Expression of nitric oxide synthases in parathyroid gland adenoma and parathyroid gland hyperplasia.
OBJECTIVE
The aim of the presented study was to perform the immunohistochemical detection of endothelial (eNOS) and inducible (iNOS) isoform of nitric oxide synthase in the adenomatous and hyperplastic parathyroid gland in relation to the apoptotic process.


METHODS
Tissue samples from 12 patients with parathyroid gland adenoma (PGA) and 10 patients with secondary parathyroid gland hyperplasia (PGH) were collected during surgery at the Department of Otorhinolaryngology and Head and Neck Surgery of The First Faculty of Medicine in Prague.


METHODS
Three-step immunoperoxidase reaction on acetone-fixed cryostat sections was performed using both polyclonal and monoclonal antibodies against eNOS and iNOS. The detection of apoptotic cells was done using antibody against cleaved caspase-3 as an apoptotic marker.


RESULTS
The immunoreactivity to eNOS antibody was observed in the endothelial lining of vessels in PGA, PGH and in the rim of normal parathyroid gland adjacent to PGA sample. Variable expression of eNOS was confirmed in arteries, arterioles, capillaries and veins in the glandular parenchyma as well as in the surrounding connective tissue. There was no iNOS immunoreactive cell detected in any examined sample. No apoptotic cells were detected.


RESULTS
Our findings confirm that eNOS is regularly expressed in the vasculature of PGA and PGH.


CONCLUSIONS
eNOS observed in the vasculature of the enlarged parathyroid glands can serve as a factor that contributes to the viability of hypertrophic pathologic tissue. The lack of stimulating signals may be a reason for negative iNOS detection and negligible apoptotic rate.
Kucera
Tomás
T
Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic. tkucer@lf1.cuni.cz
Veselý
David
D
Pácová
Hana
H
Martínek
Jindrich
J
Astl
Jaromír
J
D000236:Adenoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis; D006801:Humans; D006965:Hyperplasia; D007124:Immunoenzyme Techniques; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010280:Parathyroid Glands / Q000098:blood supply / Q000201:enzymology* / Q000473:pathology; D010282:Parathyroid Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology
C496314:NOS3 protein, human; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III