Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the effects of exogenous human recombinant Vasostatin-1 (VS-1), Vasostatin-2 (VS-2) and the human Chromogranin A (CGA) 7-57 synthetic peptides on the mechanical performance of the isolated and perfused working eel (Anguilla anguilla) heart. Under basal conditions, the three peptides decreased stroke volume (SV) and stroke work (SW), thus exerting negative inotropism. The VS-1-mediated negative inotropism was abolished by exposure to inhibitors of either Gi/o protein (pertussis toxin; PTx) or M1 muscarinic receptors (Pirenzepine) or calcium (Lantanum and Diltiazem) and potassium (Ba2+, 4-aminopyridine, tetraethylammonium, glibenclamide) channels, while it required an intact endocardial endothelium (EE). Using NG-monomethyl-L-arginine (L-NMMA) as an inhibitor of nitric oxide (NO) synthase (NOS), and hemoglobin as a NO scavenger, we demonstrated the obligatory role of NO signaling in mediating the vasostatin response. Pretreatment with either a specific inhibitor of soluble guanylate cyclase (GC) 1H-(1,2,4)oxadiazolo-(4,3-a)quinoxalin-1-one (ODQ), or the inhibitor of the cGMP-activated protein kinase (PKG) KT5823, abolished the VS-1-mediated inotropism, indicating the cGMP-PKG component as a crucial target of NO signaling. Of note, VS-1 was effective in counteracting the adrenergic (Isoproterenol and Phenylephrine)-mediated positive inotropism. These findings provide the first evidence that vasostatins exert cardiotropic action in fish, thus suggesting their long evolutionary history as well as their species-specific mechanisms of action.
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PMID:Influence of vasostatins, the chromogranin A-derived peptides, on the working heart of the eel (Anguilla anguilla): negative inotropy and mechanism of action. 1547 32

1. The aim of the present study was to compare and elucidate the effects of alpha(1)-adrenoceptor (alpha(1)-AR) subtype-selective inverse agonists on non-pregnant and late-pregnant rat cervical tone. 2. Cervical resistance was investigated in in vitro stretching tests in the absence or presence of alpha(1)-AR subtype-selective inverse agonists (WB 4101, AH 11110A and BMY 7378; all at 10(-6) mol/L), whereas the mRNA levels and density of the alpha(1)-AR subtypes and the G-protein-activating effects of the inverse agonists were determined by reverse transcription-polymerase chain reaction, western blot and [(35)S]-GTPgammaS binding techniques, respectively. 3. The inverse agonists did not cause any change in resistance in non-pregnant and 18-day-pregnant samples. WB 4101 increased cervical resistance from Day 20, whereas AH 11110A had no effect and BMY 7378 exhibited such an action only on Day 21. Phenylephrine (10(-4) mol/L) had no effect on cervical resistance on Day 22. The mRNA levels and density of all alpha(1)-AR subtypes were increased on Day 18, but no further changes were observed after that. The [(35)S]-GTPgammaS binding studies revealed increased G-protein activation of alpha(1A)-AR and a moderate G-protein activation of alpha(1B)- and alpha(1D)-AR. The effect of WB 4101 to increase [(35)S]-GTPgammaS binding was blocked by pertussis toxin (50 ng/mL). Phenylephrine caused a slight and significant decrease in the amount of activated G-protein on Day 22. 4. The effects of inverse agonists on the alpha(1A)-AR can enhance cervical resistance in the late-pregnant rat in vitro. This action is mediated, at least in part, by a pertussis toxin-sensitive G(i)-protein. This effect of the alpha(1A)-AR inverse agonist WB 4101 may offer a new therapeutic target in the prevention of premature labour.
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PMID:Effect of alpha-adrenoceptor subtype-selective inverse agonists on non-pregnant and late-pregnant cervical resistance in vitro in the rat. 1720 34


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