TY - JOUR
T1 - Age-related effects of St Thomas' Hospital cardioplegic solution on isolated cardiomyocyte cell volume
AU - Danetz, J. S.
AU - Clemo, H. F.
AU - Davies, R. D.
AU - Embrey, R. P.
AU - Damiano, Jr
AU - Baumgarten, C. M.
N1 - Funding Information:
Supported by National Institutes of Health grants HL-09817 (J.S.D., C.M.B.) and HL-46764 (C.M.B.).
PY - 1999
Y1 - 1999
N2 - Objectives: We tested the hypothesis that neonatal cells are more sensitive to cardioplegia-induced cell swelling than more mature cells and spontaneous swelling in the absence of ischemia can be prevented by cardioplegia with a physiologic KCl product. Methods: Cell volumes of isolated ventricular myocytes from neonatal (3-5 days), intermediate (10-13 days), and adult (>6 weeks) rabbits were measured by digital video microscopy. After equilibration in 37°C physiologic solution, cells were suprafused with 37°C or 9°C St Thomas' Hospital solution (standard or low Cl-) or 9°C physiologic solution followed by reperfusion with 37°C physiologic solution. Results: Neonatal cells swelled 16.2% ± 1.8% (P < .01) in 37°C St Thomas' Hospital solution and recovered during reperfusion, whereas more mature cells maintained constant volume. In contrast, 9°C St Thomas' Hospital solution caused significant age-dependent swelling (neonatal, 16.8% ± 1.5%; intermediate, 8.6% ± 2.1%; adult, 5.6% ± 1.1%). In contrast to more mature cells, neonatal cells remained significantly edematous throughout reperfusion (8.1% ± 1.5%). Swelling was not due to hypothermia because 9°C physiologic solution did not affect volume. Lowering the KCl product of St Thomas' Hospital solution by partially replacing Cl- with an impermeant anion prevented cellular edema in all groups. Conclusion: In the absence of ischemia, neonatal cells were more sensitive to cardioplegia-induced cellular edema than more mature cells, and edema observed in all groups was avoided by decreasing the KCl product of St Thomas' Hospital solution to the physiologic range. Differences in cell volume regulation may explain the sensitivity of neonatal hearts to hyperkalemic cardioplegic arrest and suggest novel approaches to improving myocardial protection.
AB - Objectives: We tested the hypothesis that neonatal cells are more sensitive to cardioplegia-induced cell swelling than more mature cells and spontaneous swelling in the absence of ischemia can be prevented by cardioplegia with a physiologic KCl product. Methods: Cell volumes of isolated ventricular myocytes from neonatal (3-5 days), intermediate (10-13 days), and adult (>6 weeks) rabbits were measured by digital video microscopy. After equilibration in 37°C physiologic solution, cells were suprafused with 37°C or 9°C St Thomas' Hospital solution (standard or low Cl-) or 9°C physiologic solution followed by reperfusion with 37°C physiologic solution. Results: Neonatal cells swelled 16.2% ± 1.8% (P < .01) in 37°C St Thomas' Hospital solution and recovered during reperfusion, whereas more mature cells maintained constant volume. In contrast, 9°C St Thomas' Hospital solution caused significant age-dependent swelling (neonatal, 16.8% ± 1.5%; intermediate, 8.6% ± 2.1%; adult, 5.6% ± 1.1%). In contrast to more mature cells, neonatal cells remained significantly edematous throughout reperfusion (8.1% ± 1.5%). Swelling was not due to hypothermia because 9°C physiologic solution did not affect volume. Lowering the KCl product of St Thomas' Hospital solution by partially replacing Cl- with an impermeant anion prevented cellular edema in all groups. Conclusion: In the absence of ischemia, neonatal cells were more sensitive to cardioplegia-induced cellular edema than more mature cells, and edema observed in all groups was avoided by decreasing the KCl product of St Thomas' Hospital solution to the physiologic range. Differences in cell volume regulation may explain the sensitivity of neonatal hearts to hyperkalemic cardioplegic arrest and suggest novel approaches to improving myocardial protection.
UR - http://www.scopus.com/inward/record.url?scp=0032888042&partnerID=8YFLogxK
U2 - 10.1016/S0022-5223(99)70184-4
DO - 10.1016/S0022-5223(99)70184-4
M3 - Article
C2 - 10469961
AN - SCOPUS:0032888042
SN - 0022-5223
VL - 118
SP - 467
EP - 476
JO - Journal of Thoracic and Cardiovascular Surgery
JF - Journal of Thoracic and Cardiovascular Surgery
IS - 3
ER -