Heterogeneity,position, and functional capability of the macrophages in Peyer's patches

Summary Radioenzymatic assays and light microscope radioautographic studies performed on photophores of Porichthys notatus demonstrated (1) significant amounts of catecholamines (dopamine, noradrenaline, adrenaline) and 5-hydroxytryptamine (serotonin) in these organs; (2) selective uptake and storage of ³H]noradrenaline (³H]NA) by axon terminals innervating the photocytes, and (3) strong accumulation of ³H]5-hydroxytryptamine (³H]5-HT) within the photocytes. Uptake and storage of ³H]NA in the nerve fibers were seemingly unaffected by the addition of ten-fold molar concentrations of unlabelled serotonin. Accumulation of ³H]5-HT by the photocytes was dose-dependent and diminished markedly in the presence of ten-fold molar concentrations of non-radioactive noradrenaline. Neither neuronal uptake of ³H]5-HT or ³H]A, nor photocytic accumulation of ³H]A were detectable under the conditions of the present experiments. This information should provide a framework for further investigations of the regulation of photophore luminescence by the biogenic amines.Supported by grants from the National Research Council and Medical Research Council of CanadaJacques de Champlain and Lise Farley provided facilities and expertise with the radioenzymatic techniques. The technical assistance of Sylvia Garcia and Marie-Hélène Parizeau was also appreciated