title: [Changes in the innervation of the taste buds in diabetic rats].
abstract: BACKGROUND
  Abnormal sensations such as pain and impairment of taste are symptoms of approximately 10% of patients having diabetes mellitus.
  
  
  OBJECTIVE
  The aim of the study was to investigate and quantify the different neuropeptide containing nerve fibres in the vallate papilla of the diabetic rat.
  
  
  METHODS
  Immunohistochemical methods were used to study the changes of the number of different neuropeptide containing nerve terminals located in the vallate papillae in diabetic rats. Diabetes was induced in the rats with streptozotocin.
  
  
  RESULTS
  Two weeks after streptozotocin treatment the number of the substance P, galanin, vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve terminals was significantly increased (p<0.05) in the tunica mucosa of the tongue. The number of the lymphocytes and mast cells was also increased significantly. Some of the immunoreactive nerve terminals were located in the lingual epithelium both intragemmally and extragemmally and were seen to comprise dense bundles in the lamina propria just beneath the epithelium. No taste cells were immunoreactive for any of the investigated peptides. Vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve fibres were not detected in the taste buds. For weeks after streptozotocin administration the number of the substance P, calcitonin gene related peptide and galanin immunoreactive nerve terminals was decreased both intragemmally and intergemmally. In case of immediate insulin treatment, the number of the immunoreactive nerve terminals was similar to that of the controls, however, insulin treatment given 1 week later to diabetic rats produced a decreased number of nerve fibers. Morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds (per papilla).
  
  
  CONCLUSIONS
  Increased number of immunoreactive nerve terminals and mast cells 2 weeks after the development of diabetes was the consequence of neurogenic inflammation which might cause vasoconstriction and lesions of the oral mucosa. Taste impairment, which developed 4 weeks after streptozotocin treatment could be caused by neuropathic defects and degeneration or morphological changes in the taste buds and nerve fibres.
authors.affiliation: Semmelweis Egyetem, Fogorvos-tudományi Kar Budapest.
authors.forename: Helén
authors.initials: H
authors.lastname: Hevér
authors.forename: Károly
authors.initials: K
authors.lastname: Altdorfer
authors.forename: Tivadar
authors.initials: T
authors.lastname: Zelles
authors.forename: Bayarchimeg
authors.initials: B
authors.lastname: Batbayar
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Fehér
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology; D003929:Diabetic Neuropathies / Q000378:metabolism* / Q000473:pathology*; D019004:Galanin / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007150:Immunohistochemistry; D007328:Insulin / Q000008:administration & dosage; D018655:Lymphocyte Count; D008297:Male; D008407:Mast Cells; D009411:Nerve Endings / Q000378:metabolism* / Q000473:pathology; D009478:Neuropeptide Y / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013311:Streptozocin; D013373:Substance P / Q000378:metabolism*; D013650:Taste Buds / Q000378:metabolism* / Q000473:pathology*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D009478:Neuropeptide Y; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D013311:Streptozocin; D019004:Galanin; D015740:Calcitonin Gene-Related Peptide