Cerebral prostaglandin synthesis during the dietary and pathological stresses of essential fatty acid deficiency and experimental allergic encephalomyelitis.

Rats of the Lewis strain were fed diets adequate or deficient in essential fatty acids (EFA). At 70-80 days of age experimental allergic encephalomyelitis (EAE) was induced using adjuvants containing either Mycobacterium butyricum or Mycobacterium tuberculois H37Ra. When the former Mycobacterium was used, the incidence of EAE was greater in the EFA-deficient than in EFA-adequate controls; but when the rats challenged with M. tuberculosis, the incidence of the disease was the same in both dietary groups. Brain slices from EFA-deficient rats had a marginally depressed synthesis of prostaglandin F (PGF) compared to that of controls. Immunochallenge with adjuvant alone or adjuvant plus antigen tended to depress further PGF synthesis by brain slices from EFA-deficient rats and significantly depressed synthesis by slices from rats receiving adequate EFA. Whether or not rats were paralyzed had no effect on PGF synthesis when the diet was adequate in EFA, but a significant difference was seen in the EFA-deficient group. The results indicate a possible role for PGF synthesis in the degree of susceptibility of the rats to EAE under different dietary regimens.