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Restriction of placental and fetal growth in sheep alters fetal blood pressure responses to angiotensin II and captopril
Author(s) -
Edwards L. J.,
Simonetta G.,
Owens J. A.,
Robinson J. S.,
McMillen I. C.
Publication year - 1999
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1999.897ab.x
Subject(s) - captopril , blood pressure , fetus , gestation , medicine , endocrinology , angiotensin ii , mean arterial pressure , pregnancy , biology , heart rate , genetics
1 We have measured arterial blood pressure between 115 and 145 days gestation in normally grown fetal sheep (control group; n = 16 ) and in fetal sheep in which growth was restricted by experimental restriction of placental growth and development (PR group; n = 13 ). There was no significant difference in the mean gestational arterial blood pressure between the PR (42.7 ± 2.6 mmHg) and control groups (37.7 ± 2.3 mmHg). Mean arterial blood pressure and arterial P O 2were significantly correlated in control animals ( r = 0.53, P < 0.05, n = 16 ), but not in the PR group. 2 There were no changes in mean arterial blood pressure in either the PR or control groups in response to captopril (7.5 μg captopril min −1 ; PR group n = 7 , control group n = 6 ) between 115 and 125 days gestation. After 135 days gestation, there was a significant decrease ( P < 0.05 ) in the fetal arterial blood pressure in the PR group but not in the control group during the captopril infusion (15 μg captopril min −1 ; PR group n = 7 , control group n = 6 ). 3 There was a significant effect ( F = 14.75 ; P < 0.001 ) of increasing doses of angiotensin II on fetal diastolic blood pressure in the PR and control groups. The effects of angiotensin II were different ( F = 8.67 ; P < 0.05 ) in the PR and control groups at both gestational age ranges. 4 These data indicate that arterial blood pressure may be maintained by different mechanisms in growth restricted fetuses and normally grown counterparts and suggests a role for the fetal renin‐angiotensin system in the maintenance of blood pressure in growth restricted fetuses.