Agonist efficacy denoting the "strength" of agonist action is a cornerstone in the proper assessment of agonist selectivity and signalling bias. The simulation models are very accurate but complex and hard to fit experimental data. The parsimonious operational model of agonism (OMA) has become successful in the determination of agonist efficacies and ranking them. In 1983, Black and Leff introduced the slope factor to the OMA to make it more flexible and allow for fitting steep as well as flat concentration-response curves. First, we performed a functional analysis to indicate the potential pitfalls of the OMA. Namely, exponentiation of operational efficacy may break relationships among the OMA parameters. The fitting of the Black & Leff equation to the theoretical curves of several models of functional responses and the experimental data confirmed the fickleness of the exponentiation of operational efficacy affecting estimates of operational efficacy as well as other OMA parameters. In contrast, fitting The OMA based on the Hill equation to the same data led to better estimates of model parameters. In conclusion, Hill equation-based OMA should be preferred over the Black & Leff equation when functional-response curves differ in the slope factor. Otherwise, the Black & Leff equation should be used with extreme caution acknowledging potential pitfalls.

• MeSH
• biologické modely * MeSH
• počítačová simulace MeSH
• signální transdukce * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Muscarinic acetylcholine receptors expressed in the central nervous system mediate various functions, including cognition, memory, or reward. Therefore, muscarinic receptors represent potential pharmacological targets for various diseases and conditions, such as Alzheimer's disease, schizophrenia, addiction, epilepsy, or depression. Muscarinic receptors are allosterically modulated by neurosteroids and steroid hormones at physiologically relevant concentrations. In this review, we focus on the modulation of muscarinic receptors by neurosteroids and steroid hormones in the context of diseases and disorders of the central nervous system. Further, we propose the potential use of neuroactive steroids in the development of pharmacotherapeutics for these diseases and conditions.

• Klíčová slova
• Alzheimer’s disease, Parkinson’s disease, cholesterol, depression, muscarinic receptors, neuroactive steroids, neurosteroids, schizophrenia, substance abuse,
• MeSH
• centrální nervový systém MeSH
• cholinergní látky MeSH
• hormony MeSH
• neurosteroidy * farmakologie   MeSH
• receptory muskarinové MeSH
• steroidy farmakologie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cholinergní látky MeSH
• hormony MeSH
• neurosteroidy * MeSH
• receptory muskarinové MeSH
• steroidy MeSH

G-protein coupled receptors (GPCRs) are membrane proteins that convey extracellular signals to the cellular milieu. They represent a target for more than 30% of currently marketed drugs. Here we review the effects of membrane cholesterol on the function of GPCRs of Class A. We review both the specific effects of cholesterol mediated via its direct high-affinity binding to the receptor and non-specific effects mediated by cholesterol-induced changes in the properties of the membrane. Cholesterol binds to many GPCRs at both canonical and non-canonical binding sites. It allosterically affects ligand binding to and activation of GPCRs. Additionally, it changes the oligomerization state of GPCRs. In this review, we consider a perspective of the potential for the development of new therapies that are targeted at manipulating the level of membrane cholesterol or modulating cholesterol binding sites on to GPCRs.

• Klíčová slova
• GPCRs, allosteric modulation, cholesterol,
• MeSH
• alosterická regulace MeSH
• anticholesteremika farmakologie   terapeutické užití   MeSH
• buněčná membrána metabolismus   MeSH
• cholesterol chemie   metabolismus   MeSH
• cílená molekulární terapie metody   MeSH
• lidé MeSH
• ligandy MeSH
• receptory spřažené s G-proteiny chemie   klasifikace   metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• anticholesteremika MeSH
• cholesterol MeSH
• ligandy MeSH
• receptory spřažené s G-proteiny MeSH