Distribution of immunoreactive alpha- and beta-subunit isoforms of Na,K-ATPase in the gerbil inner ear.

Abstract

(3A3171).Biochemical and histochemical studies have demonstrated abundant Na,K-ATPase in the inner ear and provided new information concerning the ion transport capcities of specialized cell types. To extend these earlier observations, we immunostained inner ears from adult gerbils with antibodies specific for the three known a-and the two known P-isoforms of Na,K-ATPase. Merent inner ear cell types contained specific and distinct combinations of a-and P-subunit isoforms. Strial marginal cells and vestibular dark cells expressed the al-and P2-isoforms, whereas other positive epithelial cells e x p r d a1 in combination with Pl. Ganglion neurons and their peripheral processes showed positive immunostaining

Immunohistochemical Localization of the Na-K-Cl Co-transporter (NKCC1) in the Gerbil Inner Ear

“…A comparison of the immunostaining pattern for NKCC1 with previous data mapping the distribution of the Na,K-ATPase pump and its isoforms in inner ear tissues (McGuirt and Schulte 1994;Schulte and Steel 1994), indicates the co-localization of these two ion transport mediators in distinct subsets of inner ear fibrocytes. On the basis of their location and gap junctional connections with other cell types, these specialized fibrocytes comprise the initial segments of syncytial cellular networks believed to have evolved for resorbing K ϩ leaked or effluxed from endolymph through hair cell activity and releasing it near epithelial cells for recycling back to endolymph (Schulte and Steel 1994;Spicer and Schulte 1996).…”

Two Na,K-ATPase β2 subunit isoforms are differentially expressed within the central nervous system and sensory organs during zebrafish embryogenesis

“…In humans and rodents, the major expression sites of the ␤2 gene are brain (Shyjan et al, 1990a), pineal gland (Shyjan et al, 1990b), eye (Schneider et al, 1991), and ear (McGuirt and Schulte, 1994;Schulte and Steel, 1994). Together, the expression patterns for atp1b2a and atp1b2b closely parallel that seen for the single mammalian ␤2 gene.…”

Abundance and Diversity of Glycoconjugates Visualized Cytochemically in the Nervous System.

“…The distribution of VC 1.1 antigen and associated proteoglycan corresponded precisely with that of Na,K-ATPase and Na+ channels in nodes of Ranvier [24,32] and on the surface of neurons in the nucleus of the eighth nerve root [16]; and VC1.1 unaccompanied by proteoglycan colocalized with Na,KATPase on unmyelinated afferent terminals beneath cochlear and vestibular hair cells [23,27]. Moreover, the VC 1.1 epitope shown to occur as a constituent of chondroitin 6-SO4 proteoglycan on rod outer segments occurs at the site where Na+ channels function importantly in the response to light [21].…”