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Han Y, Zhang Y, Zhang X, Huang Z, Kong J, Wang X, Chen L, Wang Y, Cao J, Zhou T, Shen M. PAM-1: an antimicrobial peptide with promise against ceftazidime-avibactam resistant Escherichia coli infection. Front Microbiol 2024; 15:1291876. [PMID: 38765679 PMCID: PMC11099939 DOI: 10.3389/fmicb.2024.1291876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 04/10/2024] [Indexed: 05/22/2024] Open
Abstract
Introduction Antibiotic misuse and overuse have led to the emergence of carbapenem-resistant bacteria. The global spread of resistance to the novel antibiotic combination ceftazidime-avibactam (CZA) is becoming a severe problem. Antimicrobial peptide PAM-1 offers a novel approach for treating infections caused by antibiotic-resistant bacteria. This study explores its antibacterial and anti-biofilm activities and mechanisms against CZA-resistant Escherichia. Coli (E. coli), evaluating its stability and biosafety as well. Methods The broth microdilution method, growth curve analysis, crystal violet staining, scanning electron microscopy, and propidium iodide staining/N-phenyl-1-naphthylamine uptake experiments were performed to explore the antibacterial action and potential mechanism of PAM-1 against CZA-resistant E. coli. The biosafety in diverse environments of PAM-1 was evaluated by red blood cell hemolysis, and cytotoxicity tests. Its stability was further assessed under different temperatures, serum concentrations, and ionic conditions using the broth microdilution method to determine its minimum inhibitory concentration (MIC). Galleria mellonella infection model and RT-qPCR were used to investigate the in vivo antibacterial and anti-inflammatory effects. Results and discussion In vitro antibacterial experiments demonstrated that the MICs of PAM-1 ranged from 2 to 8 μg/mL, with its effectiveness sustained for a duration of 24 h. PAM-1 exhibited significant antibiofilm activities against CZA-resistant E. coli (p < 0.05). Furthermore, Membrane permeability test revealed that PAM-1 may exert its antibacterial effect by disrupting membrane integrity by forming transmembrane pores (p < 0.05). Red blood cell hemolysis and cytotoxicity tests revealed that PAM-1 exerts no adverse effects at experimental concentrations (p < 0.05). Moreover, stability tests revealed its effectiveness in serum and at room temperature. The Galleria mellonella infection model revealed that PAM-1 can significantly improve the survival rate of Galleria mellonella (>50%)for in vivo treatment. Lastly, RT-qPCR revealed that PAM-1 downregulates the expression of inflammatory cytokines (p < 0.05). Overall, our study findings highlight the potential of PAM-1 as a therapeutic agent for CZA-resistant E. coli infections, offering new avenues for research and alternative antimicrobial therapy strategies.
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Affiliation(s)
- Yijia Han
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Yi Zhang
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Xiaodong Zhang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zeyu Huang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jingchun Kong
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Xiuxiu Wang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Lijiang Chen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yue Wang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jianming Cao
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Tieli Zhou
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Mo Shen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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Ádám D, Arany J, Tóth KF, Tóth BI, Szöllősi AG, Oláh A. Opioidergic Signaling-A Neglected, Yet Potentially Important Player in Atopic Dermatitis. Int J Mol Sci 2022; 23:4140. [PMID: 35456955 PMCID: PMC9027603 DOI: 10.3390/ijms23084140] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/04/2023] Open
Abstract
Atopic dermatitis (AD) is one of the most common skin diseases, the prevalence of which is especially high among children. Although our understanding about its pathogenesis has substantially grown in recent years, and hence, several novel therapeutic targets have been successfully exploited in the management of the disease, we still lack curative treatments for it. Thus, there is an unmet societal demand to identify further details of its pathogenesis to thereby pave the way for novel therapeutic approaches with favorable side effect profiles. It is commonly accepted that dysfunction of the complex cutaneous barrier plays a central role in the development of AD; therefore, the signaling pathways involved in the regulation of this quite complex process are likely to be involved in the pathogenesis of the disease and can provide novel, promising, yet unexplored therapeutic targets. Thus, in the current review, we aim to summarize the available potentially AD-relevant data regarding one such signaling pathway, namely cutaneous opioidergic signaling.
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Affiliation(s)
- Dorottya Ádám
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - József Arany
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Kinga Fanni Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Balázs István Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
| | - Attila Gábor Szöllősi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.Á.); (J.A.); (K.F.T.); (B.I.T.)
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Fu Y, Leng C, Fan Y, Ma X, Li X, Wang X, Guo Z, Wang X, Shang R. In Vitro and In Vivo Activity of 14- O-[(4,6-Diamino-pyrimidine-2-yl) thioacetyl] Mutilin against Methicillin-Resistant Staphylococcus aureus. Molecules 2021; 26:3277. [PMID: 34071703 PMCID: PMC8199141 DOI: 10.3390/molecules26113277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/13/2021] [Accepted: 05/20/2021] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a major human pathogen that requires new antibiotics with unique mechanism. A new pleuromutilin derivative, 14-O-[(4,6-Diamino-pyrimidine-2-yl) thioacetyl] mutilin (DPTM), has been synthesized and proved as a potent antibacterial agent using in vitro and in vivo assays. In the present study, DPTM was further in vitro evaluated against methicillin-resistant Staphylococcus aureus (MRSA) isolated from dairy farms and outperformed tiamulin fumarate, a pleuromutilin drug used for veterinary. Moreover, a murine skin wound model caused by MRSA infection was established, and the healing effect of DPTM was investigated. The results showed that DPTM could promote the healing of MRSA skin infection, reduce the bacterial burden of infected skin MRSA and decrease the secretion of IL-6 and TNF-α inflammatory cytokines in plasma. These results provided the basis for further in-depth drug targeted studies of DPTM as a novel antibacterial agent.
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Affiliation(s)
- Yunxing Fu
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Chunqing Leng
- Department of Animal Production, Jinhua Polytechnic, Jinhua 321000, China;
| | - Yuan Fan
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture and Rural Affairs, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of CAAS, Lanzhou 730050, China;
| | - Xia Ma
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Xianghui Li
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Xuefei Wang
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Zhenghuan Guo
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Xiujun Wang
- Zhengzhou Key Laboratory of Immunopharmacology of Effective Components of Chinese Veterinary Medicine, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China; (Y.F.); (X.M.); (X.L.); (X.W.); (Z.G.)
- Henan Provincial Research Center for the Inheritance and Innovation of Chinese Veterinary Medicine Classic Prescriptions, College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China
| | - Ruofeng Shang
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture and Rural Affairs, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of CAAS, Lanzhou 730050, China;
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Gein SV, Baeva TA. [Endomorphins: structure, localization, immunoregulatory activity]. ACTA ACUST UNITED AC 2020; 66:78-86. [PMID: 33351316 DOI: 10.14341/probl10364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/09/2019] [Accepted: 01/25/2020] [Indexed: 11/06/2022]
Abstract
Endomorphins – endogenous tetrapeptides with the highest affinity for the µ-opioid receptor. Currently, two tetrapeptides that differ in one amino acid residue have been isolated and characterized. The structure of endomorphins differs from the structure of members of three main families of opioid peptides: endorphins, enkephalins, and dynorphins, which contain the same N-terminal sequence. In the central nervous system, endomorphins are distributed everywhere, where they are primarily responsible for antinociception. Distribution of endomorphins in the immune system, similar to that of other opioid peptides, has allowed to suggest their active participation in the processes of immune regulation. This review summarizes modern views on the structure of endomorphins, their localization, possible intracellular mechanisms of signal transmission and their effects on the processes of activation, proliferation and differentiation of cells of innate and adaptive immunity. Endomorphins actively modulate the functions of the cells of the immune system. Peptides predominantly suppress adaptive immunity reactions. There effects on the functions of innate immunity cells (granulocytes, macrophages, monocytes, dendritic cells) depending on the conditions and can have either an inhibitory or stimulating orientation. Thus, endomorphins can be promising compounds that can effectively regulate both nociceptive signals and processes in the immune system.
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Affiliation(s)
- Sergey V Gein
- Institute of ecology and genetics of microorganisms - branch of the Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences; Perm State University
| | - Tatyana A Baeva
- Institute of ecology and genetics of microorganisms - branch of the Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences
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Frączek K, Ferraiolo M, Hermans E, Bujalska-Zadrozny M, Kasarello K, Erdei A, Kulik K, Kowalczyk A, Wojciechowski P, Sulejczak D, Sosnowski P, Granica S, Benyhe S, Kaczynska K, Nagraba L, Stolarczyk A, Cudnoch-Jedrzejewska A, Kleczkowska P. Novel opioid-neurotensin-based hybrid peptide with spinal long-lasting antinociceptive activity and a propensity to delay tolerance development. Acta Pharm Sin B 2020; 10:1440-1452. [PMID: 32963942 PMCID: PMC7488486 DOI: 10.1016/j.apsb.2020.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/01/2020] [Accepted: 04/20/2020] [Indexed: 01/04/2023] Open
Abstract
The behavioral responses exerted by spinal administration of the opioid-neurotensin hybrid peptide, PK23, were studied in adult male rats. The antinociceptive effect upon exposure to a thermal stimulus, as well as tolerance development, was assessed in an acute pain model. The PK23 chimera at a dose of 10 nmol/rat produced a potent pain-relieving effect, especially after its intrathecal administration. Compared with intrathecal morphine, this novel compound was found to possess a favourable side effect profile characterized by a reduced scratch reflex, delayed development of analgesic tolerance or an absence of motor impairments when given in the same manner, though some animals died following barrel rotation as a result of its i.c.v. administration (in particular at doses higher than 10 nmol/rat). Nonetheless, these results suggest the potential use of hybrid compounds encompassing both opioid and neurotensin structural fragments in pain management. This highlights the enormous potential of synthetic neurotensin analogues as promising future analgesics.
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Endomorphin-2- and Neurotensin- Based Chimeric Peptide Attenuates Airway Inflammation in Mouse Model of Nonallergic Asthma. Int J Mol Sci 2019; 20:ijms20235935. [PMID: 31779093 PMCID: PMC6929018 DOI: 10.3390/ijms20235935] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 11/21/2022] Open
Abstract
We examined anti-inflammatory potency of hybrid peptide-PK20, composed of neurotensin (NT) and endomorphin-2 (EM-2) pharmacophores in a murine model of non-atopic asthma induced by skin sensitization with 2,4-dinitrofluorobenzene and intratracheal challenge of cognate hapten. Mice received intraperitoneally PK20, equimolar mixture of its structural elements (MIX), dexamethasone (DEX), or NaCl. Twenty-four hours following hapten challenge, the measurements of airway responsiveness to methacholine were taken. Bronchoalveolar lavage (BALF) and lungs were collected for further analyses. Treatment with PK20, similarly to dexamethasone, reduced infiltration of inflammatory cells, concentration of mouse mast cell protease, IL-1β, IL-12p40, IL-17A, CXCL1, RANTES in lungs and IL-1α, IL-2, IL-13, and TNF-α in BALF. Simple mixture of NT and EM-2 moieties was less potent. PK20, DEX, and MIX significantly decreased malondialdehyde level and secretory phospholipase 2 activity in lungs. Intensity of NF-κB immunoreactivity was diminished only after PK20 and DEX treatments. Neither PK20 nor mixture of its pharmacophores were as effective as DEX in alleviating airway hyperresponsiveness. PK20 effectively inhibited hapten-induced inflammation and mediator and signaling pathways in a manner seen with dexamethasone. Improved anti-inflammatory potency of the hybrid over the mixture of its moieties shows its preponderance and might pose a promising tool in modulating inflammation in asthma.
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Rational Design of Hybrid Peptides: A Novel Drug Design Approach. Curr Med Sci 2019; 39:349-355. [PMID: 31209802 DOI: 10.1007/s11596-019-2042-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/15/2019] [Indexed: 12/16/2022]
Abstract
Peptides play crucial roles in various physiological and pathological processes. Consequently, the investigation of peptide-based drugs is a highlight in the research and development of new drugs. However, natural peptides are not always ideal choices for clinical application due to their limited number and sometimes cytotoxicity to normal cells. Aiming to gain stronger or specific or novel biological effects and overcome the disadvantages of natural peptides, artificial hybrid peptides have been designed by combining the sequence of two or more different peptides with varied biological functions. Compared to natural peptides, hybrid peptides have shown better therapeutic potentials against bacteria, tumors, and metabolic diseases. In this review, design strategies, structure features and recent development of hybrid peptides are summarized; future directions for the research and development of hybrid peptide drugs are also discussed.
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Han HM, Ko S, Cheong MJ, Bang JK, Seo CH, Luchian T, Park Y. Myxinidin2 and myxinidin3 suppress inflammatory responses through STAT3 and MAPKs to promote wound healing. Oncotarget 2017; 8:87582-87597. [PMID: 29152103 PMCID: PMC5675655 DOI: 10.18632/oncotarget.20908] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/27/2017] [Indexed: 02/07/2023] Open
Abstract
Skin wounds are continuously exposed to bacteria and can easily become infected. Infected wounds require antibiotic treatment, and infections caused by drug-resistant bacteria are an important public health problem. Antimicrobial peptides have broad-spectrum antibacterial activity, induce little or no drug resistance and may be suitable for treating skin infections caused by drug-resistant bacteria. We previously reported the design and function of myxinidin and myxinidin analogues. Here we showed that myxinidin2 and myxinidin3 exhibit antimicrobial and anti-biofilm activities against antibiotic-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa in high salt environments and in gelatin. Moreover, these peptides facilitated infected wound healing by decreasing inflammation through suppression of IL-6, IL-8, and TNF-α and regulation of downstream mediators such as STAT3, p38, JNK, and EGFR. In a mouse skin wound model infected with antibiotic-resistant bacteria, myxinidin2 and myxinidin3 eliminated the infection and enhanced wound healing. We therefore propose the use of these peptides for treating infected wounds and burns.
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Affiliation(s)
- Hyo Mi Han
- Department of Biomedical Science, Chosun University, Gwangju, Korea
| | - Sujin Ko
- Department of Biomedical Science, Chosun University, Gwangju, Korea
| | - Min-Ju Cheong
- Department of Life Science, Chosun University, Gwangju, Korea
| | - Jeong Kyu Bang
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Korea
| | - Chang Ho Seo
- Department of Bioinformatics, Kongju National University, Kongju, Korea
| | - Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Yoonkyung Park
- Department of Biomedical Science, Chosun University, Gwangju, Korea.,Research Center for Proteinaceous Materials, Chosun University, Gwangju, Korea
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Kaczyńska K, Wojciechowski P, Jampolska M, Lipkowski AW, Kleczkowska P. Cardiovascular and respiratory activity of PK20, opioid and neurotensin hybrid peptide in anesthetized and awake rats. Eur J Pharmacol 2017; 797:20-25. [PMID: 28089918 DOI: 10.1016/j.ejphar.2017.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 01/09/2017] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
AIM Chimeric compound - PK20 despite its therapeutic activity on nociceptive and inflammatory processes may affect respiration and blood pressure. Our objective was to evaluate influence of the hybrid composed of endomorphin-2 and neurotensin fragments on ventilation, heart rate and blood pressure in anesthetized and awake rats. METHODS The effects of PK20 (1mg/kg) were studied either after its intravenous administration in anesthetized rats or intraperitoneal injection in awake state. Tidal volume and the timing components of the breathing pattern, arterial blood pressure, and heart rate were recorded. RESULTS Intravenous administration of PK20 in the neurally intact rats evoked a dose-dependent apnoea followed by a transient insignificant increase in tidal volume and breathing rate. The blood pressure changes were biphasic: transient increase was replaced by prolonged hypotension. Midcervical vagotomy abrogated all post-PK20 respiratory effects. Hypotension was eliminated after blockade of neurotensin NTS1 receptor, while respiratory changes were reduced by blockade of both: NTS1 and μ opioid receptors. After PK20 intraperitoneal injection awake rats did not show any significant changes in ventilation and blood pressure. CONCLUSION This chimeric peptide should be used with care via intravenous administration in anesthetized animals since PK20 may evoke respiratory apnoea and hypotension. Nevertheless, applied intraperitoneally in the same dose in conscious rats induced no adverse effects.
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Affiliation(s)
- Katarzyna Kaczyńska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland.
| | - Piotr Wojciechowski
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Monika Jampolska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Andrzej W Lipkowski
- Department of Neuropeptides, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Kleczkowska
- Department of Neuropeptides, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland; Department of Pharmacodynamics, Centre for Preclinical Research and Technology, Medical University of Warsaw, Poland
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