EFFECTS OF INSULIN AND INSULIN-LIKE GROWTH FACTORS ON SATELLITE CELL PROLIFERATION IN VITRO (SOMATOMEDINS, RECEPTORS).

Persistent Link:
http://hdl.handle.net/10150/188065
Title:
EFFECTS OF INSULIN AND INSULIN-LIKE GROWTH FACTORS ON SATELLITE CELL PROLIFERATION IN VITRO (SOMATOMEDINS, RECEPTORS).
Author:
Dodson, Michael Verne
Issue Date:
1985
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Primary cultures of skeletal muscle satellite cells were induced to proliferate by exposure to physiologic levels of somatomedins and pharmacologic levels of insulin. Dexamethasone inclusion in serum containing medium facilitated the ovine somatomedin (oSm) (P < 0.05), but that both were different than the proliferation induced by MSA/rIGF-II (P < 0.05). In the presence of insulin concentrations that promote maximum proliferation, addition of oSm did not produce an additive effect, whereas the addition of MSA/rIGF-II did produce a significant increase in satellite cell proliferation above that induced by insulin. A more, in depth, analysis of the interaction of MSA/rIGF-II with its satellite cell receptor under a variety of experimental conditions revealed that binding of ¹²⁵I-MSA/rIGF-II was inhibited by oSm and MSA/rIGF-II, but not by insulin. Migration, and localization of ¹²⁵I-MSA/rIGF-II-receptor complexes in 7% sodium dodecyl sulfate polyacrylamide gels suggest that these complexes are Type II IGF receptors. In addition, this receptor system of satellite cells was shown to be modulated by other hormones; notably, pre-exposure of cells with insulin increased ¹²⁵I-MSA/rIGF-II binding, while oSm, or MSA/rIGF-II preincubation decreased the binding of ¹²⁵I-MSA/rIGF-II. Therefore, the proliferative effects of MSA/rIGF-II appeared not as a consequence of MSA/rIGF-II induction of other receptor types such as the insulin, or Type I IGF receptor systems. Concommitant to the previous experimentation, oSm was further examined in an initial attempt to elucidate its biologic binding mechanism in myogenic satellite cells. Binding of ¹²⁵I-oSm was inhibited by MSA/rIGF-II, insulin and IGF-I; thus these data suggest that oSm may be the ovine analog to human IGF-I. In addition, pre-exposure of cells to MSA/rIGF-II and oSm down-regulated the ability of satellite cells to bind oSm, while only concentrations of insulin greater than 550 ng insulin had this ability. Collectively, these data support the hypothesis that somatomedins play an important role in the control of postnatal muscle growth by providing a link between these hormones and satellite cells, one of the significant target cells involved in the growth process.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Somatomedin.; Insulin.; Growth.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Animal Physiology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Allen, Ronald E.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleEFFECTS OF INSULIN AND INSULIN-LIKE GROWTH FACTORS ON SATELLITE CELL PROLIFERATION IN VITRO (SOMATOMEDINS, RECEPTORS).en_US
dc.creatorDodson, Michael Verneen_US
dc.contributor.authorDodson, Michael Verneen_US
dc.date.issued1985en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractPrimary cultures of skeletal muscle satellite cells were induced to proliferate by exposure to physiologic levels of somatomedins and pharmacologic levels of insulin. Dexamethasone inclusion in serum containing medium facilitated the ovine somatomedin (oSm) (P < 0.05), but that both were different than the proliferation induced by MSA/rIGF-II (P < 0.05). In the presence of insulin concentrations that promote maximum proliferation, addition of oSm did not produce an additive effect, whereas the addition of MSA/rIGF-II did produce a significant increase in satellite cell proliferation above that induced by insulin. A more, in depth, analysis of the interaction of MSA/rIGF-II with its satellite cell receptor under a variety of experimental conditions revealed that binding of ¹²⁵I-MSA/rIGF-II was inhibited by oSm and MSA/rIGF-II, but not by insulin. Migration, and localization of ¹²⁵I-MSA/rIGF-II-receptor complexes in 7% sodium dodecyl sulfate polyacrylamide gels suggest that these complexes are Type II IGF receptors. In addition, this receptor system of satellite cells was shown to be modulated by other hormones; notably, pre-exposure of cells with insulin increased ¹²⁵I-MSA/rIGF-II binding, while oSm, or MSA/rIGF-II preincubation decreased the binding of ¹²⁵I-MSA/rIGF-II. Therefore, the proliferative effects of MSA/rIGF-II appeared not as a consequence of MSA/rIGF-II induction of other receptor types such as the insulin, or Type I IGF receptor systems. Concommitant to the previous experimentation, oSm was further examined in an initial attempt to elucidate its biologic binding mechanism in myogenic satellite cells. Binding of ¹²⁵I-oSm was inhibited by MSA/rIGF-II, insulin and IGF-I; thus these data suggest that oSm may be the ovine analog to human IGF-I. In addition, pre-exposure of cells to MSA/rIGF-II and oSm down-regulated the ability of satellite cells to bind oSm, while only concentrations of insulin greater than 550 ng insulin had this ability. Collectively, these data support the hypothesis that somatomedins play an important role in the control of postnatal muscle growth by providing a link between these hormones and satellite cells, one of the significant target cells involved in the growth process.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectSomatomedin.en_US
dc.subjectInsulin.en_US
dc.subjectGrowth.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAnimal Physiologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorAllen, Ronald E.en_US
dc.contributor.committeememberGoll, Darrel E.en_US
dc.contributor.committeememberWiseen_US
dc.contributor.committeememberChiassonen_US
dc.contributor.committeememberKecken_US
dc.contributor.committeememberShimizuen_US
dc.identifier.proquest8529397en_US
dc.identifier.oclc696792318en_US
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