophic axis, lactotrophic axis, gonadotrophic axis  and thyrotropic axis  are the different axis involved in adaptation. One of the best, consistent and spontaneous response to stress is the activation of the HPA axis. The HPA axis get activated when an animal receives stress through various sense organs. Activation of HPA results in secretion of steroid hormones from the adrenal gland. Activation of pituitary component of HPA axis can be mediated by several neuroendocrine hormones such as corticotropin releasing hormone (CRH) and adreno corticotrophic hormone (ACTH). Secretion of steroids from the adrenal cortex is stimulated by ACTH from the anterior pituitary. The endocrine action of ACTH, CRH and Vasopressin (VP) mediate glucocorticoid secretion from the adrenal cortex. Glucocorcoids activation plays a vital role in inducing hepatic gluconeogenesis to support the adaptation process. Glucocorticoids also stimulate the synthesis of epinephrine from the adrenal medulla. All these findings indicates the crucial role played by HPA axis in controlling the neuroendocrine mechanisms that regulate the complex adaptive responses of livestock to environmental challenges.

Key words: Adaptation, Adrenal, Climate change, HPA axis, Hypothalamus, Livestock, Glucocorticoid, Pituitary