Vitamins Q and E, extracorporal circulation and hemolysis

Area of Science:

• Biochemistry
• Cardiovascular Surgery
• Nutritional Science

Background:

• Oxidative stress is a concern during cardiopulmonary bypass.
• Antioxidant vitamins like Q and E play crucial roles in protecting cell membranes.

Purpose of the Study:

• To investigate the changes in plasma ubiquinone (vitamin Q) and alpha-tocopherol (vitamin E) levels during open chest surgery.
• To assess the relationship between antioxidant vitamin levels and free cholesterol during extracorporeal circulation.

Main Methods:

• Whole blood and plasma samples were collected from 10 male patients undergoing open chest surgery.
• Levels of vitamin Q, vitamin E, and free cholesterol were measured at baseline and during surgery.
• Vitamin levels were normalized for free cholesterol (NQ and NE) to account for variations.

Main Results:

• Plasma vitamin Q and E levels showed a continuous decrease throughout the surgery.
• Hemolysis in later samples affected vitamin E measurements.
• Normalized values (NQ and NE) also decreased, with higher initial levels correlating with greater depletion.
• Evidence suggested active liver vitamin Q release in patients with high baseline antioxidant levels.

Conclusions:

• Open chest surgery and extracorporeal circulation lead to significant depletion of antioxidant vitamins Q and E.
• High baseline levels of these vitamins may predispose to greater depletion during surgery.
• This depletion did not appear to prevent membrane damage, erythrocyte fragility, and hemolysis.