Localization of inducible heat shock protein mRNA in the guinea pig cochlea with a nonradioactive in situ hybridization technique.

Cell types of the guinea pig cochlea that contain mRNA of the inducible heat shock protein (HSP72) were determined with an in situ hybridization technique, using a biotinylated oligonucleotide probe. Staining was present in the spiral limbus, spiral prominence, stria vascularis, and organ of Corti (supporting, pillar, outer hair, and interdental cells). In sections digested with pepsin, only spiral ganglion cells stained. The pattern of staining was similar in normal and heat-stressed animals. Therefore, HSP72 mRNA is present in many guinea pig cochlear cell types, some of which have not previously been shown to contain HSP72 protein. Differences in HSP72 mRNA and protein staining may be attributable to stress or processing techniques, but they may also suggest mechanisms unique to guinea pigs and primates, who normally express the inducible form of HSP.