PMID- 18434373 OWN - NLM STAT- MEDLINE DCOM- 20090708 LR - 20131121 IS - 1479-6805 (Electronic) IS - 0022-0795 (Linking) VI - 197 IP - 2 DP - 2008 May TI - Plasma brain-derived neurotrophic factor daily variations in men: correlation with cortisol circadian rhythm. PG - 429-35 LID - 10.1677/JOE-07-0376 [doi] AB - Expression and secretion of neurotrophins, including brain-derived neurotrophic factor (BDNF), are regulated also by neuronal activity. Data available in the literature suggest that BDNF central levels are influenced by light and dark. Diurnal changes of BDNF mRNA and protein contents have been demonstrated in the rat central nervous system. Based on these pieces of evidence, we investigated the hypothesis of a possible diurnal variation of BDNF circulating levels in human males. Moreover, we looked for a possible correlation with cortisol circadian rhythm, since both BDNF and cortisol are implicated in the maintenance of cerebral functions. In this study, 34 healthy young male volunteers were included. Five blood samples were drawn from each subject thrice in a month at regular 4-h intervals (0800, 1200, 1600, 2000, and 2400 h). BDNF and cortisol were measured in all samples. BDNF was determined by ELISA method. Our results show that plasma BDNF levels, as well as cortisol levels, are significantly higher in the morning when compared with the night (P<0.001), with a trend of constant decrease during the day. Furthermore, plasma BDNF and cortisol are positively correlated (Spearman index=0.8466). The present study is the first to demonstrate the presence of a diurnal rhythm of BDNF in humans. Moreover, the correlation found out between BDNF and cortisol circadian trend allows us to speculate that these two factors may be physiologically co-regulated, in order to maintain the homeostasis of integrated cerebral activities. FAU - Begliuomini, Silvia AU - Begliuomini S AD - Division of Gynecology and Obstetrics, Department of Reproductive Medicine and Child Development, University of Pisa, Pisa 56100, Italy. FAU - Lenzi, Elena AU - Lenzi E FAU - Ninni, Filippo AU - Ninni F FAU - Casarosa, Elena AU - Casarosa E FAU - Merlini, Sara AU - Merlini S FAU - Pluchino, Nicola AU - Pluchino N FAU - Valentino, Valeria AU - Valentino V FAU - Luisi, Stefano AU - Luisi S FAU - Luisi, Michele AU - Luisi M FAU - Genazzani, Andrea R AU - Genazzani AR LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - England TA - J Endocrinol JT - The Journal of endocrinology JID - 0375363 RN - 0 (Brain-Derived Neurotrophic Factor) RN - 0 (RNA, Messenger) RN - WI4X0X7BPJ (Hydrocortisone) SB - IM MH - Adult MH - Brain-Derived Neurotrophic Factor/*blood/genetics/physiology MH - Circadian Rhythm/*physiology MH - Humans MH - Hydrocortisone/*blood/physiology MH - Male MH - RNA, Messenger/analysis EDAT- 2008/04/25 09:00 MHDA- 2009/07/09 09:00 CRDT- 2008/04/25 09:00 PHST- 2008/04/25 09:00 [pubmed] PHST- 2009/07/09 09:00 [medline] PHST- 2008/04/25 09:00 [entrez] AID - 197/2/429 [pii] AID - 10.1677/JOE-07-0376 [doi] PST - ppublish SO - J Endocrinol. 2008 May;197(2):429-35. doi: 10.1677/JOE-07-0376.