Effects of cholera and E. coli enterotoxins on cyclic adenosine 3',5'-monophosphate levels and intermediary metabolism in the thyroid.
Effects of cholera and E. coli enterotoxins on cyclic adenosine 3',5'-monophosphate levels and intermediary metabolism in the thyroid.
复制标题
霍乱和大肠杆菌肠毒素对甲状腺中环腺苷 3,5-单磷酸水平和中间代谢的影响。
作者：
Keith Mashiter;Gail D. Mashiter;Richard L. Hauger;James B. Field
研究了霍乱肠毒素对犬甲状腺环磷酸腺苷（cAMP）水平及中间代谢的影响，并与促甲状腺激素（TSH）和大肠杆菌（E.大肠杆菌肠毒素虽然TSH刺激环AMP和14 CO2的形成在几分钟内，粗品和纯化的霍乱肠毒素（choleragen）需要25分钟，刺激环AMP和45分钟，以增加1 - 14 C-葡萄糖氧化。E.大肠杆菌肠毒素刺激14 CO2的形成，在45分钟的孵育过程中没有产生任何变化的环AMP。然而，E.大肠杆菌肠毒素在两小时的孵育过程中确实增加了环AMP水平。霍乱原和霍乱肠毒素增加腺苷酸环化酶的活性，从甲状腺切片制备的匀浆已预先孵育的肠毒素。与TSH不同，当直接加入匀浆中时，它们没有任何作用。choleragen对环磷酸腺苷形成的影响发生在没有，但增强，10- 2 M茶碱。尽管…
The effects of cholera enterotoxin on dog thyroid cyclic adenosine 3',5'–monophosphate (cyclic AMP) levels and intermediary metabolism were studied and compared to those of thyrotropin (TSH) and E. coli enterotoxin. Although TSH stimulates cyclic AMP and 14CO2 formation within minutes, both crude and purified cholera enterotoxin (choleragen) required 25 min to stimulate cyclic AMP and 45 min to increase l–14C—glucose oxidation. E. coli enterotoxin stimulated 14CO2 formation during a 45–min incubation without producing any change in cyclic AMP. However, E. coli enterotoxin did increase cyclic AMP levels during a two—hr incubation. Choleragen and cholera enterotoxin increased adenylate cyclase activity in homogenates prepared from thyroid slices which had been previously incubated with the enterotoxins. Unlike TSH, they had no effect when added directly to the homogenate. The effect of choleragen on cyclic AMP formation occurred in the absence of, but was potentiated by, 10-2M theophylline. Despite the dela...