Long-term hypoxia induces changes in the substance P immunoreactivity pattern in laryngeal nerve paraganglia.
We previously showed that long-term hypoxia increases the dopamine content in rat laryngeal nerve paraganglia. In the present study paraganglia of rats exposed to hypoxia (10 +/- 0.5% O2) for 14 days were examined immunohistochemically to detect changes in the expression of neuropeptides and catecholamine-synthesizing enzymes. Hypoxia induced an intense cellular substance P (SP)-like immunoreactivity (LI) in some paraganglia and an increase in the number of stromal nerve fibers showing SP-LI in others. The patterns of tyrosine hydroxylase-, dopamine-beta-hydroxylase-, phenylethanolamine-N-methyltransferase-, vasoactive intestinal polypeptide-, neuropeptide-Y and calcitonin gene-related peptide-LI were not changed in response to hypoxia. The results show that hypoxia induces changes in the pattern of SP immunoreactivity in laryngeal nerve paraganglia and may indicate that SP plays a role in the regulation of catecholamine metabolism in this tissue.
D000818:Animals; D005455:Fluorescent Antibody Technique; D007823:Laryngeal Nerves / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008856:Microscopy, Fluorescence; D006899:Mixed Function Oxygenases / Q000032:analysis; D010100:Oxygen / Q000494:pharmacology*; D010234:Paraganglia, Nonchromaffin / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology; D010455:Peptides / Q000032:analysis; D010625:Phenylethanolamine N-Methyltransferase / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000032:analysis / Q000187:drug effects* / Q000276:immunology
D010455:Peptides; D013373:Substance P; D006899:Mixed Function Oxygenases; D010625:Phenylethanolamine N-Methyltransferase; D010100:Oxygen