scholarly journals Peptide fragments of bradykinin show unexpected biological activity not mediated by B1 or B2 receptors

Author(s):  
Igor Souza-Silva ◽  
Cristiane de Paula ◽  
Lucas Bolais-Ramos ◽  
Anderson Santos ◽  
Filipe da Silva ◽  
...  

Background and purpose: Bradykinin [BK-(1-9)] is an endogenous nonapeptide involved in multiple physiological and pathological processes. A long-held belief is that peptide fragments of BK-(1-9) are biologically inactive. Here, we have tested the biological activities of BK-(1-9) and two major peptide fragments in human and animal systems. Experimental Approach: Levels of BK peptides in male Wistar rat plasma were quantified by mass spectrometric methods. Nitric oxide was quantified in human, mouse and rat cells, and loaded with DAF-FM. We used aortic rings from adult male Wistar rats to test vascular reactivity. Changes in blood pressure and heart rate were measured in conscious adult male Wistar rats. Key results: Plasma levels of BK-(1-7) and BK-(1-5) in rats were increased following infusion of BK-(1-9). All tested peptides induced NO production in all cell types tested. However, unlike BK-(1-9), NO production elicited by BK-(1-7) or BK-(1-5) was not inhibited by B or B receptor antagonists. BK-(1-7) or BK-(1-5) also induced concentration-dependent vasorelaxation of aortic rings, without involving B or B receptors. In vivo, either intravenous or intra-arterial administration of BK-(1-7) or BK-(1-5) induced similar hypotension response. Conclusions and implications: BK-(1-7) and BK-(1-5) are endogenous peptides present in plasma. They are formed, at least partially, through the BK-(1-9) proteolysis. BK-related peptide fragments show biological activity, not mediated by B or B receptors. These BK-fragments could constitute new, active components of the kallikrein-kinin system.

2019 ◽  
Vol 20 (4) ◽  
pp. 302-308 ◽  
Author(s):  
Carla R.F. Volobuff ◽  
Pedro C.O. Junior ◽  
Sidney M. dos Santos ◽  
Zefa V. Pereira ◽  
Diego C. Ferreira ◽  
...  

Background: The genus Psychotria and Palicourea are reported as a source of alkaloids and iridoids, which exhibit biological activities. This study aimed to evaluate antiproliferative and anticholinesterase activities and quantification of the alkaloids of seven species among the genus found in Mato Grosso do Sul region in Brazil. Methods: Concentrations of alkaloids were measured spectrophotometrically. The extracts were submitted to antiproliferative activity against ten cell lines. The anticholinesterase activity of the extracts was developed using brain structures of male Wistar rats: cerebral cortex, hippocampus, hypothalamus and striatum by the Ellman method. Results: Alkaloids from Psychotria and Palicourea species were quantified which showed values of 47.6 to 21.9 µg/g. Regarding the antiproliferative potential, Palicourea crocea demonstrated selectivity against the 786-0 cell line (GI50: 22.87 µg/mL). Psychotria leiocarpa inhibited cell growth against OVCAR-3 (GI50: 3.28 µg/mL), K-562 (GI50: 5.26 µg/mL), HaCaT (GI50: 27.20 µg/mL), PC-3 (GI50: 34.92 µg/mL), MCF-7 (GI50: 35.80 µg/mL) and P. capillacea showed activity against OVCAR-3 (GI50: 2.33 µg/ml) and U251 (GI50: 16.66 µg/ml). The effect of acetylcholinesterase inhibition was more effective in the hippocampus, demonstrating inhibition for Paliourea crocea, Psychotria deflexa, P. brachybotrya and P. leiocarpa of 70%, 57%, 50% and 40%, respectively, followed by P. poeppigiana and P. capillacea, inhibiting 21%, compared to the control. Conclusion: Herein, the present work showed for the first time, anticholinesterasic and antiproliferative activities of extracts of Palicourea and Psychotria seem to be mainly associated with the levels of alkaloids in the leaves of these species.


Author(s):  
Yasmin Olsson ◽  
Helga Höifödt Lidö ◽  
Klara Danielsson ◽  
Mia Ericson ◽  
Bo Söderpalm

AbstractApproved medications for alcohol use disorder (AUD) display modest effect sizes. Pharmacotherapy aimed at the mechanism(s) by which ethanol activates the dopamine reward pathway may offer improved outcomes. Basal and ethanol-induced accumbal dopamine release in the rat involve glycine receptors (GlyR) in the nucleus accumbens (nAc). Glycine transporter 1 (GlyT-1) inhibitors, which raise extracellular glycine levels, have repeatedly been shown to decrease ethanol intake in the rat. To further explore the rational for elevating glycine levels in the treatment of AUD, this study examined accumbal extracellular glycine and dopamine levels and voluntary ethanol intake and preference in the rat, after systemic treatment with glycine. The effects of three different doses of glycine i.p. on accumbal glycine and dopamine levels were examined using in vivo microdialysis in Wistar rats. In addition, the effects of the intermediate dose of glycine on voluntary ethanol intake and preference were examined in a limited access two-bottle ethanol/water model in the rat. Systemic glycine treatment increased accumbal glycine levels in a dose-related manner, whereas accumbal dopamine levels were elevated in a subpopulation of animals, defined as dopamine responders. Ethanol intake and preference decreased after systemic glycine treatment. These results give further support to the concept of elevating central glycine levels to reduce ethanol intake and indicate that targeting the glycinergic system may represent a pharmacologic treatment principle for AUD.


Biomarkers ◽  
2021 ◽  
pp. 1-15
Author(s):  
Akpotu E. Ajirioghene ◽  
Samuel I. Ghasi ◽  
Lawrence O. Ewhre ◽  
Olusegun G. Adebayo ◽  
Jerome N. Asiwe

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
A. C. Keller ◽  
L. A. Knaub ◽  
R. L. Scalzo ◽  
S. E. Hull ◽  
A. E. Johnston ◽  
...  

In the vasculature, sedentary behavior leads to endothelial abnormalities, resulting in elevated cardiovascular disease risk. Endothelial nitric oxide synthase (eNOS) aberrations characterize endothelial dysfunction; eNOS also regulates mitochondrial function. We hypothesized that sepiapterin (a precursor to eNOS cofactor tetrahydrobiopterin (BH4)) supplementation would improve endothelium-dependent vascular relaxation in sedentary animals via modulation of NOS function and mitochondrial activity. Sedentary male Wistar rats were fed ad libitum for a total of 10 weeks. Sepiapterin was administered in diet during the final 5 weeks. Intraperitoneal insulin and glucose tolerance tests (IP-ITT/IP-GTT) were conducted at baseline and endpoint. Aorta was assessed for vasoreactivity and mitochondrial respiration. Insulin tolerance, determined by IP-ITT, significantly improved in rats treated with sepiapterin (p<0.05, interaction of time and treatment). Acetylcholine- (ACh-) driven vasodilation was significantly greater in aorta from sepiapterin-treated rats as compared with control (76.4% versus 54.9% of phenylephrine contraction at 20 μM ACh, p<0.05). Sepiapterin treatment resulted in significantly elevated state 3 (9.00 oxygen pmol/sec∗mg versus 8.17 oxygen pmol/sec∗mg, p<0.05) and 4 (7.28 oxygen pmol/sec∗mg versus 5.86 oxygen pmol/sec∗mg, p<0.05) aortic mitochondrial respiration with significantly lower respiratory control ratio (p<0.05) during octanoylcarnitine-driven respiration. Vasodilation and insulin sensitivity were improved through targeting NOS via sepiapterin supplementation.


Author(s):  
Carlos Edmundo Rodrigues FONTES ◽  
Ana Paula de ABREU ◽  
Aretuza Zaupa GASPARIM

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal’s tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.


2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Adelaja Abdulazeez Akinlolu ◽  
Olaide Ghazali ◽  
Adebayo Kehinde Adefule

2015 ◽  
Vol 1 (1) ◽  
pp. 25
Author(s):  
Laila Fitrotuz Zahroh ◽  
Rahmawati Sri Praptiningsih ◽  
Moh. Baehaqi

Background: Oral mucosa ulceration which often occurs usually in the form of white-yellowish spot with concave surface, reddish edge and pain. Based on previous research, Aloe vera process anti-inflammation substance that could help quickening ulceration healing process. This research aims to know the effect of Aloe vera flesh extract on Male wistar rats oral mucosa ulceration in-vivo. Method: this research was quasi experimental research with the post-test only control group design using Male wistar rats as the testing animal. In the research, there were three treatment groups: The first groups which was given aquadest treatment, second groups with Aloe vera flesh extract, and third groups which was given chlorhexidine gluconate 0,2% treatment. The data collecting was based on histopathology observation concerning the increase of fibroblast quantity. Result: The research result based on comparison test among the three groups with One Way Anova showed that on Day 3th, the average quantity of fibroblast didn't have significant difference between the treatment group and control group positive that was p>0,05, meanwhile on Day 7th every group showed significant difference p<0,05. Conclusion: It concluded that Aloe vera flesh extract has influence on the healing of Male wistar rats oral mucosa ulceration as shown by fibroblast increasing quantity.


2014 ◽  
Vol 31 (02) ◽  
pp. 075-081
Author(s):  
A. Akinlolu ◽  
O. Akinola ◽  
P. Khobe ◽  
K. Obasi ◽  
O. Dada

Abstract Introduction: AAzathioprine and Methotrexate are both used in the treatment of cancer; and are classified as cytotoxic drugs with reported adverse effects such as oxidative damage to the DNA/RNA, the testes and sperm cells. This study, therefore, tested the hypothesis that AAzathioprine and Methotrexate administrations impair the morphology and functions of the testes in adult male wistar rats. Methods: AAzathioprine (50-150mg per day) and Methotrexate (2.5mg per week) are used in the treatment of cancer in adult Man. We tested the hypothesis that AAzathioprine and Methotrexate impair the morphology and functions of testes in rats. Forty adult male wistar rats (150-230g) were employed in the study: Control Group I received physiological saline while Experimental Groups II - V received oral administrations of 5mg/kg/bodyweight of AAzathioprine per day, 15mg/kg/bodyweight of AAzathioprine per day, 8mg/kg/bodyweight of Methotrexate per week and 20mg/kg/bodyweight of Methotrexate per week respectively for 35 days. Results: Histological examinations of the testes of rats of Groups II - V showed dose-dependent morphological anomalies such as fewer collagen ibers of connective tissues, disrupted seminiferous tubules and scanty spermatozoa when compared to rats of Group I. Statistical analyses showed dose-dependent elevated levels (P≤0.05) of superoxide dismutase and malondialdehyde in testes homogenates of rats of Groups II - V when compared to rats of Group I. This implied increased oxidative stress in rats of Groups II - V. Evaluations of Follicle Stimulating Hormone and Testosterone showed dose-dependent significantly elevated levels (P≤0.05) in rats of Groups II - V when compared to rats of Group I. Conclusions: Our findings are consistent with the stated hypothesis.


2020 ◽  
Vol 3 (1) ◽  
pp. 31-44
Author(s):  
Bermansyah ◽  
Gama Satria ◽  
Ahmad Umar

Introduction.Pulmonary contusions can cause a progressive inflammatory response. Activation of TNF-α cytokines and reactive oxygen species (ROS) can cause pulmonary cell death. Antioxidants can have the potential to neutralize ROS. The purpose of this study is to determine the effectiveness of antioxidant administration in maintaining pulmonary cell function in wistar rats that have been induced to experience pulmonary contusions through caspase-3 levels. Methods.This study was an in vivo experimental study conducted on thirty male wistar rats and divided into five groups (n = 6): control, pulmonary contusion + asthaxanthine 5 mg/kgBW, pulmonary contusion + vitamin C and E 50 mg/kgBW, pulmonary contusion + vitamin C and E 100 mg/kgBW, pulmonary contusion + vitamin C and E 200 mg/kgBW. The value of Caspase-3 is evaluated by the IHC. All data analyzes used SPSS 18. Results. Low doses of antioxidants have the potential to reduce pulmonary cell death in wistar rats induced by pulmonary contusions.Conclussion. Vitamin C and E effective to reduce polmonary cell death in pulmonary contusion.Keywords: antioxidants, vitamin C, vitamin E, pulmonary contusions animal model, apoptosis, caspase-3


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