1.Effects of 2-APB on store-operated Ca2+ channel currents of hepatocytes after hepatic ischemia/reperfusion injury in rats.
Changzhou, HUANG ; Zongming, ZHANG ; Fazu, QIU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2005;25(1):39-41
The effects of hepatic ischemia/reperfusion (1/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 micromol/L,) produced a concentration-dependent decrease of Isoc with IC50 value of 64. 63 +/- 10.56 micromol/L, (n = 8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.
Boron Compounds/*pharmacology
;
Calcium Channel Blockers/*pharmacology
;
Calcium Channels/drug effects
;
Cell Separation
;
Hepatocytes/metabolism
;
Liver/*blood supply
;
Liver/metabolism
;
Rats, Sprague-Dawley
;
Reperfusion Injury/*metabolism
2.Histopathological changes of testes and eyes by neutron irradiation with boron compounds in mice.
Yeon Joo KIM ; Won Ki YOON ; SI Yun RYU ; Ki Jung CHUN ; Hwa Young SON ; Sung Whan CHO
Journal of Veterinary Science 2006;7(1):19-23
This study was performed to investigate the biological effects of boron neutron capture therapy (BNCT) on the testes and eyes in mice using HANARO Nuclear Reactor, Korea Atomic Energy Research Institute. BNCT relies on the high capacity of (10)B in capturing thermal neutrons. Sodium borocaptate (BSH, 75 ppm, iv) and boronophenylalanine (BPA, 750 ppm, ip) have been used as the boron delivery agents. Mice were irradiated with neutron (flux: 1.036739E +09, Fluence 9.600200E+12) by lying flat pose for 30 (10 Gy) or 100 min (33 Gy) with or without boron carrier treatment. In 45 days of irradiation, histopathological changes of the testes and eyes were examined. Thirty-three Gy neutron irradiation for 100 min induced testicular atrophy in which some of seminiferous tubules showed complete depletion of spermatogenic germ cells. Lens epithelial cells and lens fiber were swollen and showed granular changes in an exposure time dependent manner. However, boron carrier treatment had no significant effect on the lesions. These results suggest that the examination of histopathological changes of lens and testis can be used as "biological dosimeters" for gauging radiation responses and the HANARO Nuclear Reactor has sufficient capacities for the BNCT.
Animals
;
Boranes/*pharmacology
;
Borohydrides/*pharmacology
;
Boron Neutron Capture Therapy/*methods
;
Eye/pathology/*radiation effects
;
Histocytochemistry
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Neutrons
;
Phenylalanine/*analogs&derivatives/pharmacology
;
Seminiferous Tubules/pathology/*radiation effects
;
Specific Pathogen-Free Organisms
;
Sulfhydryl Compounds/*pharmacology
3.UTP regulates spontaneous transient outward currents in porcine coronary artery smooth muscle cells through PLC-IP(3) signaling pathway.
Peng-Yun LI ; Xiao-Rong ZENG ; Yan YANG ; Fang CAI ; Miao-Ling LI ; Zhi-Fei LIU ; Jie PEI ; Wen ZHOU
Acta Physiologica Sinica 2008;60(1):65-73
The aim of the present study was to investigate the effects of inositol 1,4,5-trisphosphate (IP(3))-generating agonist UTP on spontaneous transient outward currents (STOCs), and explore the role of intracellular Ca(2+) release in the current response mediated by IP(3) in porcine coronary artery smooth muscle cells (CASMCs). The coronary artery was excised from the fresh porcine heart and cut into small segments (2 mm × 5 mm) and then transferred to enzymatic dissociation solution for incubation. Single CASMCs were obtained by two-step enzyme digestion at 37 °C. STOCs were recorded and characterized using the perforated whole-cell patch-clamp configuration in freshly isolated porcine CASMCs. The currents were amplified and filtered by patch-clamp amplifier (Axopatch 200B), and then the digitized data were recorded by pClamp 9.0 software and further analyzed by MiniAnalysis 6.0 program. The results were as follows: (1) UTP led to conspicuous increases in STOC amplitude by (57.54±5.34)% and in frequency by (77.46±8.42)% (P<0.01, n=38). (2) The specific blocker of phospholipase C (PLC) - U73122 (5 μmol/L) remarkably reduced STOC amplitude by (31.04±7.46)% and frequency by (41.65±16.59)%, respectively (P<0.05, n=10). In the presence of U73122, UTP failed to reactivate STOCs (n=7). (3) Verapamil (20 μmol/L) and CdCl2 (200 μmol/L), two blockers of L-type voltage-dependent Ca(2+) channels, had little effects on STOCs initiated by UTP (n=8). (4) 1 μmol/L bisindolylmaleimide I (BisI), a potent blocker of protein kinase C (PKC), significantly increased STOC amplitude by (65.44±24.66)% and frequency by (61.35±21.47)% (P<0.01, n=12); UTP (40 μmol/L), applied in the presence of 1 μmol/L BisI, could further increase STOC activity (P<0.05, P<0.01, n=12). Subsequent application of ryanodine (50 μmol/L) abolished STOC activity. (5) In the presence of UTP (40 μmol/L), inhibition of IP(3) receptors (IP(3)Rs) by 2-aminoethoxydiphenyl borate (2-APB, 40 μmol/L) reduced STOC amplitude by (24.08±3.97)% (P<0.05, n=8), but had little effect on STOC frequency (n=8). While application of 2-APB (80 μmol/L) significantly reduced STOC amplitude by (31.43±6.34)% and frequency by (40.59±19.01)%, respectively (P<0.05, P<0.01, n=6). Subsequent application of ryanodine (50 μmol/L) completely blocked STOC activity. Pretreatment of cells with 2-APB (40 μmol/L) or ryanodine (50 μmol/L), UTP (40 μmol/L) failed to reactivate STOCs. The results suggest that UTP activates STOCs mainly via PLC and IP(3)-dependent mechanisms. Complex Ca(2+)-mobilization pathways are involved in UTP-mediated STOC activation in porcine CASMCs.
Animals
;
Boron Compounds
;
pharmacology
;
Calcium
;
metabolism
;
Coronary Vessels
;
cytology
;
Inositol 1,4,5-Trisphosphate
;
metabolism
;
Myocytes, Smooth Muscle
;
metabolism
;
Protein Kinase C
;
metabolism
;
Ryanodine
;
pharmacology
;
Signal Transduction
;
Swine
;
Type C Phospholipases
;
metabolism
;
Uridine Triphosphate
;
metabolism