Effects of hypoxia, anoxia, and endogenous ethanol on thermoregulation in goldfish, Carassius auratus.
Effects of hypoxia, anoxia, and endogenous ethanol (EtOH) on selected temperature (T(sel)) and activity in goldfish were evaluated. Blood and brain EtOH concentrations ([EtOH]) and brain oxygen partial pressure (PO(2)) were quantified at crucial ambient oxygen pressures. Below a threshold value near 31 Torr, T(sel) decreased as a function of environmental PO(2). T(sel) of 15 degrees C-acclimated fish was approximately 10 degrees C at the onset of anoxia and changed little over 2 h. Activity showed a similar response pattern. Brain [EtOH] was significantly elevated above control levels after 1 h anoxia. In normoxic water, T(sel) remained different in previously anoxic and normoxic control fish for approximately 20 min. Blood [EtOH] of previously anoxic fish remained significantly elevated ([EtOH] >4.0 micromol/g blood), and activity was significantly depressed at 20 min. Brain PO(2) reached normal levels in <3 min. We conclude that [EtOH] (brain or blood) and brain PO(2) are not proximal causes of either behavioral anapyrexia (hypothermia) or inactivity in goldfish exposed to oxygen-depleted environments.
Rausch
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Department of Biology, Organismal Section, Portland State University, Portland 97207, Oregon.
Crawshaw
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Wallace
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D000222:Adaptation, Physiological; D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D000431:Ethanol; D006054:Goldfish / Q000502:physiology*; D000860:Hypoxia
D000431:Ethanol