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1262. Some more lathyrogens
NATURAL PRODUCTS
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Close on the heels of recent reports of goitrogenic activity in the Nigerian food cassava and in the volatile constituent of onions (Cited in F.C.T. 1967, 5, 125) comes the news that yet another article of diet has been implicated. The present investigation was undertaken following a suspicion that in an endemic--goitre area of Spain a possible relationship may exist between the intake of walnuts and thyroid enlargement. In rats, which had been fed on a walnut diet for 75 days, thyroidal radioiodine (1311) uptake was almost double that of the control when measured 6--48 hr after intraperitoneal injection of mI. There was an increase in plasma levels of both protein-bound and nonprotein bound mI and a decrease in the level of protein-bound stable iodine (127I). Histological changes in the thyroid resembled those following the administration of thyroid stimulating hormone. The results obtained so far suggest that a loss of thyroxine, perhaps by the faecal route, is responsible for the goitrogenic effect. 1261. Chick oedema factor still defiant Campbell, T. C. & Friedman, L. (1966). Chick edema factor: Some tissue distribution data and toxicologic effects in the rat and chick. Proc. Soc. exp. Biol. Med. 121, 1283. The chick oedema factor (COF), which has been traced to the unsaponifiable fraction of processed fat present in the feed, has been tentatively identified as hexachlorohexahydrophenanthrene (Cited in F.C.T. 1964, 2, 389). The toxic response in rats and monkeys differs from that in chicks. Orally-intubated doses of an unsaponifiable fraction of toxic fat providing up to 48 pg COF/kg/day for 6 days in chicks and up to 18/~g COF/kg/day for 2 wk in rats elicited toxic effects, characteristic of each species. Gas-chromatographic analysis of the unsaponifiable fraction revealed eight or nine components of COF. In rats, COF was detected in the liver and faeces but was absent from the kidneys, adrenals and urine. The liver contained only two components while the faeces contained two compounds differing slightly from these, together with all the remaining components. Similar components were detected in chick liver and faeces. The suggestion is made that the toxic components of COF are the two present in the liver where they undergo metabolism before being excreted via the bile into the intestine of both species. 1262. Some more lathyrogens Rao, S. L. N. & Sarma, P. S. (1966). Neurotoxic properties of N-substituted oxamic acids. Indian J. Biochem. 3, 57. Lathyrism, a neurological disorder in man caused by the ingestion of lathyrus seeds, is now attributed in the main to fl-aminopropionitrile although other factors have been implicated (Cited in F.C.T. 1966, 4, 240). Following up their discovery that fl-N-oxalyl-L-a,fl-diaminopropionic acid (I) is lathyrogenie to the day-old chick (Rao et aL Biochemistry 1964, 3, 432), the present authors have synthesized a series of eight N-substituted oxamic acids in an effort to establish the structureactivity relationships of the compounds in chicks. Decarboxylated I (2'-aminoethyloxamic acid) and 2'-hydroxyethyloxamicacid proved inactive, but N-oxalyl-fl-alanine, which could arise by reductive deamination of I, was active. Other N-oxalyl amino acids were also active and it was suggested that neurotoxicity residues in those N-substituted oxamic acids whose N-substituent carries another carboxylic group. 1263. Toxicity of excess phenylalanine to chicks Tamimie, H. S. & Pscheidt, G. R. (1966). Effect of feeding 5 per cent L-phenylalanine to young chicks. Comp. Biochem. Physiol. 17, 609.
271
Close on the heels of recent reports of goitrogenic activity in the Nigerian food cassava and in the volatile constituent of onions (Cited in F.C.T. 1967, 5, 125) comes the news that yet another article of diet has been implicated. The present investigation was undertaken following a suspicion that in an endemic--goitre area of Spain a possible relationship may exist between the intake of walnuts and thyroid enlargement. In rats, which had been fed on a walnut diet for 75 days, thyroidal radioiodine (1311) uptake was almost double that of the control when measured 6--48 hr after intraperitoneal injection of mI. There was an increase in plasma levels of both protein-bound and nonprotein bound mI and a decrease in the level of protein-bound stable iodine (127I). Histological changes in the thyroid resembled those following the administration of thyroid stimulating hormone. The results obtained so far suggest that a loss of thyroxine, perhaps by the faecal route, is responsible for the goitrogenic effect. 1261. Chick oedema factor still defiant Campbell, T. C. & Friedman, L. (1966). Chick edema factor: Some tissue distribution data and toxicologic effects in the rat and chick. Proc. Soc. exp. Biol. Med. 121, 1283. The chick oedema factor (COF), which has been traced to the unsaponifiable fraction of processed fat present in the feed, has been tentatively identified as hexachlorohexahydrophenanthrene (Cited in F.C.T. 1964, 2, 389). The toxic response in rats and monkeys differs from that in chicks. Orally-intubated doses of an unsaponifiable fraction of toxic fat providing up to 48 pg COF/kg/day for 6 days in chicks and up to 18/~g COF/kg/day for 2 wk in rats elicited toxic effects, characteristic of each species. Gas-chromatographic analysis of the unsaponifiable fraction revealed eight or nine components of COF. In rats, COF was detected in the liver and faeces but was absent from the kidneys, adrenals and urine. The liver contained only two components while the faeces contained two compounds differing slightly from these, together with all the remaining components. Similar components were detected in chick liver and faeces. The suggestion is made that the toxic components of COF are the two present in the liver where they undergo metabolism before being excreted via the bile into the intestine of both species. 1262. Some more lathyrogens Rao, S. L. N. & Sarma, P. S. (1966). Neurotoxic properties of N-substituted oxamic acids. Indian J. Biochem. 3, 57. Lathyrism, a neurological disorder in man caused by the ingestion of lathyrus seeds, is now attributed in the main to fl-aminopropionitrile although other factors have been implicated (Cited in F.C.T. 1966, 4, 240). Following up their discovery that fl-N-oxalyl-L-a,fl-diaminopropionic acid (I) is lathyrogenie to the day-old chick (Rao et aL Biochemistry 1964, 3, 432), the present authors have synthesized a series of eight N-substituted oxamic acids in an effort to establish the structureactivity relationships of the compounds in chicks. Decarboxylated I (2'-aminoethyloxamic acid) and 2'-hydroxyethyloxamicacid proved inactive, but N-oxalyl-fl-alanine, which could arise by reductive deamination of I, was active. Other N-oxalyl amino acids were also active and it was suggested that neurotoxicity residues in those N-substituted oxamic acids whose N-substituent carries another carboxylic group. 1263. Toxicity of excess phenylalanine to chicks Tamimie, H. S. & Pscheidt, G. R. (1966). Effect of feeding 5 per cent L-phenylalanine to young chicks. Comp. Biochem. Physiol. 17, 609.