Vasodilation in human subcutaneous arteries induced by neuropeptide Y is mediated by neuropeptide Y Y1 receptors and is nitric oxide dependent

2000 ◽  
Vol 78 (3) ◽  
pp. 251-255 ◽  
Author(s):  
T Nilsson ◽  
H Lind ◽  
J Brunkvall ◽  
L Edvinsson

Neuropeptide Y (NPY) is known as a potent vasoconstrictor of peripheral blood vessels both in vivo and in vitro. There have been reports suggesting that NPY also has a dilatory effect. The aim of the present study was to elucidate whether NPY dilates small human subcutaneous arteries. Subcutaneous arteries, obtained from patients undergoing abdominal surgery, were mounted in in vitro tissue baths, and the vascular responses to NPY were investigated. The presence of mRNA encoding the human NPY Y1 receptor in endothelial cells from human umbilical veins was studied by the use of reverse transcriptase - polymerase chain reaction (RT-PCR). In arteries precontracted with the prostaglandin analogue U46619, NPY induced a concentration-dependent vasodilation (Emax 30 ± 10% of the U46619-induced contraction), which was significantly inhibited by the NPY Y1 receptor antagonist BIBP3226 (1 µM), causing a rightward shift of the concentration-response curve, pEC50 7.1 ± 0.3 vs. 7.7 ± 0.3 for NPY alone. After pretreatment with the nitric oxide synthetase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) (10 µM), the dilation was abolished (Emax 6 ± 5% of the U46619-induced contraction). mRNA encoding the human NPY Y1 receptor was detected in endothelial cells from human umbilical veins. It was concluded that NPY induces vasodilation in human subcutaneous arteries. The dilation is mediated via the NPY Y1 receptor and is dependent on nitric oxide.Key words: vasodilation, neuropeptide Y, BIBP3226, nitric oxide, human.

1996 ◽  
Vol 270 (1) ◽  
pp. H411-H415 ◽  
Author(s):  
L. Morbidelli ◽  
C. H. Chang ◽  
J. G. Douglas ◽  
H. J. Granger ◽  
F. Ledda ◽  
...  

Vascular endothelial growth factor (VEGF) is a secreted protein that is a specific growth factor for endothelial cells. We have recently demonstrated that nitric oxide (NO) donors and vasoactive peptides promoting NO-mediated vasorelaxation induce angiogenesis in vivo as well as endothelial cell growth and motility in vitro; in contrast, inhibitors of NO synthase suppress angiogenesis. In this study we investigated the role of NO in mediating the mitogenic effect of VEGF on cultured microvascular endothelium isolated from coronary postcapillary venules. VEGF induced a dose-dependent increase in cell proliferation and DNA synthesis. The role of NO was determined by monitoring proliferation or guanosine 3',5'-cyclic monophosphate (cGMP) levels in the presence and absence of NO synthase blockers. The proliferative effect evoked by VEGF was reduced by pretreatment of the cells with NO synthase inhibitors. Exposure of the cells to VEGF induced a significant increment in cGMP levels. This effect was potentiated by superoxide dismutase addition and was abolished by NO synthase inhibitors. VEGF stimulates proliferation of postcapillary endothelial cells through the production of NO and cGMP accumulation.


2000 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Michael J. HICKEY

Constitutively produced nitric oxide released by endothelial cells has been shown to act as an endogenous agent which inhibits the rolling and adhesion of leucocytes in the microcirculation. However, during various types of inflammation, expression of the inducible form of nitric oxide synthase (iNOS) can dramatically increase the amount of nitric oxide present in tissues. Furthermore, as iNOS can be expressed by a wide variety of cell types, the distribution of nitric oxide is likely to be altered relative to that in unstimulated tissue. Under these conditions, it is less well understood whether iNOS-derived nitric oxide retains the anti-adhesive capabilities of constitutively produced nitric oxide. This review summarizes work done to examine this issue. Three main approaches have been used. In vitro studies have examined the role of iNOS in adhesive interactions between stimulated endothelial cells and leucocytes, providing evidence of an anti-adhesive effect of iNOS. In addition, the role of iNOS has been examined in vivo in animal models of inflammation using pharmacological iNOS inhibitors. These experiments were extended by the advent of the iNOS-deficient (iNOS-/-) mouse. Intravital microscopy studies of these mice have indicated that, under conditions of low-dose endotoxaemia, iNOS-derived nitric oxide can inhibit leucocyte rolling and adhesion. The potential mechanisms for these effects are discussed. In contrast, several other studies have observed either no effect or an enhancing effect of iNOS on inflammatory leucocyte recruitment. Taken together, these studies suggest that the importance of iNOS in modulating leucocyte recruitment can vary according to the type of inflammatory response.


2000 ◽  
Vol 279 (2) ◽  
pp. H657-H671 ◽  
Author(s):  
Arjun Vadapalli ◽  
Roland N. Pittman ◽  
Aleksander S. Popel

The problem of diffusion of O2 across the endothelial surface in precapillary vessels and its utilization in the vascular wall remains unresolved. To establish a relationship between precapillary release of O2 and vascular wall consumption, we estimated the intravascular flux of O2 on the basis of published in vivo measurements. To interpret the data, we utilized a diffusion model of the vascular wall and computed possible physiological ranges for O2 consumption. We found that many flux values were not consistent with the diffusion model. We estimated the mitochondrial-based maximum O2 consumption of the vascular wall (Mmt) and a possible contribution to O2 consumption of nitric oxide production by endothelial cells (MNO). Many values of O2 consumption predicted from the diffusion model exceeded Mmt + MNO. In contrast, reported values of O2consumption for endothelial and smooth muscle cell suspensions and vascular strips in vitro do not exceed Mmt. We conjecture that most of the reported values of intravascular O2 flux are overestimated, and the likely source is in the experimental estimates of convective O2 transport at upstream and downstream points of unbranched vascular segments.


1997 ◽  
Vol 248 (4) ◽  
pp. 490-497 ◽  
Author(s):  
Carla Marchetti ◽  
Andrea Casasco ◽  
Amalia Di Nucci ◽  
Marcella Reguzzoni ◽  
Simone Rosso ◽  
...  

2014 ◽  
Vol 46 (16) ◽  
pp. 583-592 ◽  
Author(s):  
Lisa K. Akison ◽  
Michael J. Boden ◽  
David J. Kennaway ◽  
Darryl L. Russell ◽  
Rebecca L. Robker

Oviducts play a critical role in gamete and embryo transport, as well as supporting early embryo development. Progesterone receptor (PGR) is a transcription factor highly expressed in oviductal cells, while its activating ligand, progesterone, surges to peak levels as ovulation approaches. Progesterone is known to regulate oviduct cilia beating and muscular contractions in vitro, but how PGR may mediate this in vivo is poorly understood. We used PGR null mice to identify genes potentially regulated by PGR in the oviducts during the periovulatory period. Histologically, oviducts from PGR null mice showed no gross structural or morphological defects compared with normal littermates. However, microarray analysis of oviducts at 8 h posthuman chorionic gonadotropin revealed >1,000 PGR-dependent genes. Using reverse-transcription polymerase chain reaction (RT-PCR) we selected 10 genes for validation based on their potential roles in oocyte/embryo transport and support. Eight genes were confirmed to be downregulated ( Adamts1, Itga8, Edn3, Prlr, Ptgfr, Des, Myocd, and Actg2) and one upregulated ( Agtr2) in PGR null oviducts. Expression of these genes was also assessed in oviducts of naturally cycling mice during ovulation and day 1 and day 4 of pregnancy. Adamts1, Itga8, Edn3, Prlr, and Ptgfr were significantly upregulated in oviducts at ovulation/mating. However, most genes showed basal levels of expression at other times. The exceptions were Prlr and Ptgfr, which showed pulsatile increases on day 1 and/or day 4 of pregnancy. This is the first, comprehensive study to elucidate putative PGR-regulated genes in the oviduct and reveals key downstream targets potentially mediating oocyte and embryo transport.


2012 ◽  
Author(s):  
Ευάγγελος-Παναγιώτης Δασκαλόπουλος

Τα ηπατικά κυτοχρώματα CYPs (P450s) είναι μια μεγάλη υπερ-οικογένεια πρωτεϊνών, οι οποίες εντοπίζονται σε όλους τους ζωντανούς οργανισμούς. Η σημασία τους είναι τεράστια, αφού μεταβολίζουν μια τεράστια ποικιλία ενδογενών ουσιών αλλά και ξενοβιοτικών. Οι πιο σημαντικές υποοικογένειες κυτοχρωμάτων CYP είναι η CYP3A, η CYP2C και η CYP2D, εξαιτίας του ρόλου τους στο μεταβολισμό της πλειονότητας των πιο συχνά συνταγογραφούμενων φαρμάκων. Η γνώση όσον αφορά τους παράγοντες, που μπορούν να προκαλέσουν επαγωγή ή αναστολή των κυτοχρωμάτων CYP είναι εξαιρετικής σημασίας, αφού κάθε μεταβολή στην έκφραση και την δραστικότητά τους μπορεί να έχει σοβαρότατες συνέπειες στην αποτελεσματικότητα της φαρμακευτικής αγωγής αλλά και στην φαρμακοτοξικότητα. Η αναστολή των ηπατικών CYPs μπορεί να οδηγήσει σε αυξημένα επίπεδα ενός φαρμάκου-υποστρώματος στο πλάσμα και στην ανάπτυξη τοξικών εκδηλώσεων. Αντίθετα, η επαγωγή των CYPs μπορεί να οδηγήσει σε μειωμένη αποτελεσματικότητα ή ακόμη και πλήρη αποτυχία της φαρμακοθεραπείας. Σκοπός της παρούσας μελέτης ήταν η διερεύνηση στον επίμυ της επίδρασης του στρες στη ρύθμιση της έκφρασης των πιο σημαντικών για τον μεταβολισμό φαρμάκων κυτοχρωμάτων, των CYP3A, CYP2C και CYP2D. Επίσης, διερευνήθηκε ο ρόλος των αδρενεργικών υποδοχέων, των γλυκοκορτικοειδών καθώς και των μονοπατιών μεταγωγής σήματος (cAMP/PKA, JNK, GH/STAT5b) στη ρύθμιση των ανωτέρω κυτοχρωμάτων. Μελετήθηκε επίσης, ο ρόλος των D2-ντοπαμινεργικών υποδοχέων στη ρύθμιση της έκφρασης των CYP γονιδίων καθώς και η συμμετοχή του μονοπατιού μεταγωγής σήματος PI3K/Akt/FoxO1, αλλά και του μεταγραφικού παράγοντα STAT5b. Για την ερευνητική προσέγγιση αυτών των θεμάτων, έγιναν τόσο in vivo πειράματα με ενήλικες αρσενικούς επίμυες, όσο και in vitro πειράματα με καλλιέργειες πρωτογενών ηπατοκυττάρων, που απομονώθηκαν από το ήπαρ επιμύων. Οι μέθοδοι, οι οποίες χρησιμοποιήθηκαν συμπεριλαμβάνουν την Υγρή Χρωματογραφία Υψηλής Απόδοσης (HPLC) για την μέτρηση την ενζυμικής δραστικότητας των υπό μελέτην CYP3A, CYP2C και CYP2D, την ανοσοαποτύπωση κατά Western για την εκτίμηση των μεταβολών σε επίπεδο αποπρωτεΐνης, καθώς και την μέθοδο real-time polymerase chain reaction (RT-PCR, q-PCR) για την ποσοτική εκτίμηση των επιπέδων mRNA των ανωτέρω CYP γονιδίων. Τα αποτελέσματα αυτής της μελέτης κατέδειξαν ότι το ψυχολογικό στρες είναι ένας παράγοντας τεράστιας σημασίας για τη ρύθμιση της έκφρασης των CYPs. Πιο συγκεκριμένα, το στρες της μητρικής αποστέρησης, στο οποίο εκτέθηκαν οι επίμυες σε πολύ μικρή ηλικία προκάλεσε την αύξηση της έκφρασης των CYP3A1/2 και CYP2C11, ενώ το CYP2D δεν επηρεάστηκε σημαντικά. Αντιθέτως, το στρες περιορισμού προκάλεσε σημαντικές μεταβολές στην έκφραση του CYP3A2, του CYP2D και μικρότερες μεταβολές στο CYP2A. Επιπροσθέτως, επιβεβαιώθηκε η επαγωγική δράση των γλυκοκορτικοειδών στο CYP3A και η κατασταλτική τους δράση στο CYP2C. Σημαντικά ευρήματα μετά από in vivo και in vitro πειράματα, τα οποία επικεντρώθηκαν στη μελέτη των αδρενεργικών μονοπατιών φανέρωσαν ότι τα μονοπάτια cAMP/PKA, JNK και του άξονα GH/STAT5b διαδραματίζουν σημαντικό ρόλο στον έλεγχο της ρύθμισης της έκφρασης των CYPs. Η συμμετοχή των πυρηνικών υποδοχέων PXR, RXR και HNF4α φαίνεται να είναι σημαντική στις μεταβολές που παρατηρήθηκαν στην έκφραση αυτών των CYPs. Eπιπλέον, η αναστολή των D2-ντοπαμινεργικών υποδοχέων in vivo, οδήγησε σε μεγάλη καταστολή των CYP3A, CYP2C και CYP2D. Αντιθέτως, αναστολή των ηπατικών D2-υποδοχέων in vitro, οδήγησε σε επαγωγή αυτών των CYPs. Αυτό το εύρημα οδήγησε στην υπόθεση ότι η ινσουλίνη πιθανόν διαδραματίζει στρατηγικής σημασίας ρόλο στον έλεγχο της ρύθμισης της έκφρασης των CYPs, αφού αποδείχθηκε ότι η αναστολή in vivο των D2-υποδοχέων ενεργοποιεί το ινσουλινοεξαρτώμενο μονοπάτι PI3K/Akt, ενώ περαιτέρω έρευνες έδειξαν τον FoxO1 ως τελικό μεταγραφικό παράγοντα ρύθμισης. Παράλληλα, ο άξονας GH/STAT5b φαίνεται να παίζει επίσης πολύ σημαντικό ρυθμιστικό ρόλο και στην περίπτωση των D2-ντοπαμινεργικών μονοπατιών. Συμπερασματικά, η μελέτη αυτή έδειξε ότι το στρες, τα γλυκοκορτικοειδή και αγωνιστές αδρενεργικών υποδοχέων αποτελούν παράγοντες, που πρέπει πάντα να λαμβάνονται υπόψιν πριν τη συνταγογράφηση σε ασθενείς. Επιπλέον, η μελέτη αυτή κατέδειξε για πρώτη φορά την επίδραση των παγκρεατικών D2-ντοπαμινεργικών υποδοχέων και του μονοπατιού PI3K/Akt/FoxO1 στη ρύθμιση της έκφρασης των CYP3A, CYP2C και CYP2D. Διαπιστώθηκε επίσης, η συμμετοχή της GH, της PRL και των θυρεοειδικών ορμονών στις μεταβολές που προκάλεσαν οι φαρμακολογικοί χειρισμοί των D2-ντοπαμινεργικών υποδοχέων.


2010 ◽  
Vol 82 (3) ◽  
pp. 927-932 ◽  
Author(s):  
Haige Wu ◽  
Ziang Yao ◽  
Xuefang Bai ◽  
Yuguang Du ◽  
Xiaojun Ma

Author(s):  
Ching Giap Tan ◽  
Aini Ideris ◽  
Abdul R. Omar ◽  
Chen Pei Yii ◽  
Stanley H. Kleven

The present study was based on the reverse transcription polymerase chain reaction (RT-PCR) of the 16S ribosomal nucleic acid (rRNA) of Mycoplasma for detection of viable Mycoplasma gallisepticum. To determine the stability of M. gallisepticum 16S rRNA in vitro, three inactivation methods were used and the suspensions were stored at different temperatures. The 16S rRNA of M. gallisepticum was detected up to approximately 20–25 h at 37 °C, 22–25 h at 16 °C, and 23–27 h at 4 °C. The test, therefore, could detect viable or recently dead M. gallisepticum (< 20 h). The RT-PCR method was applied during an in vivo study of drug efficacy under experimental conditions, where commercial broiler-breeder eggs were inoculated with M. gallisepticum into the yolk. Hatched chicks that had been inoculated in ovo were treated with Macrolide 1. The method was then applied in a flock of day 0 chicks with naturally acquired vertical transmission of M. gallisepticum, treated with Macrolide 2. Swabs of the respiratory tract were obtained for PCR and RT-PCR evaluations to determine the viability of M. gallisepticum. This study proved that the combination of both PCR and RT-PCR enables detection and differentiation of viable from non-viable M. gallisepticum.


2002 ◽  
Vol 283 (6) ◽  
pp. H2371-H2378 ◽  
Author(s):  
Xue Zhao ◽  
Xiangru Lu ◽  
Qingping Feng

We recently demonstrated that mice deficient in endothelial nitric oxide (NO) synthase (eNOS) have congenital septal defects and postnatal heart failure. However, the mechanisms by which eNOS affects heart development are not clear. We hypothesized that deficiency in eNOS impairs myocardial angiogenesis. Myocardial capillary densities were measured morphometrically in neonatal mouse hearts. In vitro tube formation on Matrigel was investigated in cardiac endothelial cells. In vivo myocardial angiogenesis was performed by implanting Matrigel in the left ventricular myocardium. Myocardial capillary densities and VEGF mRNA expression were decreased in neonatal eNOS−/− compared with neonatal wild-type mice ( P < 0.01). Furthermore, in vitro tube formation from cardiac endothelial cells and in vivo myocardial angiogenesis were attenuated in eNOS−/− compared with wild-type mice ( P < 0.01). In vitro tube formation was inhibited by N G-nitro-l-arginine methyl ester in wild-type mice and restored by a NO donor, diethylenetriamine-NO, in eNOS−/− mice ( P < 0.05). In conclusion, deficiency in eNOS decreases VEGF expression and impairs myocardial angiogenesis and capillary development. Decreased myocardial angiogenesis may contribute to cardiac abnormalities during heart development in eNOS−/− mice.


2020 ◽  
Vol 8 (2) ◽  
pp. 36-38
Author(s):  
Zailatul Hani Mohamad Yadzir ◽  
Brenda Leecyous ◽  
Amelia Suhana Zamri

Shellfish is an important source of food and plays a significant role in human nutrition and health. However, shellfish allergy is a long-lasting disorder which mostly persists throughout life and is often associated with severe reactions [1]. Among the various consumed shellfish, prawns and crabs are the most widely consumed and can lead to the most severe reactions. At present, allergies to shellfish are diagnosed similarly to other food allergies. The diagnosis relies upon careful evaluation of history, the presence of appropriate clinical signs and confirmation with in vivo or in vitro tests to demonstrate the presence of allergen-specific immunoglobulin E (IgE) [2]. However, both in vivo or in vitro diagnostic approaches are mainly based on the use of crude allergen extracts. Crude allergen extracts are obtained from biological sources and consist of mixture of allergenic components with high amounts of undesirable products that can interfere with diagnosis. In many cases, only few of the several proteins found in crude allergen extracts act as the essential allergens in the majority of patients that are allergic to the substance. The most important ones are called major allergens. Problems associated with using crude allergen extracts for allergy diagnosis may be overcome with recombinant allergens. Recombinant allergens with high purity can be produced by using controlled production procedures that yield defined molecules with known molecular, immunologic and biological characteristics [1]. Tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus, are among the widely consumed shellfish in Malaysia. Our earlier study involving 131 atopic patients in Allergy Clinic, Kuala Lumpur Hospital demonstrated that patients in Malaysia suffering from allergic responses to shellfish including tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus. Amongst the shellfish extracts tested, prawn elicited the highest frequency of positive reactivity in 39% of the patients. Further, crab was the second most common shellfish to elicit a positive reaction in 24% of the patients [3]. Our first phase study has successfully identified tropomyosin and arginine kinase as the major allergens in both species of shellfish. However, more information about the individual allergenic species-specific components is needed. Therefore, we continued our study to isolate and clone the tropomyosin and arginine kinase from these two species of shellfish, tiger prawn Penaeus monodon and blue swimming crab Portunus trituberculatus. Tropomyosin and arginine kinase were isolated from the total RNA (Ribonucleic Acid) obtained from both prawn and crab muscles followed by RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction). The RT-PCR products were then cloned into the cloning vector, pJET 1.2 and transformed into Escherichia coli host. Transformants were screened for positive clones by PCR (Polymerase Chain Reaction) colony and sequenced. The 855 bp tropomyosins have been isolated and sequenced from both prawn and crab. Arginine kinases isolated and sequenced from prawn and crab were 1071 bp and 1074 bp, respectively (Figure 1). The GenBank BLAST search for the sequences showed high homology to the targeted proteins as shown in Table 1. Tropomyosin is a 34 to 38 kDa heat-stable protein that belongs to a highly conserved family of actin filament binding proteins, which plays a functional role in contractile activities in muscle cells [4]. Arginine kinase is a 40 to 42 kDa heat-labile protein that plays an important role in regenerating adenosine triphosphate (ATP) during bursts of cellular activity [5]. Tropomyosin and arginine kinase from the prawn and crab have been isolated and the full-length sequences were obtained. Current ongoing study focuses on sub-cloning and full-length expression of tropomyosin and arginine kinase in order to produce respective recombinant proteins, and subsequently investigate their physicochemical and allergenic characteristics.


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