Withyachumnarnkul B, Nonaka K O, Santana C, Attia A M, Reiter R J
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284-7762.
J Interferon Res. 1990 Aug;10(4):403-11. doi: 10.1089/jir.1990.10.403.
The effect of interferon-gamma (IFN-gamma) on melatonin production was determined in rat pineal glands in organ culture. IFN-gamma enhanced the production of melatonin in the glands incubated with either 10 nM or 1,000 nM isoproterenol (ISO, a beta-adrenergic receptor agonist) but decreased the 100 nM ISO response. The enhanced melatonin production was accompanied by either unchanged or a lower level of N-acetyltransferase (NAT) activity, whereas the suppression was accompanied by a reduced NAT activity. IFN-gamma did not change the activity of the enzyme hydroxyindole-O-methyltransferase (HIOMT) in the ISO-stimulated pineal glands. The results indicate that IFN-gamma has a dual action on the pineal gland: One is to increase melatonin production through yet unknown mechanisms, and the other is to suppress NAT activity. These results also suggest that the pineal gland, under physiological stimulation, is modulated by IFN-gamma to increase melatonin production. A hypothetical model is proposed to explain the delicate regulation of pineal function by the immune system.
在器官培养的大鼠松果体中测定了γ-干扰素（IFN-γ）对褪黑素生成的影响。IFN-γ增强了在与10 nM或1000 nM异丙肾上腺素（ISO，一种β-肾上腺素能受体激动剂）一起孵育的腺体中褪黑素的生成，但降低了100 nM ISO的反应。褪黑素生成的增强伴随着N-乙酰转移酶（NAT）活性不变或水平降低，而抑制则伴随着NAT活性降低。IFN-γ在ISO刺激的松果体中未改变羟基吲哚-O-甲基转移酶（HIOMT）的活性。结果表明，IFN-γ对松果体有双重作用：一是通过未知机制增加褪黑素生成，另一是抑制NAT活性。这些结果还表明，在生理刺激下，松果体受IFN-γ调节以增加褪黑素生成。提出了一个假设模型来解释免疫系统对松果体功能的精细调节。
