THE EFFECT OF IONIZING RADIATION UPON SULFUR METABOLISM

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Acta Univ. Carolinae, Med.

OSTI ID:4094165

Neuwirt, J

The effect of ionizing radiation on protein sulfhydryl groups was investigated in Wistar rats. The animals were exposed to 600-r doses of 200-kv whole-body x irradiation and at various intervals (4 and 24 hr and 4 days) changes in proteins in testis and spleen were examined. In some cases S/sup 35/- labeled amino acids had been injected in the rats. Nonprotein nitrogen levels rose approximately 75% at 4 hr but had returned to normal four days postirradiation. The cystine plus glutathione and lysine contents of the tissues rose approximately 50% 4 hr after exposure. Proteinbound sulfhydryl groups increased in both tissues immediately after irradiation, presumably due to splitting of protein disulfide groups. Some S is also split from the protein molecule by irradiation. This splitting of protein S is manifested by an increase of the nonprotein S in the radiosensitive tissues. Simultaneously the protein S decreases. In proteins labeled with S/sup 35/ before irradiation, the specific activities of protein S decreased immediately after exposure. In the first hours after exposure in radiosensitive tissues, also a significant reduction of the incorporation of S-containing amino acids into the tissue proteins was noted. Using the labeled amino acids methionine and cysteine, it was shown that the increased excretion of S after irradiation originates only from the S split from proteins. Ionizing radiation ihhibited the utilization of methionine by the liver. The unique radio-sensitivity of protein-bound S is discussed. (BBB)

• Research Organization: Charles Univ., Prague
• NSA Number: NSA-18-013420
• OSTI ID: 4094165
• Journal Information: Acta Univ. Carolinae, Med., Journal Name: Acta Univ. Carolinae, Med. Vol. Vol: 7
• Country of Publication: Country unknown/Code not available
• Language: Czech

Related Subjects

AMINO ACIDS
BIOLOGY AND MEDICINE
BODY
CYSTINE
FREE RADICALS
GLUTATHION
GONADS
HYDROLYSIS
LABELLED COMPOUNDS
LIVER
LYSINE
MEASURED VALUES
METABOLISM
NITROGEN
ORGANIC SULFUR COMPOUNDS
PROTEINS
RADIATION DOSES
RADIATION EFFECTS
RADIOSENSITIVITY
RATS
SPLEEN
SULFHYDRYL RADICALS
SULFUR 35
TESTES
TISSUES
X RADIATION