皮質醇

皮質醇，由腎上腺分泌的荷爾蒙，在應付壓力中扮演重要角色，故又被稱為「壓力荷爾蒙」。皮質醇會提高血壓、血糖水平和產生免疫抑制作用。在藥理學，人工合成的皮質醇稱作氫羥腎上腺皮質素（hydrocortisone），除了補充皮質醇不足外，也會用作治療過敏症和發炎。最初被用作治療類風濕性關節炎時，皮質醇被稱作Compound E（合成物E）。

生理反應

血液中皮質醇含量在日中會變化，早上的水平最高，下降至午夜時最低。剛出生嬰孩的皮質醇日中含量變化並非跟隨上述規律；相關規律成形於兩周至九個月大。^[1] 有關晝夜節律的訊息，相信由視網膜傳送至下丘腦的視交叉上核（suprachiasmatic nuclei）。

研究發現，特定的皮質醇水平變化與失常的促腎上腺皮質素水平、憂鬱症、壓力有關，也與血糖過低、疾病、發熱、創傷、敬畏、痛楚和極端溫度等會引起因壓力而來之生理反應的事件有關。

作用

正常含量的皮質醇（如其他糖皮質激素）有助身體在壓力下回復體內平衡。長期壓力會導致長時間分泌皮質醇。

胰島素: 皮質醇提高糖原分解和脂類、蛋白質的分解，促進製造肝外胺基酸和酮類，變相中和胰島素作用。這會間接增加血液中的葡萄糖含量，肝臟也會增加分解糖原。^[2] 長期分泌皮質醇會導致多糖症。

胺基酸: 皮質醇通過抑制膠原質形成、減低肌肉吸收胺基酸和抑制蛋百質合成，提升血清中的胺基酸含量。^[3]

消化系統分泌: 皮質醇會刺激胃酸分泌^[4]，從而增加腹瀉時鉀和酸的流失。

鈉: 皮質醇有助哺乳類動物抑制鈉從腸流失。^[5] 但鈉的流失不影響皮質醇分泌^[6]。

鉀: 皮質醇會導致鉀從細胞流失，主要通過補回同等數目的鈉來實現。^[7] 這較不會影響身體pH值，因為正常來說每3個鉀離子流失只會有2個鈉離子補回。

水: 皮質醇是利尿劑荷爾蒙，腸部一半的利尿作用由它控制。^[8]

銅: 皮質醇可增加免疫作用中銅的含量，從而刺激含銅的酵素^[9]，包括超氧化物歧化酶（superoxide dismutase）^[10]，該種酶用作抵抗細菌。

免疫系統: 皮質醇可削弱免疫系統的活動，妨礙T細胞的繁殖^[11]

參考資料

↑ de Weerth C, Zijl R, Buitelaar J. Development of cortisol circadian rhythm in infancy. Early Hum Dev. 2003, 73 (1-2): 39–52. PMID 12932892.
↑ Freeman, Scott (2002). Biological Science. Prentice Hall; 2nd Pkg edition (December 30, 2004). ISBN 0-13-218746-9.
↑ Manchester, K.L., 「Sites of Hormonal Regulation of Protein Metabolism. p. 229」, Mammalian Protein [Munro, H.N., Ed.]. Academic Press, New York. On p273.
↑ Soffer, L.J.; Dorfman, R.I.; Gabrilove, J.L,. 「The Human Adrenal Gland」. Febiger, Phil.
↑ Sandle, G.I.; Keir, M.G.; Record, CO. (1981) 「The Effect of Hydrocortisone on the Transport of Water, Sodium, and Glucose in the Jejunum」. Scandinavian Journal of Gastroenterol. 16: 667,.
↑ Mason, P.A.; Fraser, R.; Morton, J.J. (1977) 「The Effect of Sodium Deprivation and of Angiotensin II Infusion on the Peripheral Plasma Concentration of 18 Hydroxycorticosterone, Aldosterone, and Other Corticosteoids in Man」. Steroid Biochemistry 8: 799,
↑ Knight, R.P., Jr.; Kornfield, D.S.; Glaser, G.H. & Bondy, P.K. (1955) 「Effects of Intravenous Hydrocortisone on Electrolytes in Serum and Urine in Man」. Journal of Clinical Endocrinology 15: 176-181,.
↑ Sandle, G.I.; Keir, M.G.; Record, CO. (1981) 「The Effect of Hydrocortisone on the Transport of Water, Sodium, and Glucose in the Jejunum」. Scandinavian Journal of Gastroenterol. 16: 667,.
↑ Weber, C.E (1984). 「Copper Response to Rheumatoid Arthritis」. Medical Hypotheses 15: 333-348, on p337,.
↑ Flohe, L.; Beckman, R.; Giertz, H.; Loschen, G. 「Oxygen Centered Free Radicals as Mediators of Inflammation. p. 405」, Oxidative Stress (Sies H, ed) Academic Press, New York.
↑ Palacios R., Sugawara I. Hydrocortisone abrogates proliferation of T cells in autologous mixed lymphocyte reaction by rendering the interleukin-2 Producer T cells unresponsive to interleukin-1 and unable to synthesize the T-cell growth factor. Scand J Immunol. 1982, 15 (1): 25–31. PMID 6461917. doi:10.1111/j.1365-3083.1982.tb00618.x.

[1] Weerth C, Zijl R, Buitelaar J. Development of cortisol circadian rhythm in infancy. Early Hum Dev. 2003, 73 (1-2): 39–52. PMID 12932892.

[2] Freeman, Scott (2002). Biological Science. Prentice Hall; 2nd Pkg edition (December 30, 2004). ISBN 0-13-218746-9.

[3] Manchester, K.L., 「Sites of Hormonal Regulation of Protein Metabolism. p. 229」, Mammalian Protein [Munro, H.N., Ed.]. Academic Press, New York. On p273.

[4] Soffer, L.J.; Dorfman, R.I.; Gabrilove, J.L,. 「The Human Adrenal Gland」. Febiger, Phil.

[5] Sandle, G.I.; Keir, M.G.; Record, CO. (1981) 「The Effect of Hydrocortisone on the Transport of Water, Sodium, and Glucose in the Jejunum」. Scandinavian Journal of Gastroenterol. 16: 667,.

[6] Mason, P.A.; Fraser, R.; Morton, J.J. (1977) 「The Effect of Sodium Deprivation and of Angiotensin II Infusion on the Peripheral Plasma Concentration of 18 Hydroxycorticosterone, Aldosterone, and Other Corticosteoids in Man」. Steroid Biochemistry 8: 799,

[7] Knight, R.P., Jr.; Kornfield, D.S.; Glaser, G.H. & Bondy, P.K. (1955) 「Effects of Intravenous Hydrocortisone on Electrolytes in Serum and Urine in Man」. Journal of Clinical Endocrinology 15: 176-181,.

[8] Sandle, G.I.; Keir, M.G.; Record, CO. (1981) 「The Effect of Hydrocortisone on the Transport of Water, Sodium, and Glucose in the Jejunum」. Scandinavian Journal of Gastroenterol. 16: 667,.

[9] Weber, C.E (1984). 「Copper Response to Rheumatoid Arthritis」. Medical Hypotheses 15: 333-348, on p337,.

[10] Flohe, L.; Beckman, R.; Giertz, H.; Loschen, G. 「Oxygen Centered Free Radicals as Mediators of Inflammation. p. 405」, Oxidative Stress (Sies H, ed) Academic Press, New York.

[11] Palacios R., Sugawara I. Hydrocortisone abrogates proliferation of T cells in autologous mixed lymphocyte reaction by rendering the interleukin-2 Producer T cells unresponsive to interleukin-1 and unable to synthesize the T-cell growth factor. Scand J Immunol. 1982, 15 (1): 25–31. PMID 6461917. doi:10.1111/j.1365-3083.1982.tb00618.x.

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求真百科

皮質醇

目錄

生理反應

作用

參考資料