Glycerophosphrylocholine (GPC) is a renal medullary compatible organic osmolyte that is derived from choline via phosphatidylcholine, which is catalyzed in part by phospholipase A2 (PLA2) and its degradation by GPC: choline phosphodiesterase (GPC: choline PDE). We found that caffeine elevated intracellular free calcium ([Ca2+]i) and GPC level in cultured MDCK cells, canine kidney epithelial cells, and propose a possible biochemical mechanism. When MDCK cells were incubated for 3 h with 1 to 10 mM caffeine, cellular GPC was elevated in a dose-dependent manner, and this occurred independently of the extracellular osmolality. Caffeine stimulated the rate of [14C]choline incorporation into [14C]GPC and PLA2 activity. Whereas, GPC: choline PDE activity was accompanied by less of increase. These enzyme changes demonstrate the increased net synthesis of MDCK GPC. In order to identify what triggers the PLA2 activation, [Ca2+]i was measured by using a fluorescence dye, Fura-2. Caffeine (10 mM) resulted in a typical transient increase in MDCK [Ca2+]i concentration, and this increase was greatly inhibited by pretreatment of MDCK cells with 10 mM ryanodine for 5 min. Ryanodine (10 mM) also inhibited the caffeine-induced stimulation of PLA2 activity. These findings provide the first evidence that caffeine in MDCK cells causes a ryanodine-inhibitable increase of [Ca2+]i and PLA2 activity, resulting in cellular GPC accumulation.
Animal ; Caffeine/pharmacology* ; Calcium/metabolism* ; Carbon Radioisotopes ; Cell Line ; Choline/metabolism ; Dogs ; Glycerylphosphorylcholine/metabolism* ; Kidney/cytology ; Phospholipases A/metabolism* ; Phospholipases A/drug effects ; Phospholipases A/antagonists & inhibitors ; Phosphoric Diester Hydrolases/metabolism ; Phosphoric Diester Hydrolases/drug effects ; Ryanodine/pharmacology* ; Ryanodine/metabolism

Androgen has been claimed for so long as a pivotal hormone in regulating male sexual function, acting both at the central and peripheral level. We believe that androgen is indeed the main synchronizer of sexual activity regulating libido and enzymes as nitric oxide synthase (NOS) and phosphodiesterase type 5 ( PDE5) , which are crucial for the erectile process. The main action of androgen is to timely adjust the erectile process as a function manifestation of sexual desire, therefore finalizing erection to sex.
Androgens ; pharmacology ; physiology ; Animals ; Male ; Nitric Oxide Synthase ; metabolism ; Penile Erection ; drug effects ; physiology ; Phosphoric Diester Hydrolases ; metabolism ; Rats

OBJECTIVETo investigate the changes in the expression of phospholipase C-gamma1tyr783 (PLC-γ1tyr783) in the condylar cartilage of a young rat during functional mandibular protraction. This work also explores the function of PLC-γ1tyr783 in the rat mandibular condylar cartilage bone remodeling, which could provide experimental evidence for clinical bone ortho- pedic work.

METHODSA total of 60 four-week-old male Sprague-Dawley (SD) rats were used in this study. The rats were divided equally and randomly into experimental group and control group. The functional appliances that were fitted to the upper incisors of the animals in the experimental group were worn 24 h a day after the rats were fed for 7 d with homemade pellet feed. The animals in the experimental group, along with their matched controls, were sacrificed after 1, 3, 7, 14, 21, and 28 d. The bilateral condylar was fixed, decalcified, dehyded, and then conventional paraffin embedded. Immunohisto- chemistry of PLC-γ1tyr783 was applied to observe its express distribution and variation.

RESULTSThe expression of PLC-γ1tyr783 decreased gradually in the control group, which showed age-related changes (P > 0.05). On the 14th day, PLC-γ1tyr783 expres- sion in the experimental group was significantly higher than that in the control group. PLC-γ1tyr783 expression began to appear statistically and significantly different between the two groups (P < 0.01).

CONCLUSIONPLC-γ1tyr783 is involved in the bone remodeling process of the rat condylar cartilage after functional mandibular-protraction.

Animals ; Bone Remodeling ; Cartilage ; Male ; Mandibular Condyle ; Phospholipase C gamma ; Phosphoric Diester Hydrolases ; Rats ; Rats, Sprague-Dawley

BACKGROUND AND OBJECTIVES: Time-phasic development of nitrate tolerance in cardiovascular diseases is very important because it can contribute to the advent of blunted vasodilation or rebound ischemia even during continuous NTG treatment. In such a condition, we should change the therapeutic regimen of nitrate treatment to prevent the worsening of symptoms. MATERIALS AND METHODS: We created a nitrate-tolerant rat model using an osmotic minipump, and we examined the hemodynamic response to bolus NTG infusion in vivo. We checked the phosphodiesterase (PDE) 1A1 mRNA and protein level by relative quantitative RT-PCR and western blot analysis. We used 8-cpt-cGMP for investigating the development of a time-phasic nitrate tolerance mechanism after nitrate infusion. RESULTS: NTG-treated rats revealed a significant decrease in NTG-induced MAP drop (nitrate tolerance) from 1-day and this continued to the third day. The mRNA and protein levels of PDE1A1 similarly increased during these periods. CONCLUSION: This study revealed the development of time-phasic nitrate tolerance from the the aspects of in vivo hemodynamic responses and PDE 1A1 gene expression, and our work supports the need for further investigation to come up with a different therapeutic strategy and new drugs.
Animals ; Aorta ; Blotting, Western ; Cardiovascular Diseases ; Gene Expression ; Hemodynamics* ; Ischemia ; Models, Animal ; Nitrates ; Phosphoric Diester Hydrolases ; Rats ; RNA, Messenger ; Vasodilation

BACKGROUND: Ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) generates inorganic pyrophosphate, a solute that serves as an essential physiological inhibitor of calcification. Inactivating mutations of ENPP1 are associated with generalized calcification in infancy and an increased risk of developing type 2 diabetes mellitus (T2DM). We hypothesized that the ENPP1 K121Q variant may be associated with increased coronary artery calcification in T2DM patients. METHODS: The study subjects were aged 34 to 85 years and showed no evidence of clinical cardiovascular disease prior to recruitment. A total of 140 patients with T2DM were assessed for their coronary artery calcium (CAC) scores and ENPP1 K121Q polymorphisms were identified. RESULTS: The prevalence of subjects carrying the KQ genotype was 12.9% (n = 18). There were no 121QQ homozygotes. Patients with the KQ genotype did not show a significantly higher CAC score (122 vs. 18; P = 0.858). We matched each patient with the KQ genotype to a respective control with the KK genotype by gender, age, and duration of diabetes. When compared to matched controls, we observed no significant difference in CAC score (P = 0.959). CONCLUSIONS: The ENPP1 K121Q polymorphism does not appear to be associated with coronary artery calcification in patients with T2DM.
Aged ; Calcium ; Cardiovascular Diseases ; Coronary Vessels ; Diabetes Mellitus, Type 2 ; Diphosphates ; Genotype ; Homozygote ; Humans ; Lifting ; Phosphoric Diester Hydrolases ; Prevalence ; Pyrophosphatases

OBJECTIVEFindings from the previous studies have suggested a relationship between ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP-1) or plasma cell membrane glycoprotein 1 (PC-1) gene single nucleotide polymorphism (K121Q, rs1044498) and genetic susceptibility to obesity. However, such relationship is not reproduced by some currently available studies. In this context, the present study is aimed to quantitatively analyze the association of K121Q variant with obesity in all published case-control studies in European adult populations.

METHODSPublished literature from PubMed, EMBASE, and ISI web of science databases were retrieved. The studies evaluating the association of ENPP1/PC1 gene K121Q polymorphism with obesity were included, in which sufficient data were presented to calculate the odds ratio (OR) with 95% confidence intervals (CIs).

RESULTSTen case-control studies meeting the inclusion criteria identified a total of 24,324 subjects including 11,372 obese and 12,952 control subjects. The meta-analysis results showed a statistically significant association of K121Q with obesity [OR (95%CI): 1.25 (1.04-1.52) P=0.021] under a recessive model of inheritance (QQ vs. KK+KQ) without heterogeneity or publication bias.

CONCLUSIONSThe results from the present study have indicated that ENPP1/PC1 Q121 variant may increase the risk of obesity and that more well-designed studies based on a larger population will be required to further evaluate the role of ENPP1/PC1 gene K121Q polymorphism in obesity and other related metabolic syndromes.

Europe ; epidemiology ; Genetic Predisposition to Disease ; Humans ; Obesity ; epidemiology ; genetics ; Odds Ratio ; Phosphoric Diester Hydrolases ; genetics ; Polymorphism, Genetic ; Pyrophosphatases ; genetics ; Risk Factors

Autotaxin (ATX), a member of nucleotide pyrophosphatase/phosphodiesterase (NPP) family, is also named as phosphodiesterase Iα (PD-Iα) or NPP2. ATX is the unique member among the NPPs that can function as a lysophospholipase D (lysoPLD), converting lysophosphatidylcholine into lysophosphatidic acid (LPA). LPA acts on specific G-protein-coupled receptors to elicit a wide range of cellular response, including cell proliferation, cell migration and cell contraction, etc. As the major LPA-producing phospholipase, many ATX's features and functions are dependent on the production of LPA. ATX and LPA together form the ATX-LPA functional axis. The present review summarizes the current progress in function and biological activities of ATX-LPA axis.
Animals ; Cell Movement ; physiology ; Cell Proliferation ; Humans ; Lysophosphatidylcholines ; metabolism ; Lysophospholipids ; metabolism ; physiology ; Phospholipases ; metabolism ; Phosphoric Diester Hydrolases ; metabolism ; physiology ; Receptors, G-Protein-Coupled ; physiology

OBJECTIVETo compare the differences of expressions of adenylyl cyclase (AC) and phosphodiesterase (PDE) in ejaculated spermatozoa between healthy volunteers and the patients with asthenospermia.

METHODSEjaculated spermatozoa were collected from healthy volunteers and the patients with asthenospermia. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect mRNA expression of AC and PDE subtypes in human spermatozoa. The concentrations of cAMP and cGMP in the samples were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSCompared with healthy volunteers, expression of sAC mRNA and concentration of cAMP were significantly decreased in the patients with asthenospermia (P < 0.01) , while the expression of PDE4C mRNA was significantly increased at the same time (P <0.01). There were no marked differences in the expression of ACIII mRNA and concentration of cGMP between the two groups.

CONCLUSIONThe sAC down-regulation and PDE4C up-regulation are possible reasons for asthenospermia.

Adenylyl Cyclases ; biosynthesis ; Asthenozoospermia ; metabolism ; Cyclic AMP ; metabolism ; Humans ; Male ; Phosphoric Diester Hydrolases ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa ; metabolism

Animals ; Anti-Asthmatic Agents ; therapeutic use ; Asthma ; drug therapy ; etiology ; Humans ; Phosphodiesterase Inhibitors ; pharmacology ; Phospholipase D ; physiology ; Phosphoric Diester Hydrolases ; physiology

PURPOSE: Nitric oxide (NO) and phosphodiesterases (PDEs) play key roles in mediating relaxation of corpus cavernosal smooth muscle by increasing intracellular cGMP level. Here, we investigated effects of NO-donor (sodium nitroprusside, SNP) and penile specific type-V PDE inhibitor (zaprinast) in human and rabbit corpus cavernosal cells and tissues in vitro. MATERIALS AND METHODS: The cultured smooth muscle cells and tissues of human and rabbit corpus cavernosum were treated with increasing concentrations of SNP or zaprinast for 5 and 20 minutes, respectively, and intracellular cGMP levels were measured by radioimmunoassay. Organ bath study was performed to measure the relaxation effects of drugs on precontracted corpus cavernosal muscle strips. RESULTS: Although both NO-donor and type-V PDE inhibitor effectively stimulated the accumulation of cGMP in a dose-dependent manner, magnitude of cGMP increase and specificity of drug were found to be species-dependent. In human corpus cavernosal tissues, cGMP was increased upto 10- and 5-folds by SNP and zaprinast, respectively. However, magnitude of increase was much less in cultured smooth muscle cells. In rabbit, SNP effect was most prominent in cultured cells and effects of SNP and zaprinast were modest in tissues. Both agents also resulted in effective relaxation of human and rabbit cavernosal tissue strips. Similar patterns of dose-response curves were shown between results from the organ bath studies and cGMP radioimmunoassay with cavernosal smooth muscle cells. CONCLUSIONS: Present results show that effects of SNP and zaprinast are not coincident in different species, suggesting possible species-specificities of these two agents. Measurement of cGMP changes in cultured cavernosal smooth muscles cells could be reflected to the relaxation effects of drugs on corpus cavernosal muscle strips.
Baths ; Cells, Cultured ; Cyclic GMP ; Erectile Dysfunction ; Humans* ; Male ; Muscle, Smooth* ; Myocytes, Smooth Muscle ; Negotiating ; Nitric Oxide ; Nitroprusside ; Phosphoric Diester Hydrolases ; Radioimmunoassay ; Relaxation* ; Sensitivity and Specificity ; Signal Transduction*