Journal of Thermal Biology 31 (2006) 30–39 Review The somatotropic axis in sleep and thermoregulation: A tribute to Ferenc Oba´l, Jr. (1948–2004) Peter Alfo¨ldi a , Levente Kapa´s b , Eva Szentirmai a,c , Ping Taishi c , Janos Gardi c,d , Zoltan Peterfi a , Ba´lint Kacso´h e , James M. Krueger c,Ã a Department of Physiology, A. Szent-Gyo¨rgyi Medical Center, University of Szeged, Szeged, Hungary b Department of Biological Sciences, Fordham University, Bronx, New York c Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, WA, USA d Endocrine Unit, A. Szent-Gyo¨rgyi Medical Center, University of Szeged, Szeged, Hungary e Division of Basic Medical Sciences and the Department of Pediatrics, Mercer University School of Medicine, Macon, GA, USA Accepted 22 November 2005 Abstract Hypothalamic growth hormone-releasing hormone (GHRH) is one of the key neurohumoral regulators of non-rapid eye movement sleep. The focus of the present paper is the role of GHRH in the regulation of sleep and body temperature in the context of a larger biochemical regulatory network. This network includes other members of the somatotopic axis such as growth hormone, insulin-like growth factor-1, somatostatin and ghrelin and members of the cytokine family such as interleukin-1. r 2005 Elsevier Ltd. All rights reserved. Keywords: Growth hormone-releasing hormone; Growth hormone; Somatostatin; Insulin-like growth factor; Ghrelin; Interleukin Contents 1. Introduction ................................................................................. 30 2. GHRH ..................................................................................... 32 3. SRIH ...................................................................................... 32 4. GH/IFG-1 .................................................................................. 33 5. Ghrelin ..................................................................................... 33 6. Chronically altered GHRH–GH systems ............................................................. 33 7. Sleep-related variations in peptides of the somatotropic axis ............................................... 34 8. Thermoregulation ............................................................................. 35 9. Relationships of GHRH to IL1b................................................................... 36 10. Conclusion .................................................................................. 36 Acknowledgements ................................................................................ 36 References ...................................................................................... 36 1. Introduction Our quality of life, performance, and mental well-being are all adversely affected by even a single night’s loss of sleep. Chronic sleep loss is associated with multiple ARTICLE IN PRESS www.elsevier.com/locate/jtherbio 0306-4565/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.jtherbio.2005.11.012 Ã Corresponding author. E-mail address: krueger@vetmed.wsu.edu (J.M. Krueger).