scholarly journals Approximation of A1 adenosine receptor reserve appertaining to the direct negative inotropic effect of adenosine in hyperthyroid guinea pig left atria

2014 ◽  
Vol 33 (02) ◽  
pp. 177-188 ◽  
Author(s):  
Krisztian Pak ◽  
Csaba Papp ◽  
Zoltan Galajda ◽  
Tamas Szerafin ◽  
Balazs Varga ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Adenosine Receptor ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
A1 Adenosine Receptor ◽  
Receptor Reserve

scholarly journals The guinea pig atrial A1 adenosine receptor reserve for the direct negative inotropic effect of adenosine

2014 ◽  
Vol 32 (03) ◽  
pp. 325-335 ◽  
Author(s):  
Zsuzsanna Kiss ◽  
Krisztian Pak ◽  
Judit Zsuga ◽  
Bela Juhasz ◽  
Balazs Varga ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Adenosine Receptor ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
A1 Adenosine Receptor ◽  
Receptor Reserve

scholarly journals FSCPX, a Chemical Widely Used as an Irreversible A1 Adenosine Receptor Antagonist, Modifies the Effect of NBTI, a Nucleoside Transport Inhibitor, by Reducing the Interstitial Adenosine Level in the Guinea Pig Atrium

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2186 ◽  
Author(s):  
Tamas Erdei ◽  
Adrienn Szabo ◽  
Nora Lampe ◽  
Katalin Szabo ◽  
Rita Kiss ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Receptor Antagonist ◽  
Adenosine Receptor ◽  
Negative Inotropic Effect ◽  
Nucleoside Transport ◽  
Original Form ◽  
Nucleoside Transporter ◽  
A1 Adenosine Receptor ◽  
Adenosine Receptor Antagonist ◽  
Receptor Reserve

Based on in silico results, recently we have assumed that FSCPX, an irreversible A1 adenosine receptor antagonist, inhibits the action of NBTI that is apparent on E/c curves of adenosine receptor agonists. As a mechanism for this unexpected effect, we hypothesized that FSCPX might modify the equilibrative and NBTI-sensitive nucleoside transporter (ENT1) in a way that allows ENT1 to transport adenosine but impedes NBTI to inhibit this transport. This assumption implies that our method developed to estimate receptor reserve for agonists with short half-life such as adenosine, in its original form, overestimates the receptor reserve. In this study, therefore, our goals were to experimentally test our assumption on this effect of FSCPX, to improve our receptor reserve-estimating method and then to compare the original and improved forms of this method. Thus, we improved our method and assessed the receptor reserve for the direct negative inotropic effect of adenosine with both forms of this method in guinea pig atria. We have found that FSCPX inhibits the effects of NBTI that are mediated by increasing the interstitial concentration of adenosine of endogenous (but not exogenous) origin. As a mechanism for this action of FSCPX, inhibition of enzymes participating in the interstitial adenosine production can be hypothesized, while modification of ENT1 can be excluded. Furthermore, we have shown that, in comparison with the improved form, the original version of our method overestimates receptor reserve but only to a small extent. Nevertheless, use of the improved form is recommended in the future.

scholarly journals Persistent Activation by and Receptor Reserve for an Irreversible A1-Adenosine Receptor Agonist in DDT1 MF-2 Cells and in Guinea Pig Heart

1997 ◽  
Vol 52 (3) ◽  
pp. 491-498 ◽  
Author(s):  
Jiahui Zhang ◽  
Luiz Belardinelli ◽  
Kenneth A. Jacobson ◽  
Deborah H. Otero ◽  
Stephen P. Baker
Keyword(s):  
Guinea Pig ◽  
Adenosine Receptor ◽  
Receptor Agonist ◽  
A1 Adenosine Receptor ◽  
Guinea Pig Heart ◽  
Receptor Reserve ◽  
Adenosine Receptor Agonist

Functional and autoradiographic characterization of dopamine D2-like receptors in the guinea pig heart

2002 ◽  
Vol 80 (6) ◽  
pp. 578-587 ◽  
Author(s):  
María de Jesús Gómez ◽  
Guy Rousseau ◽  
Réginald Nadeau ◽  
Roberto Berra ◽  
Gonzalo Flores ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Western Blot ◽  
Dopamine Receptors ◽  
Negative Inotropic Effect ◽  
Cyclase Activity ◽  
Inotropic Effect ◽  
Receptor Subtypes ◽  
Guinea Pig Heart ◽  
Additional Information ◽  
The Right

Dopamine receptors include the D1- (D1 and D5 subtypes) and D2-like (D2, D3, and D4 subtypes) families. D1-like receptors are positively and D2-like receptors negatively coupled to the adenylyl cyclase. Dopamine D2-like (D4 subtype) receptors have been identified in human and rat hearts. However the presence of D2 and D3 receptor subtypes is unclear. Furthermore, their role in cardiac functions is unknown. By autoradiographic studies of guinea pig hearts, we identified D3 and D4 receptors, using the selective radioligands [3H]-7-OH-DPAT and [3H]emonapride (YM-09151-2 plus raclopride). Western blot analysis confirmed D3 and D4 receptors in the right and left ventricle of the same species. Selective agonists of D3 and D4 receptors (±)-7-OH-DPAT and PD 168 077 (10–9 to 10–5 M, respectively) induced a significant negative chronotropic and inotropic effect in the isolated guinea pig heart preparation. Negative inotropic effect induced by PD 168 077 was associated with an inhibition in cyclase activity. No changes in cyclase activity were found with (±)-7-OH-DPAT. The aim of this study is to support the presence of D3 and D4 receptors in the heart. Although our results suggest that D3 and D4 receptors are functionally active in the heart, we need additional information with an antagonist and an agonist of improved potency and selectivity to understand the respective roles of D3 and D4 receptors in the cardiac functions.Key words: Dopamine receptors (D2, D3, D4 subtypes), autoradiography, Western blot, cAMP, heart.

scholarly journals Thyroid hormones decrease the affinity of 8-cyclopentyl-1,3-dipropylxanthine (CPX), a competitive antagonist, for the guinea pig atrial A1 adenosine receptor

2012 ◽  
Vol 31 (04) ◽  
pp. 389-400 ◽  
Author(s):  
Rudolf Gesztelyi ◽  
Zsuzsa Kiss ◽  
Judit Zsuga ◽  
Krisztian Pak ◽  
Csaba Papp ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Thyroid Hormones ◽  
Adenosine Receptor ◽  
A1 Adenosine Receptor

Calcium channels and excitation–contraction coupling in cardiac cells. II. A pharmacological study of the biphasic contraction in guinea-pig papillary muscle

1987 ◽  
Vol 65 (9) ◽  
pp. 1832-1839 ◽  
Author(s):  
E. Honoré ◽  
M. M. Adamantidis ◽  
B. A. Dupuis ◽  
C. E. Challice ◽  
P. Guilbault
Keyword(s):  
Guinea Pig ◽  
Papillary Muscle ◽  
Positive Inotropic Effect ◽  
Pharmacological Study ◽  
Negative Inotropic Effect ◽  
Cardiac Cells ◽  
Inotropic Effect ◽  
Free Solution ◽  
Contraction Coupling ◽  
Rich Solution

Biphasic contractions were obtained in guinea-pig papillary muscle by inducing partial depolarization in K+-rich solution (17 mM) in the presence of 0.3 μM isoproterenol. Mn2+ ions inhibited the two components of contraction in a similar way. Nifedipine and particularly Cd2+ ions specifically inhibited the second component of contraction. Isoproterenol and BAY K 8644 markedly increased the amplitude of the second component (P2) of contraction. Nevertheless, a moderate positive inotropic effect of isoproterenol was found on the first component (P1) of contraction when excitability was restored by 0.2 mM Ba instead of isoproterenol. Acetylcholine and hypoxia decreased the amplitude of the second component of contraction to a greater extent. In the presence of digoxin or Na+-free solution, P1was strongly increased. When sarcoplasmic reticular function was hindered by 1 mM caffeine or in the presence of Ca2+-free Sr2+ solution, digoxin always induced a negative inotropic effect on P2. Inversely in these conditions the transient positive inotropic effect of Na+-free solution was strongly reduced. These results are consistent with the hypothesis that the late component of contraction is triggered by the slow inward Ca2+ current and that the early component is due to Ca2+ release from the sarcoplasmic reticulum.

scholarly journals Potentiation of the negative inotropic effect of adenosine on guinea pig atria by cinepazide.

1980 ◽  
Vol 30 ◽  
pp. 133
Author(s):  
Hideki Moritoki ◽  
Shinji Fujita ◽  
Masao lakei ◽  
Yukio Ishida ◽  
Akira Akashi
Keyword(s):  
Guinea Pig ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
Guinea Pig Atria

The Negative Inotropic Effect of β3-Adrenoceptor Stimulation in the Beating Guinea Pig Heart

2000 ◽  
Vol 35 (5) ◽  
pp. 786-790 ◽  
Author(s):  
Tetsuya Kitamura ◽  
Katsuya Onishi ◽  
Kaoru Dohi ◽  
Tsutomu Okinaka ◽  
Naoki Isaka ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
Guinea Pig Heart

scholarly journals Negative Inotropic Effect of Diazepam in Isolated Guinea Pig Heart.

2001 ◽  
Vol 63 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Yukio HARA ◽  
Hiroe KOBAYASHI ◽  
Satomi OOSHIRO ◽  
Keisuke FUTAMURA ◽  
Takeshi NISHINO ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Negative Inotropic Effect ◽  
Inotropic Effect ◽  
Guinea Pig Heart
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