Department of Dermatology and Venerology, HELIOS-Klinikum Aue, Gartenstrasse 6, D-08280 Aue, Germany.
Exp Dermatol. 2009 Dec;18(12):1064-6. doi: 10.1111/j.1600-0625.2009.00886.x.
Various glutamate receptors have been described in both keratinocytes and melanocytes. L-Glutamate is the physiological agonist of the glutamate receptor family. The source of this transmitter had not yet been identified. In normal human epidermal keratinocytes (NHEK) and HaCaT-keratinocytes, cell supernatants were sampled in various stages of cell density and the l-glutamate content photometrically determined. The following examination time-points were defined: non-confluent (ca. 33%), subconfluent (ca. 70%) and confluent (90-100%). The L-glutamate concentration originally in the culture medium was 14.7 mg/l (0.1 mm/l). The L-glutamate concentration in the cell supernatant increased in NHEK with increasing cell density: non-confluent 39.9 + or - 4 mg/l, subconfluent 60.6 + or - 15.8 mg/l, confluent 100.7 + or - 33.2 mg/l. A linear increase of L-glutamate concentration was also found for HaCaT cells. The investigations show that keratinocytes are capable of producing and releasing L-glutamate. Thus they are a source of L-glutamate which acts as a transmitter on epidermal glutamate receptors.
各种谷氨酸受体已在角质形成细胞和黑素细胞中被描述。L-谷氨酸是谷氨酸受体家族的生理激动剂。这种递质的来源尚未确定。在正常的人表皮角质形成细胞（NHEK）和 HaCaT-角质形成细胞中，在不同的细胞密度阶段取样细胞上清液，并通过比色法测定 l-谷氨酸含量。定义了以下检查时间点：非汇合（约 33%）、亚汇合（约 70%）和汇合（90-100%）。培养基中最初的 L-谷氨酸浓度为 14.7mg/l（0.1mm/l）。随着细胞密度的增加，NHEK 细胞上清液中的 L-谷氨酸浓度增加：非汇合时为 39.9 + or - 4mg/l，亚汇合时为 60.6 + or - 15.8mg/l，汇合时为 100.7 + or - 33.2mg/l。HaCaT 细胞也发现了 L-谷氨酸浓度的线性增加。这些研究表明，角质形成细胞能够产生和释放 L-谷氨酸。因此，它们是 L-谷氨酸的来源，L-谷氨酸作为表皮谷氨酸受体的递质发挥作用。
