Electrophysiology of Vascular Smooth Muscle. In: Sperelakis N, editor. Physiology and Pathophysiology of the Heart. Boston: Springer US; 1989. pp. 773-811. [DOI: 10.1007/978-1-4613-0873-7_38]

Spasmolytic Activity of 1,3-Disubstituted 3,4-Dihydroisoquinolines

This article concerns the spasmolytic activities of some novel 1,3-disubstituted 3,4-dihydroisoquinolines. These compounds can be evaluated as potential therapeutic candidates according to Lipinski's rule of five, showing high gastrointestinal absorption and the ability to cross the blood-brain barrier, which is a very important parameter in the drug discovery processes. In silico simulation predicted smooth muscle relaxant activity for all the compounds. Since smooth muscle contractile failure is a characteristic feature of many disorders, in the current paper, we concentrate on the parameters of the spontaneous contractile responses of smooth muscle (SM) cells compared to the well-known drug mebeverine. Two of the newly synthesized substances can be identified as essential modulating regulators and potentially used as therapeutic molecules. One of these molecules also showed significant DPPH antioxidant activity compared to rutin.

New drugs are not enough‑drug repositioning in oncology: An update

Drug repositioning refers to the concept of discovering novel clinical benefits of drugs that are already known for use treating other diseases. The advantages of this are that several important drug characteristics are already established (including efficacy, pharmacokinetics, pharmacodynamics and toxicity), making the process of research for a putative drug quicker and less costly. Drug repositioning in oncology has received extensive focus. The present review summarizes the most prominent examples of drug repositioning for the treatment of cancer, taking into consideration their primary use, proposed anticancer mechanisms and current development status.

Ionic currents in single cells from human cystic artery

The patch-clamp technique was used to study the electrophysiological properties of single smooth muscle cells obtained from the human cystic artery. These cells contracted on exposure to high K+ and had a mean resting potential of -36 +/- 7 mV. Under current clamp, regenerative responses could not be elicited when depolarizing pulses were applied. Voltage-clamp measurements demonstrated that a large fraction of the outward current was inhibited by tetraethylammonium (5-10 mM) or Ca2+ channel blockers and that it was enhanced by increasing [Ca2+]o, suggesting that it is a Ca(2+)-activated K+ current. In addition, spontaneous transient outward currents that were sensitive to extracellular Ca2+ were observed in some cells. In cell-attached patch-clamp recordings, Ca(2+)-activated K+ channels that had a conductance of 117 pS were consistently identified. At negative potentials (approximately -60 mV), these single-channel events deactivated completely and very quickly, suggesting that they do not control the resting membrane potential in healthy cystic artery cells. Ca2+ currents that were recorded using Ba2+ (10 mM) as the charge carrier were enhanced by the dihydropyridine agonist, Bay K 8644, and blocked by nifedipine (0.1 microM). Only one type of Ca2+ current, the L-type, could be identified in these cells. These results demonstrate that the major ionic currents in the human cystic artery are similar to other mammalian arteries and indicate that this tissue will be a useful model for studying the metabolic and pharmacological modulation of ionic currents in human vascular smooth muscle.