S57Abstracts / Cell Biology International 32 (2008) S1eS67

dependence in mice. The results obtained indicate that sinomenine may atten-

uate morphine addiction and significantly alleviate morphine withdrawal

symptoms, and that the molecular mechanism may be associated with the ef-

fect of sinomenine on the CO/NO-cGMP signaling cascade in the cerebellum

and spinal cord.

CALCIUM BINDING-PROTEINS EXPRESSION IN THEVENTRAL HORN FOLLOWING HEMISECTION OF RATSPINAL CORDLiang Huang, Xiao Qiong Wu, Wu Zhu, Wei Jun Cai, Xue Gang LuoDepartment of Anatomy and Neurobiology, Central South University,ChinaPrevious studies suggest that the spontaneous recovery of locomotion may

concern with interneurons after subtotal spinal cord injury. Calcium binding-

proteins have the effects on neuronal function activity by mediating intracel-

lular-free calcium, which are extensively distributed in interneurons of nervous

system. Therefore we hypothesized that alteration of expression of calcium

binding-proteins in the interneurons might contribute to this spontaneous re-

covery of locomotion after subtotal spinal cord injury. The aim of this study

was to seek for the expression pattern of calcium binding-proteins following

T10 spinal cord hemisection in rats. SD rats were randomly divided. The L5

spinal segments were taken for detection of expression of calcium binding-

proteins (calbindin, CB; parvalbumin, PV; Calreticulin, CR) by immunohisto-

chemistry. We found that CB-, PV- and CR e immunoreactions were mainly

distributed in small or medium interneurons of laminel VII, VIII in the ventral

horn of normal control group and experimental groups. Interestingly, a few

PV-ir large motoneurons were observed only on 12h post injury. Furthermore

optic density analysis showed that CB-, PV- and CR expressions in the injured

lateral were upregulated transiently after spinal cord hemisection, but the high-

est expression of CB occurred at 12h post injury whereas PV or CR appeared

on day 7. Subsequently, the expression levels of three calcium binding-proteins

decreased and returned to normal levels on day 14 post injury. However, there

was no significant difference of CB-, PV- and CR expressional quantities be-

tween normal control and the injured contralateral. The data demonstrate the

spatiotemporal patterns of the expression of CB, PV and CR in the interneu-

rons of ventral horn following spinal cord hemisection, which were related

to different modulation of intracellular-free calcium, implying that calcium

binding-proteins in the interneurons may participate in spontaneous recovery

of locomotion after subtotal spinal cord injury.

EXPRESSION OF P-TrkB RECEPTOR IN RAT RETINAFOLLOWING ACUTE HIGH INTRAOCULAR PRESSUREWITH BDNF PRE-TREATEDLi Zhu Jiang 1,2, Ju Ffang Huang 2, Jian Bin Tong 2, Dan Chen 2,Le Ping Zeng 2

1 Department of Neuropsychopathy, clinical medical school, DaliUniversity, Dali, China2 Department of Anatomy and Neurobiology, Xiangya MedicalSchool, Central South University, Changsha, ChinaTo investigate the expression of p-TrkB receptor in rat retina following acute

high intraocular pressure (HIOP) with BDNF pre-treated, seventy-two adult

rats were randomly divided into acute HIOP group, BDNF pre-treated HIOP

group and vehicle pre-treated HIOP group. The left eyes of rats in BDNF

pre-treated HIOP group and vehicle pre-treated HIOP group were injected

with BDNF or vehicle respectively 2 days before HIOP. The intraocular pres-

sure of all left eyes was increased until b wave of flash electroretinogragh

(fERG) disappeared and such pressure maintained for 60 minutes. All the right

eyes were served as normal control group. The rats were sacrificed after 1, 3, 7

or 14 days, and immunohistochemistry for detecting the expression of p-TrkB

was used. We found that compared to the normal control group, the expression

of p-TrkB was decreased significantly (P<0.05) during reperfusion in the

acute HIOP group. The expression of p-TrkB during reperfusion in vehicle

control group was similar to that in acute HIOP group. In the BDNF pre-

treated HIOP group, the expression of p-TrkB was also decreased, but signif-

icantly higher than that in the acute HIOP group at all time points. The results

indicate that down-regulation of p-TrkB following HIOP was relieved by ex-

ogenous BDNF, which may be involved in the protection role of BDNF to the

injured retina following HIOP.

EFFECT OF INTRATHECAL INJECTION OF MK-801, L-NNAAND MORPHINE ON THE NOCICEPTIVE BEHAVIORALREACTION DURING INFLAMMATORY PAINHong Bo Jin, Wei Wang, Yong Zhou, Tie Shan Zhang, YongBin Yang, Yu Rong LiDepartment of Physiology, Harbin Medical University, Harbin, ChinaIn order to explore the changes of nociceptive response by intrathecal injec-

tion of NMDA receptor antagonist MK-801, NOS inhibitor L-NNA and

Morphine in tail flick test and formalin test, SD rats were randomly distrib-

uted into formalin test group (intrathecal injection of saline), MK-801 group,

L-NNA group and Morphine group. All groups were treated with 5% forma-

lin 100 ml injections in the right hind paw of rats. MK-801, L-NNA and Mor-

phine groups were treated with intrathecal injection of 10, 20,40 nmol/L

respectively before 20 min of injecting formalin. The nociceptive behavioral

reaction was recorded. Also, the change of the tail flick latency (TFL) of rats

in heat tail-flick test was observed. The nociceptive reaction induced by in-

jection of formalin in hind paw exhibited two phases. The weighted pain

scores of second phase were significantly reduced by intracecal injection

of MK-801, L-NNA and Morphine. The TFL of rats was significantly pro-

longed by intrathecal injection of MK-801, while the TFL of rats were

more significantly prolonged by intrathecal injection of Morphine. However,

in the heat tail-flick test, the TFL and maximum percent effect (MPE) did

not change significantly when the lower concentration of L-NNA was

used, and the hyperalgesia happened when the higher concentration of

L-NNA was used. These results suggest that MK-801, L-NNA and morphine

had significant analgesic effect. But the analgesic effect of MK-801 and

L-NNA was weaker than that of Morphine. NMDA receptor and NO play

an important role in the pain transduction and modulation in the spinal

cord. This study was supported by the Youth Science and Technology

Special Foundation of Heilongjiang Province (QC06C060), Medical Basic

Subjects Youth Science Foundation of Harbin Medical University (060014)

and Science and Technology Foundation of Heilongjiang Provincial Health

Department (2006-472).

DEVELOPMENTAL POTENTIAL STUDIES OF HEXAPLOIDEMBRYOS PRODUCED BY BLASTOMERES FUSION OFDIPLOID AND TETRAPLOID EMBRYOS AT 2-CELL STAGELei Lei, Na Guan, Yan Ning Xu, Qing Hua Zhang, Xiao Fei Yan, JianJiang Dong, Shu Qi Zhong, Lian Hong JinDepartment of Histology and Embryology, The Basic sciencesCollege, Harbin Medical UniversityThe polyploid mouse embryos are important models for understanding the

cleavage and preimplantation development mechanism in mammalian. Here

we report the produce of the Kun Ming (KM) hexaploid embryos by exchang-

ing and electrofusing blastomeres from diploid and tetraploid KM mouse em-

bryos at 2-cell stage. Firstly, the tetraploid embryos were made by inducing

two blastomeres fusion at 2-cell stage. About 20 hours after fusion, tetraploid

embryos could develop to 2-cell stage. At this moment, one blastomere was

taken out and transferred to a normal diploid 2-cell stage embryo, in which

one blastomere had been taken out already. Electrofusion was performed in

0.28 M mannitol solution when the micromanipulation was done. The assess-

ment of the hexaploid embryos which derived from the 2n/4n embryonic fu-

sion was evaluated by in vitro culture, karyotype analysis, nuclear number

count, cytoskeleton and Oct4 immunofluorescence. In results, hexaploid em-

bryos were able to develop to the blastocyst stage at 72.7 % which was lower

than that of normal diploid embryos (98.0 %, P<0.05) but no significant dif-

ference with tetraploid blastocyst development (86.2 %). However, the cell

number in hexaploid blastocyst was less than that in diploid or tetraploid blas-

tocyst (12.3 � 2.0 vs 52.2 � 7.2, 18.4 � 3.5). Karyotype analysis confirmed

that the number of chromosomes in hexaploid embryos were 120. Further-

more, b-tubulin and Oct-4 immunofluorescence indicated that hexaploid