The effects of photosensitizers and ultraviolet irradiation on the biosynthesis and metabolism of prostaglandins

Abstract

Prostaglandin biosynthesis from arachidonic acid by skin microsomal fraction preparation was enhanced by UV-irradiation at wavelengths of 254 and 360 nm. In the presence of 8-methoxy psoralen (8 MOP) and coal tar, prostaglandin biosynthesis was further enhanced approximately 2-fold by UV-irradiation at 254 nm. Stimulation was less by UV-irradiation at 360 nm. 8-MOP enhanced the conversion of PGE2 into PGF2-9-ketoreductase prepared from skin high speed supernatant fractions. UV-irradiation at 254 nm and 360 nm with or without the photosensitizers had no effect on the activity of the PGE2-9-ketoreductase. These data therefore indicate that the action of UV-irradiation, 8-methoxy psoralen and coal tar on the skin may in part be due to their regulation of the biosynthesis and metabolism of prostaglandins in this tissue.

The effects of photosensitizing antibiotics and ultraviolet irradiation on the biosynthesis of prostaglandins

“…Our interest was to identify the more stable prostaglandins already known to be involved in cutaneous inflammatory reactions. These results are similar to a previous report from this laboratory (Lord et al, 1976) on the effects of UV-irradiation on 8methoxypsoralen, a photosensitizer currently in use for the management of psoriatic lesions. Although the precise mechanism for the enhancement of prostaglandin biosynthesis in vitro by UV-irradiation plus the photosensitizers is not fully clear, it is interesting to note that the exposure of unsaturated fatty acids to UV-irradiation is known to result in light-initiated cyclic peroxidation (Heath & Packer, 1968).…”

“…Exposure to UV-irradiation was similar to that described above. Fractionation and identiflcation of radioactive prostaglandins by thin layer chromatography on silica gel G were as reported previously (Lord et al, 1976).…”

“…These results suggest that a relationship exists between UVirradiation, the formation and release of prostaglandins and the development of erythema in the skin. In our continuing eifort to elucidate the mechanism of action of photosensitizing compounds, we recently reported that a photosensitiziting compound, 8-methoxypsoralen when exposed to UVirradiation, markedly stimulated the formation of prostaglandins from arachidonic acid in vitro (Lord et al, 1976). Among another group of compounds reported to cause blistering erythema are two cyclic antibiotics, tetracycline and demethylchlortetracycline (Ealk, i960;Cullen, Catalano & Helfman, 1966;Blank, Cullen & Catalano, 1968;Frost, Weinstein & Gomez, 1971;Schorr & Monash, 1963).…”

Visible Light-Sensitized Oxidation of Arachidonic Acid in the Presence of Inperatorin.

“…It has recently been recognized that drug phototoxicity can also be caused by UVA (320400nm) and visible light, which have far less biological effect than UVB (290320nm) and do not produce erythema by themselves (1). Although many photosensitized oxidation studies of lipids have been conducted by irradiation with UV light (3)(4)(5)(6)(7)(8), the mechanistic significance of visible light in the drug phototoxic ity has not been fully studied thus far. Inperatorin was a generous gift from Santen Pharmaceutical Co. Ltd ., Osaka, Japan.…”

Photochemotherapy: A review

“…Action on actively dividing or activated immune cells especially on T cell, explain their action in immune mediated disease like psoriasis, lichen planus, graft versus host disease. [10,[15][16][17][18] …”