Florjanc T I, Erjavec F
Department of Pharmacology, Medical Faculty, Ljubljana, Yugoslavia.
Agents Actions. 1991 May;33(1-2):33-6. doi: 10.1007/BF01993120.
The basis of this study was the assumption that mast cells can take up tele-methylhistamine (MeHi), as is known for other biogenic amines. The influence of extracellular MeHi on its uptake (active or passive) in isolated rat mast cells and in different rat tissues was studied in vitro. Rat peritoneal mast cells were incubated for 15 or 30 min at 37 or 1 degree C with different concentrations of MeHi. Submandibular gland, skeletal muscle, lung and heart of the rat (200-500 mg of each) were chopped and incubated for 20 min at 37 or 1 degrees C in buffer containing MeHi. Histamine (Hi) and MeHi in the cells and in the tissues were then determined by HPLC assay. Mast cells were capable of taking up MeHi in a time- and dose-dependent manner. MeHi levels increased from 5-10 ng per ml of incubated cell suspension (control) to 60-100 ng/ml after 15 min incubation. It can be assumed that the accumulation of MeHi in mast cells is due to a simple diffusion process since no significant change was noticed at 1 degree C. The preincubation of the cells with serotonin reduced MeHi accumulation, thus indicating MeHi competes with the same binding sites in mast cells as Hi and serotonin. Tissues showed high capacity for MeHi accumulation and MeHi surmounted endogenous Hi levels. Uptake was reduced at 1 degree C, yet the accumulation of MeHi was still high. The results indicate that mast cells can take up a smaller portion of free MeHi and they can have a function in its micro-regulation whereas other tissue cells have a predominant role in the removal of free MeHi from the blood.
本研究的依据是这样一种假设，即肥大细胞能够摄取tele-甲基组胺（MeHi），这与其他生物胺的情况相同。体外研究了细胞外MeHi对其在分离的大鼠肥大细胞和不同大鼠组织中的摄取（主动或被动）的影响。将大鼠腹膜肥大细胞在37℃或1℃下用不同浓度的MeHi孵育15或30分钟。将大鼠的下颌下腺、骨骼肌、肺和心脏（各200 - 500毫克）切碎，在含有MeHi的缓冲液中于37℃或1℃孵育20分钟。然后通过高效液相色谱法测定细胞和组织中的组胺（Hi）和MeHi。肥大细胞能够以时间和剂量依赖的方式摄取MeHi。孵育15分钟后，MeHi水平从每毫升孵育细胞悬液5 - 10纳克（对照）增加到60 - 100纳克/毫升。可以推测，肥大细胞中MeHi的积累是由于简单扩散过程，因为在1℃时未观察到显著变化。用血清素对细胞进行预孵育可降低MeHi的积累，这表明MeHi与Hi和血清素在肥大细胞中竞争相同的结合位点。组织显示出对MeHi积累的高能力，并且MeHi超过了内源性Hi水平。在1℃时摄取减少，但MeHi的积累仍然很高。结果表明，肥大细胞能够摄取一小部分游离MeHi，它们在其微调节中可能具有一定功能，而其他组织细胞在从血液中清除游离MeHi方面起主要作用。
