RESUMO
We examined the effect of alpha-linolenic acid (18:3 (n-3)) pretreatment on the metabolism of omega-3 and omega-6 polyunsaturated fatty acids and histamine content and release of RBL-2H3 cells. RBL-2H3 cells grew without reduction in number when incubated with subculture media for 3 d and then placed again in serum-free medium with bovine serum albumin (BSA) and epidermal growth factor (EGF). Cholesterol pullulan (10 micrograms/ml) emulsified alpha-linolenic acid (20 micrograms/ml) was recommended as an additional form serum free medium. We determined the fatty acid composition in all neutral lipids, free fatty acids and all phospholipids in alpha-linolenic acid-treated cells. In all cases the concentration of alpha-linolenic acid and docosahexenoic acid (DHA, 22:6 (n-3)) was increased, while linolenic acid (18:2 (n-6)) was slightly and arachidonic acid (20:4 (n-6)) was markedly decreased. Content of histamine in alpha-linolenic acid-treated cells was remarkably lower than that of untreated cells. Accordingly, net histamine release stimulated by antigen or A23187 was also markedly decreased in the alpha-linolenic acid-treated cells, as was the percent histamine release stimulated by antigen. Results from our in vitro experiment suggest that the anti-allergic effect of alpha-linolenic acid may be caused either by the decrease in histamine content or by inhibition of the release of chemical mediator resulting from changes in the fatty acid composition.
Assuntos
Gorduras Insaturadas na Dieta/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Ácidos Graxos Insaturados/metabolismo , Liberação de Histamina/efeitos dos fármacos , Ácido alfa-Linolênico/farmacologia , Animais , Basófilos/citologia , Basófilos/efeitos dos fármacos , Basófilos/metabolismo , Calcimicina/farmacologia , Divisão Celular/efeitos dos fármacos , Colesterol/química , Cromatografia Líquida de Alta Pressão , Dinitrofenóis/farmacologia , Relação Dose-Resposta a Droga , Emulsões , Fator de Crescimento Epidérmico/química , Ácidos Graxos Ômega-6 , Glucanos/química , Haptenos/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Leucemia Basofílica Aguda/patologia , Metabolismo dos Lipídeos , Fosfolipídeos/metabolismo , Ratos , Soroalbumina Bovina/química , Soroalbumina Bovina/farmacologia , Células Tumorais CultivadasRESUMO
A competitive ELISA technique using digoxin-specific antibody has been developed to determine digoxin and its related compounds in hairy root cultures of Digitalis lanata. The ELISA could detect 0.2-2 nM digoxin and closely related cardenolides. Hairy roots cultured in the dark accumulated very small amounts of cardenolides (0.02-0.07 micrograms/g dry wt), while the content of cardenolides in green hairy roots cultured in the light was increased maximally 600-fold (16.5 micrograms/g dry wt) compared to those in the dark.