Histopathological studies on sun-exposed hexachlorobenzene-induced porphyric rat skin.

Abstract

Hexachlorobenzene (HCB) is a porphyrogenic agent. The inducement of skin changes was attempted through repeated exposure of the skin of HCB-induced porphyric rats to sunlight. The following skin changes were produced in the porphyric rats; erythema, erosion, crust, skin thickening and scarring. Histopathological examination revealed the presence of acanthosis, vacuolization of the malpighian cells, subepidermal vesicle, fibrosis, dilatation and increase of the blood vessels and perivascular cell infiltration composed of lymphocytes, histiocytes and mast cells. The PAS stainability of blood vessel walls was slightly intensified. The assumption is that photosensitive flares were elicited within the short 2-month period though destruction of endothelial cells was not prominent. There were no distinct skin changes, clinically or histopathologically, in any of the three control groups.hexachlorobenzene; porphyric rat; skin changes Porphyria cutanea tarda (PCT), a very common type of porphyric, exhibits skin photosensitivity on exposed areas and is characterized by excess excretion of uroporphyrin in the urine. Ockner and Schmid (1961) reported that hexachlorobenzene (HCB) could induce experimental porphyric in rats which then excreted a high level of urinary uroporphyrin. Because the metabolic pattern in rats seems to resemble that in human PCT (Stonard 1974), we have used them as a model for PCT.In the present paper, we analyzed acute cutaneous changes after sun exposure of HCB-induced porphyric rats, both clinically and histopathologically. MATERIALS AND METHODSRats. Sprague-Dawley albino female rats initially weighing 150-200 g were used for this study.Induction of porphyric rat. Twenty rats were fed 0.25% (W/W) HCB-diet for two months and then normal diet for two months. Another 20 rats were kept on normal diet.Porphyrin analysis o f urine. Urinary porphyrins in individual excreta were determined by Rimington's method (Rimington 1971).Sunlight exposure. Rats were divided into four groups; (1) 10 normal rats kept in the dark, (2) 9 sun-exposed normal rats, (3) 6 porphyric rats kept in the dark, and (4) 8