Biosynthesis of bufadienolides in toads. V. the origin of the cholesterol used by toad parotoid glands for biosynthesis of bufadienolides

Sodium (1- 14 C) acetate and (5- 3 H) mevalonate were incubated with Bufo vienarum toad parotoid gland and liver tissues. Both labelled compounds were incorporated into cholesterol produced by liver while the incubations with parotoid gland produced no labelled cholesterol. Low and high density lipo...

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Detalles Bibliográficos
Autores principales: Santa Coloma, ?.A., Garraffo, H.M., Pignataro, O.P., Charreau, E.H., Gros, E.G.
Formato: JOUR
Materias:
bufadienolide
cholesterol
animal cell
mouth
nonhuman
parotid gland
priority journal
Animals
Binding Sites
Biological Transport, Active
Bufanolides
Bufo arenarum
Cholesterol
Cholesterol Esters
Female
Lipoproteins, HDL
Lipoproteins, LDL
Liver
Parotid Gland
Animalia
Anura
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0039128X_v44_n1_p11_SantaColoma
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Sodium (1- 14 C) acetate and (5- 3 H) mevalonate were incubated with Bufo vienarum toad parotoid gland and liver tissues. Both labelled compounds were incorporated into cholesterol produced by liver while the incubations with parotoid gland produced no labelled cholesterol. Low and high density lipoproteins isolated from toad plasma were iodinated and used for binding studies. Membrane preparations of paratoid gland showed high affinity binding sites for 125 I-LDL and 125 I-HDL. In addition, while colchicine inhibits the in vitro uptake of ( 3 H) cholesteryl linoleate-LDL into parotoid gland tissue an opposite effect was seen with ( 3 H) cholesteryl linoleate-HDL. The above mentioned results would support the hypothesis that the cholesterol used by the parotoid gland for the biosynthesis of bufalienolides would be produced in the liver, transported by the circulating lipoproteins and incorporated by the glands by a receptor-mediated mechanism. © 1984.

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