AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a no...AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.展开更多
Objective To test Calcium ion(Ca2+) flow at the head and end of outer hair cells(OHCs) in resting state and in response to Nimodipine treatment.Methods Non-invasive micro-test techniques were used to study Ca2+ in iso...Objective To test Calcium ion(Ca2+) flow at the head and end of outer hair cells(OHCs) in resting state and in response to Nimodipine treatment.Methods Non-invasive micro-test techniques were used to study Ca2+ in isolated OHCs in adult guinea pigs.Results Four types of Ca2+ transport were identified in OHCs on basilar membrane tissue fragments:influx at the head of with efflux at the bottom(type 1):efflux at the head of OHCs with influx at the bottom(type 2);influx at the both head and bottom(type 3);and efflux at the both head and bottom(type 4).However,only type 1 and type 3 of Ca2+ ion transport were detected in the cochlea.We propose that Ca2+ ion transport exists in adult guinea pig cochlear OHCs in resting state and is variable.Ca2 + flow in OHC can be inhibited by Nimodipine in resting state.展开更多
基金Supported by The National Natural Science Foundation of China,No.30270532 and No.30670774Tsinghua-Yue-Yuen Medical Science Foundation,No.20240000531 and No.20240000547
文摘AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.
文摘Objective To test Calcium ion(Ca2+) flow at the head and end of outer hair cells(OHCs) in resting state and in response to Nimodipine treatment.Methods Non-invasive micro-test techniques were used to study Ca2+ in isolated OHCs in adult guinea pigs.Results Four types of Ca2+ transport were identified in OHCs on basilar membrane tissue fragments:influx at the head of with efflux at the bottom(type 1):efflux at the head of OHCs with influx at the bottom(type 2);influx at the both head and bottom(type 3);and efflux at the both head and bottom(type 4).However,only type 1 and type 3 of Ca2+ ion transport were detected in the cochlea.We propose that Ca2+ ion transport exists in adult guinea pig cochlear OHCs in resting state and is variable.Ca2 + flow in OHC can be inhibited by Nimodipine in resting state.
