THE RELATIVE PROTECTIVE EFFECT OF PYRIDOXINE, p-AMINOBENZOIC ACID, AND VARIOUS CYSTEAMINE DERIVATIVES ON THE X-RAY INDUCED DEGRADATION OF PYRIDOXAL-5-PHOSPHATE
The relative rate of radical inactivation by p-aminobenzoic acid, pyridoxine, 2-mercaptoethylguanidine, Ndimethylcysteamine, N-(2-mercaptoethyl)- piperidine, and N-dibutylcysteamine have been studied in a two-solute system with pyridoxal-5-phosphate as indicator of radiation damage. The protection indices of these compounds were found to be 3.1 (extrapolated to zero concentration of the indicator), 1.3, 1.2, 0.8, 0.6, and 0.5, respectively. When the concentration of the indicator was increased from 9 x l0/sup -5/ M to 2.l x 10/ sup -4/ M, the protection index of p-aminobenzoic acid decreased from 2.3 to 1.4, thus giving evidence of energy transfer from p-aminobenzoic acid to the indicator. The lack of correlation between radical scavenging effect in vitro and the ability of the compounds to exert radioprotection in vivo, suggests that this effect in vivo is largely dependent on biochemical factors. (auth)
- Research Organization:
- Norwegian Radium Hospital, Montebello, Norway
- NSA Number:
- NSA-16-006363
- OSTI ID:
- 4813035
- Journal Information:
- Strahlentherapie (West Germany), Vol. Vol: 116; Other Information: Orig. Receipt Date: 31-DEC-62
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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