Reevaluation of impaired histamine metabolism in skin of autoimmune mice

139 P-19

REEVALUATION OF IMPAIRED HISTAMINE METABOLISM OF AUTOIMMUNE MICE T. Tachibana, F. Furukawa, Department of Dermatology,

IN SKIN

OBSERVATION OF INTRAMSMBRANE PARTICLES OF PHIALOPHORA VERRUCOSA CELLS WITH FREEZE FRACTURE TECHNIQUE

S. Taniguchi and S. Imamura Kyoto University

of

We examined histamine metabolism in the skin of autoimmune mice, MRL/l and BXSB, to clarify its contribution to the mechanism(s) of the development of lupus dermatoses. The back and tail skins of MRL/l mice showed an age-related decrease of histamine contents whereas those of control mice, MRL/n, C57BLf6J and BALE/c, showed an age-related increase. However, autoimmune-prone male EXSB mice showed similar age-related increase to non-autoimmune female BXSB mice. MRL/l mice showed an age-related decrease in the activity of histamine-N-methyltransferase (HMT), a major degrading enzyme in skin of mice, though controls showed an age-related increase. In addition, HMT activity in the back skin of MRL/l mice, which had spontaneous LE-like lesions, was much lower than that in non-lesional tail skin. Male BXSB mice showed simila+ age-related increase to female BXSB mice. These results suggested that HMT activity was basically regulated by genetic factors and that the acquired impairment of histamine metabolism was closely related to the pathogenesis of murine cutaneous LE.

ULTRASTRUCTURAL

STUDIES ON MALASSEZIA

FURFUR

T. Saitoh, M. Oguchi, Y.Asada, Y. Matsuda and Y. Soh. Department of Dermatology, Kansai Medical Univ., Moriguchi, Public Health Research Institute of Kobe and Kobe Central Municipal Hospital, Kobe. Though sidered

to

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of P. strains

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previously

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Characteristic

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elements as

results suggested

well that

I. Tanaka, Dermatology,

K.

Hirayama, K. Osaka Medical

Kiyokane Coll.,

and M. Yasuhara. Osaka, Japan

Department

To demonstrate the location of inrramembrane particles of Pbialophora verrucosa cells (P-V cells) and Trichophyton mentagrophytes, the P face of the cell membrane was examined with the Freeze-fracture technique. 1. P face of P-V cells showed a dispersed distribution of inrramembrane particles in the cells fixed with glutaraldehyde after culture for 14 days at 27°C. 2. It showed an irrenular disrribbtion and a decrease in number of the particles after culture for 2 hours at 42’C. 3. P face of Trichophyton mentagrophyres showed a dispersed

distribution of the particles after culture 4. Ultrathin sections showed that the

at 27’C and at 42’C. structure of P-V cells

did not change after culture far 2 hours at 42°C after culture for 7 days at 42’C. These findings indicate that distribution-change intramembrane particles in the influence of hear of P-V cells.

and

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damaged

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the

damage