MOBILIZATION OF PLACENTAL GLYCOGEN IN DIABETIC RATS
MOBILIZATION OF PLACENTAL GLYCOGEN IN DIABETIC RATS
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DOI：
10.1016/s0143-4004(05)80197-3
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发表时间：
1990-11-01
期刊：
影响因子：
3.8
通讯作者：
SHAFRIR, E
中科院分区：
文献类型：
--
作者：
BARASH, V;SHAFRIR, E
由于糖原在糖尿病的胎盘中积累，并且一般来说似乎对禁食的影响不敏感，因此在非糖尿病和糖尿病大鼠中研究了儿茶酚胺引起糖原分解的能力。注射肾上腺素或异丙肾上腺素引起非糖尿病，妊娠20天大鼠的胎盘糖原在20分钟内减少，与血清葡萄糖和乳酸的上升。与异丙肾上腺素孵育诱导糖原分解胎盘切片从非糖尿病和糖尿病大鼠，几乎与乳酸的生产相称。异丙肾上腺素的这种作用是浓度依赖性的，在非糖尿病和糖尿病大鼠胎盘中具有相似的幅度。胰高血糖素在体内或体外均不能诱导胎盘糖原分解。通过给予霍乱毒素对儿茶酚胺受体的促肾上腺皮质激素刺激可显著降低胎盘糖原，糖尿病大鼠胎盘糖原含量显著高于非糖尿病大鼠。这些结果表明，胎盘糖原是服从动员激素刺激影响磷酸化酶的激活。
Since glycogen accumulates in the placenta in diabetes and does not appear to be susceptible, in general, to the effect of fasting, the capacity of catecholamines to elicit glycogenolysis was investigated in non-diabetic and diabetic rats. Injection of epinephrine or isoproterenol caused a decrease in placental glycogen within 20 min in non-diabetic, 20 day pregnant rats, in association with the rise in serum glucose and lactate. Incubation with isoproterenol induced glycogenolysis in placental slices from non-diabetic and diabetics rats, nearly commensurate with lactate production. This effect of isoproterenol was concentration dependent and of similar magnitude in non-diabetic and diabetic rat placentas. Glucagon was ineffective in inducing placental glycogenolysis in vivo or in vitor. Protracted stimulation of the catecholamine receptor by the administration of cholera toxin effected a pronounced decrease in placental glycogen, percentagewise higher in diabetic than non-diabetic rats. These results show that placental glycogen is amenable to mobilization by hormonal stimuli effecting phosphorylase activation.