调节钙磷代谢的激素

调节钙、磷代谢的激素

✧甲状旁腺激素, PTH

✧降钙素, CT

✧维生素D3

钙平衡

血钙浓度的高低直接关系到可兴奋组

织的兴奋性、腺体的分泌以及骨代谢

的平衡2+衡

血Ca 2

低钙抽搐

甲状旁腺

主细胞

↓

甲状旁腺素

Parathyroid hormone PTH

Parathyroid hormone

甲状旁腺素

Parathyroid hormone

Parathyroid hormone

甲状旁腺素是含84个氨基酸

的直链肽

甲状旁腺激素的作用—↑血钙、↓血磷

✧↑肾小管（远曲）对钙的重吸收、↓肾小管（近曲）对磷的重吸收✧↑ (+) 肾1α羟化酶→↑ 1,25-(OH)2 D3→↑小肠钙吸收

✧↑骨钙入血，溶骨

骨钙入血溶骨

血钙↓

PTH的分泌主要受血钙水平调节

PTH ↑

骨钙入血

(＋)肾内1α羟化酶

125(OH)D 肾重吸收钙↑1,25-(OH)

2-D 3↑小肠吸收钙↑血钙↑

降钙素

Calcitonin, CT

甲状腺滤泡旁细胞（C细胞）分泌的32肽

parafollicular cell

parafollicular cell

Calcitonin 作用降钙素

作用：

⏹

抑制破骨细胞介导的溶骨作用，增强成骨过程。CT

⏹抑制肾小管对钙、磷的重吸收

Ca 2+分泌调节

2

主要受血[Ca 2+] 的控制。

CT 与PTH 在钙稳定的调节作用方面PTH 相互对抗，从而形成双重激素调节

维生素D

3

VitD需要经过活化才具有激素的活性

主要活性形式为1,25(OH)2D3

维生素D

3

促进小肠粘膜对钙的吸收

活化的维生素D能升高血钙和血磷水平并促进骨质的矿化过程✧促进小肠粘膜对钙的吸收。VitD→核受体→基因转录→钙结合蛋白→肠道钙转运↑✧调节骨钙沉积和释放。

VitD→成骨细胞→骨钙素等骨基质蛋白→成骨

VitD 间接作用破骨细胞↑溶骨VitD→间接作用→破骨细胞↑→溶骨

✧促进肾小管对钙、磷的重吸收

佝偻病

rachitic rosary

褪黑素Melatonin

褪黑素是松果体分泌的激素之一

褪黑素的生物学作用

⏹促进睡眠

抑制下丘脑-腺垂体-甲状腺轴和肾上腺皮质功能

⏹抑制下丘脑腺垂体甲状腺轴和肾上腺皮质功能⏹

调节衰老过程⏹调整生物节律

Jet lag

Melatonin improves ⏹Melatonin improves

recovery and

prevents jet lag

prevents jet lag

⏹Take 3-6 mg 30 min

before bed time at

your destination

Discovery of Leptin （瘦素）⏹Leptin was discovered in 1994 by Dr. Jeffrey

Friedman (Rockefeller University) and others

Dr Friedman sho ed that mice that had been

⏹Dr. Friedman showed that mice that had been

deprived of the ob gene through genetic

engineering were grossly obese and diabetic. The d f h b i l i product of the ob gene is leptin .

The discovery of leptin ushered in an explosion of ⏹

The discovery of leptin ushered in an explosion of research and a great increase in knowledge about regulation of the human feeding and eating cycle.Jeffrey M. Friedman

M D Ph D M.D., Ph.D.

Effects of Leptin

Leptin Disorder in Mice ⏹ob/ob (lep-/-) mouse

recessive mutation of leptin gene

db/db mouse

⏹db/db mouse

mutation of leptin receptor

Leptin Disorder in human?

⏹Regional Fat Distribution

☐Men: abdominal and visceral

Women:buttocks thighs upper arm and breasts ☐Women: buttocks, thighs, upper arm, and breasts

Summary

Summary