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Effect of prostaglandin F2 alpha (PGF2 alpha) on oviductal nitric oxide synthase (NOS) activity: possible role of endogenous NO on PGF2 alpha-induced contractions in rat oviduct.
- Source :
-
Prostaglandins & other lipid mediators [Prostaglandins Other Lipid Mediat] 1998 Jun; Vol. 56 (2-3), pp. 155-66. - Publication Year :
- 1998
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Abstract
- In this paper, we evaluated the hypothesis that prostaglandin F2 alpha (PGF2 alpha) regulates NOS activity and we also investigated, by means of nitric oxide inhibitors (N-monomethyl-L-arginine monoacetate, L-NMMA) the role of endogenous NO on PGF2 alpha-induced contractions in rat oviduct. NOS activity was determined by measuring the conversion of 14[C]-L-arginine to 14[C]-L-citrulline on oviductal homogenates from estrogenized rats (1 microgram/rat). The presence of PGF2 alpha (10(-8) M) in the incubation medium produced an increase in NOS activity (p < or = 0.05). The effect of the prostanoid was blocked completely by the presence of two NOS inhibitors: N-nitro-L-arginine methyl ester (L-NAME, 0.6 mM) and aminoguanidine (Ag, 0.5 mM). These results suggested that PGF2 alpha could be modulating the Ca(2+)-independent NOS activity. We determined NOS activity using 1 mM EGTA, a chelator of Ca2+, in a free Ca2+ medium. These results indicated that PGF2 alpha produces an increase in Ca(2+)-independent NOS activity (p < or = 0.05). PGF2 alpha induces contraction of the oviductal smooth muscle in a concentration dependent manner. L-NMMA enhanced PGF2 alpha induced contraction of the oviduct, providing indirect evidence that there is a basal release of NO in the oviduct, which may reduce and/or modulate the contractile effects of PGF2 alpha.
- Subjects :
- Animals
Arginine metabolism
Calcium pharmacology
Chelating Agents
Citrulline metabolism
Egtazic Acid pharmacology
Enzyme Inhibitors pharmacology
Fallopian Tubes enzymology
Female
Guanidines pharmacology
Muscle, Smooth physiology
NG-Nitroarginine Methyl Ester pharmacology
Nitric Oxide Synthase antagonists & inhibitors
Rats
Rats, Wistar
Dinoprost pharmacology
Fallopian Tubes physiology
Muscle Contraction drug effects
Nitric Oxide physiology
Nitric Oxide Synthase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1098-8823
- Volume :
- 56
- Issue :
- 2-3
- Database :
- MEDLINE
- Journal :
- Prostaglandins & other lipid mediators
- Publication Type :
- Academic Journal
- Accession number :
- 9785385
- Full Text :
- https://doi.org/10.1016/s0090-6980(98)00050-1