Na+/HCO3- cotransporter immunoreactivity changes in neurons and expresses in astrocytes in the gerbil hippocampal CA1 region after ischemia/reperfusion.

Abstract

The maintenance of intracellular pH is important in neuronal function. Na(+)/HCO(3)(-) cotransporter (NBC), a bicarbonate-dependent acid-base transport protein, may contribute to cellular acid-base homeostasis in pathophysiological processes. We examined the alterations of NBC immunoreactivity and its protein levels in the hippocampal CA1 region after transient cerebral ischemia in gerbils. In the sham-operated group, moderate NBC immunoreactivity was detected in CA1 pyramidal neurons, and, 12 h after I/R, the immunoreactivity in the pyramidal neurons was markedly increased over controls. Three days after I/R, NBC immunoreactivity nearly disappeared in the CA1 pyramidal neurons. However, NBC immunoreactivity was detected in the non-pyramidal neurons of the ischemic CA1 region at 3 days after I/R. From double immunofluorescence study with glial markers, NBC immunoreactivity was detected in astrocytes, not in microglia, at 4 days after I/R. NBC protein level in the CA1 region was significantly increased at 12 h post-ischemia and significantly decreased at 2 days post-ischemia. Thereafter, NBC protein level was again increased and returned to the level of the sham-operated group at 4 days post-ischemia. On the other hand, treatment with 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS), an inorganic anion exchanger blocker including Cl-bicarbonate exchanger, protected CA1 pyramidal neurons from I/R injury at 4 days post-ischemia. These results indicate that changes in NBC expressions may play an important role in neuronal damage and astrocytosis induced by transient cerebral ischemia.

• Authors: Youdong Sohn, Ki-Yeon Yoo, Ok Kyu Park, Seung-Hae Kwon, Choong Hyun Lee, Jung Hoon Choi, In Koo Hwang, Jeong Yeol Seo, Jun Hwi Cho, Moo-Ho Won
• Journal: Neurochemical research (Neurochem Res) Vol. 36 Issue 12 Pg. 2459-69 (Dec 2011) ISSN: 1573-6903 [Electronic] United States
• PMID: 21833843 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Sodium-Bicarbonate Symporters
• 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid

Topics

• 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid (pharmacology)
• Animals
• Astrocytes (metabolism)
• CA1 Region, Hippocampal (metabolism, pathology)
• Gerbillinae
• Ischemic Attack, Transient (physiopathology)
• Male
• Neurons (immunology, metabolism)
• Reperfusion Injury (immunology, metabolism)
• Sodium-Bicarbonate Symporters (biosynthesis, immunology)