Histochemical and ultrastructural studies on pancreatic A cells. Evidence for glucagon and non-glucagon components of the α granule

G. Bussolati, C. Capella, G. Vassallo, E. Solcia

Research output: Contribution to journalArticlepeer-review


Glucagon-storing cells were detected in the pancreatic islets of horse, guinea pig, rabbit, rat, dog and man by means of indirect immuno-histochemical procedures using fluorescein or peroxidase as markers of antiglucagon sera. By subsequently staining horse islets with selective staining techniques for A, B or D cells, it was directly ascertained that only A cells reacted to antiglucagon sera. A comparison of methods known to stain a granules with immuno-histochemical methods, as well as in vitro experiments on natural and synthetic glucagon, showed that the xanthydrol method, and perhaps also the o-phthalaldehyde method, should be regarded as specific histochemical tests for glucagon whereas the HCl-basic dye technique and phosphotungstic haematein should be considered as unspecific glucagon-staining methods,and Grimelius' silver as a method likely to be unrelated to glucagon. In ultrastructural investigations on the human pancreas, the core of the a granule heavily reacted to phosphotungstic acid and peroxidase-marked antiglucagon antibodies, while being unreactive to Grimelius' silver; conversely, the peripheral halo of the α granule heavily reacted to Grimelius' silver, while being poorly reactive or unreactive to phosphotungstic acid and anti-glucagon antibodies. Thus, both light and electron microscopy findings point to a structural and chemical hetereogeneity of the α granule.

Original languageEnglish
Pages (from-to)181-188
Number of pages8
Issue number3
Publication statusPublished - Jun 1971


  • α-granule stains
  • A cells
  • electron histochemistry
  • glucagon
  • Grimelius' silver
  • HCl-basic dye
  • immuno-histochemistry
  • o-phthalaldehyde
  • Pancreatic islets
  • phosphotungstic acid
  • xanthydrol

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism


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