| Popis: |
1. 1. In tissues taken from sheep, cattle, pigs, horses, monkeys, ferrets, and hens histamine was concentrated mainly in the gastro-intestinal tract and lungs. 2. 2. Histamine inactivation occurred primarily in the kidney, liver, spleen, and intestinal walls. 3. 3. L -Histidine decarboxylase (E.C. 4. 1. 1. 22) could not be detected on radiometric assay. 4. 4. Non-specific aromatic L -amino-acid decarboxylase (E.C. 4. 1. 1. 26) was demonstrated in several tissues on bioassay; no potentiation by benzene occurred. 5. 5. It was concluded that the non-specific enzyme may be of importance in the physiological formation of histamine. 6. 6. The suggestion that carnivores derive their histamine from the diet while herbivores form it endogenously by the decarboxylation of histidine is no longer tenable. |
