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Tolerance of the developing heart to ischemia: impact of hypoxemia from birth. Am J Physiol 1995 Mar;268(3 Pt 2):H1165-73

Date

03/01/1995

Pubmed ID

7900870

DOI

10.1152/ajpheart.1995.268.3.H1165

Scopus ID

2-s2.0-0028931270   77 Citations

Abstract

Many infants who require cardiac surgery have cyanotic heart disease. We assessed the relative tolerances to ischemia of hearts from immature normoxemic rabbits versus hearts from immature rabbits subjected to hypoxemia since birth. Normoxemic animals were raised from birth in an environment where the inspired fractional concentration of oxygen (FIO2) was 0.21; for the hypoxemic studies FIO2 was reduced to 0.09. Hearts (n = 6/group) from normoxemic and chronically hypoxemic rabbits at 7-12, 21-28, 35-44, and 51-56 days of age underwent aerobic "working" perfusion with Krebs bicarbonate buffer, and cardiac function was measured. Hearts were then arrested by a 3-min infusion with either cold (14 degrees C) Krebs buffer (hypothermia alone group) or St. Thomas' Hospital II solution (hypothermia plus cardioplegia group) before 6 h of hypothermic (14 degrees C) global ischemia. Hearts were reperfused, and postischemic creatine kinase leakage and recovery of function were measured. For hearts protected with hypothermia alone, recovery of aortic flow was better in hearts hypoxemic from birth compared with normoxemic controls at 7-12 days (78 +/- 7 vs. 60 +/- 6%, P < 0.05) and 21-28 days old (81 +/- 12 vs. 26 +/- 28%, P < 0.05). Protection with hypothermia plus cardioplegia was also better in hearts hypoxemic from birth compared with normoxemic controls at 7-12 days (74 +/- 8 vs. 63 +/- 10%, P < 0.05) and 21-28 days old (84 +/- 3 vs. 71 +/- 5%, P < 0.05). Protection with hypothermia alone and hypothermia plus cardioplegia was no different within chronically hypoxemic age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Author List

Baker EJ, Boerboom LE, Olinger GN, Baker JE

Author

John E. Baker PhD Professor in the Surgery department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Age Factors
Animals
Animals, Newborn
Bicarbonates
Calcium Chloride
Cardioplegic Solutions
Creatine Kinase
Disease Models, Animal
Female
Heart
Hypothermia, Induced
Hypoxia
In Vitro Techniques
Isoenzymes
L-Lactate Dehydrogenase
Magnesium
Myocardial Ischemia
Myocardial Reperfusion Injury
Perfusion
Potassium Chloride
Pregnancy
Rabbits
Sodium Chloride
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a