title: Digestive cells from Mytilus galloprovincialis show a partial regulatory volume decrease following acute hypotonic stress through mechanisms involving inorganic ions.
abstract: The response of isolated digestive cells of the digestive gland of Mytilus galloprovincialis to hypotonic shock was studied using videometric methods. The isolated cells exposed to a rapid change (from 1100 to 800 mosmol kg(-1) ) of the bathing solution osmolality swelled but thereafter underwent a regulatory volume decrease (RVD), tending to recover the original size. When the hypotonic stress was applied in the presence of quinine and glibenclamide, known inhibitors of swelling activated ion channels, the cells did not exhibit an RVD response; in addition, they showed a larger increase in size in respect to control cells. These observations suggest that the digestive cells of the digestive gland have the machinery to cope with the hyposmotic shock allowing them to exhibit a small but significant RVD preventing an excessive increase in cell size. The pharmacological treatment of digestive cells during the RVD experiments suggests that cell volume is regulated by K(+) and Cl(-) efflux followed by an obliged water efflux from the cell. The involvement of organic osmolytes such as taurine and betaine seems to be excluded by NMR measurement on digestive cells.
authors.affiliation: Dipartimento di Scienze Biologiche ed Ambientali, Università di Messina, 98166 Messina, Italy.
authors.forename: Agata
authors.initials: A
authors.lastname: Torre
authors.forename: Francesca
authors.initials: F
authors.lastname: Trischitta
authors.forename: Carmelo
authors.initials: C
authors.lastname: Corsaro
authors.forename: Domenico
authors.initials: D
authors.lastname: Mallamace
authors.forename: Caterina
authors.initials: C
authors.lastname: Faggio
mesh_terms: D000818:Animals; D001622:Betaine / Q000737:chemistry; D004068:Digestive System Physiological Phenomena; D007477:Ions / Q000737:chemistry*; D049878:Mytilus / Q000737:chemistry / Q000502:physiology; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D013654:Taurine / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D007477:Ions; D014867:Water; D013654:Taurine; D001622:Betaine
keywords: Mytilus galloprovincialis; digestive gland; inorganic ions; organic osmolytes; partial RVD