| Evidence of a nonendothelial source of nitric oxide in the isolated perfused hindlimb vasculature of the pregnant rat. | |
| | |
MedLine Citation:
|
PMID: 10463996 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
OBJECTIVE: This study was undertaken to further elucidate the roles of the vascular endothelium and nitric oxide (NO) in the regulation of vascular tone and constrictor responsiveness in pregnancy. METHODS: The perfusion pressure-flow relationship was measured in isolated, perfused, norepinephrine-constricted (1) endothelium-intact, (2) endothelium-denuded, and (3) N omega-nitro-L-arginine methyl ester (L-NAME)-treated hindlimbs from nonpregnant and term-pregnant rates. RESULTS: Baseline perfusion pressure at a flow rate of 2 mL/min was similar (approximately 20 min Hg) in all hindlimbs. Norepinephrine (0.5 muM) increased perfusion pressure in both nonpregnant (+21.6 +/- 2.4 mm Hg) and pregnant (+13.6 +/- 0.9 mm Hg) endothelium-intact rat hindlimbs. In nonpregnant rat hindlimbs, endothelium removal and L-NAME increased norepinephrine vasoconstriction similarly (+44.3 +/- 4.0 mm Hg and +46.4 +/- 8.6 mm Hg, respectively). In pregnant-rat hindlimbs, L-NAME increased norepinephrine vasoconstriction by 43.5 +/- 10.8 mm Hg, similar to that in nonpregnant-rat hindlimbs, but endothelium removal only increased norepinephrine vasoconstriction by 28.0 +/- 2.2 mm Hg. Perfusion pressure increased linearly as the flow rate was increased from 2 to 4 mL/min, and the slope of the regression line of the endothelium-intact pregnant-rat hindlimbs (7.0 +/- 0.6) was slightly, but not significantly, lower than that of the nonpregnant-rat hindlimbs (9.6 +/- 0.9). Endothelium removal increased the slopes of the regression lines, but that of pregnant-rat hindlimbs (12.8 +/- 1.6) was significantly lower (p < or = 0.05) than that of the nonpregnant-rat hindlimbs (23.8 +/- 1.8). L-NAME caused a similar increase in the pressure-flow slopes of nonpregnant-rat (36.5 +/- 3.4) and pregnant-rat (32.1 +/- 5.3) hindlimbs. CONCLUSIONS: These results suggest that nonendothelial nitric oxide production may be increased in the hindlimb resistance vasculature of the pregnant rat, which may play a role in the normal pregnancy blunting of constrictor responsiveness and reduction of vascular resistance. |
| | |
Authors:
|
S L Lubarsky; B M Sibai; R A Ahokas |
Related Documents
:
|
3322566 - Calcium content in liver and heart and its intracellular distribution in liver during e... 9755126 - Dietary k+ restriction upregulates total and sch-28080-sensitive bicarbonate absorption... 8123666 - Hepatic metabolism during constant infusion of fructose; comparative studies with 31p-m... 1099006 - In situ separation of bacterial trapping and killing functions of the perfused liver. 8345536 - Lack of effect of carcinogen treatment on development of tumors arising spontaneously i... 4015736 - Induction of cytochrome p-450 isozymes in liver microsomes of rats treated with the car... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Hypertension in pregnancy : official journal of the International Society for the Study of Hypertension in Pregnancy Volume: 18 ISSN: 1064-1955 ISO Abbreviation: Hypertens Pregnancy Publication Date: 1999 |
Date Detail:
|
Created Date: 2000-03-20 Completed Date: 2000-03-20 Revised Date: 2009-05-12 |
Medline Journal Info:
|
Nlm Unique ID: 9421297 Medline TA: Hypertens Pregnancy Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 11-21 Citation Subset: IM |
Affiliation:
|
Department of Obstetrics and Gynecology, University of Tennessee, Memphis 38103, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acetylcholine
/
pharmacology Animals Endothelium, Vascular / drug effects, metabolism* Enzyme Inhibitors / pharmacology Female Hindlimb / blood supply NG-Nitroarginine Methyl Ester / pharmacology Nitric Oxide / biosynthesis* Norepinephrine / pharmacology Pregnancy Rats Rats, Inbred WKY Vasoconstrictor Agents / pharmacology Vasodilator Agents / pharmacology |
| Chemical | |
Reg. No./Substance:
|
0/Enzyme Inhibitors; 0/Vasoconstrictor Agents; 0/Vasodilator Agents; 10102-43-9/Nitric Oxide; 50903-99-6/NG-Nitroarginine Methyl Ester; 51-41-2/Norepinephrine; 51-84-3/Acetylcholine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: 24-hour ECG frequency-domain measures in preeclamptic and healthy pregnant women during and after pr...
Next Document: Maternal factors modulate the increase in vasoactive substances during rat pregnancy.