17-Hydroxyprogesterone caproate reverses induced vasoconstriction of the fetoplacental arteries by the thromboxane mimetic U46619.
OBJECTIVE
This study was undertaken to determine whether 17-hydroxyprogesterone caproate (17P) has a vasoactive effect on fetoplacental vasculature.


METHODS
Two cotyledons were obtained from each of 5 placentas. Baseline perfusion was established with Hanks-based solution. One cotyledon from each pair was then infused with perfusate to which U46619 a thromboxane sympathomimetic had been added. After 30 minutes, a dose of 17P was then administered to each cotyledon. Finally, a vasoconstricting dose of angiotensin II was administered to each cotyledon. Perfusion pressures were recorded throughout. Statistical analysis of pressure change for a single cotyledon was performed by using a paired t test. Statistical analysis of mean perfusion pressure difference between U46619 exposed and nonexposed cotyledons was analyzed by using a students t test.


RESULTS
17P did not significantly alter the perfusion pressure of the control cotyledon. (30.6 +/- 8.3 mm Hg vs 30.1 +/- 7.8 mm Hg P = .48). 17P administration significantly lowered the perfusion pressure of the U46619 preconstricted vessels in comparison with preadministration. (60.1 +/- 13 mm Hg vs 27.3 +/- 7.1 mm Hg P = .03). Both groups of cotyledons responded with vasoconstriction to angiotension II with no difference in response between groups (38.3 +/- 12 mm Hg vs 45.8 +/- 8.2 mm Hg P = .63).


CONCLUSIONS
17P reverses induced vasoconstriction by U46619 in fetoplacental arteries.
Paonessa
Damian J
DJ
Division of Maternal-Fetal Medicine, Madigan Army Medical Center, Tacoma, WA 98431-1100, USA. dmpaonessa2000@yahoo.com
Shields
Andrea D
AD
Howard
Bobby C
BC
Gotkin
Jennifer L
JL
Deering
Shad H
SH
Hoeldtke
Nathan J
NJ
Napolitano
Peter G
PG
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology*; D000077713:17 alpha-Hydroxyprogesterone Caproate; D000804:Angiotensin II / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D005333:Fetus / Q000098:blood supply*; D006801:Humans; D006908:Hydroxyprogesterones / Q000494:pharmacology*; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D014661:Vasoconstriction / Q000187:drug effects*
D016207:Cytokines; D006908:Hydroxyprogesterones; D000804:Angiotensin II; D000077713:17 alpha-Hydroxyprogesterone Caproate; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid