Hypothermia produced by tributyl S,S,S-phosphorotrithioate (DEF)

Area of Science:

• Pharmacology
• Physiology
• Toxicology

Background:

• Thermogenesis is crucial for maintaining body temperature.
• Hypothalamia plays a key role in regulating thermogenesis.
• Chemical agents can disrupt thermoregulatory processes.

Purpose of the Study:

• To investigate the mechanism by which Tributyl S,S,S-phosphorotrithioate (DEF) induces hypothermia.
• To determine if DEF affects peripheral thermogenic capacity or central thermoregulation.

Main Methods:

• Administration of DEF to rats, mice, and guinea pigs.
• Measurement of body temperature, shivering, and non-shivering thermogenesis.
• Assessment of peripheral thermogenic capacity through metabolic and in vitro assays.
• Evaluation of responses to anterior hypothalamic stimulation.

Main Results:

• DEF induced profound hypothermia in tested species.
• DEF inhibited both shivering and non-shivering thermogenesis.
• Peripheral thermogenic capacity remained intact, with normal metabolic responses and lipolysis.
• DEF blocked temperature increases from anterior hypothalamic stimulation.

Conclusions:

• DEF-induced hypothermia is likely due to a selective action on central thermogenic control.
• The mechanism does not involve a generalized failure of peripheral thermogenic capacity.
• A DEF metabolite may be responsible for the observed central effects.