Thesis (MSc (Physiological Sciences)--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Although muscle tissue demonstrates a remarkable capacity for regeneration
following injury, this process is slow and often accompanied by the formation
of scar tissue and a subsequent decrease in contractile capacity following
regeneration. Treatment options are few and mostly supportive in nature.
This regeneration process involves muscle stem cells (satellite cells) which
ultimately give rise to the regenerated muscle.
The contentious field of low level laser therapy (LLLT) has made remarkable
claims in facilitating wound healing in soft tissue injuries of various types. Yet,
the mechanism(s) invoked in these beneficial effects are poorly understood.
We have investigated the effects of LLLT using a 638 nm laser on satellite
cells in culture and in-vivo. Using an array of techniques we have measured,
amongst other things, metabolic responses to laser irradiation, signaling
pathways activated/altered and antioxidant status.
In response to laser irradiation satellite cells in culture showed an increase in
MTT values (a measure of metabolic activity) and a decrease in antioxidant
status (measured using the ORAC assay). In addition laser irradiation also
altered the expression and phosphorylation state of several signaling
pathways, including Akt and STAT-3.
Following on from this the effects of laser irradiation on satellite cells in-vivo
was assessed in a rat model of contusion injury. No significant differences in
satellite cell number was found following laser irradiation, changes were seen
in tissue antioxidant status and blood antioxidant status (measured using the
ORAC assay).
In the course of this study several standard techniques were used to
investigate the effects of laser irradiation on satellite cells both in-vitro and invivo.
It has become apparent that several of these techniques have
problems associated with them that possibly make them inappropriate for
vi
further use in studies involving laser irradiation. However the results indicate
that laser therapy is induces satellite cell behavior and further study is
warranted in this field. / AFRIKAANSE OPSOMMING: Alhoewel spierweefsel merkwaardige regenerasie kapasiteit vertoon ten
opsigte van besering, is hierdie proses stadig en word soms vergesel met die
vorming van letselweefsel asook ‘n gevolglike afname in kontaktiele
kapasiteit na afloop van regenerasie. Behandelingsmoontlikhede is skaars
en meesal ondersteunend van aard. Hierdie proses sluit spierstamselle
(satelietselle), wat uiteindelik die ontstaan van die regenerasie van spier tot
gevolg het, in.
Die kontroversiële veld van lae vlak laserterapie (Engels: Low level laser
therapy (LLLT)) het merkwaardige aansprake in die fasilitering met verskeie
sagteweefsel wondgenesing. Nietemin, die meganisme(s) wat voordelige
effekte induseer, word nog nie goed begryp nie.
Ons het die effek van LLLT, deur gebruik te maak van ‘n 638 nm laser op
kultuur in vitro satelietselle sowel in-vivo, ondersoek. Deur gebruik te maak
van verskeie tegnieke is onder meer die metaboliese, sowel die
seinstransduksie weë en antioksidantstatus na laserbestraling, gemeet.
In reaksie op die laserbestraling het satelietselle (in kultuur) ‘n toename in
MTT waardes getoon (‘n maatstaf van die metaboliese aktiwiteit) en ‘n
afname in die antioksidantstatus (gemeet deur van die ORAC toets).
Addisioneel het laserbestraling ook uitdrukking en fosforilering van verskeie
proteïene betrokke in seintransduksieweë beïnvloed, insluitend Akt, STAT-3).
Na afloop van hierdie effekte op satelietselle na laserbestraling, is daar
gebruik gemaak van ‘n kneusbeseringsrotmodel om hierdie effekte in vivo te
ondersoek. Geen betekenisvolle verskille in die aantal satelietselle na
laserbestraling is opgemerk nie, maar veranderings is wel opgemerk in
weefsel- en bloed-antioksidantstatus (gemeet deur van die ORAC toets
gebruik te maak).
Gedurende die verloop van die studie is van verskeie standaardtegnieke
gebruik gemaak om die effekte van laserbestraling op beide satelietselle in
vitro en in vivo te ondersoek.
iv
Dit het duidelik na vore gekom dat daar wel gepaardgaande probleme met
van hierdie tegnieke voorgekom het, en dat van hierdie tegnieke nie gepas is
vir ondersoek in laserbestralingsstudies nie. Nietemin, die resultate toon wel
dat laserbehandeling. satelietselgedrag induseer wat verdere studie in hierdie
veld noodsaak
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/4074 |
| Date | 03 1900 |
| Creators | Van Niekerk, Gustavus |
| Contributors | Smith, Robert M., University of Stellenbosch. Faculty of Science. Dept. of Physiological Sciences. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 169 p. :ill. |
| Rights | University of Stellenbosch |
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