Local and systemic estradiol-17 beta: effects on uterine and systemic vasodilation.
Systemic estradiol-17 beta (E2 beta) administration increases uterine blood flow (UBF), cardiac output (CO), heart rate (HR), and plasma renin activity (PRA). We sought to determine if the E2 beta-induced systemic responses were dependent on the observed uterine responses. Nonpregnant, ovariectomized ewes (n = 5) received 3 micrograms E2 beta into both uterine arteries followed 120 min later by systemic E2 beta, 1 microgram/kg. At 120 min after local E2 beta, UBF increased from 26 +/- 5 to 161 +/- 21 ml/min (P less than 0.05); uterine vascular resistance (UVR) decreased 83 +/- 2.5% (P less than 0.05); and systemic parameters were unchanged. At 120 min after systemic E2 beta, UBF remained elevated and CO had increased gradually from 4.4 +/- 0.2 to 5.5 +/- 0.32 l/min (26 +/- 3.4%, P less than 0.05), reflecting a 37 +/- 3.9% (P less than 0.05) increase in HR; mean arterial pressure (MAP) remained unchanged. The increased CO was associated with a 20 +/- 3.1% (P less than 0.05) fall in systemic vascular resistance (SVR), with % delta SVR less than % delta UVR (P less than 0.05). Base-line PRA and angiotensin II, 1.31 +/- 0.2 ng.ml-1.h-1 and 10.3 +/- 2.1 pg/ml, respectively, were unchanged by local E2 beta; systemic E2 beta caused increases to 3.56 +/- 0.51 ng.ml-1.h-1 (P less than 0.05) and 34.1 +/- 11.3 pg/ml (P less than 0.05), respectively. E2 beta-induced uterine hyperemia occurs independent of its systemic effects and is not responsible for systemic cardiovascular alterations, and the relative uterine vascular responses exceed systemic responses.(ABSTRACT TRUNCATED AT 250 WORDS)
Magness
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RR
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235.
Rosenfeld
C R
CR
D000804:Angiotensin II / Q000097:blood; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007700:Kinetics; D010052:Ovariectomy; D012039:Regional Blood Flow / Q000187:drug effects; D012083:Renin / Q000097:blood; D012756:Sheep; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D000804:Angiotensin II; D004958:Estradiol; D012083:Renin