碩士 / 國立成功大學 / 細胞生物及解剖學研究所 / 98 / Dexamethasone (a synthetic glucocorticoid) is widely used to treat adults’ inflammatory and autoimmune diseases. In preterm infants’ long term follow up, dexamethasone has central nervous side effects, such as neurologic dysfunction, decreasing brain volume and learning potential. However, dexamethasone is still used in preterm infants’ neonatal respiratory distress syndrome while surfactant and emergent resuscitation are useless.
The hippocampus is rich in glucocorticoid receptors and belongs to the limbic system. The hippocampus plays important roles in long-term memory, spatial navigation, and related to mental illness. This study attempted to find out the hippocampus status after dexamethasone treatment.
Wistar neonatal rats were for animal model. Two major groups are determinated P3 (post natal day 3) and P7 (post natal day 7). In P3 and P7 groups, normal saline subgroup for control study had intraperitoneal injection 0.9% normal saline 0.5mg/kg. Dexamethasone subgroup and acupuncture subgroup for experimental study had intraperitoneal injection 0.5mg/kg dexamethasone (Oradexon, Organon, Netherlands). P3 acupuncture subgroup neonatal rats had acupuncture Zusanli (ST-36) in P3,4,5 (post natal day 3,4,5) and were sacrificed in P6 (post natal day 6).
Zusanli (ST-36) is an acupoint located 3 mm lateral and distal to the anterior tubercle of the tibia of human. Zusanli (ST-36) was usefull in the treatment of cerebrovascular diseases in human and animals.
P7 acupuncture subgroup had acupuncture Zusanli (ST-36) in P7,8,9 (post natal day 7,8,9) and were sacrificed in P10 (post natal day 10).
Hippocampal dentate gyrus cells amounts and morphologic differences were observed through 5-bromo-2’-deoxyuridine (BrdU), Neuronal nuclei (NeuN, a neuronal marker) and Glial fibrillary acidic protein (GFAP, an astrocyte marker) immunohistochemistry methods. Nissl’s stain was used for counter staining. Immunofluorescence double labling method was used to identify the proliferating cells. Image Pro Plus (Media Cyberhetics, USA) was used for BrdU(+) cells density analysis. The hippocampal dentate gyrus anatomy is according to The Rat Brain compact third ediation, Paxions and Watson 1997.
The brain of neonatal rats brain development is equal to full term infants at P7. (Hagberg et al., 1997) Thus, P7 group was used to mimic full term infants under treatments.
The dexamethasone subgroup was using one single dose dexamethasone (0.5mg/kg) to mimic postnatal infant dosage. Intraperitoneal injection in P1 to mimic the preterm infants’ resuscitation status. Hippocampal dentate gyrus discontinuous with cells amount decreased was noted after dexamethasone injection in our previous study.
The results showed that dexamethasone lead to damage the hippocampus, and acupuncture Zusanli (ST-36) increased the dentate gyrus proliferation. Dexamethasone significantly decreased the increasing body weight/ P1 body weight then control group. In P3 normal saline and P7 acupuncture subgroups, the periventricular area also had BrdU(+) cells. Besides, the double labeling cells density of BrdU(+) ＆ NeuN(+) were more than the density of BrdU(+) ＆ GFAP(+) double labeling cells of the dentate gyrus .
In conclusion, acupuncture improve the dentate gyrus neuron damage caused by Dex. Acupuncture also increase the neuron cells proliferation in dentate gyrus.
| Identifer | oai:union.ndltd.org:TW/098NCKU5391010 |
| Date | January 2010 |
| Creators | Wei-TingLin, 林威廷 |
| Contributors | Chi-Hsien Chien, 簡基憲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 48 |
Page generated in 0.0019 seconds