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001-es BibID:	BIBFORM057912
Első szerző:	Gesztelyi Rudolf (kísérletes farmakológus)
Cím:	Positive inotropic effect of the inhibition of cyclic GMP-stimulated 3',5'-cyclic nucleotide phosphodiesterase (PDE2) on guinea pig left atria in eu- and hyperthyroidism / R. Gesztelyi, J. Zsuga, P. Hajdú, J. Zs. Szabó, A. Cseppentő, A. J. Szentmiklósi
Dátum:	2003
ISSN:	0231-5882
Megjegyzések:	The significance of PDE2 on the atrial inotropy was studied in eu- and hyperthyroidism. The contractile force was measured and negative inotropic capacity of N6-cyclopentyladenosine (CPA) was determined on left atria isolated from 8-day thyroxine- or solvent-treated guinea pigs, in the presence or absence of EHNA (adenosine deaminase and PDE2 inhibitor) or NBTI (nucleoside transporter inhibitor). EHNA was administered to inhibit PDE2, while NBTI was used to model the accumulation of endogenous adenosine. The reduction of the contractile force caused by EHNA was smaller in the thyroxine-treated atria than in the solvent-treated samples. Contrary, NBTI induced a decrease in the contractile force without significant difference between the two groups. In addition, EHNA enhanced the efficiency of CPA in thyroxine-treated atria and did not affect it in solvent-treated samples, while the response to CPA was decreased by NBTI in all atria, especially in hyperthyroidism. On the basis of greater retention of the contractile force and sustained/enhanced responsiveness to CPA in the presence of EHNA we conclude that PDE2's inhibition has a significant positive inotropic effect in guinea pig atria and this effect is proven to be augmented in hyperthyroidism.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	General Physiology and Biophysics. - 22 : 4 (2003), p. 501-513. -
További szerzők:	Zsuga Judit (1973-) (neurológus, pszichoterapeuta, egészségügyi szakmanager) Hajdu Péter (1975-) (biofizikus) Szabó Judit Zsuzsanna (farmakológus, klinikai laboratóriumi szakorvos) Cseppentő Ágnes (1953-) (orvos) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM028062
Első szerző:	Gesztelyi Rudolf (kísérletes farmakológus)
Cím:	Special sensitization pattern in adenosine-induced myocardial responses after thyroxine-treatment / Gesztelyi Rudolf, Zsuga Judit, Cseppentő Ágnes, Bajza Ágnes, Varga Angelika, Szabó Zs. Judit, Szentmiklósi József A.
Dátum:	2003
Megjegyzések:	Chronic thyroxine treatment reduces the susceptibility of atrial myocardium to adenosine. While the possible role of membrane adenosine receptors in this action is supported by several studies, the involvement of intracellular adenosine mechanisms has not been defined. The present experiments were carried out in electrically driven euthyroid and hyperthyroid guinea pig atrial myocardium. The extracellular and intracellular actions of adenosine were analyzed pharmacologically by the use of specific blockers of membrane adenosine transport and intracellular adenosine deaminase (ADA). The involvement of phosphoprotein phosphatase, phospholamban, and sarcoplasmic reticulum Ca2+ ATPase (SERCA) in the adenosine-induced responses was also studied. The major findings were as follows: i) pD(2)- and E(max)-values for adenosine-induced decrease of mechanical activity were significantly reduced after an 8-day thyroxine treatment in atrial tissues; ii) in atria of thyroxine-treated animals, membrane purine transport inhibitors (dipyridamole, NBTI) induced similar leftward shifts in concentration-response curves for adenosine in both euthyroid and hyperthyroid atrial myocardium without altering the depressed E(max) values; iii) the leftward displacement evoked by inhibitors of intracellularly located ADA (coformycin, EHNA) was more striking in hyperthyroid than euthyroid myocardia. ADA inhibitors induced a complete reversal of the maximum adenosine actions; iv) inhibition by cantharidin of phosphoprotein phosphatases (after inhibition of ADA) reduced the adenosine-induced responses. This inhibition was stronger in hyperthyroid atria; v) pharmacological elimination of sarcoplasmic reticulum Ca2+ ATPase by cyclopiazonic acid did not alter the cardiac responses to adenosine and this was independent of thyroid status. It is suggested that distinct modulation of the extra- and intracellular adenosine actions is present in eu- and hyperthyroid hearts. In the latter, a predominance of intracellular adenosine mechanisms can be proposed.
Tárgyszavak:	Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of pharmacological sciences 91 : 4 (2003), p. 295-304. -
További szerzők:	Zsuga Judit (1973-) (neurológus, pszichoterapeuta, egészségügyi szakmanager) Cseppentő Ágnes (1953-) (orvos) Bajza Ágnes (1970-) (biológus) Varga Angelika (1977-) (biológus) Szabó Judit Zsuzsanna (farmakológus, klinikai laboratóriumi szakorvos) Szentmiklósi József András (1948-) (farmakológus, klinikai laboratóriumi szakorvos)
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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