Results: Cardiac BPA exposure resulted in prolonged PR segment and decreased epicardial conduction velocity (0.1 100 μM BPA), prolonged action potential duration (1 100 μM BPA), and delayed atrioventricular conduction (10 100 μM BPA).
It is possible that the prolonged action of galanin can reflect its internalization in the target cells and/or a formation of galanin fragments which have prolonged action in vivo (Schött et al. 1998; Jansson et al. 2000).
Although both nanostructures showed prolonged action profiles and improved serum stability compared to the parent peptide, the morphology of the nanostructures is highly critical to manipulate the release profile of the free peptide from the assembly and regulate their bioactivity.
In particular, in vitro expanded adult, but not fetal, cardiac fibroblasts significantly deteriorated electrical and mechanical function of the co-cultured cardiomyocytes, as evidenced by slower action potential conduction, prolonged action potential duration, weaker contractions, higher tissue stiffness, and reduced calcium transient amplitude.
It could be predicted that the established DNA-PLA-PEG-NPs with a delayed release effect could keep the loaded DNA prolonged action in vivo.
Pharmacological studies using 4-aminopyridine showed that prolonged action potential duration and reduced maximum capture rate in tissue constructs as compared with native ventricles could be explained by decreased transient outward potassium current.
Advances in ocular drug delivery system research are expected to provide new tools for the treatment of posterior segment diseases, providing improved drug penetration, prolonged action, higher efficacy, improved safety and less invasive administration, resulting in higher patient compliance.
Injectable in situ gels have caused much attention and have been studied quite a lot in the fields of drug delivery, possibly due to their ease of preparation, ease of control in quality, non-use of organic solvents, site-specific delivery, prolonged action periods, and improved patient compliance (Matsumura and Maeda 1986).
This is concordant with the major requirement for nickel carcinogenicity, which is prolonged action on the target tissue.
This results in an increase in cytoplasmic calcium content and a decrease in calcium outward current resulting in prolonged action potential duration and increased myocardial stiffness.
