Cell and Tissue Research

, Volume 186, Issue 3, pp 453–463

Calcium and sulphur in neurosecretory granules and calcium in mitochondria as determined by electron microscope X-ray microanalysis

  • Tom Christian Normann
  • Theodore A. Hall
Article

DOI: 10.1007/BF00224934

Cite this article as:
Christian Normann, T. & Hall, T.A. Cell Tissue Res. (1978) 186: 453. doi:10.1007/BF00224934

Summary

Sections of neurosecretory cells fixed in glutaraldehyde and osmium tetroxide were studied by means of an EMMA-4 analytical microscope. Secretory granules in neurosecretory cells of the corpus cardiacum and of the brain, both in the desert locust Schistocerca and in the blowfly Calliphora, as well as neurosecretory granules in posterior pituitaries of the frog Rana and of the albino rat all contain a high concentration of calcium. A distinct sulphur peak was also a constant feature.

In neurosecretory cells of the corpus cardiacum of Schistocerca the chromatin contained a high concentration of calcium. The mitochondria also contained much calcium, but part of this disappeared during preparation except when fixative and wash contained calcium chloride. By block staining with uranyl acetate most calcium is displaced from the mitochondria, whereas most of the calcium remains in the neurosecretory granules. Since the calcium peaks in spectra from neurosecretory granules appear of similar size, regardless of variations in the preparative procedure, this calcium must be firmly bound. The possible role of the calcium bound to the neurosecretory substance is discussed.

The presence of sulphur in insect neurosecretory granules indicates the presence of a protein besides the hormone, i.e., an insect neurophysin.

Key words

Neurosecretory granules (Insects)MitochondriaCalciumSulphurMicroanalysis

Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • Tom Christian Normann
    • 1
  • Theodore A. Hall
    • 1
  1. 1.Department of ZoologyUniversity of CambridgeCambridgeEngland
  2. 2.Institute of General Zoology, University of CopenhagenCopenhagen ØDenmark