Abstract: | 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. |