Abstract
We examined protein components of the gap junctions between acinar cells of the parotid, sublingual and submandibular glands of the rat, using type-specific antibodies directed against major gap junction proteins, connexin 32 (Cx32) and connexin26 (Cx26). Double-immunofluorescence microscopy revealed that fluorescent spots of both connexins in the parotid and sublingual glands were distributed between the apposed regions of acinar cells. They appeared together, or were co-localized. The intensity of the Cx26-associated fluorescent signals was relatively weak in the submandibular glands compared with the other glands and was absent from some acini. When present, these spots were always co-localized with Cx32 immunoreactive positive spots. The results suggest that Cx32 and Cx26 in rat salivary glands are colocalized within the same gap junctional plaques when simultaneously expressed by the same acinar cells.
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Barrio LC, Suchyna T, Bargiello T, Xu LX, Roginski RS Bennett MVL, Nicholson BJ (1991) Gap junctions formed by connexins 26 and 32 alone and in combination are differently affected by applied voltage. Proc Natl Acad Sci USA 88: 8410–8414
Bennett MVL, Barrio LC, Bargiello TA, Spray DC, Hertzberg E, Sáez JC (1991) Gap junctions: new tools, new answers, new questions. Neuron 6:305–320
Hatae T, Iida H, Kuraoka A, Shibata Y (1993) Cytoplasmic surface ultrastructures of gap junctions in bovine lens fibers. Invest Ophthalmol Vis Sci 34:2164–2173
Hennemann H, Kozjek G, Dahl E, Nicholson B, Willecke K (1992) Molecular cloning of mouse connexin 26 and-32: similar genomic organization but distinct promotor sequences of two gap junction genes. Eur J Cell Biol 58:81–89
Kanno Y, Shiba Y, Sasaki Y (1989) Autonomic control of intercellular communication in salivary glands. Proc Finn Dent Soc 85:301–305
Kater SB, Galvin NJ (1978) Physiological and morphological evidence for coupling in mouse salivary gland acinar cells. J Cell Biol 79:20–26
Kim SK, Nasjleti CE, Han SS (1972) The secretion processes in mucous and serous secretory cells of the rat sublingual gland. J Ultrastruct Res 38:371–389
Kuraoka A, Iida H, Hatae T, Shibata Y, Itoh M, Kurita T (1993) Localization of gap junction proteins, connexins 32 and 26, in the rat and guinea pig livers as revealed by quick-freeze, deep-etch immunoelectron microscopy. J Histochem Cytochem 41:971–980
Nicholson B, Dermietzel R, Teplow D, Traub O, Willecke K, Revel J-P (1987) Two homologous protein components of hepatic gap junctions. Nature 329:732–734
Paul DL, Ebihara L, Takemoto LJ, Swenson KI, Goodenough DA (1991) Connexin46, a novel lens gap junction protein, induces voltage-gated currents in nonjunctional plasma membrane ofXenopus oocytes. J Cell Biol 115:1077–1089
Pinkstaff CA (1980) The cytology of salivary glands. Int Rev Cytol 63:141–261
Shimono M, Yamamura T, Fumagalli G (1980) Intercellular junctions in salivary glands: freeze-fracture and tracer studies of normal rat sublingual gland. J Ultrastruct Res 72:286–299
Takeda A, Kanoh M, Shimazu T, Takeuchi N (1988) Monoclonal antibodies recognizing different epitopes of the 27-kDa gap junction protein from rat liver. J Biochem 104:901–907
Traub O, Look J, Dermietzel R, Brümmer F, Hülser D, Willecke K (1989) Comparative characterization of the 21-kD and 26-kD gap junction proteins in murine liver and cultured hepatocytes. J Cell Biol 108:1039–1051
Zhang J-T, Nicholson BJ (1989) Sequence and tissue distribution of a second protein of hepatic gap junctions, Cx26, as deduced from its cDNA. J Cell Biol 109:3391–3401
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Kuraoka, A., Yamanaka, I., Miyahara, A. et al. Immunocytochemical studies of major gap junction proteins in rat salivary glands. Eur Arch Otorhinolaryngol 251 (Suppl 1), S95–S99 (1994). https://doi.org/10.1007/BF02565230
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DOI: https://doi.org/10.1007/BF02565230