Immunogold staining procedure for the localisation of regulatory peptides.
The use of protein A- and IgG-conjugated colloidal gold staining methods for the immuno-localisation of peptide hormones and neurotransmitters at light- and electron microscope level are described and discussed. Bright-field and dark-ground illumination modes have been used to visualise the gold-labelled antigenic sites at the light microscope level. Immunogold staining procedures at the ultrastructural level using region-specific antisera have been adopted to localise specific molecular forms of peptides including gastrin (G17 and G34), glucagon and pro-glucagon, insulin and pro-insulin, in normal tissue and in tumours of the gastroenteropancreatic system. Similar methods have been used to demonstrate the heterogeneity of p-type nerves in the enteric nervous system. Vasoactive intestinal polypeptide (VIP) has been localised to granular sites (mean +/- S.D. granule diameter = 98 +/- 19 nm) in nerve terminals of the enteric plexuses and in tumour cells of diarrhoeogenic VIP-producing neoplasias (mean +/- S.D. granule diameter = 126 +/- 37 nm) using immunogold procedures applied to ultraviolet-cured ultrathin sections. Co-localisation of amines and peptides in carotid body type I cells and in chromaffin cells of normal adrenal medulla and phaeochromocytomas has also been demonstrated. Advantages of the immunogold procedures over alternative immunocytochemical techniques are discussed.
D000818:Animals; D002415:Cats; D005755:Gastrins / Q000032:analysis; D005934:Glucagon / Q000032:analysis; D006046:Gold; D006168:Guinea Pigs; D006651:Histocytochemistry / Q000379:methods*; D006736:Horses; D007328:Insulin / Q000032:analysis; D008854:Microscopy, Electron; D009420:Nervous System / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling; D013205:Staphylococcal Protein A; D013552:Swine
D005755:Gastrins; D007328:Insulin; D010455:Peptides; D013205:Staphylococcal Protein A; D006046:Gold; D005934:Glucagon