Science
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The addition of cortisol acetate and deoxycorticosterone acetate to cultured heart cells from rats, 4 to 6 days old, stimulated and prolonged beating. Protein synthesis was slowed down in the presence of steroids. Addition of steroids to cells that had stopped beating caused the reestablishiment of the beat.
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The anesthetizing concentrations in water of diethyl ether, chloroform, halothane (CF(3)CClBrH), and methaxyflurane (CHCl(2)CF(2)OCH(3)) have been determined for temperature-acclimated goldfish (Carassius auratus) at 5 degrees to 30 degrees C. At 20 degrees C, the concentrations that anesthetize 50 percent of the fish are 2160, 167, 76.4, and 57.0 mg/ liter, respectively; the corresponding partial pressures are 13.0, 3.36, 4.12, and 0.67 mm-Hg. The anesthetizing partial pressures increase with body temperature, with enthalpies of 8.6, 13.2, 12.5, and 12.3 kcal/ mole, respectively.
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Severe depletion of endogenous norepinephrine was observed in the brain, heart, liver, and spleen of albino rabbits in which hemorrhagic shock had been induced. On the other hand, the epinephrine content of these tissues was significantly elevated above the levels in tissues of control animals. The norepinephrine and epinephrine levels of skeletal muscle in shocked animals remained unaffected.