Alterations of the fetal capillary bed in the guinea pig placenta following long-term hypoxia.
Oxygen supply is an important regulator of the fetal placental capillarization. To determine the effects of long-term hypoxia on the fetal placental vessel arrangement pregnant guinea pigs were kept under hypoxic conditions (12% O2 for 45 days). Vessel casts showed a significant difference in branching and orientation of the vessels between the controls and the hypoxic animals. The hypoxic group had a less orientated capillary bed with increased branching and coiling. By light- and transmission electron microscopical studies, there was a decreased diffusion distance, a decreased diameter of the fetal capillaries, and an increased number of capillary cross-sections. These results are consistent with the hypothesis that chronic hypoxia is responsible for increased branching and coiling of the capillaries resulting in a dense network of short and narrow capillaries in the placenta.
Scheffen
I
I
Dept. of Anatomy, Medical Faculty, Technical University of Aachen, F.R.G.
Kaufmann
P
P
Philippens
L
L
Leiser
R
R
Geisen
C
C
Mottaghy
K
K
D000818:Animals; D002196:Capillaries / Q000378:metabolism / Q000473:pathology; D005260:Female; D005333:Fetus / Q000098:blood supply / Q000378:metabolism; D006168:Guinea Pigs; D000860:Hypoxia / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D010920:Placenta / Q000098:blood supply* / Q000378:metabolism; D011247:Pregnancy; D011248:Pregnancy Complications / Q000378:metabolism / Q000473:pathology*
D010100:Oxygen