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Pressure dependence of so‐called transtrophoblastic channels during fetal perfusion of human placental villi
Author(s) -
Kertschanska Sonya,
Kosanke Georg,
Kaufmann Peter
Publication year - 1997
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/(sici)1097-0029(19970701/15)38:1/2<52::aid-jemt7>3.0.co;2-w
Subject(s) - perfusion , fetus , placenta , chemistry , fetal membrane , biophysics , andrology , obstetrics , medicine , biology , pregnancy , genetics
To test the influence of perfusion pressures on structural preservation of human placental villi and on the dilatation of the so‐called transtrophoblastic channels, cotyledons of 32 term human placentas have been perfused in vitro. Periods of perfusion with isotonic Ringer solution under various arterial and venous hydrostatic pressures were followed by perfusion fixation. In some experiments, lanthanum hydroxide as an extracellular marker was added to the fixative. Distention of the fetal vascular system, stromal edema and continuity, as well as trophoblastic vacuolization were studied via electron microscopy with subsequent morphometry. The findings suggest that arterial hydrostatic pressures in the perfusion system of about 80 cm H 2 O are needed to guarantee homogeneous perfusion of the fetal vascular system. To avoid stromal edema and trophoblastic vacuolization, venous hydrostatic pressures of 4 cm H 2 O and arterial hydrostatic pressures of 80 cm H 2 O should not be exceeded. It is concluded that the trophoblastic vacuoles are dilated segments of the so‐called transtrophoblastic channels. The functional importance of in vivo variations of fetal intravascular hydrostatic pressure for the dilatation of transtrophoblastic channels and for fetal water balance is discussed. Microsc. Res. Tech. 38:52–62, 1997. © 1997 Wiley‐Liss, Inc.