Myocyte contractility can be maintained by storing cells with the myosin ATPase inhibitor 2, 3 butanedione monoxime. Issue 6 (28th June 2015)

• Record Type: Journal Article
• Authors: Chung, Charles S.; Mechas, Charles; Campbell, Kenneth S.
• Is Part Of: Physiological reports. Volume 3:Issue 6(2015:Jun.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-06-28
• Subjects: BDM (2, 3‐Butanedione monoxime) -- blebbistatin -- calcium -- cardiomyocyte -- cross‐bridge -- sarcomere; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.12445
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Isolated intact myocytes can be used to investigate contractile mechanisms and to screen new therapeutic compounds. These experiments typically require euthanizing an animal and isolating fresh cells each day or analyzing cultured myocytes, which quickly lose their rod‐shaped morphology. Recent data suggest that the viability of canine myocytes can be prolonged using low temperature and N‐benzyl‐p‐toluene sulfonamide (an inhibitor of skeletal myosin ATPase). We performed similar studies in rat myocytes in order to test whether the cardiac myosin ATPase inhibitors 2, 3‐Butanedione monoxime (BDM) and blebbistatin help to maintain cell‐level function over multiple days. Myocytes were isolated from rats and separated into batches that were stored at 4°C in a HEPES‐buffered solution that contained 0.5 mmol L −1 Ca 2+ and (1) no myosin ATPase inhibitors; (2) 10 mmol L −1 BDM; or (3) 3 μ mol L −1 blebbistatin. Functional viability of myocytes was assessed up to 3 days after the isolation by measuring calcium transients and unloaded shortening profiles induced by electrical stimuli in inhibitor‐free Tyrode's solution. Cells stored without myosin ATPase inhibitors had altered morphology (fewer rod‐shaped cells, shorter diastolic sarcomere lengths, and membrane blebbing) and were not viable for contractile assays after 24 h. Cells stored in BDM maintained morphology and contractile function for 48 h. Storage in blebbistatin maintained cell morphology for 72 h but inhibited contractility. These data show that storing cells with myosin ATPase inhibitors can extend the viability of myocytes that will be used for functional assays. This may help to refine and reduce the use of animals in experiments. Abstract : Intact myocytes are used in experiments to probe molecular mechanisms and to test potential therapies. Being able to use myocytes for several days postisolation could help reduce and refine animal use. Myosin ATPase inhibitors can facilitate long‐term use.