Detail of "80-99-9"

Reference

Sterol metabolism by cultured mouse epidermal keratinocytes in terminal differentiation and the effect of chemical carcinogen and tumor promoter on it

Sterol metabolism by cultured mouse epidermal keratinocytes in terminal differentiation and the effect of chemical carcinogen and tumor promoter on it. Okamoto, Tetsuji (Dent. Coll., Hiroshima Univ., Hiroshima, Japan). Hiroshima Daigaku Shigaku Zasshi, 16(1), 36-49 (Japanese) 1984. CODEN: HUDJAN. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Section cross-reference(s): 2 In isolated mouse epithelium, lathosterol [80-99-9] was detected 3 days after birth, and the ratio of lathosterol/cholesterol [57-88-5] in the epithelium was increased, peaked on day 10, and remained const. thereafter. In the control medium, cell differentiation was induced and lathosterol formation was increased. Tracer studies with [2-14C]acetate and [methyl-3H]thymidine indicated that sterol formation and DNA formation by mouse epidermal keratinocytes in a low-Ca medium were active. When keratinocytes were transferred form a low-Ca medium to a control medium to induce differentiation, DNA formation was markedly inhibited, and sterol formation was barely maintained. In the low-Ca medium, the majority of [2-14C]acetate was incorporated into cholesterol. Treatment of keratinocytes in low-Ca media with DMBA (I) [57-97-6] to induce differentiation resulted in an inhibition of lathosterol formation at 24 h after differentiation. The lathosterol formation was restored after 48 h. By contrast, TPA [16561-29-8] treatment induced differentiation but had no effect on sterol formation.

Lecithin-dependent phytosterol utilization by larvas of Culex pipiens (Diptera:Culicidae)

Lecithin-dependent phytosterol utilization by larvas of Culex pipiens (Diptera:Culicidae). Dadd, R. H.; Kleinjan, J. E. (Div. Entomol. Parasitol., Univ. California, Berkeley, CA 94720, USA). Ann. Entomol. Soc. Am., 77(5), 518-25 (English) 1984. CODEN: AESAAI. ISSN: 0013-8746. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) Without sterol in synthetic dietary media C. pipiens could not develop beyond the 2nd instar. With cholesterol [57-88-5] as the only dietary lipid, good development to the adult stage occurred, whereas with ergosterol [57-87-4] or stigmasterol [83-48-7] development was no better than in the absence of sterol, and with all other phytosterols tested development was variously restricted. When the basic diet incorporated a lipid supplement contg. the arachidonic acid [506-32-1] needed for newly emerged adults to fly and survive, larval/pupal development and adult viability with ergosterol, stigmasterol, and most phytosterols were as good as with cholesterol. Besides arachidonic acid, the lipid supplement contained an antioxidant, ascorbyl palmitate, and synthetic dipalmitoyl lecithin as a dispersing agent; but with lecithin alone supplementing the basic diet, good development to the adult stage was facilitated with ergosterol, stigmasterol, and other phytosterols, although adults lacking arachidonic acid were not viable. On the basis of diets supplemented with lecithin, it was concluded that ergosterol, stigmasterol, sitosterol [83-46-5], 24-methylenecholesterol [474-63-5], fucosterol [17605-67-3], desmosterol [313-04-2] and perhaps 7-dehydrocholesterol [434-16-2] could support growth and development as well, or almost so, as cholesterol. With cholesterol, development to the 4th instar was good, but nearly all individuals failed to metamorphose. With lathosterol [80-99-9] or 22-trans-cholestadienol [34347-28-9], development was markedly inferior compared with cholesterol and the well utilized phytosterols, and survival through metamorphosis was severely reduced. These results are discussed in relation to current views on the metab. of sterols by phytophagous/omnivorous insects.