Premium
Expression of G protein α subunits in the lateral wall of the rat cochlea
Author(s) -
Khan Khalid M.,
Sarfaraz Noorjehan,
Siddiqui Sammer,
Malik Zainab A.,
Salim Zeenat
Publication year - 2003
Publication title -
journal of anatomy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 118
eISSN - 1469-7580
pISSN - 0021-8782
DOI - 10.1046/j.1469-7580.2003.00159.x
Subject(s) - cochlea , spiral ligament , microbiology and biotechnology , biology , protein subunit , messenger rna , complementary dna , immunolabeling , immunohistochemistry , anatomy , biochemistry , organ of corti , gene , immunology
Expression of five G protein α subunits was investigated in the rat cochlea by reverse transcription‐polymerase chain reaction (RT‐PCR) in order to understand their role in the cochlear signal transduction mechanisms. Immunohistochemical techniques were employed to study their distribution in the lateral wall of the cochlea. Total RNA was extracted with guanidine thiocyanate from cochleas and brains of 14–21‐day‐old rats. The extract was treated with DNase to degrade genomic DNA. After RT, the resulting cDNA was amplified by PCR using primers specific for the nucleotide sequences representing α subunits of heterotrimeric G proteins. The results indicated that mRNA for all five α subunits was expressed in the brain and cochlear samples. For immunohistochemical localization, temporal bones of 6‐week‐old rats were fixed in 4% paraformaldehyde and 0.1% glutaraldehyde and processed for embedding in paraffin wax. The dewaxed, midmodiolar sections of the cochlea were incubated with subunit‐specific polyclonal antibodies. The pattern of immunoreactivity varied for the five G protein α subunits studied in the stria vascularis and spiral ligament. The significance of these findings and the role of G protein α subunits in cochlear fluid homeostasis are discussed.