An electron microscopic study of noradrenaline storage vesicles isolated from bovine splenic nerve trunk

Abstract

A partially purified homogenate of bovine splenic nerve trunk was layered over sucrose—heavy water density gradients to obtain a fraction with a relatively high NA:protein content. Fixation of this NA fraction with glutaraldehyde in suspension and during centrifugation results in the sedimentation of relatively pure vesicles in a large layer at the top of the pellet. With this combination of techniques it has been possible for the first time to identify homogeneous populations of isolated NA storage vesicles by electron microscopy. The vesicle size and morphology are entirely similar to those seen in axons of the starting material. The vesicles can be filled and depleted of matrix material by the same biochemical procedures known to produce parallel results in NA content. There are morphological similarities with isolated adrenal medullary vesicles.