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Objective · To observe effect of 17β estrodial (17β E2) with different concentrations on C type natriuretic peptide (CNP), insulin like growth factor 1 (IGF1), and natriuretic peptide receptor B (NPR-B) expression and proliferation of growth plate chondrocytes of rats in vitro. Methods · Eight Wistar rats were sacrificed and their epiphyseal cartilages of the upper tibias were separated to obtain chondrocytes on the 14th day after birth. Then chondrocytes were cultured with 17β E2 in different concentrations (10-4、10-6、10-8、10-10 and 10-12 mol/L) for 48 h, while control group was cultured without 17β E2. CCK8 method, ELISA and qRT-PCR were used to analyze the proliferation of chondrocytes, the levels of CNP and IGF1 in culture medium and mRNA levels of CNP, NPR-B and IGF1, respectively. Results · 17β E2 in different concentrations affected the proliferation of growth plate chondrocytes significantly. When the concentration of 17β E2 was 10-8 mol/L, it had the strongest effect on the cell proliferation. When the concentration increased to 10-4 mol/L, the proliferation of chondrocytes was inhibited. With the increasement of 17β E2 concentration, the levels of CNP in the culture medium and the mRNA levels of CNP in the chondrocytes were significantly different. The highest levels of CNP protein and mRNA both appeared in 10-8 mol/L group, while the lowest levels both appeared in 10-4 mol/L group. IGF1 and its mRNA also reached the highest levels in 10-8 mol/L group,but the lowest concentration and mRNA level were in 10-10 mol/L group and 10-12 mol/L, respectively. Both CNP mRNA and protein levels were positive correlated with the proliferation of chondrocytes (P=0.000). Nevertheless, there was no significant correlation between the proliferation of chondrocytes and IGF1 mRNA or protein levels (P>0.05). Conclusion · 17β E2 modulates proliferation of rat growth plate chondrocytes in a dose-effect manner. It enhances proliferation at relatively low concentrations (10-10-10-8 mol/L) and inhibits proliferation at high concentration. This effect is positively related to CNP expression in chondrocytes.
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Objective To study the effects of serum C-type natriuretic peptide (CNP) ,insulin-like growth factor II (IGF-Ⅱ ) , endothelin (ET) ,neuron-specific enolase (NSE) and S100B protein(S100B) on the prognosis of the patients with traumatic brain injury .Methods A total of 110 patients with craniocerebral trauma admitted in our hospital from January 2016 to January 2017 se-lected as the craniocerebral trauma group and further divided into the mild ,moderate and severe craniocerebral trauma groups ac-cording to the Glasgow Coma Scale (GCS) .Then the levels of serum CNP ,IGF-Ⅱ ,ET ,NSE and S100B in all cases were analyzed by enzyme-linked immunosorbent assay (ELISA) .Their influence on the prognosis of the patients with craniocerebral trauma and the correlation among various indicators were analyzed .Results The levels of CNP and IGF-Ⅱat admission in the craniocerebral trauma group were significantly decreased ,while the levels of ET ,NSE and S100B were significantly increased ,the difference com-pared with the control group was statistically significant (P<0 .05) .Serum CNP and IGF-Ⅱlevels in the death group ,plant survival group and disabled group were significantly decreased .The difference was statistically significant (P<0 .01) .Serum CNP and IGF-Ⅱlevels in the moderate and severe craniocerebral trauma groups were gradually increased with the disease course progress ,while serum ET ,NSE and S100B levels were gradually decreased with the disease course progress ,the difference was statistically signifi-cant(P<0 .05) .In the patients with craniocerebral trauma ,the positive correlation existed between CNP and IGF-Ⅱ ,between ET and S100B ,between ET and NSE ,and between NSE and S100B(P<0 .01) ,while the negative correlation existed between IGF-Ⅱand ET ,between IGF-Ⅱ and S100B ,between CNP and ET ,and between IGF-Ⅱand NSE (P<0 .01) .Conclusion Serum CNP , IGF-Ⅱ ,ET ,NSE and S100B are correlated to the severity of craniocerebral trauma ,which has a higher clinical application value for judging the disease condition ,evaluating the prognosis in cradiocerebral trauma .
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C-type natriuretic peptide (CNP) is a newly discovered type of local regulatory factor that mediates its biological effects through the specic, membrane-bound natriuretic peptide receptor-B (NPR-B). Recent studies have established that CNP is closely related to male reproductive function. The aims of this study were to determine the distribution of CNP/NPR-B in human ejaculated spermatozoa through different methods (such as immunolocalization, real time polymerase chain reaction and Western Blot), and then to evaluate the influence of CNP on sperm function i n vitro, such as motility and acrosome reaction. Human semen samples were collected from consenting donors who met the criteria of the World Health Organization for normozoospermia. Our results show that the specic receptor NPR-B of CNP is localized in the acrosomal region of the head and the membrane of the front-end tail of the sperm, and there is no signal of CNP in human sperm. Compared with the control, CNP can induce a signicant dose-dependent increase in spermatozoa motility and acrosome reaction. In summary, CNP/NPR-B can affect sperm motility and acrosome reaction, thus regulating the reproductive function of males. CNP may be a new key factor in regulating sperm function.
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Introducción: El péptido natriurético tipo C (CNP) ha cobrado relevancia por sus efectos sobre la regulación de la función y la morfología del corazón y los vasos sanguíneos. Previamente demostramos in vitro que el CNP incrementa la actividad del sistema del óxido nítrico (NO) en ratas espontáneamente hipertensas (SHR). Objetivo: Estudiar el efecto del tratamiento crónico con CNP sobre la presión arterial sistólica (PAS), la función cardíaca y vascular y el sistema del NO en ratas espontáneamente hipertensas y normotensas. Material y métodos: Se emplearon ratas Wistar macho de 12 semanas de edad normotensas y espontáneamente hipertensas. Los animales recibieron infusión crónica de solución salina o CNP (0,75 mg/hora/rata) durante 14 días mediante la implantación de bombas osmóticas subcutáneas. Se midió la PAS y se realizaron un electrocardiograma y un ecocardiograma. Se extrajeron el ventrículo izquierdo y la arteria aorta torácica y se determinó la actividad, con L-[U14C]-arginina, de la óxido nítrico sintasa (NOS) y se realizaron estudios de reactividad vascular. Resultados: La administración crónica de CNP disminuyó la PAS en las SHR. Se observó menor volumen minuto en las SHR y el CNP incrementó dicho volumen, en tanto que no indujo cambios en las ratas normotensas. En las SHR se observó un desequilibrio en las respuestas vasodilatadora y vasoconstrictora en la arteria aorta y el tratamiento con CNP mejoró la función vascular respecto de las ratas normotensas. En ambos tejidos, la actividad de la NOS fue mayor en las SHR y se incrementó con la infusión durante 14 días de CNP. Sin embargo, dicho incremento fue menor en las SHR. Conclusión: El CNP induce cambios a nivel cardiovascular y en el sistema del NO que podrían resultar beneficiosos en este modelo de hipertensión arterial.
Background: C-type natriuretic peptide (CNP) plays an important role in the regulation of cardiovascular function and morphology. We have previously demonstrated that CNP increases nitric oxide (NO) system activity in vivo in spontaneously hypertensive rats (SHR). Objective: The goal of this study is to evaluate the effect of chronic CNP administration on systolic blood pressure (SBP), cardiovascular function and the NO system in spontaneously hypertensive and normotensive rats. Methods: Twelve-week-old normotensive male Wistar rats and SHR were used. They received chronic infusion of saline or CNP (0.75 mg/h/rat) for 14 days via subcutaneously implanted osmotic pumps. Systolic blood pressure was measured and an electrocardiogram and echocardiogram were performed. The left ventricle and the thoracic aorta were resected; nitric oxide synthase (NOS) activity was determined using L-[U14C]-arginine and vascular reactivity was assessed. Results: Chronic administration of CNP decreased SBP in SHR. Cardiac output was lower in SHR and increased with CNP; however, CNP had no effect in normotensive rats. Spontaneously hypertensive rats had unbalanced aortic vasodilation and vasoconstriction responses, and CNP improved the vascular function. Nitric oxide synthase activity was greater in SHR and increased with the 14-day CNP infusion, but this increase was lower than in normotensive rats. Conclusion: C-type natriuretic peptide induces cardiovascular and NO system changes which may be beneficial in this model of hypertension.
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Objectives To study the expression features of C-type natriuretic peptide (CNP)/natriuretic peptide receptor-B (NPR-B) axis and two parallel elimination pathways, natriuretic peptide receptor-C (NPR-C) and neutral endopeptidase (NEP) in unilateral ureteral obstruction (UUO) rats. Methods CNP, NPR-B, NPR-C, NEP, Col-IV and type IV collagen (Col-IV) mRNA and proteins were determined by in situ hybridization, real-time PCR, immunohistochemistry and western blot in UUO rats at 24h, 72h, 1w, 2w, 3w, 1m, 2m and 3m. Results CNP expression tended to be higher immediately after ligation and de-clined along with the progression of disease, occurring predominantly in tubular epithelial cells. A high-level CNP may attribute to the elevated expression of NPR-B in the early phase of UUO. Conclusions NEP and NPR participate in the regulation of CNP expression in tubulointerstitial fibrosis. The gradual increased expression of NPR-C and NEP may cause the subsequent de-cline of CNP.
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Objective To explore the value of amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) in evaluating the efficacy of therapy with recombinant human growth hormone ( rhGH ) in patients with idiopathic short stature (ISS) and isolated growth hormone deficiency ( IGHD ).Methods Forty-eight prepubertal children( IGHD n=25,ISS n=23 ) treated for at least 1 year with rhGH were included.Serum insulin-like growth factor- Ⅰ ( IGF- Ⅰ ) and NTproCNP levels were measured before starting treatment and 6 months later.Twelve months after starting treatment,all patients were assessed and annual growth velocity ( GV ),height standard deviation score ( HTSDS),and gained HTSDS (△HTSDS) were recorded.Results In GHD group,positive relationships between GV and change of IGF- ISDS( △IGF- ISDS ),GV and change of NTproCNP concentrations(△NTproCNP) were found( r=0.407,P=0.044 ;r=0.490,P=0.013 ).GH peak value was also positively associated with IGF- ISDS and NTproCNP before therapy ( r =0.558,P =0.004; r =0.630,P =0.001 ).△IGF- ISDS and △NTproCNP were positively associated after therapy ( r =0.466,P =0.019 ).In ISS group,GV was associated with △NTproCNP ( r=0.845,P＜ 0.01 ).Conclusions NTproCNP is a novel biomarker of growth as its level increases during growth-promoting treatment.Furthermore,IGF- Ⅰ is also valuable in evaluating the efficacy of rhGH therapy in short stature patients.
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Objective To investigate the changes of plasma adrenodullin(ADM) and C-type natriuretic peptide(CNP) level in children with chronic heart failure(CHF) and its clinical implications.Methods Forty-two children with CHF were collected.The patients suffered from dilated cardiomyopathy,congenital heart defects,and other heart diseases.According to a modified scoring system described by Ross and Reithman,16 patients were classified as class Ⅱ,14 as class Ⅲ,and 12 as class Ⅳ.Plasma levels of ADM and CNP were measured by radioimmunoassay assay in these patients and 11 healthy children.Echocardiography was performed to measure left ventricular function and the ratio of E/A.Results Plasma ADM and CNP levels of CHF patients were significantly elevated as compared with those of the control subjects [(218.27?106.53) ng/L vs(74.39?53.99) ng/L,P=0;(190.27?108.38) ng/L vs(92.59?(59.46) ng/L),P0.05).ADM levels were elevated with the advancing severity of CHF determined by a modified scoring system described by Ross.However,the plasma CNP levels in the normal state wasn′t significantly different from those observed in class Ⅱ.Likewise,the plasma CNP level in the class Ⅲ was not significantly different from that observed in class Ⅱ.Conclusions ADM and CNP might play a compensatory and defensive roles in the pathophysiology of the pediatric CHF.ADM may be a biochemical marker for evaluation the severity of the chronic heart failure in children,but also a new prognostic indicator of this syndrome.
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The present study was designed to investigate the effects renin-angiotensin-aldosterone system (RAAS), endothelin (ET) and local natriuretic peptide (NP) system for glomerulopathy induced in the experimental bilateral ureteral obstructive rats. Sprague-Dawley male rats (200~220 g body weight) were bilaterally obstructed by ligation of the proximal ureters for 24 hours. Control rats were treated in the same ways, except that no ligature was made. The glomeruli were isolated from cortex by graded sieve methods, and the mRNA expressions of local renin-angiotensin system (RAS), aldosterone synthase (CYP11B2), endothelin-1 (ET-1) and NP system were determined by real-time polymerase chain reaction. Following the bilateral ureteral obstruction, the mRNA expressions of renin, angiotensin converting enzyme 1 as well as ET-1 were increased, while that of angiotensin converting enzyme 2 was not changed. The expressions of CYP11B2 and angiotensin II receptors were not changed. C-type natriuretic peptide (CNP) expression was increased, while its receptors (natriuretic peptide receptor-B) were not changed. We suggest that the upregulation of local RAS and ET play a role in the progressive glomerular injury, and that the enhanced CNP activity also plays a compensatory role in obstructive uropathy in the glomerulus.
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Animals , Humans , Male , Rats , Cytochrome P-450 CYP11B2 , Endothelin-1 , Endothelins , Ligation , Natriuretic Peptide, C-Type , Peptidyl-Dipeptidase A , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction , Receptors, Angiotensin , Renin , Renin-Angiotensin System , RNA, Messenger , Up-Regulation , Ureter , Ureteral ObstructionABSTRACT
C-type natriuretic peptide (CNP), a member of natriuretic peptide family, is mainly synthesized in the endothelium and central nervous system. But CNP is also involved in the growth and differentiation of other peripheral organs. Although we have reported the local synthesis and localization of CNP in the adult submandibular glands (SMG), it is not known that the expression and biological activity of CNP following the morphogenesis, differentiation and aging. This study aimed to examine the expression of CNP and its receptors in the developing and differentiating stages of mouse SMG, and the changes of biological activity of its receptors with aging. The SMG, obtained from 14, 16, 18 days-old embryos (E) and 1 day, 2 weeks, 1, 2, 12, and 24 month-old C57BL/6N mouse, were processed for RT-PCR, in situ hybridization, immunohistochemistry and cGMP assay. CNP was strongly expressed in the epithelial clusters of primitive SMG, which was maintained before birth but was markedly decreased after birth. CNP was localized in the intercalated duct and granular convoluted tubules of adult SMG, where NPRC was specifically expressed but NPRB was not. CNP mRNA was gradually decreased from E16 to 2 M but ANP mRNA was opposed. NPRB and NPRC were the same pattern of the expression of CNP but NPRA was weakly expressed. In addition, CNP mRNA was also expressed in the craniofacial tissues such as tooth germs, tongue, premaxilla and bone forming area in which NPRC was specifically expressed but NPRB was not. In the SMG of 2 M, the membrane of duct cells markedly produced cGMP by CNP whereas acini produced cGMP by ANP and BNP rather than CNP. The biological activity of cGMP production of SMG gradually decreased with age. cGMP production was dominant by CNP in SMG of 1M but was by ANP after 2M. These results shows that CNP may play roles both in the morphogenesis and differentiation via NPRC and in the maintenance of duct system via NPRB in the mouse SMG and that the biological activity of its receptors may decreased with aging.
Subject(s)
Adult , Animals , Child, Preschool , Female , Humans , Mice , Pregnancy , Aging , Atrial Natriuretic Factor , Central Nervous System , Embryonic Development , Embryonic Structures , Endothelium , Immunohistochemistry , In Situ Hybridization , Membranes , Morphogenesis , Natriuretic Peptide, C-Type , Parturition , Receptors, Peptide , RNA, Messenger , Submandibular Gland , Tongue , Tooth GermABSTRACT
C-type natriuretic peptide(CNP),mainly expressed in central nervous system and vascular endothelial cells maintains renal homeostasis by autocrine or paracrine pathway,which regulates water-electrolyte metabolism,vascular resistance,glomerular permeability,and cell proliferation.Thus,clarifying the characteristics of CNP metabolism in kidney would appear promising to develop some new prospects for the evaluation of kidney injury and the targeted therapy.
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C-type natriuretic peptide (CNP) shows remarkable sequence homology to atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) within the 17-residue ring portion formed by a pair of cysteine residues and being the third member of the natriuretic peptide family. Sequence analysis reveals that there are at least two exons in the coding region for preproCNP. Mature forms of CNP in body are CNP22 and its N-termi-nally elongated form CNP53. As an agonist, CNP selectively bind to natriuretic peptide receptor B (NPR-B) which has a single member-spanning helical domain and exert its biological effects by activating its C-teminal guanylate cyclase to catalyse formation of cyclic guanosine monophosphate (cGMP). CNP can also bind to natriuretic peptidereceptor C (NPR-C) which has high binding affinities for all of the natriuretic peptides. The synthesis and release of CNP are regulated by many cy-tokines, and CNP is metabolized by two main pathways : internalization and degradation through the binding with NPR-C or hydrolysis by neutral endopeptidase. CNP and its receptor distribute widespreadly in various tissues including vessels, blood and central neural systems, and produce effects of vasodilation, antianxiely effect and regulations of cell proliferation and endocrine.