Acetylcholinesterase activity in the adrenal chromaffin vesicles of Urodela.

The presence of acetylcholinesterase (AChE) activity in the adrenal chromaffin cells of Necturus maculosus and Ambystoma maculatum (Amphibia, Urodela) has been demonstrated by cytochemical method at the electron microscope level. The enzymatic activity is localized in RER and perinuclear cisternae, on the plasma membrane and within the chromaffin vesicles, both in adrenaline (A) and noradrenaline (N) cells. Moreover N cells appear to be more reactive than A cells and Necturus more reactive than Ambystoma. The possible function of the AChE activity inside the vesicles is discussed as a mechanism of protons donor or as peptidasic activity acting on various peptides present in the vesicle.

Acetylcholinesterase and pseudocholinesterases in developing chick adrenal.

The distribution of acetylcholinesterase (AChE) and pseudocholinesterases (PsChE) in chick adrenal gland during the first phases of organogenesis was studied. Acetylthiocholine iodide and butyrylthiocholine iodide were used as substrates for the two enzymes, respectively, whereas BW284c51 (1,5 bis (4-allyldimethylammonium-phenyl)pentan-3-one-dibromide) and ISO-OMPA (tetraisopropylpyrophosphoramide) were used as respective inhibitors of AchE and PsChE. AchE was present on the plasma membrane, in the perinuclear cisterna and in some cisternae of the rough endoplasmic reticulum of both interrenal and chromaffin cells; moreover enzymatic activity was found in the same sites of ganglion cells and mesenchymatic undifferentiated cells, i.e. on the inside and in the proximity of the glandular anlage. PsChE activity was localized in the perinuclear space and in the rough endoplasmic reticulum of all types of cells in the anlage. It is suggested that these enzymatic activities may be implicated in morphogenetic mechanisms.

Active cell movements and embryonic cholinesterase in the postmetamorphic completion of the adrenal morphogenesis in frogs.

The adrenal gland in Rana esculenta complex, as in other advanced anurans, is not yet in its definitive position at the end of the metamorphosis and reaches it subsequently, before sexual maturity. The displacement takes place by various means, among which active cellular movements prevail. These are demonstrated by the presence of acetylcholinesterase (AChE) in noninnervated cells (embryonic AChE). The disintegration of the connective tissues which delimit the cords of the adrenal gland, the passive transport of cells by the blood vessels and the movements of adjacent renal and mesenchymal cells collaborate with the active movements of the adrenal cells.

[Chyliform effusions in rheumatoid arthritis. Cytochemical and ultrastructural studies of the foam cells]. / Les épancehements chyliformes de la polyarthrite chronique évolutive. Etudes cytochimiques et ultrastructurales des cellules spumeuses.

The authors studied the cell composition and the cytochemistry and ultrastructure of the frothy cells in two periarticular chyliform effusions in rheumatoid arthritis. Compared with the polymorphonuclear cells, the mononuclear cells were very numerous with many frothy cells. Cholesterol crystals, identified by X-ray diffraction, were detected in fluids by polarised light, but only cytochemically and with the transmission electron microscope in the spumous cells. The latter contained not only neutral fat, but also hydrophobic lipids and phospholipids, but no cholesterol esters. A theory has been advanced that once phagocytosis has been accomplished, cholesterol crystal metabolism is not rapid and is too insufficient for cholesterol or its esters to accumulate in the cytoplasm. The polymorphonuclear leukocytes play only a small role in the phagocytosis of crystals and this probably plays a role in the absence of acute inflammation in structures which contain chyliform effusions.

Comparative acid phosphatase distribution in the suprarenal gland of Discoglossus pictus, Xenopus laevis and Bufo bufo (Anurans, Amphibia).

Acid phosphatase activity was found to have a similar distribution in the suprarenal glands of Discoglossus pictus, Xenopus laevis and Bufo Bufo (Anurans, Amphibia) as determined by light and electron histochemical localization. The enzymatic activity is localized in the lysosomes of both the interrenal cells and the chromaffin cells. It is, moreover, positive on the granule membranes of the adrenaline cells whereas it appears only occasionally on the granule membranes of the noradrenaline cells. Some precipitates can also be seen occasionally at the level of the Golgi membranes.