Format

Send to

Choose Destination
Int J Hyperthermia. 2018 Sep;34(6):834-839. doi: 10.1080/02656736.2017.1394502. Epub 2017 Nov 20.

Head-out immersion in hot water increases serum BDNF in healthy males.

Author information

1
a Department of Rehabilitation Medicine, School of Medicine , Wakayama Medical University , Wakayama , Japan.
2
b Department of Rehabilitation Medicine, School of Medicine , Yokohama City University , Yokohama , Kanagawa , Japan.
3
c Department of Forensic Medicine, School of Medicine , Wakayama Medical University , Wakayama , Japan.

Abstract

PURPOSE:

Brain-derived neurotrophic factor (BDNF) is an important neurotrophin. The present study investigated the effects of head-out water immersion (HOI) on serum BDNF concentrations.

METHODS:

Eight healthy men performed 20 min head-out water immersion at 42 °C (hot-HOI) and 35 °C (neutral-HOI). These experimental trials were administered in a randomised order separated by at least 7 days. Venous blood samples were withdrawn at rest, immediately after the 20-min HOI, as well as at 15 and 30 min after the end of the HOI. Serum BDNF and S100β, plasma cortisol, platelet and monocyte counts, and core body temperature (Tcb) were measured.

RESULTS:

Tcb was higher at the end of the hot-HOI and 15 min after hot-HOI (p < 0.01), but recovered to pre-HOI level at 30 min after hot-HOI. No change in Tcb was recorded during neutral-HOI. BDNF level was higher (p < 0.05) at the end of the hot-HOI and at 15 min after the end of hot-HOI, and returned to the baseline at 30 min after hot-HOI. S100β, platelet count and monocyte count remained stable throughout the study. Cortisol level was lower at the end of the hot-HOI and returned to pre-HOI level during the recovery period. BDNF and S100β, cortisol, and platelet and monocyte counts did not change throughout the neutral-HOI study.

CONCLUSIONS:

The present findings suggested that the increase in BDNF during 20-min hot-HOI was induced by hyperthermia through enhanced production, rather than by changes in permeability of the blood-brain barrier (BBB), platelet clotting mechanisms or secretion from monocytes.

KEYWORDS:

Hyperthermia; S100β; central nervous system; core temperature; cortisol

PMID:
29157042
DOI:
10.1080/02656736.2017.1394502
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center