Bluegill fingerlings, Lepomis macrochirus, exposed to six different pesticide formulations, developed hemorrhaging and fractures of the caudal vertebrae 4 to 8 hours after treatment. Fish exposed to Dyrene(R) Akton(R), methyl parathion, trichlorfon, phosalone and demeton developed vertebral injury. Injury was observed at concentrations above and below the LC50for each chemical. Disturbance of fish during the early hours of exposure increased mortality and hemorrhage rates. (Use of trade names does not constitute endorsement by the U.S. Environmental Protection Agency.)

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Oxygen uptake of liver, kidney and brain slices was determined from intact and castrated male rats exposed to cold (2 ± 2°C) and treated with either testosterone propionate or sesame oil. Rats were treated with 1 mg testosterone propionate or 0.1 cc sesame oil daily for periods of 15 and 50 days. Another group of intact and castrated rats were maintained at room temperature (23 ± 2°C) and treated similarly to the animals exposed to cold. The oxygen uptake of the tissue slices was compared to that observed in tissue slices from control rats receiving no treatment. Castration caused an increase in oxygen uptake and treatment with testosterone propionate caused a decrease. Treatment of intact and castrated rats with testosterone propionate during cold exposure resulted in increased oxygen uptake. Sesame oil alone, likewise, resulted in increased oxygen uptake of liver and brain slices from castrated rats treated during cold exposure. The oxygen uptake of kidney slices from castrated rats was not affected by exposure to cold.

Oxygen uptake of liver, kidney and brain slices from cold-and heat-exposed adult, male mice was studied using the Warburg constant volume respirometer. In general, oxygen uptake showed certain similarities for both groups. The greatest oxygen increase from the control was observed after 72 hours of cold or heat exposure. For liver slices this was 21 and 6%, respectively; for kidney it was 23 and 27%; and for brain 33 and 31%, respectively. The lowest rate of oxygen uptake was seen after 48 hours of cold or heat exposure. For liver slices this was –27 and 6%; kidney, –7 and +14%; and for brain –10 and –2%, respectively. The mortality rate was increased in the heat-exposed more than in the cold-exposed animals. It is concluded that the response of oxygen uptake of these tissues from animals exposed to these divergent stresses (cold and heat) conforms to the pattern of the General-Adaptation-Syndrome.

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