Accession Number : ADA185731

Title :   Exercise in the Heat: Effects of Dinitrophenol Administration,

Corporate Author : ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Personal Author(s) : Francesconi, R ; Hubbard, R ; Matthew, C ; Durkot, M ; Bosselaers, M

PDF Url : ADA185731

Report Date : 26 Jul 1987

Pagination or Media Count : 28

Abstract : Although dinitrophenol (DNP) stimulates excessive heat production by uncoupling oxidative phosphorylation, its effects on performance and thermoregulation during exercise in the heat have not been assessed. DNP was administered in two equal dosages (20mg/kg, 30 min interval); the second injection was followed immediately by exercise (9.14m/min) in the heat (30 C) or at room temperature (21 C) until exhaustion or 99 min. At 21 C control (saline-treated) rats manifested a mean endurance of 94 min which was reduced to 32 min among DNP-treated animals. Respective increments in Tre for both groups were 0.02 C/min and 0.08 C/min. At 30 C control rats ran for 65 min (Tre/min=0.05 C) while DNP-treated animals had a mean endurance of only 12 min (Tre/min-0.22 C). DNP-treated rats (30 C) certainly manifested no decrement in tail-skin heat loss (Tsk/min=0.17 C vs 0.10 C) or saliva secretion (0.78g/min,DNP vs 0.19g/min, control) for their brief treadmill duration. Heat stress and DNP prevented the normal reduction in hematocrit and plasma protein levels during exercise while DNP increased osmolality and potassium levels post-exercise.

Descriptors :   *DRUGS, *ENDURANCE(PHYSIOLOGY), *HEAT STRESS(PHYSIOLOGY), *EXERCISE(PHYSIOLOGY), BLOOD PLASMA, BLOOD PROTEINS, BODY TEMPERATURE, BLOOD CHEMISTRY, HYPODERMIC INJECTIONS, DOSAGE, HEMATOCRIT, OSMOSIS, PHYSIOLOGICAL EFFECTS, OXIDATION, PHOSPHORYLATION, RATS, ROOM TEMPERATURE, SALIVA, SECRETION, TEMPERATURE CONTROL, TIME, TREADMILLS

Subject Categories : Pharmacology
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE