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Function of skeletal muscle tissue formed after myoblast transplantation into irradiated mouse muscles
Author(s) -
Wernig A.,
Zweyer M.,
Irintchev A.
Publication year - 2000
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.2000.t01-2-00333.x
Subject(s) - transplantation , myocyte , skeletal muscle , function (biology) , chemistry , irradiation , muscle tissue , anatomy , biology , pathology , microbiology and biotechnology , medicine , physics , nuclear physics
1 Pretreatment of muscles with ionising radiation enhances tissue formation by transplanted myoblasts but little is known about the effects on muscle function. We implanted myoblasts from an expanded, male‐donor‐derived, culture (i28) into X‐ray irradiated (16 Gy) or irradiated and damaged soleus muscles of female syngeneic mice (Balb/c). Three to 6 months later the isometric contractile properties of the muscles were studied in vitro , and donor nuclei were visualised in muscle sections with a Y chromosome‐specific DNA probe. 2 Irradiated sham‐injected muscles had smaller masses than untreated solei and produced less twitch and tetanic force (all by about 18 %). Injection of 10 6 myoblasts abolished these deficiencies and innervation appeared normal. 3 Cryodamage of irradiated solei produced muscle remnants with few (1–50) or no fibres. Additional myoblast implantation led to formation of large muscles (25 % above normal) containing numerous small‐diameter fibres. Upon direct electrical stimulation, these muscles produced considerable twitch (53 % of normal) and tetanic forces (35 % of normal) but innervation was insufficient as indicated by weak nerve‐evoked contractions and elevated ACh sensitivity. 4 In control experiments on irradiated muscles, reinnervation was found to be less complete after botulinum toxin paralysis than after nerve crush indicating that proliferative arrest of irradiated Schwann cells may account for the observed innervation deficits. 5 Irradiation appears to be an effective pretreatment for improving myoblast transplantation. The injected cells can even produce organised contractile tissue replacing whole muscle. However, impaired nerve regeneration limits the functional performance of the new muscle.