Umbilical blood pressures and utero-placental blood flow in spontaneously hypertensive rats.
Some substrains of spontaneously hypertensive rats (SHR) are hypertensive at birth, suggesting the possibility of pre-natal hypertension. Fetal haemodynamics are sensitive to utero-placental blood flow changes. Thus, we used micropuncture to measure umbilical vein blood pressure (BP) in SHR and Wistar-Kyoto rats (WKY) at 18 and 20 days post-conception. We determined utero-placental blood flow (UPBF) at 17 and 20 days post-conception by the microsphere method. Results showed that SHR fetuses were hypertensive only at 20 days. Fetal heart:body weight ratio was higher in SHR, decreased with age and was not associated with BP or heart rate. Utero-placental weight was not affected by either age or strain. However, utero-placental blood flow was low in SHR at 20 days. Thus, in SHR pre-natal hypertension occurs between 18 and 20 days post-conception; pre-natal hypertension is associated with low utero-placental blood flow.
Azar
S
S
Meyer
M W
MW
Myers
J
J
D000818:Animals; D001794:Blood Pressure; D005314:Embryonic and Fetal Development; D005260:Female; D006973:Hypertension / Q000235:genetics* / Q000503:physiopathology; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011919:Rats, Inbred Strains / Q000502:physiology*; D014471:Umbilical Veins / Q000502:physiology*