Sanders R B, Sagur V
Pharmacology. 1978;16(6):321-32. doi: 10.1159/000136788.
The administration of L-tryptophan prevented the normal rise in blood sugar concentration that usually follows the injection of epinephrine into rats. Of the several possible mechanisms by which tryptophan could inhibit epinephrine-induced hyperglycemia, one might be that tryptophan prevented the activation of the enzyme, phosphorylase, which is an indirect result of epinephrine action on the liver. This report presents evidence supporting this hypothesis: (1) The injection of tryptophan (2.5 mM/kg) prevented epinephrine-induced glycogenolysis in the liver of rats by 100%. (2) The time courses of epinephrine-induced hyperglycemia and activation of phosphorylase in liver were nearly identical. (3) The injection of tryptophan completely inhibited (100%) the epinephrine-induced phosphorylase activation. (4) The addition of tryptophan in vitro completely inhibited (100%) the epinephrine-induced activation of phosphorylase. (5) Tryptophan inhibition of epinephrine-induced hyperglycemia occurs immediately after tryptophan administration. (6) The addition of cyclic AMP blocked the tryptophan inhibition of epinephrine-induced phosphorylase activation. This evidence suggests that tryptophan may inhibit epinephrine-induced hyperglycemia in rats by preventing the activation of liver phosphorylase.
给予L-色氨酸可阻止大鼠注射肾上腺素后通常会出现的血糖浓度正常升高。在色氨酸抑制肾上腺素诱导的高血糖的几种可能机制中，一种可能是色氨酸阻止了磷酸化酶的激活，而这是肾上腺素作用于肝脏的间接结果。本报告提供了支持这一假设的证据：（1）注射色氨酸（2.5 mM/kg）可使大鼠肝脏中肾上腺素诱导的糖原分解被100%抑制。（2）肾上腺素诱导的高血糖和肝脏中磷酸化酶激活的时间进程几乎相同。（3）注射色氨酸可完全抑制（100%）肾上腺素诱导的磷酸化酶激活。（4）在体外添加色氨酸可完全抑制（100%）肾上腺素诱导的磷酸化酶激活。（5）色氨酸给药后立即发生对肾上腺素诱导的高血糖的抑制。（6）添加环磷酸腺苷可阻断色氨酸对肾上腺素诱导的磷酸化酶激活的抑制。这一证据表明，色氨酸可能通过阻止肝脏磷酸化酶的激活来抑制大鼠中肾上腺素诱导的高血糖。
