Objective To investigate the expression and characteristics distribution of ciliary neurotrophic factor (CNTF) and its receptor during the development of retina of healthy Sprague-Dawley(SD)and Royal College of Surgeons (RCS) rats with hereditary retinal degeneration. Methods The expression and distribution of ciliary neurotrophic factor and its receptor were detected by immunohistochemical staining in the retinal paraffin sections of SD and RCS rats from newborn to 12 moths old. Results In the normal retina of SD rats 0-7 days after birth, positive CNTF staining was found in all of the retinal layers and the staining of ganglion cells strengthened and other cells weakened as the age of rats increased; the staining of ganglion cells reached the peak at the 4th week and lasted till the agedness. The same results of the CNTF staining were also found in RCS rats retina. Weak positive staining of CNTFR in all of the retinal layers was seen in the 0-3-day-old SD rats; the ganglion cells were darkly stained and incontinuous positive staining at the site which would develop to be the external segment was found; as the age increased, the positive staining of external segment of photoreceptor enhanced and reached the peak at the 14-28th day after birth. At the 56th day, the staining of ganglion cells in retina of SD rats was strengthened while the staining of external segment weakened till the agedness. The expression of CNTFR in retina of 3-14-day-old RCS rats was the same as which of normal SD rats basically, but the staining of external segment weakened obviously from the 21st day on, and negative staining of external and positive ganglion cells were detected at the 28th day till the agedness. Conclusions Expression of CNTF in normal SD rats and RCS rats with hereditary retinal degeneration is almost the same. The presence of significant difference of expression of CNTFR between normal SD rats retina and RCS rats retina may provide the experimental gist for the CNTF treatment to retinal degeneration.

To explore the effects of long-term treatment of different dietary energy levels on ovarian expression of mRNAs for LHR and FSHR,the present study was performed in nine growth-matched littermate crossbred (Land-race×Large White X Duroc) prepubertal gilts. At approximately 30 kg of body weight and 50 day of age,gilts were housed with individual feeding stalls and placed on a normal level of feeding for 90 days (dl-90) with free ac-cess to water and food throughout the whole research. From d91 ,littermates were divided and randomly assigned to one of the following three treatment lines for 3 weeks till d112:Group H,Group M, and Group L, fed the high energy level diet (n = 3, digestible energy 14.87 MJ/kg), moderate energy level diet (n = 3, digestible energy 12.39 MJ/ kg), and low energy level diet (n = 3, digestible energy 9.98 MJ/kg), respectively. When gilts were slaughtered on d112 after 3 weeks energy treatment, both ovaries of every gilts were collected,snap frozen in liquid nitrogen and re-tained at -80℃ for use to determine and analysis the relative amount of ovarian LHR and FSHR mRNAs using semi-quantitative RT-PCR. Results showed that the effect of dietary energy treatment was notable: the ovarian ex-pression of mRNAs for LHR and FSHR was significantly higher (P<0.05) in gilts treated with high energy diet compared to gilts treated with moderate and low energy diets, while gilts treated with low energy diet had a signifi-cantly lower (P<0.05) ovarian LHR and FSHR expression compared with gilts treated with moderate and high en-ergy diets. These results revealed that ovarian expression of I.HR and FSHR in prepubertal gilts increased as the lev-el of dietary energy intake elevated,i, e. , high energy diet can markedly enhance ovarian expression of mRNAs for LHR and FSHR,whereas energy deficit markedly suppress the expression.