AIM: To study the expression of glycine receptor (GlyR) in adult rat cardiac tissue and cultured cardiomyocytes from neonatal rat hearts. METHODS: Total RNA and membrane protein were extracted from cardiac tissue of adult rats and primary cultured cardiomyocytes from neonatal rat hearts, ?1 and ? subunits mRNA and protein of GlyR were detected with the method of reverse transcription nest DNA polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: The mRNA and protein expression of ? subunit were identified in the adult rat heart tissue and cultured cardiomyocytes, similar to the sequence and immunogenicity generated from GlyR ? subunit of the rat spinal cord; for ?1 subunit, mRNA was found in only cultured cardiomyocytes. CONCLUSION: These data demonstrate that adult rat cardiac tissue and cultured cardiomyocytes from neonatal rat hearts express mRNA and protein of GlyR subunits similar to the GlyR that expresses in the spinal cord, suggesting that GlyR exists in the membrane of the rat cardiomyocytes.

AIM: To investigate whether glycine receptor is involved in the protection of glycine against(anoxia/reoxygenation) injury in cardiomyocytes by detecting oxygen free radical metabolism,apoptosis and intracellular calcium overload.METHODS: The neonatal rat cardiomyocytes were cultured and exposed to anoxia and reoxygenation((A/R)) in the presence of glycine receptor antagonist,glycine or in free chloride buffer.The superoxide dismutase(SOD) activity,the contents of malondialdehyde(MDA) and nitric oxide(NO),the intracellular free calcium concentration and the apoptotic rate in the cardiomyocytes were determined.RESULTS: SOD activity and NO content in cardiomyocytes were lower,but MDA content,intracellular free calcium concentration and apoptotic rate in cardiomyocytes were higher in A/R group than those in control.Pretreatment with glycine inhibited the above changes caused by A/R,which was reversed by strychnine treatment and in the free chloride medium.CONCLUSIONS: Glycine inhibits free radical production,attenuates calcium overload,decreases apoptotic rate and increases SOD activity and NO release in cardiomyocytes exposed to(A/R).These findings suggest that glycine exerts a protective effect against A/R injury via glycine receptor and glycine protects the neonatal rat cardiomycytes from A/R-induced injury in a chloride-dependent manner.

At present, the cats play a more and more important role in medical experiments as an experimental animal,especially for the studies of neurology,physiology and toxicology. Compared with rodent animals,the physiological characteristics, anatomical features, pathological and biochemical reactions of cats are closer to human beings, and compared with the primate animals,they have advantages of economy,abundant resources and so on. Therefore,cat has an extensive application prospect in animal models of human diseases. This article mainly reviews and summarizes the establishing method and research status of cats as an animal model of human diseases in ophthalmology, nervous system, tumor and other fields in recent years.