Volume 8, Issue 2, Pages 93-98 (December 2001) Activation of histamine H1 receptor results in enhanced proteoglycan synthesis by human articular chondrocyte: involvement of protein kinase C and intracellular Ca2+  Satoshi Sohen, Hisayuki Ooe, Makoto Hashima, Tohgo Nonaka, Kanji Fukuda, Chiaki Hamanishi  Pathophysiology  Volume 8, Issue 2, Pages 93-98 (December 2001) DOI: 10.1016/S0928-4680(01)00066-9

Fig. 1 Effect of histamine and its antagonist on PG synthesis. Human articular chondrocytes were cultured for 24 h in the absence or presence of histamine and an antagonist. PG synthesis was measured based on the incorporation of [35S] sulfate. (1) Control; (2) histamine (1 μM); (3) histamine (1 μM)+chlorpheniramine (H1 antagonist, 1 μM); (4) histamine (1 μM)+cimetidine (H2 antagonist, 1 μM). One representative experiment of three is shown. Columns and bars show the mean and S.E.M. for six wells. *, P<0.05 (vs. histamine+chlorpheniramine and histamine+cimetidine), **, P<0.01 (vs. control). Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)

Fig. 2 Histamine-mediated [Ca2+]i mobilization in human articular chondrocytes. Cells were loaded with Fura-2 AM, and histamine was added (arrowhead). During data acquisition period, each cell was stimulated with one histamine concentration ((×) 0.1; (•) 1; (○) 10 μM of histamine, respectively). The ratio signals (340/380 nm) were recorded and the concentration was calibrated, using calcium calibration buffer kits. One representative experiment of four is shown. Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)

Fig. 3 Effect of an antagonist on histamine-mediated [Ca2+]i mobilization in human articular chondrocytes. In the absence of an antagonist, 1 μM of histamine evoked a significant increase in [Ca2+]i (•) compared with base line (P<0.01). Chlorpheniramine ((×) H1 antagonist) and cimetidine ((○) H2 antagonist) were added 15 min before histamine challenge (arrow head). One representative experiment of three is shown. Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)

Fig. 4 Effect of histamine on PKC activity. Histamine was added and PKC activity was measured using Biotrak Kits. Columns and bars show the mean and S.E.M. for six wells. *, P<0.05, **, P<0.01 (vs. none). Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)

Fig. 5 Effect of bradykinin on [Ca2+]i mobilization in human articular chondrocytes. Bradykinin (○) and its specific antagonist (×) was added 15 min before bradykinin challenge (arrowhead). One representative experiment of four is shown. Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)

Fig. 6 Effect of bradykinin and ionomycin on PG synthesis. Human articular chondrocytes were cultured in the absence or presence of bradykinin (1 μM), and ionomycin (0.1 μM) for 24 h. PG synthesis was measured, based on incorporation of [35S] sulfate. (1) Control; (2) bradykinin (1 μM); (3) ionomycin (0.1 μM). One representative experiment of three is shown. Columns and bars show the mean and S.E.M. for six wells. **, P<0.01 (vs. control). Pathophysiology 2001 8, 93-98DOI: (10.1016/S0928-4680(01)00066-9)