IN-VIVO MODULATION OF PROLIFERATING CELL NUCLEAR ANTIGEN IN GROWTH-PLATE CHONDROCYTES FROM NORMAL, HYPOPHYSECTOMIZED, AND GROWTH HORMONE-TREATED HYPOPHYSECTOMIZED RATS - A COMPARATIVE IMMUNOHISTOCHEMICAL STUDYWITH IMAGE-ANALYSIS

Citation
Y. Tajima et al., IN-VIVO MODULATION OF PROLIFERATING CELL NUCLEAR ANTIGEN IN GROWTH-PLATE CHONDROCYTES FROM NORMAL, HYPOPHYSECTOMIZED, AND GROWTH HORMONE-TREATED HYPOPHYSECTOMIZED RATS - A COMPARATIVE IMMUNOHISTOCHEMICAL STUDYWITH IMAGE-ANALYSIS, The Journal of histochemistry and cytochemistry, 44(7), 1996, pp. 713-720
Citations number
42
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell Biology
ISSN journal
0022-1554
Volume
44
Issue
7
Year of publication
1996
Pages
713 - 720
Database
ISI
SICI code
0022-1554(1996)44:7<713:IMOPCN>2.0.ZU;2-8
Abstract
Growth hormone (GH) regulates the proliferation and maturation of chon drocytes in the epiphyseal growth plate, in which a temporal dimension is superimposed on the septal organization of the tissue, In this stu dy we investigated the in vivo effects of hypophysectomy (Hyper) and i njection of GH into Hyper animals (Hypox + GH) on the proliferative ac tivity of the growth plate chondrocytes, We assessed the immunohistoch emical expression of proliferating cell nuclear antigen (PCNA) in para ffin-embedded tissues, using monoclonal antibody PC 10 against PCNA co mbined with immunogold-silver staining, We subjected the immunostained sections to computer-based image analysis by ACAS 570 interactive las er cytometry employing a conventional microscopic light source, Hyper was carried out on 20 rats at 8 weeks of age, half of which received a hypodermic injection of human GH at a dose of 1 IU/kg twice a day for 1 week after the operation, Another group of five rats of the same ag e were used as normal controls, In normal rats, a distinct PCNA immuno reaction was observed in the proliferative zone, whereas a remarkable diminution of the number of immunoreactive cells in this zone was appa rent in Hyper animals, On the other hand, marked hyperplasia of PCNA-p ositive tells was seen in the proliferative zone of the Hyper + GH rat growth plate, The immunoreactive cells of this zone in Hyper + GH ani mals exhibited increased nuclear size and staining intensity of PCNA c ompared with those in normal and Hyper rats, These findings were furth er confirmed by computer-based image analysis of the specimens in term s of cell integrated value, area, perimeter, and shape factor, These d ifferent patterns of PCNA expression may imply that GH specifically pr omotes the proliferation phase of the chondrocytes in the proliferativ e zone, The data also suggest that GH influences not only cell replica tion activity but also cell kinetics of chondrocytes in the growth pla te during their lifespan.