Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0406810 (NAME)
 13,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ischemic preconditioning (PC) has been shown to limit ischemia- and reperfusion-induced arrhythmias. We wished to determine whether the antiarrhythmic effect of PC would be affected by inhibition of the L-arginine nitric oxide (NO) pathway in anesthetized rats. Ischemia and reperfusion were produced by occlusion and release of a snare around the left coronary artery in all rats. The effect of PC (three cycles of 2-min coronary artery occlusion and 5-min reperfusion) on development of reperfusion-induced arrhythmias after 5-min coronary artery occlusion was studied in 12 rats. In 24 other rats, the specific NO synthesis inhibitor NG-monomethyl-L-arginine (L-NMMA 10 mg/kg, n = 12) or the muscarinic receptor antagonist-NO synthesis inhibitor nitro-L-arginine methyl ester (L-NAME 10 mg/kg, n = 12), was administered intravenously (i.v.) before PC. In control groups, solvent (n = 15), L-NAME (10 mg/kg i.v., n = 12), L-NMMA (10 mg/kg i.v., n = 12), or L-arginine (L-Arg 100 mg/kg i.v., n = 12) was administered to rats 5 min before coronary artery occlusion without PC. PC significantly reduced the incidence of ventricular premature beats (VPBs) from 100% in the non-PC solvent group to 17%, decreased the incidence of ventricular tachycardia (VT) from 93 to 8%, and abolished the incidence of reversible and irreversible ventricular fibrillation (RVF and IVF: 87 and 47% in the non-PC solvent group, respectively). L-NAME and L-NMMA did not significantly affect the protective effect of PC on reperfusion-induced arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Does the antiarrhythmic effect of ischemic preconditioning in rats involve the L-arginine nitric oxide pathway? 759 18

Bovine IVF oocytes were cultured in modified bovine embryo culture medium (mBECM) supplemented with either a nitric oxide (NO) scavenger, hemoglobin (Hb, 1 microg/mL) and/or a NO synthesis inhibitor, L(omega)-nitro-L-arginine methyl ester (L-NAME, 1 or 1000 nM) in a cumulus-granulosa cell co-culture system. In Experiment 1, a total of 1,675 cumulus-oocytes complexes was collected for 7 mo and cultured to the blastocyst stage in mBECM with or without Hb after IVM and IVF. There were significant (P<0.0024) model effects of Hb addition and month of oocyte collection on embryo development. A significant (P<0.0023) monthly variation was detected in all developmental stages. However, addition of Hb to mBECM consistently enhanced embryo development to the blastocyst stage over all months. No statistical differences were found in the interaction between Hb addition and month except for the cleavage rate. Overall, a greater percentage of oocytes developed to the 8-cell (P<0.0459), 16-cell (P<0.001), morula (P<0.0013) and blastocyst (P<0.0024) stages after the addition of Hb. In Experiment 2, addition of L-NAME to mBECM supplemented with Hb did not further stimulate prehatched development. In conclusion, the promoting effect of Hb on in vitro development of embryos is highly repeatable over an extended period of time.
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PMID:Development of bovine IVF oocytes cultured in medium supplemented with a nitric oxide scavenger or inhibitor in a co-culture system. 1072 16

The techniques of assisted reproduction have recently become the most effective methods of treatment of infertility; namely ICSI (intra-cytoplasmic sperm injection), MESA (microepididymal sperm aspiration), TESA (testicular sperm aspiration) and TESE (testicular sperm extraction). The techniques have been increasingly successful, even above the average efficiency of classical IVF (in vitro fertilization). It can be demonstrated by the percentage of ICSI-aided births percentage per 100% of embryotransfers in ISCARE; 1996 = 21.3%, 1997 = 26.15%, 1998 = 29.7%. The successful use of these techniques is associated with the rise of risks which result from the selection of couples for assisted reproduction with genetic-based infertility and with the rise of risks involving the introduction of genetic-based defects in to the next generation. Presently, a list of indications is being developed, which, while still not accepted officially, identifies patients for genetic counselling. Only the counselling center has the competence to estimate genetic risks over generations. Subsequently, after selection by the center, during 1997 and 1998 the chromosomes of 731 patients were cytogenetically examined, representing 429 infertile couples from the centres ISCARE, PRONATAL, FERTIMED, and CAR 1. LF UK. Within these 429 couples, belonging to four groups of indications, the cytogenetic examination was informative in 8.15%. This finding of a relatively high percentage (10 times more than in the general population) confirms the validity of the list of indications and the necessity of cooperation among the genetic counselling center, cytogenetic laboratory and the IVF centre.
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PMID:[Cooperation between genetic counseling centers, cytogenetic laboratories and in vitro fertilization centers in the treatment of reproductive disorders]. 1091 14

To establish a stable and real-time method to detect the production of intracellular nitric oxide (NO) of endothelial cells under different shear stresses. After the cultured endothelial cells were loaded with DAF-FM, the relative NO production was determined by fluorescence intensity, which was detected using Zeiss Axioskop 2 fluorescence microscope and ICCD-camera. The fluorescence of DAF-FM can reflect NO production. Shear stress can induce a dose-dependent increase of NO production, and the increase can be totally inhibited by L-NAME and partly inhibited by Ca(2+)-free buffer. The method can be used to detect the change of NO production in real time, and it can also be used to study the mechanism related to NO increase induced by shear stress.
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PMID:Real-time detection of nitric oxide in cultured rat aorta endothelial cells induced by shear stress. 1262 57

In the present study the authors investigated if the inhibitory effect of leptin in the ovary was mediated via nitric oxide (NO) using human granulosa cells (GCs). Human GCs were obtained from preovulatory follicles of women who underwent IVF. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that human GCs expressed mRNA of leptin and mRNA of isoforms of leptin receptor, including one long form and two types of short forms. Exposure of human GCs to leptin at concentrations of 3-30 ng/ml for 60 min dose-dependently increased the fluorescence of 4,5-diaminofluorescein (DAF-2), an NO-sensitive dye. The effect of leptin on DAF-2 fluorescence was inhibited by pretreatment of human GCs with 100 microM nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase (NOS), indicating that the increase in DAF-2 fluorescence properly reflected the intracellular NO production. FSH (1 ng/ ml) and IGF-I (30 ng/ml) stimulated 17beta-estradiol (E2) production in human GCs, respectively. FSH plus IGF-I induced a further increase in E2 production. Leptin did not significantly alter basal or FSH-dependent E2 production, but it inhibited the effect of IGF-I on E2 production and the synergistic effect of IGF-I on FSH-stimulated E2 production. The inhibitory effect of leptin on IGF-I argumentation of E2 production was attenuated by pretreatment of human GCs with 100 microM L-NAME. In conclusion, leptin could induce NO production in human GCs. The inhibitory effect of leptin on IGF-I augmentation of E2 production in human GCs was attenuated by L-NAME, strongly suggesting that NO may mediate the action of leptin in human GCs.
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PMID:Nitric oxide mediates inhibitory effect of leptin on insulin-like growth factor I augmentation of 17beta-estradiol production in human granulosa cells. 1537 Dec 74

The aim of this work was to investigate the effect of several peptides, identified before and after simulated gastrointestinal digestion of an egg white hydrolysate, on the vascular function, in rat aorta. The sequences IVF, RADHPFL and YAEERYPIL (0.1 mM) induced vasodilatation in intact aortic rings, with the maximum percentage of dilation corresponding to RADHPFL (40.5+/-7.0%). Two of the end products of the gastrointestinal digestion, RADHP and YPI, also showed vasodilator activity with degrees of relaxation higher than 50%. However, all these peptides failed to induce relaxation in endothelium-denuded aortic rings. The relaxation induced by RADHP was concentration-dependent and it was partially blocked by the nitric oxide synthase inhibitor L-NAME (100 microM) and by the B(1) bradykinin receptor antagonist Des-HOE 140 (30 nM), thus showing that it was mediated by NO production through the activation of B(1) bradykinin receptors. These findings suggest that these peptides could reduce the vascular resistance and could be used as functional food ingredients in the prevention and treatment of hypertension.
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PMID:Vasodilator effects of peptides derived from egg white proteins. 1722 24

The available evidence points to participation of PRL in regulation of mammalian oocyte maturation. The aim of the present study was to characterize pathways of PRL action on bovine oocytes. We analyzed (1) the presence of the PRL receptor and its mRNA isoforms in oocytes and cumulus cells; (2) the effect of PRL on meiosis resumption and the role of cumulus cells, the NO/NO synthase system, protein kinase C, and tyrosine kinases in this effect; and (3) PRL effects in the presence of gonadotropins on the developmental capacity of cumulus-free and cumulus-enclosed oocytes. The transcript and protein expression of the PRL receptor in the cells were detected by reverse transcription polymerase chain reaction and immunocytochemistry, respectively. The nuclear status of oocytes was assessed after culture of cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) with or without PRL (5-500 ng/mL) for 7, 14, or 24 hours. Besides, DOs were incubated for 7 hours in the absence or the presence of PRL (50 ng/mL) and/or L-NAME (an inhibitor of NO synthase), genistein (an inhibitor of tyrosine kinases), or calpostin C (a protein kinase C inhibitor). After IVM in 2 different systems containing PRL (50 ng/mL) and/or gonadotropic hormones, a part of oocytes underwent IVF and IVC and the embryo development was tracked until the blastocyst stage. Messenger RNA of long and short isoforms of the PRL receptor was revealed in both oocytes and cumulus cells. Immunocytochemistry confirmed the presence of the PRL receptor in oocytes and the cumulus investment. In the absence of gonadotropins (system 1), PRL retarded meiosis resumption in DOs but not in cumulus-enclosed oocytes, with this effect being short term, dose dependent, suppressed by L-NAME and genistein, and unaffected by calpostin. In systems containing gonadotropins, PRL did not affect nuclear maturation and the cleavage rate of cumulus-free and cumulus-enclosed oocytes. However, in the case of COCs, it raised the blastocyst yield both in system 2 (from 20.5%-40.9%, P < 0.01) and in system 3 (from 21.7%-33.9%, P < 0.05). The findings show for the first time the functioning of the direct pathway of PRL signaling into bovine oocytes, as confirmed by the expression of receptors of PRL and its direct meiosis-retarding effect involving activation of tyrosine kinases and NO synthase. Furthermore, this is the first demonstration that the beneficial effect of PRL on the oocyte developmental capacity is achieved via cumulus cells containing PRL receptors.
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PMID:Prolactin affects bovine oocytes through direct and cumulus-mediated pathways. 2521 95