Actions of cupric salts on isolated cerebral tissues

Abstract

Sections 0$\cdot $35 mm thick, cut from the cerebral hemispheres of guinea-pigs and pigeons, were incubated in oxygenated glucose salines which in some cases contained Cu$^{2+}$ at 12 to 300 $\mu $M (1 to 24 $\mu $g atom/g tissue). Though respiration was unaffected, Cu$^{2+}$ at 6 to 24 $\mu $g atom/g diminished the tissue's adenosine triphosphate, phosphocreatine and potassium content. Tissue Na was increased and the respiratory response of the tissue to electrical stimulation was diminished. Tissues which had been incubated with Cu$^{2+}$ were dispersed in sucrose solutions, microsomal fractions prepared from the dispersions, and their adenosine triphosphatase activities compared with preparations from tissues not exposed to Cu$^{2+}$. The Cu$^{2+}$ led to diminution of two categories of adenosine triphosphatase activity in the microsomal fractions. Reasons are given for considering that the changes in composition and excitability brought about by Cu$^{2+}$ in the cell-containing tissue are related to the diminished ATPase observed in the derived preparations.