Identification of novel cyclic nucleotide phosphodiesterase gene cDNAs in the brain of guinea pig.

OBJECTIVE: Cyclic nucleotide phosphodiesterase (PDE) is a critical component of the nitric oxide (NO) signaling pathway and plays critical roles in cognition and learning, Parkinson's disease, attention deficit hyperactivity disorder, psychosis and depression. The PDEs in the brain of guinea pig have not yet been reported. The present study aimed to detect the unknown Pde cDNAs in the brain of guinea pig. METHODS: Reverse transcription polymerase chain reaction (RT-PCR) and sequence comparison analysis were performed to detect the expression of Pde cDNAs and to assess the identity rates of cDNA and amino acid sequences between guinea pig and human or mouse, respectvely. The RT-PCR primers were located on the conserved region of human PDE and mouse Pde cDNAs. RESULTS: Eleven novel Pde cDNAs were detected in the brain of guinea pig (Cavia porcellus), including CpPde1a, CpPde1b, CpPde2a, CpPde4a, CpPde4d, CpPde5a, CpPde6c, CpPde7b, CpPde8a, CpPde9a, and CpPde10a. The identity rates of the Pde cDNA sequences between guinea pig and human ranged from 83.8% to 94.3%, and those of the amino acid sequences ranged from 91.9% to 100%. The identity rates of Pde cDNA sequences between guinea pig and mouse ranged from 84.6% to 92.1%, and those of amino acid sequences ranged from 91.2% to 99.2%. The average identity rate of the 11 Pde cDNA sequences between guinea pig and human was significantly higher (P < 0.01) than that between guinea pig and mouse. The putative partial amino acid sequences of guinea pig contained at least one of the conserved domains of human and mouse PDE proteins. CONCLUSION: These results indicate that the brain-expressed Pde genes are identified in guinea pig, which lays the foundation for further investigating the physiological roles of PDE proteins in the brain.

[Studies on the chemical constituents of the petroleum ether portion of Nervilia fordii].

OBJECTIVE: To study the chemical constituents of the petroleum ether portion of Nervilia fordii. METHODS: The constituents were separated and purified by using column chromatography with silica gel. These compounds were identified by their physical and spectral data. RESULTS: Six compounds were isolated and identified as Cyclohomonervilol (I), Octacosanoicacid (II), Stigmasterol (III), Cyclohomonervilol-(E)-p-hydroxy cinnamate (IV), 24(R/alpha)-dihydrocycloeucalenol-(E)-p-hydroxy cinnamate (V), Docosanoic acid (VI). CONCLUSION: Compounds I-VI are isolated from this plant for the first time.

Identification of novel cyclic nucleotide phosphodiesterase gene cDNAs in the cochlea of guinea pig (Cavia porcellus) through conserved homologous sequences.

The nitric oxide (NO) signaling pathway plays a critical role in auditory signal conversion and transduction. Cyclic nucleotide phosphodiesterase (PDE), an important component of the NO signaling pathway, has not been identified in the cochlea. Using cross-species comparison, homologous sequences of human and mouse Pde coding sequences were searched in a guinea pig genomic database and conserved homologous exons were found between human and mouse homologous sequences. Based on reverse-transcription PCR of these conserved regions, six partial Pde cDNAs were detected in the cochlea: CpPde3a, CpPde4d, CpPde8a, CpPde8b, CpPde9a, and CpPde11a. The identity rates of the six partial Pde cDNA sequences between guinea pig and human range from 83.8 to 95.5% and those of the peptide sequences range from 85.6 to 100%. The identity rates of the six Pde cDNA sequences between guinea pig and mouse range from 80.6 to 93.0% and those of peptide sequences range from 79.5 to 99.2%. The results demonstrate that multiple Pde genes are expressed in the cochlea, suggesting a NO pathway in the auditory system. Insights into this pathway will help to develop new therapeutic drugs on auditory abnormalities.