Related Experiment Videos
Ascorbic acid: a nonradioactive extracellular space marker in canine heart
G H Reil1, R Frombach, R Kownatzki
1Abteilung für Kardiologie und Biophysikalische Geräteabteilung, Medizinische Hochschule Hannover, Federal Republic of Germany.
The American Journal of Physiology
|November 1, 1987
Summary
Ascorbic acid, also known as vitamin C, functions as an extracellular space marker in myocardial tissue. Its distribution volume closely matches traditional markers, indicating its utility in research and clinical settings.
Area of Science:
- Cardiovascular Research
- Biomedical Engineering
- Pharmacology
Background:
- Ascorbic acid's role in myocardial tissue distribution is not fully understood.
- Classical extracellular space markers have limitations in safety and application.
- A novel method for measuring ascorbic acid in coronary venous blood is needed.
Purpose of the Study:
- To compare the distribution pattern of ascorbic acid with established extracellular space markers in myocardial tissue.
- To evaluate ascorbic acid as a potential nonradioactive marker for extracellular space in the heart.
- To develop and utilize a new polarographic technique for real-time ascorbic acid concentration monitoring.
Main Methods:
- Utilized an open-chest canine heart preparation (n=17 dogs).
- Infused tracers including ascorbic acid, L-[14C]ascorbic acid, [3H]-inulin, [3H]sucrose, and Na82Br.
- Calculated distribution volumes using Zierler's mean transit time method.
- Developed a polarographic technique for analogue registration of ascorbic acid in coronary venous blood.
Main Results:
- Ascorbic acid (23.6 ml/100 g wet wt) and L-[14C]ascorbic acid (24.5 ml/100 g wet wt) distribution volumes closely matched those of [3H]inulin (18.6 ml/100 g wet wt), [3H]sucrose (22.0 ml/100 g wet wt), and 82Br- (27.3 ml/100 g wet wt).
- Kinetic data confirmed ascorbic acid's physicochemical properties as an extracellular space marker.
- Ascorbic acid demonstrated slow leakage into myocardial cells, with a high transcapillary (1.8 X 10(-5) cm/s) and low transplasmalemmal penetration rate (3.7 X 10(-8) cm/s).
Conclusions:
- Ascorbic acid serves as a reliable extracellular space marker in myocardial tissue.
- Its favorable properties (low molecular weight, high diffusivity, low binding, specific penetration rates) make it a safe and simple alternative to radioactive tracers.
- This nonradioactive marker has potential applications in both experimental animal studies and human patients without adverse effects.