Disastrous physiological effects of saline on the cell membrane demonstrated in cardiac cells.
OBJECTIVE
Saline is not an ideal storage solution. It has a low pH, no buffering capacity, and lacks other ions and nutrients. The objective was to explore the effects of storing cardiac muscle in saline.


METHODS
Guinea pig papillary muscles and ventricular myocytes were exposed to saline. The effects on action potential, membrane current, contraction and cell shortening were recorded in vitro at 35-37 degrees C.


RESULTS
Saline caused transient hyperpolarization of the resting potential (-140 mV), prolonged duration of the action potential, and increased contraction amplitude, which was later reversed. The membrane resting potential depolarized after a few minutes to about -15 mV and the preparations became unexcitable. The depolarized preparations remained slightly contracted. Upon reperfusion both papillary muscles and cells became unstable and spontaneously active. Storing myocytes in saline for only 2 h resulted in excessive cell death.


CONCLUSIONS
Saline is disastrous for the function of the heart muscle and leads to depolarization, sustained contraction and unexcitable tissue. Saline should not be used as a storage medium, even for short periods of time.
Arlock
P
P
Department of Cardiothoracic Surgery, Heart and Lung Division, University Hospital, Lund, Sweden. per.arlock@thorax.lu.se
Wohlfart
B
B
Sjöberg
T
T
Steen
S
S
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects*; D022062:Electrophysiologic Techniques, Cardiac; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D012462:Saline Solution, Hypertonic / Q000633:toxicity*; D012965:Sodium Chloride / Q000633:toxicity*
D012462:Saline Solution, Hypertonic; D012965:Sodium Chloride