Long-term hypothermic preservation of cardiac myocytes isolated from the neonatal rat ventricle: A comparison of various crystalloid solutions

Abstract

In this study, the functional and biochemical effects of crystalloid solutions on immature cardiac myocytes incubated under hypothermic conditions were evaluated. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days, following which 12.5 x 10(5) myocytes per flask were incubated at 4 degrees C for 3, 6, 12, and 18 h in five types of crystalloid solutions: lactated Ringer's (LR), St. Thomas' Hospital (ST), University of Wisconsin (UW), 5% glucose-based potassium (GK), and normal saline (NS). The levels of creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) in the solutions were measured after each hypothermic incubation, following which the myocytes were cultured for an additional 24 h at 37 degrees C to evaluate the recovery of the myocyte beating rate. In the LR, UW, and NS groups, the recovery ratios of the myocyte beating rate were over 95% of the control (the beating rate prior to hypothermic incubation) at 3 h, but decreased to 20.3, 15.1, and 0%, respectively, at 18 h. The ST and GK groups had significantly lower recovery ratios than the other three groups (72.9% and 63.4%, respectively) at 3 h. The release of CPK and LDH in the LR, UW, and NS groups was significantly suppressed compared to the ST and GK groups, with the greatest suppression observed in the LR group. Moreover, the ST and GK groups had the highest CPK and LDH levels, respectively. Thus, LR solution had the least cytotoxic effects, indicating that it could be the most suitable basic solution of the various cardioplegic or preservation solutions during the neonatal period.

Effective Hypothermic Storage of Human Pluripotent Stem Cell-Derived Cardiomyocytes Compatible With Global Distribution of Cells for Clinical Applications and Toxicology Testing

“…The ability to efficiently cold-preserve functional CMs for extended periods would provide an appealing off-the-shelf solution for the treatment of cardiac diseases. Several studies have evaluated the ability to preserve adult/neonatal rat/mouse CMs at hypothermic conditions [16,[26][27][28][29]. For example, Snyder et al reported the successful hypothermic storage of neonatal rat ventricular CM monolayers for up to 72 hours in HTS.…”

A modified method for isolation of human cardiomyocytes to model cardiac diseases

“…For transport of myocardial specimen, most protocols opt for the Thomas solution [ 18 ] or cardioplegic buffer [ 19 , 20 ] as the transport medium. It has been reported that the UW solution showed beneficial effects on the recovery of myocyte viability compared to the Thomas’ Hospital and glucose-based potassium solutions [ 21 ]. Additionally, the superior myocardial protective effects of HTK solution, as compared with conventional St. Thomas crystalloid cardioplegia has been proved [ 22 ].…”

Cardiomyocyte Responses to Thermal Excursions: Implications for Electrophysiological Cardiac Mapping

“…18,[28][29][30][31] In order to accomplish this, the neonatal rat ventricular cardiomyocyte (NRVCM) in vitro cardiac model was utilized in combination with cryomapping and ablation thermal stress models. 32,33 The window of temperature exposure included three distinct thermal zones including: hyperthermia (40°C to 60°C), hypothermia (15°C to 2°C), and subfreezing temperatures reaching Ϫ20°C. Exposure intervals of 15 sec to 60 sec were employed to evaluate the temporal effects at the various temperatures.…”