Modulation of the Cardiac Myocyte Action Potential by the Magnesium-Sensitive TRPM6 and TRPM7-like Current

The cardiac Mg2+-sensitive, TRPM6, and TRPM7-like channels remain undefined, especially with the uncertainty regarding TRPM6 expression in cardiomyocytes. Additionally, their contribution to the cardiac action potential (AP) profile is unclear. Immunofluorescence assays showed the expression of the TRPM6 and TRPM7 proteins in isolated pig atrial and ventricular cardiomyocytes, of which the expression was modulated by incubation in extracellular divalent cation-free conditions. In patch clamp studies of cells dialyzed with solutions containing zero intracellular Mg2+ concentration ([Mg2+]i) to activate the Mg2+-sensitive channels, raising extracellular [Mg2+] ([Mg2+]o) from the 0.9-mM baseline to 7.2 mM prolonged the AP duration (APD). In contrast, no such effect was observed in cells dialyzed with physiological [Mg2+]i. Under voltage clamp, in cells dialyzed with zero [Mg2+]i, depolarizing ramps induced an outward-rectifying current, which was suppressed by raising [Mg2+]o and was absent in cells dialyzed with physiological [Mg2+]i. In cells dialyzed with physiological [Mg2+]i, raising [Mg2+]o decreased the L-type Ca2+ current and the total delayed-rectifier current but had no effect on the APD. These results suggest a co-expression of the TRPM6 and TRPM7 proteins in cardiomyocytes, which are therefore the molecular candidates for the native cardiac Mg2+-sensitive channels, and also suggest that the cardiac Mg2+-sensitive current shortens the APD, with potential implications in arrhythmogenesis

Determinants of Watching a Film: A Case Study on Dhallywood Film Industry, Bangladesh

The purpose of the study is to classify the different factors influencing the success of a Bengali film, and in this regard, a total sample of 296 respondents has been interviewed through a structured questionnaire. To test the study, Pearson’s product moment correlation, ANOVA and KMO statistic has been used and factor analysis is used to group the factors needed to develop for producing a successful film. The study reveals that the first factor (named convenient factor) is the most important factor for producing a film as well as to grab the attention of the audiences by 92% and competitive advantage by 71%, uniqueness by 81%, supports by 64%, features by 53%, quality of the film by 77% are next consideration consecutively according to the general people perception. The implication of the study is that the film makers and promoters should consider the factors properly for watching more films of the Dhallywood industry in relation to the foreign films especially Hindi, Tamil and English. The government can also take the initiative for the betterment of the industry through proper governance and subsidize if possible