Mechanism of Calcium Waves in Primary Cultured Rat Hepatocytes

• Published in: Japanese Journal of Pharmacology 1996, Vol.71 (suppl.1), p.164-164
• Main Authors: Toru KAWANISHI, Satoru ISHIZAKI, Takehito KIUCHI, Miyako OHTA, Hisayuki OHATA, Kazutaka MOMOSE, Takako HAYAKAWA
• Format: Article
• Language: Japanese
• ISSN: 0021-5198

In primary cultured rat hepatocytes calcium waves were induced by hormones and growth factors. Here, we analyzed the mechanism of the waves. Calcium waves were imaged using indo-1 and a rapid scanning confocal microscope, and the receptor of hepatocyte growth factor (HGF) was stained with immunohistochemistry using an antibody to c-met product. The sequential treatment of the cells with phenylephrine and HGF initiated calcium waves with the same initiation site in each cell. The localization of HGF receptor was clearly stained on plasma membrane of hepatocytes, but the distribution did not coincide with the locus where calcium waves originated. Fluo-3 was taken up into organelles and showed fluorescence images of continuous interconnected membranes as endoplasmic reticulum (ER) or trans-Golgi apparatus when its acetoxymethyl derivative was incubated with hepatocytes. There was, however, no relation between the fluorescence images and the spatial pattern of calcium waves. The localization of calreticulin, a calcium-binding protein in ER, which was stained with the antibody, did not coincide with the locus where calcium waves originated, either. These results suggested that the spatial pattern of calcium waves was not decided by the localization of receptors of agonists, but by the distribution of some mechanism of calcium release from the intracellular stores.