Immunohistochemical evidence for sympathetic denervation and reinnervation after necrotic injury in rat myocardium.
To study the short and long term effects of myocardial injury on sympathetic nerve fibers, a necrotizing lesion was performed on the diaphragmatic side of rat myocardium by freeze-thawing. Animals were sacrificed at 2, 6, 18, 28 and 105 days after the surgical procedure and paraffin-embedded hearts were subjected to peroxidase immunohistochemistry. According to previous studies cardiac nerves were visualized by staining their surrounding Schwann cells with an anti-S100 protein antibody. Catecholaminergic axons were specifically identified by an anti-tyrosine hydroxylase antibody. No S-100 positive structures were found in 2-day lesions (denervation). Starting from day 6,S-100 positive structures became progressively more evident (reinnervation) and persisted up to day 105. Many of these newly formed nerve fibers were positive for tyrosine hydroxylase, indicating that a necrotic injury of rat myocardium causes a disappearance of sympathetic innervation which is followed by a phase of sympathetic reinnervation.
Nori
S L
SL
Institute of Human Anatomy, Catholic University, Rome, Italy.
Gaudino
M
M
Alessandrini
F
F
Bronzetti
E
E
Santarelli
P
P
D000818:Animals; D015415:Biomarkers; D003714:Denervation; D005615:Freezing; D006321:Heart / Q000294:innervation*; D006352:Heart Ventricles; D007150:Immunohistochemistry / Q000379:methods; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D009412:Nerve Fibers / Q000502:physiology* / Q000648:ultrastructure; D009416:Nerve Regeneration; D051381:Rats; D017208:Rats, Wistar; D009418:S100 Proteins / Q000032:analysis; D013564:Sympathetic Nervous System / Q000502:physiology*; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D015415:Biomarkers; D009418:S100 Proteins; D014446:Tyrosine 3-Monooxygenase