1
|
Liles M, Di Girolamo N. Temperature Monitoring and Thermal Support in Exotic Animal Critical Care. Vet Clin North Am Exot Anim Pract 2023:S1094-9194(23)00019-1. [PMID: 37349184 DOI: 10.1016/j.cvex.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
Body temperature measurement is one of the most important parameters to assess the health of a patient. In small exotic mammals, rectal temperature is obtained via a similar process as in dogs or cats, with a few specific differences. In reptiles and birds, measurement of body temperature can provide important information, albeit its accuracy may be limited. In most animals, temperature should be taken at the beginning of the examination to not artificially elevate the temperature during the physical exam. Heat support is typically indicated any time a patient's temperature is below the accepted core temperature range and cooling may be indicated whenever a patient's temperature exceeds a critical point.
Collapse
Affiliation(s)
- Marina Liles
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA
| | - Nicola Di Girolamo
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
| |
Collapse
|
2
|
Klaebel JH, Lykkesfeldt J, Tveden-Nyborg P. Efficacy of Fibroblast Growth Factor 21 in non-alcoholic fatty liver disease in guinea pigs. Basic Clin Pharmacol Toxicol 2022; 130:385-393. [PMID: 35014168 DOI: 10.1111/bcpt.13705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/28/2022]
Abstract
Fibroblast Growth Factor 21 (FGF21) agonists have shown promising effects in preclinical models of non-alcoholic fatty liver disease (NAFLD) as well as in short-term clinical trials in patients with non-alcoholic steatohepatitis (NASH). Comparing drug formulation, dose, administration route and age, this exploratory study investigated effects of FGF21 on NAFLD-associated measures in a validated guinea pig model. In three separate studies, female guinea pigs received a high-fat diet prior to intervention with escalating doses of either recombinant native human FGF21 or a human FGF21 human recombinant analogue (FGF21/19 chimer) with an extended half-life. While no significant effects of native FGF21 on the investigated endpoints were observed, the long-acting FGF21/19 chimer significantly altered the levels of circulating lipids, increasing plasma concentrations of cholesterol (TC, LDLc and HDLc) in young guinea pigs (p<0.01 for all three parameters). Relative liver weights were reduced in FGF21/19-treated young animals (p<0.05) compared to mature animals, whereas FGF21/19 reduced body weights in both age groups (p<0.001). The FGF21/19 chimer effects on dyslipidemia, body and liver weights particularly in young animals, support an age-associated difference in the FGF21 response. The limited effects of the native human FGF21 highlights potential species-associated differences of this compound.
Collapse
Affiliation(s)
- Julie Hviid Klaebel
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Pernille Tveden-Nyborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| |
Collapse
|
3
|
Lane TR, Massey C, Comer JE, Freiberg AN, Zhou H, Dyall J, Holbrook MR, Anantpadma M, Davey RA, Madrid PB, Ekins S. Pyronaridine tetraphosphate efficacy against Ebola virus infection in guinea pig. Antiviral Res 2020; 181:104863. [PMID: 32682926 PMCID: PMC8194506 DOI: 10.1016/j.antiviral.2020.104863] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/22/2022]
Abstract
The recent outbreaks of the Ebola virus (EBOV) in Africa have brought global visibility to the shortage of available therapeutic options to treat patients infected with this or closely related viruses. We have recently computationally identified three molecules which have all demonstrated statistically significant efficacy in the mouse model of infection with mouse adapted Ebola virus (ma-EBOV). One of these molecules is the antimalarial pyronaridine tetraphosphate (IC50 range of 0.82-1.30 μM against three strains of EBOV and IC50 range of 1.01-2.72 μM against two strains of Marburg virus (MARV)) which is an approved drug in the European Union and used in combination with artesunate. To date, no small molecule drugs have shown statistically significant efficacy in the guinea pig model of EBOV infection. Pharmacokinetics and range-finding studies in guinea pigs directed us to a single 300 mg/kg or 600 mg/kg oral dose of pyronaridine 1hr after infection. Pyronaridine resulted in statistically significant survival of 40% at 300 mg/kg and protected from a lethal challenge with EBOV. In comparison, oral favipiravir (300 mg/kg dosed once a day) had 43.5% survival. All animals in the vehicle treatment group succumbed to disease by study day 12 (100% mortality). The in vitro metabolism and metabolite identification of pyronaridine and another of our EBOV active molecules, tilorone, suggested significant species differences which may account for the efficacy or lack thereof, respectively in guinea pig. In summary, our studies with pyronaridine demonstrates its utility for repurposing as an antiviral against EBOV and MARV.
Collapse
Affiliation(s)
- Thomas R. Lane
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Christopher Massey
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
| | - Jason E. Comer
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
| | - Alexander N. Freiberg
- Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
- Department of Pathology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, USA
| | - Huanying Zhou
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Julie Dyall
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Michael R. Holbrook
- Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD, USA
| | - Manu Anantpadma
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | - Robert A. Davey
- Texas Biomedical Research Institute, San Antonio, TX 78227, USA
| | - Peter B. Madrid
- SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| |
Collapse
|
4
|
Bernstein DI. Use of the Guinea pig model of genital herpes to evaluate vaccines and antivirals: Review. Antiviral Res 2020; 180:104821. [PMID: 32544409 PMCID: PMC10713199 DOI: 10.1016/j.antiviral.2020.104821] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/06/2020] [Accepted: 05/12/2020] [Indexed: 12/23/2022]
Abstract
Herpes simplex virus (HSV) infections type 1 (HSV-1) and type 2 (HSV-2) are common throughout the world. Infections are lifelong and may produce both acute and recurrent vesiculoulcerative disease as well as more severe diseases. Despite disappointing results from recent HSV vaccine trials new vaccines and more potent antiviral therapies continue to be developed. These newer approaches require initial evaluations in animal models. In this review I have briefly described some of the models available and then more thoroughly describe the guinea pig model of acute and recurrent genital herpes infections. As discussed, the guinea pig model most closely mimics human disease and provides several important endpoints for evaluating vaccines and antivirals.
Collapse
Affiliation(s)
- David I Bernstein
- University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| |
Collapse
|
5
|
Hajihoseini M, Mehrabani D, Vahdati A, Hosseini SE, Tamadon A, Dianatpour M, Rahmanifar F. Spermatogenesis after Transplantation of Adipose Tissue-Derived Stem Cells in Azoospermic Guinea Pigs: A Histological and Histomorphometric Study. Galen Med J 2018; 7:e1000. [PMID: 34466423 PMCID: PMC8343795 DOI: 10.22086/gmj.v0i0.1000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 09/20/2017] [Accepted: 11/17/2017] [Indexed: 11/30/2022] Open
Abstract
Background: The purpose of this research was to determine histomorphometric changes in busulfan-induced azoospermia after transplantation of Adipose Tissue-Derived Stem Cells (AdSCs) in guinea pig. AdSCs were isolated from adipose tissue around the testes of guinea pigs and characterized for mesenchymal properties. Materials and Methods: Guinea pigs were allocated into three groups, including the control group without any intervention. To induce azoospermia, groups 2 and 3 received a dose of 40 mg/kg of busulfan with 21 days interval. Group 3 received 1×106 AdSCs in their seminiferous tubules of left testes, 35 days following last busulfan injection, while right testis in the group was considered for comparison as controls. Sixty days following transplantation of cell, histomorphometric and histopathologic changes of the experiments were assessed. Results: After AdSCs’ transplantation, normal spermatogenesis appearance was noticed compared to busulfan-induced azoospermia and AdSCs recovered spermatogenesis, and our findings can be added to the literature in treating azoospermic infertilities. Conclusion: The transplanted AdSCs could induce production of germinal cells using testicular seminiferous tubules and were an effective source in treating azoospermia
Collapse
Affiliation(s)
- Mehrdokht Hajihoseini
- Department of Biology, Fars Science and Research Branch, Islamic Azad University, Fars, Iran.,Department of Biology, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Davood Mehrabani
- Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Akbar Vahdati
- Department of Biology, Fars Science and Research Branch, Islamic Azad University, Fars, Iran.,Department of Biology, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Seyed Ebrahim Hosseini
- Department of Biology, Fars Science and Research Branch, Islamic Azad University, Fars, Iran.,Department of Biology, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Amin Tamadon
- The Persian Gulf Marine Biotechnology Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Mehdi Dianatpour
- Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Medical Genetics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farhad Rahmanifar
- Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| |
Collapse
|
6
|
Abstract
Glyco-engineered recombinant antibodies are currently being developed as the next generation therapeutics to treat human diseases, including cancer, autoimmunity and infection. Antibodies lacking core fucosylation show great increase in affinity for FcγRIIIA, leading to an improved receptor-mediated effector function. While afucosyl human IgG1 exhibits 50-100-fold increase in antibody-mediated cellular cytotoxicity (ADCC), a key immune effector mechanism underlying the anti-cancer effect of some approved therapeutic antibodies, it is not clear whether such glyco-engineered antibodies would find similar use for infectious disease. Due to the species difference, human antibodies may have different binding properties towards corresponding IgG receptors from animals used for modeling infection and intoxication. During the course of studying a recombinant human IgG1 in neutralizing diphtheria toxin (DT) in Guinea pigs (Cavia porcellus), we identified a previously uncharacterized Guinea pig protein H0VDZ8 from UNIPROT database that shows high sequence homologies to human FcγRIIIA and mouse FcγRIV. This Fcγ receptor, which we named as gpFcγRIV, also demonstrates functional similarity although not to the same extent as the human and mouse counterparts, in that it binds to afucosyl human and mouse IgG much stronger than to the wild type antibodies. Thus, Guinea pigs can be used to compare the efficacies of wild type vs. afucosyl anti-DT human IgG1 in toxin removal and animal protection. Molecular and functional characterization of human FcγRIIIA and mouse FcγRIV equivalents in other species could expand the list of preclinical animal models for testing afucosyl human antibodies in treating various human diseases.
Collapse
Affiliation(s)
| | - Richard Near
- Antagen Pharmaceuticals, Inc. Boston, MA 02118, USA
| | - Wenda Gao
- Antagen Pharmaceuticals, Inc. Boston, MA 02118, USA
| |
Collapse
|
7
|
Abstract
The effects of equine chorionic gonadotropin (eCG) on follicular development and ovulation in cyclic guinea pigs were investigated by histological and immunohistochemical analyses. Three groups of guinea pigs (n=12) were administrated subcutaneously with saline, 20 or 50 IU of eCG, respectively, on cyclic Day 12 (Day 1=vaginal openings). Ovaries were collected at 4 and 8 d after administration (6 animals per group each time). The eCG administration induced significant and distinct morphological changes in the ovaries, as it promoted the luteinization of granulosa cells, but not follicular development. In addition, proliferating cell nuclear antigen (PCNA) and steroidogenic acute regulatory protein (StAR) were immunolocalized specifically in luteinized follicles. Our experiments together indicate that eCG administration can induce follicular luteinization but not superovulation in guinea pigs. The eCG in cyclic guinea pigs functions similar to that of luteinizing hormone (LH), but not follicle-stimulating hormone (FSH).
Collapse
Affiliation(s)
- Jun-rong Li
- Laboratory of Animal Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.,College of Agriculture and Bio-engineering, Jinhua Polytechnic, Jinhua 321017, China
| | - Wei Wang
- Laboratory of Animal Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Fang-xiong Shi
- Laboratory of Animal Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
8
|
Keyhanmanesh R, Bagban H, Nazemiyeh H, Mirzaei Bavil F, Alipour MR, Ahmady M. The Relaxant Effects of Different Methanolic Fractions of Nigella sativa on Guinea Pig Tracheal Chains. Iran J Basic Med Sci 2013; 16:123-8. [PMID: 24298378 PMCID: PMC3843853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 07/15/2012] [Indexed: 10/26/2022]
Abstract
OBJECTIVE(S) In regard to the high incidence of asthma and the side-effects of the drugs used, finding novel treatments for this disease is necessary. Our previous studies demonstrated the preventive effect of Nigella sativa extract on ovalbumin-induced asthma. In addition, water-soluble substances of N. sativa extract and methanol fraction of this plant were responsible for the relaxant effect of this plant on tracheal chains of guinea pigs. Therefore, for the first time, in the present study, in order to identify main constituents of the methanolic extract, the relaxant effects of five different methanolic fractions (20%, 40%, 60%, 80%, and 100%) of N. sativa on tracheal chains of guinea pigs were examined. MATERIALS AND METHODS The relaxant effects of four cumulative concentrations of each fraction (0.8, 1.2, 1.6, and 2.0 g%) in comparison with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6, and 0.8 mM) were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 µM methacholine (group 2). RESULTS In group 1, all concentrations of only theophylline showed significant relaxant effects but all concentrations of these methanolic fractions showed significant contractile effects compared with that of saline (P<0.001 to P<0.05). However, in group 2, all concentrations of theophylline and these methanolic fractions showed significant relaxant effects compared with that of saline (P<0.001 to P<0.05). CONCLUSION These results showed a potent relaxant effect of 20% methanolic fractions from N. sativa on tracheal chains of guinea pigs that were higher than that of theophylline at the used concentrations.
Collapse
Affiliation(s)
- Rana Keyhanmanesh
- Tuberculosis and Lung Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Horeyeh Bagban
- Department of Physiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Nazemiyeh
- Research Centre for Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fariba Mirzaei Bavil
- Department of Physiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Alipour
- Tuberculosis and Lung Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdy Ahmady
- Department of Physiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
9
|
Dolati K, Rakhshandeh H, Shafei MN. Effect of aqueous fraction of Rosa damascena on ileum contractile response of guinea pigs. Avicenna J Phytomed 2013; 3:248-53. [PMID: 25050281 PMCID: PMC4075714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 01/27/2013] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The use of drugs with herbal origin is increasing for treatment of gastrointestinal (GI) disorders. Rosa damascena (R. damascena) is a well-known plant suggested to have beneficial effect on GI system. In this study, the effect of aqueous fraction of R. damascena on the contractions of isolated guinea pig ileum was investigated. MATERIALS AND METHODS Aqueous fraction of plant was obtained from ethanolic extract after ethyl acetate and n-butanol fractions were discarded. To evaluate effect of this fraction on ileum contraction, guinea pig ileum was removed and mounted on organ bath and its contraction was recorded. Effect of various concentrations (0.66, 0.83, and 1.3 mg/ml) of aqueous fraction on ileum contraction in comparison with Ach in presence and absence of atropine, a muscarinic antagonist of cholinergic, was evaluated. The response of ileum to 1 µg/ml of acetylcholine was considered as 100% response. RESULTS Our results showed that aqueous fractions of R. damascena dose-dependently increased basal guinea pigs ileum contractions (p<0.05 to p<0.001). Maximal contraction of fraction (1.3 mg/ml) induced 23.4 % of maximal Ach response. The contraction of ileum to aqueous fraction was significant decreased in presence 0.001 µg/ml of atropine. CONCLUSION It is concluded that aqueous fraction of R. damascena has mild excitatory effect on ileum contraction and this fraction may be beneficial as a mild laxative agent.
Collapse
Affiliation(s)
- Karim Dolati
- Pharmacological Research Center of Medicinal Plants and Department of Pharmacology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I. R. Iran
| | - Hassan Rakhshandeh
- Pharmacological Research Center of Medicinal Plants and Department of Pharmacology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I. R. Iran
| | - Mohammad Naser Shafei
- Cognitive sciences Research Center and Department ofPhysiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I. R. Iran,Corresponding Author: Tel: +985118002230; Fax: +985118828564, E-mail:
| |
Collapse
|
10
|
Dorsch W, Hess V. Noninvasive Analysis of Lung Function in Small Animals: Compressed Air, Thoracic Gas Volume, Airway Resistance, Maximal Flow Rates, Tidal Volume, Breathing Frequency, l/E Ratio. Int Arch Allergy Immunol 2009; 99:496-498. [PMID: 34167273 DOI: 10.1159/000236323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We present a noninvasive and highly sensitive system for measuring lung function in small animals. It is based on a two-chambered body plethysmography. Head and body chambers are separated by a cuff around the head of the animal. Aerosols for pharmacologic investigations are generated. Breathing-dependent changes in pressure and/or volume are registered, the signals are digitized. All data are processed in an IBM compatible PC/AT. A multitasking real time operation system shows the signals on line. A special software offers seven different lung function parameters (compressed air, airway resistance, thoracic gas volume, maximal flow rates, tidal volume, breathing frequency, I/E ratio). The results are presented as graph and text documents. Result files are submitted to calculation by standard soft ware. The computer-aided handling allows the simultaneous performance of up to nine pharmacological tests.
Collapse
|
11
|
Kim YC, Suzuki H, Xu WX, Choi W, Kim SH, Lee SJ. Ca2+-activated K+ current in freshly isolated c-Kit positive cells in guinea-pig stomach. J Korean Med Sci 2009; 24:384-91. [PMID: 19543421 PMCID: PMC2698181 DOI: 10.3346/jkms.2009.24.3.384] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 01/29/2008] [Indexed: 11/22/2022] Open
Abstract
This study was designed to isolate Ca2+-activated K+ current (I(KCa)) and elucidate its physiological significance in freshly isolated interstitial cells of Cajal (ICCs) of guinea-pig stomach. Single ICC was freshly isolated by enzymatically dissociating from myenteric border of gastric antrum free of circular muscles, and conventional whole-cell voltage clamp technique including immunohistochemical techniques were employed to characterize the cells: In myenteric border of gastric antrum, ICC-MY (ICCs from myenteric border) were detected by immunohistochemical reactivity, and single ICC-MY which has many branches was immunohistochemically c-Kit positive. Under K+-rich and 0.1 mM ethylene glycol-bis (2-aminoethyl ether)-N,N,N',N'-tetraacetic acid pipette solution, ICC produced spontaneous inward current (-256 +/- 92.2 pA). When step-depolarizing pulse from -80 to +80 mV was applied at holding potential (V(h)) of -80 mV, voltage-dependent outward currents were recorded with superimposed spontaneous transient outward currents (STOCs). Both STOCs and outward currents were reversibly affected by tetraethylammonium chloride (TEA) and iberiotoxin (IbTX); 2 mM TEA and 200 nM IbTX completely abolished STOCs and significantly inhibited outward K+ current over the whole potential range tested for current/voltage (I/V) relationship. In addition, TEA delayed repolarization phase of spontaneous inward current. The present results indicate the presence of I(KCa) in a single ICC, and it might be involved in regulation of repolarizing phase of spontaneous inward current in guinea-pig stomach.
Collapse
Affiliation(s)
- Young Chul Kim
- Department of Physiology, Chungbuk National University, College of Medicine, Cheongju, Korea.
| | | | | | | | | | | |
Collapse
|