Open AccessDiltiazem improves contractile properties of skeletal muscle in dysferlin‐deficient BLAJ mice, but does not reduce contraction‐induced muscle damage
Author(s) -
Begam Morium,
Collier Alyssa F.,
Mueller Amber L.,
Roche Renuka,
Galen Sujay S.,
Roche Joseph A.
Publication year - 2018
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.13727
Subject(s) - eccentric , contraction (grammar) , diltiazem , dysferlin , skeletal muscle , medicine , muscle contraction , endocrinology , sarcomere , calcium , anatomy , chemistry , myocyte , physics , quantum mechanics
B6.A‐ Dysf prmd /GeneJ ( BLAJ ) mice model human limb‐girdle muscular dystrophy 2B ( LGMD 2B), which is linked to mutations in the dysferlin ( DYSF ) gene. We tested the hypothesis that, the calcium ion (Ca 2+ ) channel blocker diltiazem ( DTZ ), reduces contraction‐induced skeletal muscle damage, in BLAJ mice. We randomly assigned mice ( N = 12; 3–4 month old males) to one of two groups – DTZ ( N = 6) or vehicle ( VEH , distilled water, N = 6). We conditioned mice with either DTZ or VEH for 1 week, after which, their tibialis anterior ( TA ) muscles were tested for contractile torque and susceptibility to injury from forced eccentric contractions. We continued dosing with DTZ or VEH for 3 days following eccentric contractions, and then studied torque recovery and muscle damage. We analyzed contractile torque before eccentric contractions, immediately after eccentric contractions, and at 3 days after eccentric contractions; and counted damaged fibers in the injured and uninjured TA muscles. We found that DTZ improved contractile torque before and immediately after forced eccentric contractions, but did not reduce delayed‐onset muscle damage that was observed at 3 days after eccentric contractions.