title: Aquaporin 4: lack of mRNA expression in the rat regenerating muscle fiber under denervation.
abstract: The recently identified water channel aquaporin 4 is a major component of the orthogonal arrays observed with freeze-fracture electron microscopy. We examined the expression of aquaporin 4 mRNA and protein in rat regenerating muscle under innervated and denervated conditions. We found decreased sarcolemmal immunostaining of aquaporin 4 in denervated regenerating muscle as opposed to innervated muscle. Quantitative reverse transcription-polymerase chain reaction revealed that aquaporin 4 mRNA was expressed in the innervated regenerating muscle; whereas it was not expressed in denervated muscle. Thus, lack of aquaporin 4 protein may be due to lack of aquaporin 4 mRNA in the denervated regenerating muscle. We conclude that the nerve supply influences expression of aquaporin 4 at the mRNA level in regenerating muscle.
authors.affiliation: Division of Neurology, Department of Medicine, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Aoba-ku, 227-8501, Yokohama, Japan. jimi@poplar.ocn.ne.jp
authors.forename: T
authors.initials: T
authors.lastname: Jimi
authors.forename: Y
authors.initials: Y
authors.lastname: Wakayama
authors.forename: M
authors.initials: M
authors.lastname: Murahashi
authors.forename: S
authors.initials: S
authors.lastname: Shibuya
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Hara
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuzaki
authors.forename: N
authors.initials: N
authors.lastname: Uemura
mesh_terms: D000818:Animals; D051401:Aquaporin 4; D020346:Aquaporins / Q000096:biosynthesis* / Q000235:genetics*; D008297:Male; D009121:Muscle Denervation; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000235:genetics / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology
chemical_list: C496032:Aqp4 protein, rat; D051401:Aquaporin 4; D020346:Aquaporins; D012333:RNA, Messenger