Are beta-endorphins and thermoregulation during cold-water immersion related?
Undersea Hyperb Med
; 20(3): 205-13, 1993 Sep.
Article
en En
| MEDLINE
| ID: mdl-8401150
ABSTRACT
The purpose of this investigation was to determine the relationship between core temperature (Tre), tissue insulation (I), and beta-endorphins (beta-END) during immersion in cold water. To test this, 21 males were immersed to the first thoracic vertebra for 120 min in stirred water at either 18 degrees, 22 degrees, or 26 degrees C. Subjects were divided with respect to body fat [high fat (HF) = 18-22%, n = 11; low fat (LF) = 8-12%, n = 10] and randomly assigned to one of the three temperatures. Blood was drawn at 25 and 5 min (T-25 and T-5, respectively) before immersion, after 1 h of immersion, and 5 min before the completion of the second hour (T + 60 and T + 120, respectively). No significant relationship was found between delta beta-END and delta I or delta Tre. The relationship between the changes in thermoregulatory variables and delta beta-END did not differ between the HF and LF groups. Also, beta-END (adjusted for plasma volume) was lower (P < 0.05) in the HF vs. the LF group. beta-END (pg.ml-1) increased (P < 0.05) as time increased from T-25 to T + 60 and were not progressive with duration of immersion. Thus, beta-END did not increase in proportion to level of heat loss.
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Bases de datos:
MEDLINE
Asunto principal:
Composición Corporal
/
Regulación de la Temperatura Corporal
/
Betaendorfina
/
Frío
/
Inmersión
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Humans
/
Male
Idioma:
En
Revista:
Undersea Hyperb Med
Asunto de la revista:
FISIOLOGIA
Año:
1993
Tipo del documento:
Article