TY - JOUR
T1 - Effects of Stage of Gestation and Uterine Ligation on Ovine Placentome Development and Glycosaminoglycans
AU - Ott, Troy L.
AU - Wiley, Anne A.
AU - Bartol, Frank F.
PY - 1997/4
Y1 - 1997/4
N2 - Effects of restricting uterine space on physical, biochemical, and histochemical characteristics of ovine placental tissues were studied. Ewes (n = 20) were unilaterally ovariectomized, assigned to either control (C; n = 10) or unilateral (UPx; n = 10) pregnancy groups, mated (d 0), and hysterectomized on either d 60, 90, or 120. Placental and fetal weights and placentome wet weights (PWT) in three placental areas (AI, All, AIII) were recorded. Placentome tissue concentrations of RNA, DNA, hyaluronic acid (HA), and protein (TP) were determined. Overall, placentome numbers were reduced (P < .02) 23%, but individual PWT increased (P < .05) 27% in UPx ewes. In UPx ewes, neither total placental nor placentome weights, fetal weights, fetal crown-rump lengths, nor PWT:fetal weight ratios were affected by treatment (Trt). In the C and UPx groups, PWT increased (P < .01) from d 60 to 90. However, compensatory growth was confined to placental areas All and AIII in UPx groups (treatment x area, P < .01). Treatment did not affect concentrations of RNA, DNA, TP, or HA. However, RNA, DNA, and TP increased from d 60 to 120 (P < .01), but HA decreased (P < .01). Histologically, placentome cellularity increased from d 60 to 120 as area occupied by individual fetal chorioallantoic villi (FV) decreased. The FV stained with Alcian Blue 8X. Alcianophilia was attenuated at low pH and eliminated by pretreatment with hyaluronidase, indicating the presence of HA. Thus, increased placentomal cellularity was accompanied by loss of HA from fetal allantoic mesenchyme. Mechanisms regulating loss of HA from FV may support placental maturation and fetal growth.
AB - Effects of restricting uterine space on physical, biochemical, and histochemical characteristics of ovine placental tissues were studied. Ewes (n = 20) were unilaterally ovariectomized, assigned to either control (C; n = 10) or unilateral (UPx; n = 10) pregnancy groups, mated (d 0), and hysterectomized on either d 60, 90, or 120. Placental and fetal weights and placentome wet weights (PWT) in three placental areas (AI, All, AIII) were recorded. Placentome tissue concentrations of RNA, DNA, hyaluronic acid (HA), and protein (TP) were determined. Overall, placentome numbers were reduced (P < .02) 23%, but individual PWT increased (P < .05) 27% in UPx ewes. In UPx ewes, neither total placental nor placentome weights, fetal weights, fetal crown-rump lengths, nor PWT:fetal weight ratios were affected by treatment (Trt). In the C and UPx groups, PWT increased (P < .01) from d 60 to 90. However, compensatory growth was confined to placental areas All and AIII in UPx groups (treatment x area, P < .01). Treatment did not affect concentrations of RNA, DNA, TP, or HA. However, RNA, DNA, and TP increased from d 60 to 120 (P < .01), but HA decreased (P < .01). Histologically, placentome cellularity increased from d 60 to 120 as area occupied by individual fetal chorioallantoic villi (FV) decreased. The FV stained with Alcian Blue 8X. Alcianophilia was attenuated at low pH and eliminated by pretreatment with hyaluronidase, indicating the presence of HA. Thus, increased placentomal cellularity was accompanied by loss of HA from fetal allantoic mesenchyme. Mechanisms regulating loss of HA from FV may support placental maturation and fetal growth.
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U2 - 10.2527/1997.7541053x
DO - 10.2527/1997.7541053x
M3 - Article
C2 - 9110220
AN - SCOPUS:0031110101
SN - 0021-8812
VL - 75
SP - 1053
EP - 1062
JO - Journal of animal science
JF - Journal of animal science
IS - 4
ER -