Myocardial protection of immature rabbits: polarizing versus depolarizing.

Abstract

BACKGROUND:

This study was designed to identify the potassium-channel opener pinacidil as a cardioplegic agent vs hyperkalemic cardioplegia in terms of its efficacy in immature cardioprotection.

METHODS:

By a Langendorff model, 21 hearts of 21- to 28-day-old New Zealand rabbits underwent 90 min of global hypothermic (15 degrees C) ischemia protected with a different single dose of hypothermic (4 degrees C) cardioplegia (pinacidil [50 micromol/l], St. Thomas' solution combined with pinacidil [50 micromol/l], and St. Thomas' solution). The percent recovery of the cardiac function, creatine kinase release, and cellular ultrastructure were compared.

RESULTS:

Pinacidil (50 micromol/l) provided significantly the best postreperfused percentage recovery of the function than the other groups; pinacidil cardioplegia showed a significant reduction of creatine kinase release in the coronary flow compared with the other groups; St. Thomas' solution combined with pinacidil showed the highest release. Percentage recovery of the coronary flow, water contents, and ultrastructural changes were similar between the groups.

CONCLUSIONS:

Pinacidil provided better protection during ischemia-reperfusion in the immature rabbit heart than St. Thomas' solution, whereas pinacidil combined with St. Thomas' solution showed the worst protective effects in immature hearts.

• Authors: Jiangang Wang, Xinmin Zhou, Yuan Zhao, Hao Tang, Yerong Hu
• Journal: The Journal of surgical research (J Surg Res) Vol. 111 Issue 1 Pg. 1-7 (May 01 2003) ISSN: 0022-4804 [Print] United States
• PMID: 12842441 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Bicarbonates
• Cardiotonic Agents
• St. Thomas' Hospital cardioplegic solution
• Sodium Chloride
• Potassium Chloride
• Pinacidil
• Creatine Kinase
• Magnesium
• Calcium Chloride

Topics

• Aging
• Animals
• Bicarbonates (administration & dosage)
• Body Water
• Calcium Chloride (administration & dosage)
• Cardiotonic Agents (administration & dosage)
• Coronary Circulation (drug effects)
• Creatine Kinase (metabolism)
• Female
• Heart Arrest, Induced (methods)
• Hemodynamics
• Hyperkalemia
• Magnesium (administration & dosage)
• Male
• Microscopy, Electron
• Myocardial Ischemia
• Myocardial Reperfusion
• Myocardium (ultrastructure)
• Pinacidil (administration & dosage)
• Potassium Chloride (administration & dosage)
• Rabbits
• Sodium Chloride (administration & dosage)