title: The effect of cleft palate repair on contractile properties of single permeabilized muscle fibers from congenitally cleft goat palates.
abstract: Inherent differences in the levator veli palatini (LVP) muscle of cleft palates before palatoplasty may play a role in persistent postrepair velopharyngeal insufficiency (VPI). Contractile properties of LVP muscle fibers were analyzed from young (2-month) normal (YNP), young congenitally cleft (YCP) and again on the same YCP subjects 6 months after palatoplasty, mature repaired palate (MRP). The cross-sectional area and rate of force development (ktr) were measured. Specific force (sF(0)) and normalized power (nP(max)) were calculated. Using k(tr) to determine fiber type composition, YNP was 44% type 1 and 56% type 2, while YCP was 100% type 2. Two MRP subjects shifted to 100% type 1; 1 demonstrated increased resistance to fatigue. No differences in sF(0) were observed. nP(max) increased with presence of type 2 fibers. The persistent state of type 2 fibers following palatoplasty leads to increased fatigue in the LVP of MRP subjects and may cause VPI symptoms.
authors.affiliation: Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109-2200, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Hanes
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Weinzweig
authors.forename: Kip E
authors.initials: KE
authors.lastname: Panter
authors.forename: W Thomas
authors.initials: WT
authors.lastname: McClellan
authors.forename: Stefanie A
authors.initials: SA
authors.lastname: Caterson
authors.forename: Steven R
authors.initials: SR
authors.lastname: Buchman
authors.forename: John A
authors.initials: JA
authors.lastname: Faulkner
authors.forename: Deborah
authors.initials: D
authors.lastname: Yu
authors.forename: Paul S
authors.initials: PS
authors.lastname: Cederna
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Larkin
mesh_terms: D000818:Animals; D002972:Cleft Palate / Q000503:physiopathology* / Q000601:surgery; D004195:Disease Models, Animal; D006041:Goats; D007537:Isometric Contraction / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000737:chemistry / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000502:physiology; D010156:Palatal Muscles / Q000503:physiopathology*; D010539:Permeability; D014681:Velopharyngeal Insufficiency / Q000473:pathology / Q000503:physiopathology