Biomedical subjects

Hisanori Hirakawa

Publications and source records attributed to Hisanori Hirakawa.

3 recordsLinked to original sources

PubMed2005

Expression of tight and gap junctional proteins in the perineurial window model of the rat sciatic nerve.

Limited perineurial injury, known as a perineurial window, can lead to neuropathic pain. This article hypothesizes that the recovery of the perineurium is associated with the intercellular junctional proteins. It analyzes the expressions of occludin, ZO-1, and connexin 43 by immunoconfocal microscopy. Seven days after injury, immunoreactivities for occludin and ZO-1 were observed, although there was no connexin 43 detected. Then, 21 days after injury, immunoreactivity for connexin 43 were observed. These results indicate that recovery of the perineurium is associated with the intercellular junctional proteins and that the recovery of gap junctions is delayed compared with that of tight junctions.

Animals↗

PubMed2004

Regional differences in blood-nerve barrier function and tight-junction protein expression within the rat dorsal root ganglion.

To elucidate blood-nerve barrier function and tight-junction protein expression in the dorsal root ganglion (DRG), we analyzed the vascular permeability in the rat DRG by i.v. administration of fluorescent Evans-blue albumin (EBA) and compared it with the localization of claudin-1, claudin-5, and occludin by immunoconfocal microscopy. In the cell body-rich area within the DRG, extravascular leakage of EBA was noted and claudin-5 but neither claudin-1 nor occludin was detected. Conversely, in the nerve fiber-rich area within the DRG, no extravascular leakage of EBA was observed and both claudin-5 and occludin but no claudin-1 were detected in the blood vessel. These results demonstrate regional differences in the blood-nerve barrier function and tight-junction protein expression within the DRG.

Animals↗

PubMed2003

Loss and recovery of the blood-nerve barrier in the rat sciatic nerve after crush injury are associated with expression of intercellular junctional proteins.

The blood-nerve barrier in peripheral nerves is important for maintaining the environment for axons. Breakdown of the barrier by nerve injury causes various pathologies. We hypothesized that the breakdown and recovery of the blood-nerve barrier after injury are associated with the changes in the expression of intercellular junctional proteins. To test this hypothesis, we induced crush injuries in the rat sciatic nerve by ligation and analyzed spatiotemporal changes of claudin-1, claudin-5, occludin, VE-cadherin, and connexin43 by immunoconfocal microscopy and morphometry and compared them with changes in the permeability of the blood-nerve barrier by intravenous and local administration of Evans blue-albumin (EBA). On day 1 after removal of the ligature EBA leaked into the connective tissue in the endoneurium and then the leakage gradually decreased and disappeared on day 7. On day 1 claudin-1, claudin-5, occludin, VE-cadherin, and connexin43 had totally disappeared from the perineurium and endoneurium. Thereafter, claudin-1, claudin-5, occludin, and VE-cadherin recovered from day 2, whereas connexin43 was redetected on day 5. These results indicate that the breakdown and following recovery of the blood-nerve barrier are closely associated with changes in the expression of claudins, occludin, VE-cadherin, and connexin43 and that the recovery time course is similar but nonidentical.

Animals↗