Turnover and metabolism of norepinephrine in rat brain after 72 hours on a D-deprivation island.

Abstract

The changes in norepinephrine turnover and metabolism in brain were examined in rats maintained for 72 h on small square islands of the size shown to produce D-deprivation. The utilization of norepinephrine in brain (as reflected by the rate of disappearance of intracisternally administered norepinephrine-H3 from brain) and the apparent rate of synthesis of norepinephrine were increased after 72 h on the islands. Within 120 min after animals were removed from the islands and placed in “recovery” chambers, the rate of disappearance of norepinephrine-H3 from brain returned to approximately control values; but the apparent increase in norepinephrine synthesis persisted somewhat longer. Since many physiological alterations may have occurred under the stressful conditions of these experiments, it is not possible, on the basis of the present data, to relate (either as a specific cause or effect) the changes in norepinephrine turnover to particular alterations in the sleep cycle.