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1.
Molecules ; 27(10)2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35630814

RESUMO

(1) Background: A novel bioreactor platform of neuronal cell cultures using low-magnitude, low-frequency (LMLF) vibrational stimulation was designed to discover vibration influence and mimic the dynamic environment of the in vivo state. To better understand the impact of 40 Hz and 100 Hz vibration on cell differentiation, we join biotechnology and advanced medical technology to design the nano-vibration system. The influence of vibration on the development of nervous tissue on the selected cell line SH-SY5Y (experimental research model in Alzheimer's and Parkinson's) was investigated. (2) Methods: The vibration stimulation of cell differentiation and elongation of their neuritis were monitored. We measured how vibrations affect the morphology and differentiation of nerve cells in vitro. (3) Results: The highest average length of neurites was observed in response to the 40 Hz vibration on the collagen surface in the differentiating medium, but cells response did not increase with vibration frequency. Also, vibrations at a frequency of 40 Hz or 100 Hz did not affect the average density of neurites. 100 Hz vibration increased the neurites density significantly with time for cultures on collagen and non-collagen surfaces. The exposure of neuronal cells to 40 Hz and 100 Hz vibration enhanced cell differentiation. The 40 Hz vibration has the best impact on neuronal-like cell growth and differentiation. (4) Conclusions: The data demonstrated that exposure to neuronal cells to 40 Hz and 100 Hz vibration enhanced cell differentiation and proliferation. This positive impact of vibration can be used in tissue engineering and regenerative medicine. It is planned to optimize the processes and study its molecular mechanisms concerning carrying out the research.


Assuntos
Neurônios , Vibração , Ciclo Celular , Diferenciação Celular , Proliferação de Células
2.
Oxid Med Cell Longev ; 2021: 5596090, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34373766

RESUMO

Highly active antiretroviral therapy (HAART) is used in HIV-infected patients. Alongside the prolongation of patients' life, adverse side effects associated with long-term therapy are becoming an increasing problem. Therefore, optimizing of HAART is extremely important. The study is aimed at evaluating the toxicity of abacavir and etravirine in monotherapy on the reproductive system, liver, kidneys, and bones in young, sexually mature, male rats. Thirty-six 8-week-old male Wistar rats randomized into three 12-animal groups received either normal saline (control), abacavir 60 mg/kg (AB group), or etravirine 40 mg/kg (ET group) once daily for 16 weeks. Semen morphology, oxide-redox state parameters (MDA, SOD, catalase, GPx, glutathione, GSH/GSSG ratio) in tissue homogenates (testes, liver, kidneys), and serum samples were studied. In bones, microcomputed tomography and a four-point bending test were performed. Total sperm count, sperm concentration, motility, and sperm morphology did not differ significantly in AB or ET groups compared to the control. In the flow cytometry of semen, an increased percentage of cells with denatured DNA was noticed for both tested drugs. However, no significant changes of oxide-redox state in testicular homogenates were found, except of increased SOD activity in the AB-receiving group. Additionally, ET significantly altered catalase and GPx in the liver and SOD activity in kidneys. Abacavir decreased catalase in the liver and GSH levels in kidneys. AB caused significant changes to bone microarchitecture (bone volume fraction, trabecular number, connectivity density, total porosity) and increased Young's modulus. Etravirine had a greater impact on macrometric parameters of bones (tibial index, mid-tibial diameter, femur length). After 4 weeks in the ET group, a lower 1,25-dihydroxyvitamin D3 serum concentration was found. The results showed that abacavir and etravirine disturb oxidative stress. An increase in the percentage of sperms with chromatin damage suggests decreased fertility in rats receiving the studied drugs. Both drugs affected bone formation in growing rats. Additionally, etravirine disturbed vitamin D metabolism.


Assuntos
Fármacos Anti-HIV/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Didesoxinucleosídeos/efeitos adversos , Nitrilas/efeitos adversos , Estresse Oxidativo , Pirimidinas/efeitos adversos , Sêmen/efeitos dos fármacos , Animais , Fármacos Anti-HIV/administração & dosagem , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Catalase/metabolismo , Didesoxinucleosídeos/administração & dosagem , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Rim/efeitos dos fármacos , Rim/crescimento & desenvolvimento , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Nitrilas/administração & dosagem , Pirimidinas/administração & dosagem , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Testículo/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testículo/metabolismo
3.
In Vivo ; 24(2): 165-72, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20363989

RESUMO

Different types of cells require activation, and take part in annual, dynamic growth of deer antlers. Stem cells play the most important role in this process. This report shows the results of a two-year long observation of xenogenic implant of antlerogenic stem cells (cell line MIC-1). The cells were derived from growing antler of a deer (Cervus elaphus), seeded onto Spongostan and placed in postoperative lesions of mandibular bones of 15 experimental rabbits. The healing process observed in the implantation sites in all rabbits was normal, and no local inflammatory response was ever observed. Histological and immunohistochemical evaluations were performed after 1, 2, 6, 12 and 24 months, and confirmed the participation of xenogenic cells in the regeneration processes, as well as a lack of rejection of the implants. The deficiencies in the bones were replaced by newly formed, thick fibrous bone tissue that underwent mineralization and was later remodelled into lamellar bone. The results of the experiment with rabbits allow us to believe that antlerogenic cells could be used in reconstruction of bone tissues in other species as well.


Assuntos
Chifres de Veado/citologia , Remodelação Óssea/fisiologia , Mandíbula/patologia , Doenças Mandibulares/terapia , Transplante de Células-Tronco/métodos , Transplante Heterólogo/métodos , Animais , Cervos , Feminino , Espuma de Fibrina/farmacologia , Seguimentos , Consolidação da Fratura , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Imuno-Histoquímica , Mandíbula/diagnóstico por imagem , Doenças Mandibulares/diagnóstico por imagem , Doenças Mandibulares/patologia , Microscopia Eletrônica , Coelhos , Radiografia , Regeneração/fisiologia , Ultrassonografia
4.
Adv Clin Exp Med ; 29(9): 1101-1109, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32996724

RESUMO

BACKGROUND: Female inflorescences of hops (Humulus lupulus L.) are wildly used in the brewing industry. Hops have been also used for ages in folk medicine. Xanthohumol (XN) is a most abundant prenylated flavonoid present in hops. OBJECTIVES: To determine pharmacokinetic parameters and bioavailability of pure XN and XN given in prenylflavonoid extract obtained from spent hops (HOP). MATERIAL AND METHODS: Fifty-six Wistar rats (28 females and 28 males) were administered with XN or HOP. Xanthohumol was administered either intravenously (iv.) (10 mg/kg) or orally (per os (p.o.)) (40, 100 and 200 mg/kg). Extract obtained from spent hops was administered p.o. and its doses were based on XN content (doses were equivalent to XN dose of 40, 100 and 200 mg/kg, respectively). After administration of XN or HOP serum, XN concentration was measured at different time points (0, 0.25, 0.5, 1, 2, 4, 6, 12, 24, 48, 72, and 96 h). Non-compartmental analysis was used to assess the pharmacokinetics (PK) of XN in rats. RESULTS: The XN PK in rats after intravenous administration is characterized by extensive distribution followed by delayed elimination from the body. Enterohepatic recirculation is likely to play a role in XN PK. Some fraction of the orally administered XN reaches central compartment rapidly; however, the overall absorption is very limited and probably saturable. The formulation-dependent factors also play an important role in the bioavailability of the drug. Although the CMAX concentration was higher in female rats receiving XN orally comparing to males, the other pharmacokinetic parameters were unaffected by the rats' sex. CONCLUSIONS: The same doses of XN may be administered to male and female subjects, as its pharmacokinetics is not affected by sex.


Assuntos
Extratos Vegetais , Administração Intravenosa , Animais , Feminino , Flavonoides , Masculino , Propiofenonas , Ratos , Ratos Wistar
5.
Adv Clin Exp Med ; 28(6): 771-776, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30843675

RESUMO

BACKGROUND: Fenspiride is an antagonist of H1-histamine receptors that is used to treat acute and chronic respiratory tract infections and otitis media in children and adolescents. OBJECTIVES: The aim of the study was to assess the influence of long-term administration of fenspiride on bone mineral density (BMD) and bone turnover in young growing rats. MATERIAL AND METHODS: The experiment was carried out on 18 young (8-week-old) male Wistar rats receiving either fenspiride 15 mg/kg intragastrically (ig) (group F) or saline solution 4 mL/kg ig (group C) for 3 months. On days 1 and 93, blood samples were collected and serum levels of calcium, phosphorus and markers of bone turnover were measured. On days 2 and 92, BMD was measured with dual-energy x-ray absorptiometry (DXA) using small animal software. RESULTS: We detected no influence of fenspiride on weight gain, total body BMD (0.212 ±0.010 g/cm2 vs 0.204 ±0.024 g/cm2), hind limb BMD (0.264 ±0.016 g/cm2 vs 0.252 ±0.027 g/cm2), or bone macroscopic parameters. There were no significant differences between group F and group C in serum levels of osteocalcin (group F: 0.42 ±0.09 ng/mL vs group C: 0.43 ±0.08 ng/mL), C-terminal telopeptide of type I collagen (F: 0.31 ±0.08 ng/mL vs C: 0.29 ±0.08 ng/mL), osteoprotegerin (F: 5.47 ±0.78 pg/mL vs C: 5.35 ±1.65 pg/mL), receptor activator of nuclear factor kappa B ligand (F: 0.65 ±0.85 pg/mL vs C: 0.56 ±0.86 pg/mL), parathormone (F: 237 ±182 pg/mL vs C: 289 ±200 pg/mL), total calcium (F: 6.38 ±1.50 mg/dL vs C: 6.83 ±1.71 mg/dL), or inorganic phosphorus (F: 5.19 ±1.76 mg/dL vs C: 5.50 ±1.32 mg/dL). CONCLUSIONS: Long-term administration of fenspiride has no negative impact on BMD and bone metabolism in young growing rats.


Assuntos
Densidade Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Broncodilatadores/farmacologia , Compostos de Espiro/farmacologia , Absorciometria de Fóton , Animais , Biomarcadores , Broncodilatadores/administração & dosagem , Masculino , Ratos , Ratos Wistar , Compostos de Espiro/administração & dosagem
6.
Xenotransplantation ; 15(6): 374-83, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19152665

RESUMO

BACKGROUND: Regenerative medicine in the recent years aims at explaining involvement of stem cells in regenerative processes and applying this knowledge in fulfilling human needs to find new, more efficient therapeutic methods. Growing antlers constitute a model organ for examining regeneration processes of tissues because they are the only mammalian appendages capable of regeneration. The rate of growth of deer antlers makes them one of the quickest growing structures in mammals. The cells taking part in this process have a considerable proliferating potential. The aim of the study was to analyze the possibility of using xenogenous antlerogenic cells (AC) in regeneration of cartilaginous tissues in non-immunosuppressed animals. METHODS: We undertook to use a xenogenous implant consisting of cultured antlerogenic mesenchymal cells suspended in hemostatic sponge in the reconstruction of lesions of ear cartilage in nine rabbits. A surgical site was prepared half-way up the outer, dorsal part of the right ear. About 1 cm from the free edge of the ear, a centrally peduncled flap of skin and perichondrium was prepared, measuring 1.5 cm x 1.5 cm. The exposed cartilage was excised in an area of about 1 cm x 1 cm. In the operated rabbits, in the prepared perichondrial pocket, we placed a flake of Spongostan saturated with the suspension of AC. Xenogenous cell survival and regeneration abilities were determined by histologic, immunohistochemical, and electron microscopy analysis of the grafts. RESULTS: In each case, healing occurred properly and neither local inflammation, necrosis nor implant rejection was observed. The hyaline cartilage lesion was replaced by new fibrous cartilage. This is similar to the histologic process occurring in growing deer antlers. The histologic, immunohistochemical, and electron microscopy analysis demonstrated the presence (and thus possible participation) of exogenous cells in the reconstructive process. At the same time, the immune response was very weak, which was confirmed by immunohistochemical reactions. CONCLUSION: Implanted antlerogenic cells were not rejected and possibly took part in the reconstruction of missing sections of the scaffolding of the rabbits' ear cartilages (although the mechanism is yet unknown). Low immunogenicity of AC, simplicity, efficiency, and low costs of production of implant material are the benefits of this method. Further research should unequivocally answer the question whether the MIC-1 cells are or are not the long-sought-after ideal material for the reconstruction of cartilaginous tissue lesions in various species, including human.


Assuntos
Chifres de Veado/citologia , Chifres de Veado/transplante , Cartilagem da Orelha/citologia , Cartilagem da Orelha/cirurgia , Regeneração/fisiologia , Medicina Regenerativa/métodos , Ruminantes , Transplante Heterólogo , Animais , Chifres de Veado/crescimento & desenvolvimento , Chifres de Veado/imunologia , Linhagem Celular , Sobrevivência Celular , Cartilagem da Orelha/patologia , Feminino , Sobrevivência de Enxerto , Imuno-Histoquímica , Microscopia Eletrônica , Coelhos , Transplante Heterólogo/imunologia
7.
Pharmacol Rep ; 69(5): 1113-1119, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29031689

RESUMO

BACKGROUND: Postmenopausal osteoporosis and osteoporotic fractures constitute an increasing problem in developing countries. Kaempferol, isolated from seeds of Cuscuta chinensis, is an active flavonoid inhibiting in vitro osteoclast activity. The aim of the presented research was an assessment of kaempferol effect on estrogen-deficiency-induced bone structure disturbances in rats. METHODS: The study was performed on 24 Wistar female rats divided into 3 groups: SHAM - rats undergoing a "sham" surgery, OVX-C - control group of animals that underwent ovariectomy, OVX-K - rats undergoing ovariectomy and receiving kaempferol for 8 weeks (from day 56 to day 112). RESULTS: In the OVX-K group, contrary to the OVX-C one, there was no significant decrease in femoral bone mineral density (BMD). A significant increase in Young's modulus was observed in the OVX-K group compared to the OVX-C (15.33±2.51GPa vs. 11.14±1.93GPa, p<0.05). A decreased bone turnover was detected in the OVX-K group. Tissue volume ratio (BV/TV) and trabecular bone perimeter were increased in the OVX-K group compared to the OVX-C one (0.241±0.037 vs. 0.170±0.022, p<0.05 and 15.52±2.78mm vs. 9.67±3.07mm, p<0.05, respectively). CONCLUSION: Kaempferol has a beneficial influence on estrogen-deficiency-induced disturbances of bone structure in rats.


Assuntos
Doenças Ósseas Metabólicas/prevenção & controle , Quempferóis/farmacologia , Ovariectomia/efeitos adversos , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/etiologia , Feminino , Ratos , Ratos Wistar
8.
Otolaryngol Pol ; 59(4): 517-22, 2005.
Artigo em Polonês | MEDLINE | ID: mdl-16273854

RESUMO

UNLABELLED: 40 patients with exacerbation of a chronic maxillary sinusitis were examined. Sinus puncture was performed (sinoject) in all of the patients. Before the treatment (500 mg cefprozil orally twice a day, the recommended duration of therapy was ten days) and on the fifth day, the microorganisms from sinus were isolated (the bacteriological culture, antibiogram and MIC were determined). On the second and the fifth day, blood cefprozil level and the presence of cefprozil in the washings from maxillary sinuses were investigated. RESULTS: 17 pathogens were isolated from maxillary sinuses, only two of them were anaerobic. The bacterial strains: Staphylococcus (55%), E.coli (15%), Klebsiella (10%) and 20% of others, were found. Four of them (23.5%) were resistant to cefprozil. In all patients cefprozil was identified in maxillary sinuses (0.87-2.52 ug/ml). The value of MIC were from 0.094 to 2.0 ug/ml. A satisfactory clinical response was observed in 92.5% persons but the eradication of pathogens was obtained in 70%. The adverse clinical events (diarrhea) were observed only in one patient (2.5%). CONCLUSIONS: cefprozil well penetrates into inflammable mucous membrane of maxillary sinuses. Cefprozil obtains efficient bactericidal concentration in relation to sensitive bacteria on the fifth day of therapy. It is also well tolerated by the patients.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Sinusite Maxilar/tratamento farmacológico , Sinusite Maxilar/microbiologia , Adolescente , Adulto , Doença Crônica , Infecções por Escherichia coli/tratamento farmacológico , Feminino , Humanos , Infecções por Klebsiella/tratamento farmacológico , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Infecções Estafilocócicas/tratamento farmacológico , Resultado do Tratamento , Cefprozil
9.
Artigo em Inglês | MEDLINE | ID: mdl-26124854

RESUMO

One of the most common diseases of old age in modern societies is glaucoma. It is strongly connected with increased intraocular pressure (IOP) and could permanently damage vision in the affected eye. As there are only a limited number of chemical compounds that can decrease IOP as well as blood flow in eye vessels, the up-to-date investigation of new molecules is important. The chemical composition of the dried Cornelian cherry (Cornus mas L.) polar, iridoid-polyphenol-rich fraction was investigated. Loganic acid (50%) and pelargonidin-3-galactoside (7%) were found as the main components. Among the other constituents, iridoid compound cornuside and the anthocyans cyanidin 3-O-galactoside, cyanidin 3-O-robinobioside, and pelargonidin 3-O-robinobioside were quantified in the fraction. In an animal model (New Zealand rabbits), the influence of loganic acid and the polyphenolic fraction isolated from Cornelian cherry fruit was investigated. We found a strong IOP-hypotensive effect for a 0.7% solution of loganic acid, which could be compared with the widely ophthalmologically used timolol. About a 25% decrease in IOP was observed within the first 3 hours of use.

10.
Otolaryngol Pol ; 58(1): 79-84, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-15101264

RESUMO

Because all machines and vibration devices also produce noise, the combined activities of both factors are usually examined together. The opinion dominates that vibration exerts only a weak, additionally traumatic influence on the hearing organ. The aim of our investigation was to determine the influence of long-term, whole-body vibration on the incudo-stapedial joint which integrity is indispensable for the protection of the inner ear from the effect of noise. To realize the experimental conditions, sinusoidal vertical shaking (10 Hz, 5 mm, 1.4 g rms), an own noiseless apparatus was consisted. The experiment was carried out on 30 young, healthy, colored guinea pigs. They were subjected to vibration over 1, 3, and 6 months (132, 396, and 792 hours). The investigation was based on examination of the structures of the incudo-stapedial joint in the scanning electron microscopy. Among experimental animals two kinds of changes were ascertained which can be attributed to the activity of vibration. One was an extensive damage to the surfaces of the incudo-stapedial joint itself. The other was an often observed thickening of the bursa of the joint. The frequencies of occurrence and stages of advancement of both were in direct relationship to the duration of the experiment. The evaluation of the observed changes permits an explanation of the mechanism of the damage to hearing of persons subjected to noise and vibration. Whole-body vibration damages the incudo-stapedial joint, making its separation difficult. This may, than, facilitate the transfer of noise and its injurious influence to the inner ear.


Assuntos
Bigorna/lesões , Bigorna/ultraestrutura , Estribo/lesões , Estribo/ultraestrutura , Animais , Cobaias , Microscopia Eletrônica/métodos
11.
In Vivo ; 27(1): 97-106, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23239857

RESUMO

AIM: We characterized growth factors produced by MIC-1 antlerogenic stem cells and attempted to apply those cells to stimulate hair growth in rabbits. MATERIALS AND METHODS: We evaluated the gene and protein expression of growth factors by immunocytochemical and molecular biology techniques in MIC-1 cells. An animal model was used to assess the effects of xenogenous stem cells on hair growth. In the experimental group, rabbits were intradermally injected with MIC-1 stem cells, whereas the control group rabbits were given vehicle-only. After 1, 2 and 4 weeks, skin specimen were collected for histological and immunohistochemical tests. RESULTS: MIC-1 antlerogenic stem cells express growth factors, as confirmed at the mRNA and protein levels. Histological and immunohistochemical analysis demonstrated an increase in the number of hair follicles, as well as the amount of secondary hair in the follicles, without an immune response in animals injected intradermally with MIC-1 cells, compared to animals receiving vehicle-alone. CONCLUSION: MIC-1 cells accelerated hair growth in rabbits due to the activation of cells responsible for the regulation of the hair growth cycle through growth factors. Additionally, the xenogenous cell implant did not induce immune response.


Assuntos
Chifres de Veado/citologia , Cabelo/crescimento & desenvolvimento , Transplante de Células-Tronco/métodos , Células-Tronco/citologia , Animais , Chifres de Veado/crescimento & desenvolvimento , Chifres de Veado/metabolismo , Células 3T3 BALB , Western Blotting , Linhagem Celular , Cervos , Feminino , Expressão Gênica , Folículo Piloso/crescimento & desenvolvimento , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Masculino , Camundongos , Coelhos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células-Tronco/metabolismo , Transplante Heterólogo
12.
Eur Arch Otorhinolaryngol ; 262(4): 307-13, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15221317

RESUMO

The aim of the experiment was to determine the effect of whole-body vibration on the inner ear. The investigations were carried out on 40 guinea pigs, subjected to sinusoidal vibration (10 Hz/5 mm/1.4 g rms) for 1 to 6 months in a noiseless apparatus. Cochlear microphonic measurements were done with a phase-sensitive detection technique for the levels 70, 80 and 90 dB and the frequencies of 0.26, 0.5, 1 and 2 kHz from the apex of the cochlea and for 4 and 8 kHz from the region of the round window. Analysis of 1,440 measurements suggested the possibility of damage appearing in the upper turnings of the cochlea. The subsequent morphological analysis was based on the estimation of the state of the hair cells (a three-degree scale of injury) in a Zeiss DSM 950 scanning microscope and of the structure of the fibers of the acoustic nerve in a Zeiss EM 900 transmission microscope. Vibration-induced changes were seen in all the examined inner ears of the experimental groups. Hair-cell damage was more often seen in the region of the apex, spreading gradually in the direction of the base and from the circumference (outer hair cells of the third row) to the modiolus. The most characteristic vibrational changes of the acoustic nerve fibers occurred in 100% of the examined myelin sheaths and were visible as decreases in their electrodensity. The changes in both the assessed elements of the inner ear appeared simultaneously but independently and were directly connected with the duration of the experiment. The results obtained allow an explanation of the mechanism of hearing loss in persons subjected to whole-body vibration. The damages done to the inner ear structures may cause a worsening of hearing there, especially in the low and medium frequencies.


Assuntos
Cóclea/lesões , Cóclea/ultraestrutura , Nervo Coclear/lesões , Nervo Coclear/ultraestrutura , Vibração/efeitos adversos , Animais , Cóclea/fisiopatologia , Potenciais Microfônicos da Cóclea , Nervo Coclear/fisiopatologia , Feminino , Cobaias , Masculino , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Modelos Animais , Fatores de Tempo
13.
Pol J Pharmacol ; 55(2): 203-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12926547

RESUMO

An increase in calcium ion concentration in the cytoplasm due to the influence of various toxic agents causes disturbances in the structure and function of hepatocytes, leading to their damage and even death. Calcium ions enter the cell mostly through calcium channels, therefore, it has been suggested that calcium channel inhibitors (CCI) could protect hepatocytes from the action of toxic substances. The present study investigated the effect of the selected CCI (nifedipine, nitrendipine and verapamil) on liver function, measured by the efficiency of oxidation reaction, in this case by determination of the rate of antipyrine metabolism. The experiment was carried out using the method of extracorporeal liver perfusion (ELP). None of the studied CCI applied at a concentration of 50 micromol/l increased the rate of antipyrine metabolism over the whole period of ELP. However, supplementation of perfusion fluid with nifedipine, nitrendipine or verapamil at a concentration of 20 micromol/l considerably improved metabolic liver efficiency during the second hour of perfusion, i.e. at the time, when large number of hepatocytes started to perish, which could indicate protective action of the tested CCI. However, the CCI-induced acceleration of antipyrine metabolism was not a result of their influence on calcium channels, since these drugs block calcium channels, when given at the concentrations as high as 100-400 micromol/l. Moreover, it seems that facilitation of antipyrine metabolism during ELP was not due to their action on microsomal enzymes because CCI were administered at very low concentrations, besides, they are metabolic inhibitors, and not inducers. The present experiment suggests that low concentrations of CCI can exert hepatoprotective effect. However, confirmation of this conclusion requires further studies using other experimental methods.


Assuntos
Antipirina/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Fígado/metabolismo , Nifedipino/farmacologia , Nitrendipino/farmacologia , Verapamil/farmacologia , Animais , Quimioterapia do Câncer por Perfusão Regional , Relação Dose-Resposta a Droga , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , Masculino , Camundongos , Oxirredução , Perfusão/métodos , Ratos , Ratos Wistar , Fatores de Tempo
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