Changes in epidermal chalone activity during response of the skin to application of carcinogen and epilation

A decrease in the biological activity of epidermal G₂-chalone, isolated from the dorsal skin of rats, was demonstrated 1–2 days after treatment with the carcinogen methylnitrosourea and one day after epilation. The results of quantitative analysis of mitoses and morphological analysis of the skin which was the source of the chalones showed that this effect is based on different mechanisms.Laboratory of Experimental Histology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR. Laboratory of Experimental Tumors, N. N. Petrov Research Institute of Oncology, Ministry of Health of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Klimov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 3, pp. 354–356, March, 1978.     

Effect of epidermal chalones on growth of transplantable tumors

An alcoholic extract obtained from rat skin contains epidermal g₁- and g₂-chalones, and when added to a suspension of cells of a transplantable squamous-cell keratinizing carcinoma of the mouse cervix uteri it inhibits its growth by 72.6% when injected into recipient mice. The extract had no inhibitory action on transplantable mouse tumors of other histogenesis (hepatoma 22a, leukemia L-1210, and sarcoma 180). Epidermal chalones had only weak action (inhibiting growth by 39.2%; P>0.05) on an anaplastic transplantable mouse skin carcinoma, which had lost its primary squamous-cell structure in the course of prolonged passage (more than 10 years).Laboratory of Experimental Tumors and Laboratory of Endocrinology, N. N. Petrov Research Institute of Oncology, Minsitry of Health of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Serebrov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 466–468, October, 1977.