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Ovari I, Viczjan G, Erdei T, Takacs B, Tarjanyi V, Zsuga J, Szucs M, Szilvassy Z, Juhasz B, Gesztelyi R. The influence of the way of regression on the results obtained by the receptorial responsiveness method (RRM), a procedure to estimate a change in the concentration of a pharmacological agonist near the receptor. Front Pharmacol 2024; 15:1375955. [PMID: 38756379 PMCID: PMC11096549 DOI: 10.3389/fphar.2024.1375955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/11/2024] [Indexed: 05/18/2024] Open
Abstract
The receptorial responsiveness method (RRM) enables the estimation of a change in concentration of an (even degradable) agonist, near its receptor, via curve fitting to (at least) two concentration-effect (E/c) curves of a stable agonist. One curve should be generated before this change, and the other afterwards, in the same system. It follows that RRM yields a surrogate parameter ("cx") as the concentration of the stable agonist being equieffective with the change in concentration of the other agonist. However, regression can be conducted several ways, which can affect the accuracy, precision and ease-of-use. This study utilized data of previous ex vivo investigations. Known concentrations of stable agonists were estimated with RRM by performing individual (local) or global fitting, this latter with one or two model(s), using a logarithmic (logcx) or a nonlogarithmic (cx) parameter (the latter in a complex or in a simplified equation), with ordinary least-squares or robust regression, and with an "all-at-once" or "pairwise" fitting manner. We found that the simplified model containing logcx was superior to all alternative models. The most complicated individual regression was the most accurate, followed closely by the moderately complicated two-model global regression and then by the easy-to-perform one-model global regression. The two-model global fitting was the most precise, followed by the individual fitting (closely) and by the one-model global fitting (from afar). Pairwise fitting (two E/c curves at once) improved the estimation. Thus, the two-model global fitting, performed pairwise, and the individual fitting are recommended for RRM, using the simplified model containing logcx.
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Affiliation(s)
- Ignac Ovari
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- University of Debrecen, Doctoral School of Nutrition and Food Sciences, Debrecen, Hungary
| | - Gabor Viczjan
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamas Erdei
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Barbara Takacs
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Vera Tarjanyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Judit Zsuga
- Department of Psychiatry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklos Szucs
- Department of Urology and Andrology, Kenezy Gyula Campus, University of Debrecen, Debrecen, Hungary
| | - Zoltan Szilvassy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Bela Juhasz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Purinergic signaling in thyroid disease. Purinergic Signal 2023; 19:221-227. [PMID: 35347568 PMCID: PMC9984614 DOI: 10.1007/s11302-022-09858-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/07/2022] [Indexed: 10/18/2022] Open
Abstract
It is known that thyroid hormones play pivotal roles in a wide variety of pathological and physiological events. Thyroid diseases, mainly including hyperthyroidism, hypothyroidism, and thyroid cancer, are highly prevalent worldwide health problems and frequently associated with severe clinical manifestations. However, etiology of hyperthyroidism, hypothyroidism, and thyroid cancer is not fully understood. Purinergic signaling accounts for a complex network of receptors and extracellular enzymes responsible for the recognition and degradation of extracellular nucleotides and adenosine. It has been established that purinergic signaling modulates pathways in a wide range of physiopathological conditions including hypertension, diabetes, hepatic diseases, psychiatric and neurodegeneration, rheumatic immune diseases, and cancer. More recently, the purinergic system is found to exist in thyroid gland and play an important role in the pathophysiology of thyroid diseases. Therefore, throughout this review, we focus on elaborating the changes in purinergic receptors, extracellular enzymes, and extracellular nucleotides and adenosine in hyperthyroidism, hypothyroidism, and thyroid cancer. Profound understanding of the relationship between the purinergic signaling with thyroid diseases provides a promising research area for insights into the molecular basis of thyroid diseases and also develops new and exciting insights into the treatment of thyroid diseases, especially thyroid cancer.
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Viczjan G, Erdei T, Ovari I, Lampe N, Szekeres R, Bombicz M, Takacs B, Szilagyi A, Zsuga J, Szilvassy Z, Juhasz B, Gesztelyi R. A Body of Circumstantial Evidence for the Irreversible Ectonucleotidase Inhibitory Action of FSCPX, an Agent Known as a Selective Irreversible A 1 Adenosine Receptor Antagonist So Far. Int J Mol Sci 2021; 22:ijms22189831. [PMID: 34575993 PMCID: PMC8464902 DOI: 10.3390/ijms22189831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/04/2021] [Accepted: 09/09/2021] [Indexed: 11/18/2022] Open
Abstract
In previous studies using isolated, paced guinea pig left atria, we observed that FSCPX, known as a selective A1 adenosine receptor antagonist, paradoxically increased the direct negative inotropic response to A1 adenosine receptor agonists (determined using concentration/effect (E/c) curves) if NBTI, a nucleoside transport inhibitor, was present. Based on mathematical modeling, we hypothesized that FSCPX blunted the cardiac interstitial adenosine accumulation in response to nucleoside transport blockade, probably by inhibiting CD39 and/or CD73, which are the two main enzymes of the interstitial adenosine production in the heart. The goal of the present study was to test this hypothesis. In vitro CD39 and CD73 inhibitor assays were carried out; furthermore, E/c curves were constructed in isolated, paced rat and guinea pig left atria using adenosine, CHA and CPA (two A1 adenosine receptor agonists), FSCPX, NBTI and NBMPR (two nucleoside transport inhibitors), and PSB-12379 (a CD73 inhibitor), measuring the contractile force. We found that FSCPX did not show any inhibitory effect during the in vitro enzyme assays. However, we successfully reproduced the paradox effect of FSCPX in the rat model, mimicked the “paradox” effect of FSCPX with PSB-12379, and demonstrated the lipophilia of FSCPX, which could explain the negative outcome of inhibitor assays with CD39 and CD73 dissolved in a water-based solution. Taken together, these three pieces of indirect evidence are strong enough to indicate that FSCPX possesses an additional action besides the A1 adenosine receptor antagonism, which action may be the inhibition of an ectonucleotidase. Incidentally, we found that POM-1 inhibited CD73, in addition to CD39.
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Affiliation(s)
- Gabor Viczjan
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Tamas Erdei
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Ignac Ovari
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Nora Lampe
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Reka Szekeres
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Mariann Bombicz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Barbara Takacs
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Anna Szilagyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Judit Zsuga
- Department of Health Systems Management and Quality Management for Health Care, Faculty of Public Health, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Zoltan Szilvassy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Bela Juhasz
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
| | - Rudolf Gesztelyi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (G.V.); (T.E.); (I.O.); (N.L.); (R.S.); (M.B.); (B.T.); (A.S.); (Z.S.); (B.J.)
- Correspondence: ; Tel.: +36-52-427-899
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Accuracy and Precision of the Receptorial Responsiveness Method (RRM) in the Quantification of A 1 Adenosine Receptor Agonists. Int J Mol Sci 2019; 20:ijms20246264. [PMID: 31842299 PMCID: PMC6940880 DOI: 10.3390/ijms20246264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 12/17/2022] Open
Abstract
The receptorial responsiveness method (RRM) is a procedure that is based on a simple nonlinear regression while using a model with two variables (X, Y) and (at least) one parameter to be determined (cx). The model of RRM describes the co-action of two agonists that consume the same response capacity (due to the use of the same postreceptorial signaling in a biological system). While using RRM, uniquely, an acute increase in the concentration of an agonist (near the receptors) can be quantified (as cx), via evaluating E/c curves that were constructed with the same or another agonist in the same system. As this measurement is sensitive to the implementation of the curve fitting, the goal of the present study was to test RRM by combining different ways and setting options, namely: individual vs. global fitting, ordinary vs. robust fitting, and three weighting options (no weighting vs. weighting by 1/Y2 vs. weighting by 1/SD2). During the testing, RRM was used to estimate the known concentrations of stable synthetic A1 adenosine receptor agonists in isolated, paced guinea pig left atria. The estimates were then compared to the known agonist concentrations (to assess the accuracy of RRM); furthermore, the 95% confidence limits of the best-fit values were also considered (to evaluate the precision of RRM). It was found that, although the global fitting offered the most convenient way to perform RRM, the best estimates were provided by the individual fitting without any weighting, almost irrespective of the fact whether ordinary or robust fitting was chosen.
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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; 23:molecules23092186. [PMID: 30200192 PMCID: PMC6225130 DOI: 10.3390/molecules23092186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 11/23/2022] Open
Abstract
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.
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Methodical Challenges and a Possible Resolution in the Assessment of Receptor Reserve for Adenosine, an Agonist with Short Half-Life. Molecules 2017; 22:molecules22050839. [PMID: 28534854 PMCID: PMC6154002 DOI: 10.3390/molecules22050839] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/05/2017] [Accepted: 05/15/2017] [Indexed: 02/03/2023] Open
Abstract
The term receptor reserve, first introduced and used in the traditional receptor theory, is an integrative measure of response-inducing ability of the interaction between an agonist and a receptor system (consisting of a receptor and its downstream signaling). The underlying phenomenon, i.e., stimulation of a submaximal fraction of receptors can apparently elicit the maximal effect (in certain cases), provides an opportunity to assess the receptor reserve. However, determining receptor reserve is challenging for agonists with short half-lives, such as adenosine. Although adenosine metabolism can be inhibited several ways (in order to prevent the rapid elimination of adenosine administered to construct concentration–effect (E/c) curves for the determination), the consequent accumulation of endogenous adenosine biases the results. To address this problem, we previously proposed a method, by means of which this bias can be mathematically corrected (utilizing a traditional receptor theory-independent approach). In the present investigation, we have offered in silico validation of this method by simulating E/c curves with the use of the operational model of agonism and then by evaluating them using our method. We have found that our method is suitable to reliably assess the receptor reserve for adenosine in our recently published experimental setting, suggesting that it may be capable for a qualitative determination of receptor reserve for rapidly eliminating agonists in general. In addition, we have disclosed a possible interference between FSCPX (8-cyclopentyl-N3-[3-(4-(fluorosulfonyl)benzoyloxy)propyl]-N1-propylxanthine), an irreversible A1 adenosine receptor antagonist, and NBTI (S-(2-hydroxy-5-nitrobenzyl)-6-thioinosine), a nucleoside transport inhibitor, i.e., FSCPX may blunt the effect of NBTI.
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Hughes SJ, Cravetchi X, Vilas G, Hammond JR. Adenosine A1 receptor activation modulates human equilibrative nucleoside transporter 1 (hENT1) activity via PKC-mediated phosphorylation of serine-281. Cell Signal 2015; 27:1008-18. [DOI: 10.1016/j.cellsig.2015.02.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 10/23/2022]
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Pak K, Zsuga J, Kepes Z, Erdei T, Varga B, Juhasz B, Szentmiklosi AJ, Gesztelyi R. The effect of adenosine deaminase inhibition on the A1 adenosinergic and M2 muscarinergic control of contractility in eu- and hyperthyroid guinea pig atria. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:853-68. [PMID: 25877465 PMCID: PMC4495724 DOI: 10.1007/s00210-015-1121-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/30/2015] [Indexed: 11/26/2022]
Abstract
The A1 adenosine and M2 muscarinic receptors exert protective (including energy consumption limiting) effects in the heart. We investigated the influence of adenosine deaminase (ADA) inhibition on a representative energy consumption limiting function, the direct negative inotropic effect elicited by the A1 adenosinergic and M2 muscarinergic systems, in eu- and hyperthyroid atria. Furthermore, we compared the change in the interstitial adenosine level caused by ADA inhibition and nucleoside transport blockade, two well-established processes to stimulate the cell surface A1 adenosine receptors, in both thyroid states. A classical isolated organ technique was applied supplemented with the receptorial responsiveness method (RRM), a concentration estimating procedure. Via measuring the contractile force, the direct negative inotropic capacity of N(6)-cyclopentyladenosine, a selective A1 receptor agonist, and methacholine, a muscarinic receptor agonist, was determined on the left atria isolated from 8-day solvent- and thyroxine-treated guinea pigs in the presence and absence of 2'-deoxycoformycin, a selective ADA inhibitor, and NBTI, a selective nucleoside transporter inhibitor. We found that ADA inhibition (but not nucleoside transport blockade) increased the signal amplification of the A1 adenosinergic (but not M2 muscarinergic) system. This action of ADA inhibition developed in both thyroid states, but it was greater in hyperthyroidism. Nevertheless, ADA inhibition produced a smaller rise in the interstitial adenosine concentration than nucleoside transport blockade did in both thyroid states. Our results indicate that ADA inhibition, besides increasing the interstitial adenosine level, intensifies the atrial A1 adenosinergic function in another (thyroid hormone-sensitive) way, suggesting a new mechanism of action of ADA inhibition.
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Affiliation(s)
- Krisztian Pak
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Judit Zsuga
- />Department of Health Systems Management and Quality Management for Health Care, Faculty of Public Health, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Zita Kepes
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Tamas Erdei
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Balazs Varga
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Bela Juhasz
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Andras Jozsef Szentmiklosi
- />Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
| | - Rudolf Gesztelyi
- />Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, Nagyerdei krt. 98, 4032 Debrecen, Hungary
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Grenczer M, Pinter A, Zsuga J, Kemeny-Beke A, Juhasz B, Szodoray P, Tosaki A, Gesztelyi R. The influence of affinity, efficacy, and slope factor on the estimates obtained by the receptorial responsiveness method (RRM): a computer simulation study. Can J Physiol Pharmacol 2010; 88:1061-73. [DOI: 10.1139/y10-078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The receptorial responsiveness method (RRM) was proposed to characterize changes in the concentration of degradable agonists in the microenvironment of their receptors. The characterization is done by providing concentrations of a stable agonist for the same receptor that is equieffective with the change in concentration to be characterized. RRM is based on the analysis of concentration–effect (E/c) curves reflecting the simultaneous action of the degradable and the stable agonist. In the present study, we investigated whether dissimilar affinity and (or) efficacy of the coacting agonists as well as the steepness of the E/c curves influence the reliability of RRM. E/c curves were simulated based on the operational model and then analyzed with RRM. We found that dissimilarity in affinity of the coacting agonists did not affect the accuracy of RRM estimates. In contrast, accuracy of the estimation depended on the magnitude of the concentration to be assessed, the operational slope factor, and the operational efficacy ratio of the coacting agonists. However, our results suggest that proper choice of a stable agonist for a degradable one can help to ensure reliable results, since information about the change in concentration of a degradable agonist is otherwise difficult to obtain.
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Affiliation(s)
- Maria Grenczer
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Akos Pinter
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Judit Zsuga
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Adam Kemeny-Beke
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Bela Juhasz
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Peter Szodoray
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Arpad Tosaki
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
| | - Rudolf Gesztelyi
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, P.O. Box 8, H-4012 Debrecen, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, P.O. Box 33, H-4010 Debrecen, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, P.O. Box 31, H-4012 Debrecen, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, P.O. Box 30, H-4012 Debrecen, Hungary
- Institute of Immunology, Rikshospitalet, University of Oslo, Sognsvannsveien 20, 0027 Oslo, Norway
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Grenczer M, Zsuga J, Majoros L, Pinter A, Kemeny-Beke A, Juhasz B, Tosaki A, Gesztelyi R. Effect of asymmetry of concentration–response curves on the results obtained by the receptorial responsiveness method (RRM): an in silico study. Can J Physiol Pharmacol 2010; 88:1074-83. [DOI: 10.1139/y10-089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The receptorial responsiveness method (RRM) was proposed to estimate changes in the concentration of an agonist in the microenvironment of its receptor. Usually, this is done by providing the equieffective concentration of another agonist for the same receptor or for a largely overlapping postreceptorial signaling (“test agonist”). The RRM is a special nonlinear regression algorithm to analyze a concentration–response (E/c) curve that represents the simultaneous actions of a single agonist concentration to be estimated and of increasing concentrations of the test agonist. The aim of this study was to explore whether asymmetry of the E/c curve to be analyzed influences the reliability of the RRM. For this purpose, computer simulation was performed by constructing symmetric and asymmetric E/c curves using the operational model of agonism, and then these curves were analyzed with the RRM. To perform the RRM, 2 types of equations were used: one involving the Hill equation, the simplest model of the E/c relationship, and one containing the Richards equation, an advanced model properly handling E/c curve asymmetry. Results of this study indicate that E/c curve asymmetry does not significantly influence the accuracy of the estimates provided by the RRM. Thus, when using the RRM, it is not necessary to replace the Hill equation with the Richards equation to obtain useful estimates. Furthermore, it was found that estimation of a high concentration of a high-efficacy agonist can fail when the RRM is performed with a low-efficacy test agonist in a system characterized by a small operational slope factor.
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Affiliation(s)
- Maria Grenczer
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Judit Zsuga
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Laszlo Majoros
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Akos Pinter
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Adam Kemeny-Beke
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Bela Juhasz
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Arpad Tosaki
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
| | - Rudolf Gesztelyi
- Department of Pharmacology, Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, PO Box 8, Hungary
- Department of Neurology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 31, Hungary
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 17, Hungary
- Institute of Mathematics, Faculty of Science and Technology, University of Debrecen, H-4010 Debrecen, PO Box 33, Hungary
- Department of Ophthalmology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, PO Box 30, Hungary
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