Calcitonin gene-related peptide-immunoreactive nerves and neuroendocrine cells after lung transplantation in the rat.
Bronchial innervation is interrupted at lung transplantation. Nerve fibers with cell bodies above the section, such as sensory C fibers, should degenerate. Using histofluorescence, we evaluated calcitonin gene-related peptide (CGRP) immunoreactivity in syngeneic Lewis rats 1 and 5 mo after unilateral lung transplantation and in controls. CGRP-immunoreactive (IR) neuroendocrine cells were located within the epithelium of large and small bronchi. At 1 mo after transplantation, their number had significantly increased in large bronchi and had normalized 5 mo after transplantation. The density of CGRP-IR fibers in control lungs gradually decreased from large (0. 35 +/- 0.02 micron/micron basal lamina) to small (0.23 +/- 0.02) and peripheral bronchi (0.12 +/- 0.01). At 1 mo after lung transplantation, few CGRP-IR fibers were observed in large bronchi (0.17 +/- 0.02), fewer in small bronchi (0.04 +/- 0.01) (P < 0.01), and none in peripheral bronchi. At 5 mo after lung transplantation, transplanted lungs still had fewer CGRP-IR fibers in large (0.22 +/- 0.02) and small (0.11 +/- 0.02) bronchi (P < 0.02) than did controls, but there were, nonetheless, more in the small bronchi than at 1 mo after transplantation (P < 0.01). Additionally, few CGRP fibers were present in the peripheral bronchi (0.03 +/- 0.01) (P < 0.01). These results clearly demonstrate the occurrence of denervation followed by partial reinnervation with CGRP-IR fibers after transplantation in rat lung.
Buvry
A
A
INSERM U425, Faculté de Pharmacie, Illkirch, France.
Yang
Y R
YR
Tavakoli
R
R
Frossard
N
N
D000818:Animals; D001980:Bronchi / Q000033:anatomy & histology; D004848:Epithelium / Q000033:anatomy & histology; D016040:Lung Transplantation; D008297:Male; D009130:Muscle, Smooth / Q000033:anatomy & histology; D009416:Nerve Regeneration; D009474:Neurons / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000032:analysis / Q000378:metabolism*; D012038:Regeneration; D013997:Time Factors
D018015:Receptors, Calcitonin Gene-Related Peptide