Radiation Trypsin

The proteolytic enzymes, trypsin, chymotrypsin, and chymoral [8076-22-0] in combination, have been used for the treatment of post-operative hand trauma, athletic injuries, and sciatica (214—216). Trypsin has also been used successfully in treating hyaline membrane disease of newborn babies, a condition usually fatal without treatment (217). Immobilized preparations of trypsin are useful in treating acute radiation cystitis following pelvic x-irradiation therapy (218). 

Mitomycin C treatment of EF cells Two days later, replace EF media with 20 mL of mitomycin C media (1% mitomycin C in EF media), incubate for 3 h, carefully remove the media, and wash the cells once with PBS. (An alternative way is gamma radiation. The cells are trypsinized, rinsed, resuspended in the media, and exposed to 6,000-10,000 rads of gamma irradiation.)... 

Evidence for the activity of some radioprotectors as inhibitors of free radical processes has appeared, and the subject has been reviewed Involvement of MEA as well as of metal ionsf in free radical formation in proteins and bacteria has been observed. It was also found that cysteine and glutathione could accept electrons from irradiated proteins, whereas cystine and non-sulfur compounds did not Presence of metal ions, particularly cupric, had a protective effect for ribo-nuclease, presumably by intercepting electrons and preventing radical formation on the enzymer A protective effect of mucopolysaccharide polyanions and cysteine for trypsin and RHA, however, was not considered to be due to transfer of radiation energy to the protectors " Furthermore, substances known to react with H atoms or the aqueous electron did not protect hydrated E. coll cells from X-rays ... 

Figure 6. PARP-2" mice are sensitive to ionizing radiation. A) Kaplan-Meier survival curves after 8 Gy of whole body irradiation. Wilcoxon test p(PARP-2 vs PARP-2 ) < 10. (Taken from Minissier-de Murcia et al, with permission). B) Comparison ofy-ray survival curves of wild-type, PARP-T and PARP-2 mouse 3T3 fibroblasts. 10 fibroblasts from mid-log growing subcultures were plated in triplicate in 25 cm flasks and returned to the incubator overnight prior to irradiation. Following treatment, the flasks were supplied with 8 ml fresh medium and grown for exacdy 5 doubling times (relative to mock irradiated cells) with two changes of medium. Cells were harvested by trypsin-EDTA and scored visually under microscope. PARP-1, PARP-T and PARP-2 fibroblasts yielded a convex curve which fitted a linear-quadratic dose-dependent equation, as most usually found among various cell lines, with a pseudo-plateau relating to Cl arrest. PARP-2 fibroblasts showed a concave profile and fitted a double-exponential equation. PARP-2 fibroblasts were clearly the most sensitive ones in the low dose rai of radiation (insert) Bars,SD.

The y-irradiation-induced coupling of trypsin, pepsin, and ribonuclease to agarose has been described. In the presence of agarose, less aggregation of ribonuclease occurred than in free solution, although some radiation damage was observed. 

Cudina 1, Jovanovie SV (1988) Free radical inactivation of trypsin. Radiat Phys Chem 32 497-501... 

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