geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Pharmacological evidence of alpha1D-adrenoceptors in the rabbit ventricular myocardium: Analysis with BMY 7378


, : Pharmacological evidence of alpha1D-adrenoceptors in the rabbit ventricular myocardium: Analysis with BMY 7378. British Journal of Pharmacology 122(8): 1541-1550, Dec

1. It was examined by means of BMY 7378, a selective antagonist of alpha1D-adrenoceptors, whether alpha1D-adrenoceptors contribute to the regulation of myocardial contractility and hydrolysis of phosphoinositide (PI) in rabbit ventricular muscle. 2. BMY 7378 had a biphasic antagonistic action on the positive inotropic effect (PIE) of phenylephrine depending on the concentration. BMY 7378 at 1-10 nm shifted the concentration-response curve (CRC) for the PIE of phenylephrine to the right and downward and at 100 nM to 1 muM it antagonized the PIE in a competitive manner, the slope of Schild plot being 0.93 and the pA2 being 7.17+-0.09. 3. The inhibitory action of BMY 7378 at 1-10 nM is ascribed to the selective action on alpha1-adrenoceptors because the PIE of neither isoprenaline nor endothelin-3 and angiotensin II was affected by this compound over this concentration range. 4. In the presence of 100 nM WB 4101, the antagonistic action of BMY 7378 at 1-10 nM remained unchanged but the antagonistic action of BMY 7378 at 100-300 nM disappeared. The antagonistic action of BMY 7378 at 1 nM was unaffected by 100 nM (+)-niguldipine. 5. Following pretreatment with chloroethylclonidine, BMY 7378 at 1 nM inhibited the maximal response to phenylephrine but the pD2 value for phenylephrine was increased in the presence of BMY 7378. The CRC for phenylephrine was shifted to the left in the presence of 10-100 nM BMY 7378 but it was shifted to the right by BMY 7378 at 300 nM. 6. Stimulation of PI hydrolysis induced by phenylephrine was not affected by BMY 7378 up to 10 nM but it was reduced significantly by BMY 7378 at higher concentrations (100 nM to 1 muM). 7. BMY 7378 inhibited the (3H)prazosin specific binding to the rabbit ventricular membrane fraction in a monophasic manner with a pKi value of 7.53 +- 0.09. 8. The results indicate that in rabbit ventricular muscle, BMY 7378 at 1-10 nM suppressed the maximal response to phenylephrine (probably mediated by alpha1D-adrenoceptors) and at 10-100 nM it inhibited the negative inotropic effect of phenylephrine, the mechanisms of which remain to be characterized. At higher concentrations (100 nm to 1 muM) BMY 7378 antagonized the functional and biochemical response via a presumed interaction mainly with the alpha1B-adrenoceptor and partially with the alpha1A-adrenoceptor.

US$29.90


Other references

Medlin, L.; Cooper, A.H.ll, C.W.ieden, S.W.llbrock, U., 1995: Phylogenetic position of the Chromista plastids based on small subunit rRNA coding regions. The kingdom Chromista contains eukaryotic organisms with tubular mastigonemes on the leading flagellum of their bi-flagellated stages, and plastids within a chloroplast endoplasmic reticulum (CER). The complex series of events leading to the forma...

Syková, E.; Jendelová, P.; Simonová, Z.; Chvátal, A., 1992: K+ and pH homeostasis in the developing rat spinal cord is impaired by early postnatal X-irradiation. Activity-related transient changes in extracellular K+ concentration ([K+]e) and pH (pHe) were studied by means of ion-selective microelectrodes in neonatal rat spinal cords isolated from pups 2-14 days of age. Pups 1 to 2 days old were X-irradiat...

Dicks, E.; Ravani, P.; Langman, D.; Davidson, W.S.; Pei, Y.; Parfrey, P.S., 2007: Incident renal events and risk factors in autosomal dominant polycystic kidney disease: a population and family-based cohort followed for 22 years. For determination of the incidence of renal events in autosomal dominant polycystic kidney disease (ADPKD) all patients who had ADPKD and attended nephrology/urology clinics in Newfoundland in 1981 were identified, and members of 18 families who w...

Choy, H.E.; Adhya, S., 1993: RNA polymerase idling and clearance in gal promoters: use of supercoiled minicircle DNA template made in vivo. We have developed an in vivo system to engender supercoiled "minicircle" DNA containing a single promoter by using the integrative recombination system of bacteriophage lambda. The resulting minicircle templates allow quantitative analys...

Nair, M.S.; D'Mello, S.; Pant, R.; Poluri, K.Mohan., 2017: Binding of resveratrol to the minor groove of DNA sequences with AATT and TTAA segments induces differential stability. Interactions of a natural stilbene compound, resveratrol with two DNA sequences containing AATT/TTAA segments have been studied. Resveratrol is found to interact with both the sequences. The mode of interaction has been studied using absorption, s...

Paul, G.; Lottspeich, F.; Wieland, F., 1986: Asparaginyl-N-acetylgalactosamine. Linkage unit of halobacterial glycosaminoglycan. The cell surface glycoprotein of Halobacteria contains two different types of sulfated saccharides: hexuronic acid-containing oligosaccharides linked to the protein via asparaginylglucose, and a serially repeated saccharide unit containing amino s...

Wilczyński, J.; Lukasik, B.; Torbicka, E.; Tranda, I., 1994: The occurrence of viral respiratory tract infections in small children in the season 1992-1993. In the period October 1992 to June 1993, 361 hospitalized children, under 2 years of age were examined by immunofluorescence method for respiratory viruses. In 163 (54.2%) of cases viral etiology was established. The dates obtained in this season...

Caruso, D., 1975: Spelaeoniscus vallettai, nuova specie di isopodo terrestre dell'isola di Gozo. Animalia, 21-3: 59-66

Calamelli, E.; Caffarelli, C.; Ricci, G., 2014: Peanut sensitization profiles in Italian children and adolescents with specific IgE to peanuts. Peanuts are one of the most relevant foods implicated in IgE-mediated adverse reactions in pediatric population. This study aimed to evaluate the pattern of sensitization towards five peanut allergenic components (rAra h 1, 2, 3, 8 and 9) in a pop...

Minev, P.; Penkov, I., 1972: The effects of inbreeding on ped. Zhivotnovudstvo 26 (8) 29-30