Ethanol induced modulation of the insulin-like growth factor system in chicken embryo cranial tissue / by Steven A. Lynch.
| Author/creator | Lynch, Steven A. author. |
| Other author | Pennington, Sam N., degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 2000. |
| Description | 96 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | The purpose of this study was to gain a better understanding of the effects of alcohol exposure on the insulin-like growth factor (IGF) system during embryonic development. Fetal alcohol syndrome and fetal alcohol effects are growing problems in the United States and the world. Alcohol exposure has been shown to reduce growth, reduce rates of DNA and protein synthesis, as well as inhibit cellular proliferation. The IGF system plays a major role in normal growth and development of the embryo. Using the chicken embryo model, maternal and placental effects are eliminated, allowing observation of the direct effect of alcohol on the growing embryo. The hypothesis for this research project was that ethanol exposure reduces the bioavailability of IGFs, thus contributing to reduced growth. Type-1 IGF receptors, IGF-binding proteins (IGFBPs), IGF-1 and IGF-2 levels were measured on days 5, 6, 7 and 8 of incubation, following administration of a 1.5g/Kg dose of ethanol to the chicken embryo on day 0 of incubation. IGF-2 and type-1 IGF receptor levels were not significantly different between groups on any day measured. In ethanol treated embryos, the 30 kDa IGFBP levels were significantly higher than control levels on days 5 and 6. On day 6, IGF-1 levels were significantly lower in the ethanol treated embryos compared to control levels. The elevated IGFBP levels and reduced IGF-1 levels would tend to indicate an overall reduction in the bioavailability of IGF-1. The reduced bioavailability of IGF-1 on days 5 and 6, implied by the reduced IGF-1 levels and increased 30 kDa IGFBP levels, correlates with the decreased embryo weight observed in the ethanol treated embryos. On day 8, IGF-1 levels were significantly higher in the ethanol treated group compared to controls, and the 30 kDa IGFBP levels were significantly lower in the ethanol treated embryos when compared to control values. The increased IGF-1 levels and decreased 30 kDa IGFBP levels suggest an overall increase in IGF-1 bioavailability, which correlates with a decreasing ethanol dose in the chicken embryo. Chicken embryos exposed to ethanol catch up in weight to control embryos by hatching. An increased bioavailability of IGF-1 observed by day 8, suggested by increased IGF-1 levels and decreased 30 kDa IGFBP levels, may represent a rebound effect stimulating increased growth. |
| General note | Submitted to the faculty of the Department of Biology. |
| General note | Advisor: Sam N. Pennington |
| Dissertation note | M.S. East Carolina University 2000 |
| Bibliography note | Includes bibliographical references (leaves 82-96). |
| Genre/form | dissertations. |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | Access Content Online | ✔ Available |