作者: San-e Ishikawa , Toshikazu Saito
DOI: 10.1038/KI.1990.86
关键词: Kidney 、 Calcium 、 Renal papilla 、 Ionomycin 、 Endocrinology 、 Vasopressin 、 Arginine 、 Internal medicine 、 Chemistry 、 Fluorescence spectrometry 、 EGTA 、 Nephrology
摘要: Optimal concentration of cellular free calcium for AVP-induced cAMP in collecting tubules. The role Ca 2+ the action arginine vasopressin (AVP) has been demonstrated renal papillary tubule. We further examined whether an optimal ([Ca ]i) exists production rat tubule cells culture. [Ca ]i was measured using fura-2. When were exposed one hour to media supplemented with 0mM (containing 1mM EGTA), 1, 2, 3, 4, 6.4, or 8mM , basal ranged as below: 24.9 ± 5.6, 90.7 7.4, 107.4 9.8, 146.1 13.7, 162.0 14.6, 241.5 32.8, and 234.9 29.6 nM, respectively. medium 1 mM, × 10 −7 M AVP increased 181.5 13.2nM from 7.4nM (P obtained varying described above, though increases quantitatively variable. during three minute incubation period presence 5 −4 3-isobutyl-l-methylxanthine. Basal level 87.6 7.9 fmol/µg protein. After exposing containing levels −9 107.9 11.6 (0mM medium), 175.6 14.1 (1mM ), 198.8 9.8 (2mM 134.4 10.2 (3mM 175.3 21.1 (4mMCa 146.7 13.8 (6.4mM 59.5 9.5fmol/µtg protein (8mM between response maximal. Similar results AVP. Cells incubated 2 −6 ionophore ionomycin hour, then elevated 675.8 93.7nM. In this condition increase disappeared totally. Cellular 112.5 3.6 206.0 14.4 respectively, values significantly less than 215.0 9.3 506.3 33.5 control groups. These therefore indicate that there is cells.