Hepatic sinusoidal pseudocapillarization with aging in the non-human primate.
OBJECTIVE
Age-related changes in the hepatic sinusoid termed pseudocapillarization have been reported in the rat and human and have implications for disease susceptibility in old age. In this study, we investigated whether similar changes occur in the livers of old baboons and thus represent a widespread aging change.


METHODS
Liver tissue from five young baboons (5.4+/-0.5yrs) and five old baboons (21.8+/-0.7yrs) was compared by transmission electron microscopy, scanning electron microscopy and immunohistochemistry.


RESULTS
The thickness of the sinusoidal endothelium was increased in old baboons (130+/-8 nm versus 186+/-9 nm, P<0.001) and the frequency of endothelial fenestrae decreased, with the porosity declining from 4.2+/-0.5% to 2.4+/-0.4% (P=0.006). The expression of laminin and von Willebrands factor was more extensive in old baboons. Novel perisinusoidal ring-shaped cells, probably fat-engorged stellate cells, were prominent in the old baboons.


CONCLUSIONS
Pseudocapillarization is a significant age-related change in the baboon liver. Aging in baboons is associated with a novel aging change in the stellate cell not reported in other species. Hepatic pseudocapillarization is a widespread aging liver change found in several species including humans and other non-human primates.
Centre for Education and Research on Ageing and ANZAC Research Institute, University of Sydney, Concord RG Hospital, Sydney, NSW 2139, Australia. victoric@physiol.usyd.edu.au
Victoria C
VC
Cogger
Alessandra
A
Warren
Robin
R
Fraser
Meng
M
Ngu
Allan J
AJ
McLean
David G
DG
Le Couteur
D000375:Aging / Q000378:metabolism / Q000473:pathology* / Q000502:physiology; D000818:Animals; D002196:Capillaries / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000648:ultrastructure; D005260:Female; D022781:Hepatocytes / Q000648:ultrastructure; D007797:Laminin / Q000378:metabolism; D008099:Liver / Q000098:blood supply* / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D010215:Papio / Q000033:anatomy & histology* / Q000378:metabolism / Q000502:physiology; D014841:von Willebrand Factor / Q000378:metabolism
D007797:Laminin; D014841:von Willebrand Factor