Progestational agents prevent preterm birth induced by a nitric oxide synthesis inhibitor in the mouse.
BACKGROUND
The ability of the nitric oxide (NO) synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME) to induce preterm parturition in the mouse has been previously documented. The present study tested the ability of progestational agents to prevent preterm birth induced by L-NAME.


METHODS
L-NAME was administered subcutaneously at 90 mg/kg on gestation day 16. Progesterone, medroxyprogesterone acetate and hydroxyprogesterone caproate were administered subcutaneously at 0 (vehicle), 5 or 10 mg/kg on gestation day 16 one hour before L-NAME and on day 17. Parturition was considered preterm if occurring before gestation day 18.


RESULTS
Following treatment with L-NAME alone, 56.5% of the pregnant animals delivered before term. Treatment with progesterone, medroxyprogesterone acetate or hydroxyprogesterone caproate at 5 mg/kg or 10 mg/kg significantly and comparably reduced the rate of preterm birth caused by L-NAME.


CONCLUSIONS
Progestational agents are able to reduce preterm births induced by nitric oxide synthase (NOS) inhibition.
Tiboni
Gian Mario
GM
Sezione di Ostetricia e Ginecologia, Dipartimento di Medicina e Scienze dell'Invecchiamento, Facoltà di Medicina e Chirurgia, Università G. d'Annunzio, Chieti-Pescara, Ospedale SS. Annunziata, 66013 Chieti, Italy. tiboni@unich.it
Del Corso
Antonio
A
Marotta
Francesca
F
D000077713:17 alpha-Hydroxyprogesterone Caproate; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006908:Hydroxyprogesterones / Q000494:pharmacology; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011247:Pregnancy; D011270:Pregnancy, Animal; D047928:Premature Birth / Q000517:prevention & control; D011374:Progesterone / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D006908:Hydroxyprogesterones; D011372:Progestins; D000077713:17 alpha-Hydroxyprogesterone Caproate; D009569:Nitric Oxide; D011374:Progesterone; D017258:Medroxyprogesterone Acetate; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester