| N omega-nitro-L-arginine, an inhibitor of nitric oxide synthesis, increases blood pressure in rats and reverses the pregnancy-induced refractoriness to vasopressor agents. | |
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MedLine Citation:
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PMID: 1595813 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: With N omega-nitro-L-arginine, a potent inhibitor of nitric oxide synthesis, we tested the hypothesis that nitric oxide plays a functional role in the blunted pressor responsiveness seen during pregnancy. STUDY DESIGN: A group of six pregnant rats were instrumented on the fourteenth day of gestation and studied on days 19 and 20, as well as 7 days post partum. Another group of six virgin rats were similarly prepared and used 5 days after surgery. Blood pressure and heart rate were monitored in conscious freely moving animals before and during the administration of drugs or placebo. Results were analyzed, by one-way repeated-measures analysis of variance, with Dunnett's t test, or by paired t test where applicable. RESULTS: Basal mean arterial pressure and heart rate were 90.8 +/- 3.0 mm Hg and 330 +/- 6 beats/min in pregnant animals and 107.1 +/- 3.2 mm Hg and 315 +/- 7 beats/min in nonpregnant animals. Pressor responses to angiotensin II, vasopressin, and norepinephrine were attenuated in gravid animals. Infusion of N omega-nitro-L-arginine significantly and in a dose-dependent manner increased mean arterial pressure and reduced heart rate. These effects could be completely reversed by L-arginine administration. Changes in mean arterial pressure were higher during pregnancy as compared with postpartum values. N omega-nitro-L-arginine infusion potentiated pressor responses to all three vasopressors, resulting in dose-response curves that were significantly shifted to the left, making them virtually identical in pregnant and postpartum rats. CONCLUSION: Our data support the emerging view that nitric oxide plays a key role in the regulation of blood pressure during pregnancy. |
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Authors:
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M Molnár; F Hertelendy |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: American journal of obstetrics and gynecology Volume: 166 ISSN: 0002-9378 ISO Abbreviation: Am. J. Obstet. Gynecol. Publication Date: 1992 May |
Date Detail:
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Created Date: 1992-06-26 Completed Date: 1992-06-26 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370476 Medline TA: Am J Obstet Gynecol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 1560-7 Citation Subset: AIM; IM |
Affiliation:
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Department of Obstetrics and Gynecology, St. Louis University School of Medicine, MO 63110-0250. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Angiotensin II
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pharmacology Animals Arginine / analogs & derivatives*, pharmacology Blood Pressure / drug effects* Drug Synergism Female Heart Rate / drug effects Nitric Oxide / antagonists & inhibitors* Nitroarginine Norepinephrine / pharmacology Pregnancy Pregnancy, Animal / physiology* Rats Rats, Inbred Strains Vasoconstrictor Agents / pharmacology* Vasopressins / pharmacology |
| Chemical | |
Reg. No./Substance:
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0/Vasoconstrictor Agents; 10102-43-9/Nitric Oxide; 11000-17-2/Vasopressins; 11128-99-7/Angiotensin II; 2149-70-4/Nitroarginine; 51-41-2/Norepinephrine; 74-79-3/Arginine |
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