RRC ID 43703
著者 Watanabe S, Seale AP, Grau EG, Kaneko T.
タイトル Stretch-activated cation channel TRPV4 mediates hyposmotically induced prolactin release from prolactin cells of mozambique tilapia Oreochromis mossambicus.
ジャーナル Am J Physiol Regul Integr Comp Physiol
Abstract In teleost fish, prolactin (PRL) is an important hormone for hyperosmoregulation. The release of PRL from the pituitary of Mozambique tilapia is stimulated by a decrease in extracellular osmolality. Previous studies have shown that hyposmotically induced PRL release is linked with cell volume changes, and that stretch-activated Ca(2+) channels are likely responsible for the initiation of the signal transduction for PRL release. In this study, we identified the stretch-activated Ca(2+) channel transient receptor potential vanilloid 4 (TRPV4) from the rostral pars distalis (RPD) of tilapia acclimated to freshwater (FW). TRPV4 transcripts were ubiquitously expressed in tilapia; the level of expression in RPDs of FW-acclimated fish was lower than that found in RPDs of seawater (SW)-acclimated fish. Immunohistochemical analysis of the pituitary revealed that TRPV4 is localized in the cell membrane of PRL cells of both FW and SW tilapia. A functional assay with CHO-K1 cells showed that tilapia TRPV4 responded to a decrease in extracellular osmolality, and that its function was suppressed by ruthenium red (RR) and activated by 4α-phorbol 12,13-didecanoate (4aPDD). Exposure of dissociated PRL cells from FW-acclimated tilapia to RR blocked hyposmolality induced PRL release. PRL release, on the other hand, was stimulated by 4aPDD. These results indicate that PRL release in response to physiologically relevant changes in extracellular osmolality is mediated by the osmotically sensitive TRPV4 cation channel.
巻・号 302(8)
ページ R1004-11
公開日 2012-4-15
DOI 10.1152/ajpregu.00632.2011
PII ajpregu.00632.2011
PMID 22378774
MeSH Acclimatization / physiology Animals Lactotrophs / metabolism* Pituitary Gland, Anterior / metabolism* Prolactin / metabolism* TRPV Cation Channels / metabolism* Tilapia / metabolism* Water-Electrolyte Balance / physiology*
IF 3.026
引用数 14
WOS 分野 PHYSIOLOGY
リソース情報
ヒト・動物細胞