Influence of slow versus fast increases in core temperature on prolactin and TNF-alpha

Autor: Wright, Heather E., Friesen, Brian J., Kenny, Glen P.
Jazyk: angličtina
Rok vydání: 2011
Popis: Prolactin (PRL), a pituitary hormone regulated by neurons in the hypothalamus, has been suggested as an indicator of fatigue during exercise-induced hyperthermia (EIH) given its strong relationship with body core temperature (Tco). However, the strength of this relationship during different rates of Tco increase and subsequent recovery are unknown. In addition, given the influence that systemic inflammatory cytokines, such as Tumor necrosis factor (TNF)-α, have on the pituitary gland; it would be of interest to determine the relationship between PRL and TNF-α during EIH. PURPOSE: To examine the PRL and TNF-α heat stress responses during low (slow heating) and moderate (fast heating) exercise intensities and subsequent resting or cold water immersion recovery. METHODS: Seven trained individuals (5 males, 2 females, mean ± SE: 27.0 ± 3.3 yrs, 57.9 ± 2.2 mL·kg⁻¹nim·⁻¹, 18.5 ± 2.4 % fat) underwent 4 EIH sessions (40°C, 30% R.H.) on a treadmill to a rectal temperature (Tre), measured continuously, of 39.5°C while wearing an impermeable rain suit followed by upright seated resting or 2°C ice-water immersion recovery. Venous blood was obtained at rest (PRE; prior to exercise), during exercise (Tre 38, 39, 39.5°C), the start of recovery (5 min post 39.5°C), and subsequent recovery (Tre 39, 38°C). PRL and TNF-α (high sensitivity) were measured by an ELISA and corrected for changes in plasma volume.
American College of Sports Medicine (ACSM) 58th Annual Meeting, May 31st-June 4th, 2011, Denver, CO
Databáze: OpenAIRE