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1.
Bull Entomol Res ; 107(2): 165-173, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27573004

RESUMO

The costs and benefits of polyandry are still not well understood. We studied the effects of multiple mating on the reproductive performance of female Brontispa longissima (Coleoptera: Chrysomelidae), one of the most serious pests of the coconut palm, by using three experimental treatments: (1) singly-mated females (single treatment); (2) females that mated 10 times with the same male (repetition treatment); and (3) females that mated once with each of 10 different males (polyandry treatment). Both multiple mating treatments resulted in significantly greater total egg production and the proportion of eggs that successfully hatched (hatching success) than with the single mating treatment. Furthermore, the polyandry treatment resulted in greater total egg production and hatching success than with the repetition treatment. Thus, mate diversity may affect the direct and indirect benefits of multiple mating. Female longevity, the length of the preoviposition period, the length of the period from emergence to termination of oviposition, and the length of the ovipositing period did not differ among treatments. The pronounced fecundity and fertility benefits that females gain from multiple mating, coupled with a lack of longevity costs, apparently explain the extreme polyandry in B. longissima.


Assuntos
Besouros/fisiologia , Aptidão Genética , Comportamento Sexual Animal , Animais , Besouros/genética , Feminino , Variação Genética , Masculino , Reprodução
2.
Drug Metab Dispos ; 37(8): 1622-34, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19477946

RESUMO

The disposition and metabolism of tafluprost, an ester prodrug of the 15,15-difluoro-prostaglandin F(2alpha) antiglaucoma agent, have been studied in rats after ocular administration. Radioactivity was absorbed very rapidly into the eye and systemic circulation after a single ocular dose of 0.005% [(3)H]tafluprost ophthalmic solution, with maximum levels in plasma and most eye tissues occurring within 15 min. The absorption ratio of radioactivity was approximately 75%, suggesting the high availability of ocular administration of tafluprost. Approximately 10% of the dose was present in cornea at this time, and radioactivity concentrations in this tissue exceeded those in aqueous humor and iris/ciliary body throughout the 24-h study period. After repeated daily ocular doses, radioactivity levels remained greatest in cornea, followed by iris/ciliary body that replaced aqueous humor as the eye tissue containing the second highest radioactivity concentration. In female rats, radioactivity was excreted equally between urine and feces after a single ocular dose, whereas in male rats more was excreted in feces, reflecting the greater biliary excretion in males rats (50% dose) compared with females rats (33% dose). Tafluprost was extensively metabolized in the rat, such that intact prodrug was not detected in plasma, tissues, or excreta by radio-high-performance liquid chromatography. On the other hand, the active moiety, tafluprost acid, was the only noteworthy radioactive component in cornea, aqueous humor, and iris/ciliary body for at least 8 h after the ocular dose, and it was also a major plasma metabolite in early time points. The gender differences in conjugation reactions resulted in the differences in the excretion.


Assuntos
Olho/metabolismo , Glaucoma/tratamento farmacológico , Pró-Fármacos/administração & dosagem , Pró-Fármacos/farmacocinética , Prostaglandinas F/administração & dosagem , Prostaglandinas F/farmacocinética , Administração Tópica , Animais , Disponibilidade Biológica , Biotransformação , Cromatografia Líquida , Cães , Fezes/química , Feminino , Glucuronídeos/metabolismo , Hepatócitos/metabolismo , Humanos , Hidrólise , Injeções Intravenosas , Lactação , Macaca fascicularis , Masculino , Metabolômica/métodos , Leite/metabolismo , Soluções Oftálmicas , Placenta/metabolismo , Gravidez , Prostaglandinas F/sangue , Prostaglandinas F/urina , Ratos , Ratos Sprague-Dawley , Fatores Sexuais , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Distribuição Tecidual , Trítio
3.
Bull Entomol Res ; 92(4): 295-9, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12191437

RESUMO

Field bioassays using three different synthetic sex pheromone blends (Indian, Philippine and Japanese) based on geographic variations of Cnaphalocrocis medinalis Guenée were carried out at 11 sites in Japan and in Hangzhou, China. In all of the tests, only the Japanese pheromone blend attracted a significant number of male moths, while the Indian and Philippine pheromone blends showed no marked activity. The findings in Japan showed no evidence that moths of Philippine or Indian origin were able to migrate to Japan. The results from China also showed that most populations of C. medinalisin the Hangzhou region responded to the Japanese blend. This is consistent with the current hypothesis that most populations of C. medinalisin Japan are migrants from areas to the south of the Yangzhe Valley, including the region surrounding Hangzhou, China. Furthermore, populations in the Hangzhou region can not hibernate, but are considered migrants from the southernmost parts of China and southeast Asian countries such as Vietnam where they breed continuously. Consequently, at least some populations in these areas may respond to the Japanese pheromone blend.


Assuntos
Mariposas/fisiologia , Feromônios/fisiologia , Atrativos Sexuais/fisiologia , Animais , China , Japão , Masculino , Feromônios/síntese química , Atrativos Sexuais/síntese química
4.
Pest Manag Sci ; 57(5): 463-6, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11374165

RESUMO

Water-soluble preparations have been investigated to develop a trunk injection agent based on the poorly water-soluble anti-nematode emamectin benzoate. Following tests on the phytotoxicity of some solvents and solubilizers and demonstration of the ability of some solubilizers to dissolve emamectin benzoate in water, acetone + methanol was selected as the solvent and Polysorbate 80 as the solubilizer. This water-soluble preparation of emamectin benzoate prevented the wilting of pot-grown 4-year-old trees of the Japanese black pine, Pinus thunbergii, artificially inoculated with the pine wood nematode, Bursaphelenchus xylophilus, at a dose of 20 g emamectin benzoate per cubic metre of pine tree.


Assuntos
Inseticidas , Ivermectina , Ivermectina/análogos & derivados , Nematoides , Doenças das Plantas , Árvores , Animais , Injeções , Inseticidas/química , Ivermectina/química , Estrutura Molecular , Caules de Planta , Polissorbatos/efeitos adversos , Solubilidade , Solventes/efeitos adversos
5.
Jpn J Ophthalmol ; 45(1): 114, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11341900

RESUMO

Purpose: To confirm the intraocular dynamics of 1% deuterium (D) labeled alpha-tocopheral acetate (VEA) solution.Methods: The concentrations of D(3)-VEA and D(3)-alpha-tocopherol (VE) derived from D(3)-VEA in the aqueous humor and lens were measured after instilling 1% D(3)-VEA continuously into the cul-de-sac of rat eyes for one and three weeks. D(3)-VEA and D(3)-VE concentrations were determined by gas chromatograph/mass spectrometry.Results: D(3)-VEA and D(3)-VE concentrations in the aqueous humor after one and three weeks of continuous administration were 93.1 and 498.9, and 9.4 and 21.5 ng/mL, respectively. The concentrations in the lens were 15.0 and 6.1, and 9.8 and 4.8 ng/g, respectively.Conclusion: The penetration of VEA into the aqueous humor and lens by eyedrop application was confirmed.

6.
Jpn J Ophthalmol ; 45(2): 125-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11313042

RESUMO

PURPOSE: To confirm the aqueous humor and lens dynamics of 1% deuterium-labeled alpha-tocopherol acetate (D(3)-VEA) solution. METHODS: The concentrations of D(3)-VEA and D(3)-alpha-tocopherol (D(3)-VE), derived from D(3)-VEA, in the aqueous humor and lens were measured after continuous instillation of 1% D(3)-VEA into the cul-de-sac of rat eyes for 1 or 3 weeks. D(3)-VEA and D(3)-VE concentrations were determined by gas chromatography/mass selective detector. RESULTS: In the aqueous humor, the concentrations of D(3)-VEA and D(3)-VE were, respectively, 93.1 and 9.4 ng/mL after 1 week, and, respectively, 498.9 and 21.5 ng/mL after 3 weeks. In the lens, they were, respectively, 15.0 and 9.8 ng/g after 1 week, and 6.1 and 4.8 ng/g after 3 weeks. CONCLUSION: The penetration levels of alpha-tocopherol acetate by eyedrop application were confirmed in the aqueous humor and lens.


Assuntos
Humor Aquoso/metabolismo , Cristalino/metabolismo , Vitamina E/farmacocinética , Administração Tópica , Animais , Deutério , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Marcação por Isótopo , Soluções Oftálmicas , Ratos , Ratos Endogâmicos BN , Distribuição Tecidual
7.
Mediators Inflamm ; 10(6): 333-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11817674

RESUMO

The effects of IPD-1151T on the expression of co-stimulatory molecules, CD40, CD80 and CD86, were investigated in vivo using mice with allergic disorders. BALB/c mice were immunized intraperitoneally with two doses of dinitrophenylated ovalbumin (DNP-OVA) at 1-week intervals. These mice then were treated intraperitoneally with 100 microg/kg of IPD-1151T once a day for 14 days, starting 7 days after the first immunization. On day 21, some mice were challenged intraperitoneally with DNP-OVA and the other mice were not challenged. All mice were autopsied on day 22 and assayed for immunoglobulin E, interleuken (IL)-4 and IL-5 productions following DNP-OVA immunization. The intraperitoneal treatment with IPD-1151T strongly suppressed immunoglobulin E contents in serum, which were enhanced by DNA-OVA immunization. IPD-1151T also caused a decrease in both IL-4 and IL-5 levels in splenic lymphocytes. We next examined the influence of IPD-1151T on co-stimulatory molecule expression on splenic lymphocytes. IPD-1151T caused suppression of CD40 and CD86 expression; however, the treatments did not affect CD80 expression.


Assuntos
Antialérgicos/farmacologia , Sulfonatos de Arila/farmacologia , Linfócitos/efeitos dos fármacos , Baço/citologia , Compostos de Sulfônio/farmacologia , Animais , Antígenos CD/análise , Antígeno B7-1/análise , Antígeno B7-2 , Antígenos CD40/análise , Citometria de Fluxo , Imunoglobulina E/sangue , Terapia de Imunossupressão , Interleucina-4/análise , Interleucina-4/biossíntese , Interleucina-5/análise , Interleucina-5/biossíntese , Linfócitos/química , Linfócitos/metabolismo , Masculino , Glicoproteínas de Membrana/análise , Camundongos , Camundongos Endogâmicos BALB C
8.
J Ethnopharmacol ; 72(3): 395-402, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10996278

RESUMO

Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 microg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit (MID: 100 microg), and the leaf (MID: 400 microg) extracts. None of the extracts were significantly cytotoxic, and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, alpha-tocopherol. Antitumour-promoting activity (>95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts.


Assuntos
Antibacterianos/farmacologia , Anticarcinógenos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Rosales/química , Animais , Linhagem Celular , Decápodes , Humanos , Testes de Sensibilidade Microbiana , Testes de Toxicidade
9.
Nippon Ganka Gakkai Zasshi ; 104(7): 508-10, 2000 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-10934869

RESUMO

PURPOSE: To confirm the intraocular dynamics of 1% deuterium (D)-labeled alpha-tocopherol acetate (VEA) solution. METHODS: The concentrations of D3-VEA and D3-alpha-tocopherol (VE) derived from D3-VEA in the aqueous humor and lens were measured after instilling 1% D3-VEA continuously into the cul-de-sac of rat eyes for one and three weeks. D3-VEA and D3-VE concentrations were determined by gas chromatograph/mass spectrometry. RESULTS: D3-VEA and D3-VE concentrations in the aqueous humor after one and three weeks of continuous administration were 93.1 and 498.9, and 9.4 and 21.5 ng/ml, respectively. The concentrations in the lens were 15.0 and 6.1, and 9.8 and 4.8 ng/g, respectively. CONCLUSION: The penetration of VEA into the aqueous humor and lens by eyedrop application was confirmed.


Assuntos
Humor Aquoso/metabolismo , Cristalino/metabolismo , Vitamina E/análogos & derivados , alfa-Tocoferol/análogos & derivados , Animais , Deutério , Olho , Feminino , Instilação de Medicamentos , Ratos , Ratos Endogâmicos BN , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/farmacocinética
10.
Mediators Inflamm ; 9(1): 39-43, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10877454

RESUMO

The influence of roxithromycin (RXM) on the expression of co-stimulatory molecules, CD40, CD80 and CD86, was examined in vivo. When BALB/c mice were immunized intraperitoneally with two doses of dinitrophenylated ovalbumin (DNP-OVA) at 1 week intervals, intraperitoneal administration of RXM at 250 microg/kg once a day for 14 days strongly suppressed IgE contents in sera obtained from mice 22 days after the first immunization. In addition, RXM treatment of mice suppressed endogenous IL-4 contents in aqueous spleen extracts, which were enhanced by DNP-OVA immunization. We next examined the influence of RXM on co-stimulatory molecule expression on splenic lymphocytes. RXM treatment of the immunized mice caused suppression of CD40 expression, but this treatment did not affect CD80 and CD86 expression.


Assuntos
Antibacterianos/farmacologia , Antígenos CD/biossíntese , Antígeno B7-1/biossíntese , Antígenos CD40/biossíntese , Glicoproteínas de Membrana/biossíntese , Roxitromicina/farmacologia , Baço/efeitos dos fármacos , Animais , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Antígeno B7-2 , Células Cultivadas , Imunoglobulina E/biossíntese , Interleucina-4/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Baço/citologia , Baço/imunologia
11.
Z Naturforsch C J Biosci ; 55(3-4): 295-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10817223

RESUMO

Sixty five methanolic extracts of Sumatran rainforest plants representing 63 species of 21 families were assayed in vivo for antinematodal activity against Bursaphelenchus xylophilus using our cotton ball-fungal mat method. Extracts of 27 plants species from 14 families exhibited antinematodal activity, while 37 species were inactive. Among them, three extracts of Bischofia javanica, Knema hookeriana and Areca catechu exhibited very strong activity at minimum effective dose (MED) of 0.7 mg/cotton ball (mg/bl.). Eight extracts from Allamanda cathartica, Ervatamia corymbosa, Hoya diversifolia, Bischofia javanica, Derris malacensis, Melastoma melabathricum, Ophiorriza konsteleary and Brucea sumatrana also showed strong activity (MED, 5 mg/bl.).


Assuntos
Anti-Helmínticos/farmacologia , Nematoides/efeitos dos fármacos , Plantas/química , Árvores/parasitologia , Animais , Especificidade da Espécie
12.
Z Naturforsch C J Biosci ; 55(3-4): 300-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10817224

RESUMO

The activity-guided chromatographic purification of the methanol extract of Knema hookeriana, using pine wood nematodes Bursaphelenchus xylophilus has successfully led to the isolation and characterization of two phenolic antinematodal compounds with minimum effective dose (MED) of 4.5 and 20 microg/cotton ball (microg/bl.) or 0.018 and 0.073 microM/cotton ball (microM/bl.), respectively. Based on their chemical and spectral properties, these compounds were determined to be 3-undecylphenol (1) and 3-(8Z-tridecenyl)-phenol (2). These compounds were isolated for the first time from this species, and 2 seems to be a novel compound.


Assuntos
Anti-Helmínticos/farmacologia , Nematoides/efeitos dos fármacos , Fenóis/farmacologia , Plantas/química , Animais , Anti-Helmínticos/química , Fenóis/química , Análise Espectral
14.
J Antibiot (Tokyo) ; 53(1): 58-62, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10724009

RESUMO

Albonoursin production was greatly enhanced when cyclo (L-Leu-L-Phe) (CFL), a tetrahydro derivative of albonoursin, was added to the 2-day culture of an albonoursin-producing actinomycete, Streptomyces albulus KO-23. The increase in albonoursin production paralleled the amount of CFL added. Furthermore, the resting cells of the strain catalyzed the bioconversion of CFL to albonoursin. The optimum pH and temperature for the conversion were found to be pH 10.0 and 50 degrees C. The feeding experiments and the resting-cell reactions revealed that albonoursin is biosynthesized by dehydrogenation of CFL in the actinomycete. This is the first report for a dehydrogenation of amino acid residues at the alpha,beta-positions in cyclic dipeptides.


Assuntos
Antibacterianos/biossíntese , Actinomycetales/metabolismo , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Dipeptídeos/química , Concentração de Íons de Hidrogênio , Peptídeos Cíclicos/química , Piperazinas/química , Piperazinas/metabolismo , Streptomyces
15.
J Biosci Bioeng ; 89(6): 602-5, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-16232805

RESUMO

A bacterium, strain NM 5-3, isolated from soil exhibited the highest cyclo(Gly-Leu) (CGL)-hydrolyzing activity and was identified as Agrobacterium radiobacter. The reaction products from CGL were dipeptides (Leu-Gly and Gly-Leu) and amino acids (Leu and Gly). Inhibitors for the dipeptidase of this strain did not inhibit the hydrolysis of CGL to dipeptides, indicating that two distinct enzymes, CGLase and a dipeptidase, were involved in its hydrolysis. The activities of these two enzymes were separated by anion-exchange column chromatography. The results indicated that strain NM5-3 hydrolyzed CGL via the dipeptides to the corresponding amino acids. The CGLase fraction was found to catalyze the hydrolysis of cyclo(Gly-D-Leu), cyclo(Gly-Gly), cyclo(L-Ala-Gly), and cyclo(D-Ala-Gly). On the other hand, the dipeptidase fraction exhibited L-specific substrate specificity.

16.
J Biosci Bioeng ; 90(1): 86-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-16232823

RESUMO

The cell-free extract of an albonoursin-producing strain, Streptomyces albulus KO-23, was found to catalyze the conversion of several cyclic dipeptides having Phe and aliphatic side chain-containing amino acid residues to the corresponding dehydro derivatives. 3Z-Benzylidene-6S-methyl-2,5-piperazinedione, 3Z-benzylidene-2,5-piperazinedione, and 3Z, 6Z-dibenzylidene-2,5-piperazinedione were prepared by this conversion system. Among the dehydro cyclic dipeptides prepared, tetradehydro derivatives exhibited inhibitory activity toward the first cleavage of sea urchin embryo, while didehydro derivatives did not. We previously found that cyclo(Leu-Phe) and its didehydro derivatives did not show any inhibitory activity, in contrast to high activity in the case of albonoursin. Taken together, these findings indicate that dehydrogenation at the alpha,beta-positions of both amino acid residues in this type of cyclic dipeptide is required for the inhibitory activity.

17.
J Pharm Pharmacol ; 51(7): 791-6, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10467953

RESUMO

Abstract Evidence for carrier-mediated transport of levofloxacin in the isolated rabbit cornea has been found. However, it is not known whether this mechanism is located in the epithelium or the endothelium. To resolve this question, we have measured the kinetics of levofloxacin uptake in primary cultures of rabbit corneal epithelial cells. The results indicate that levofloxacin accumulation was time dependent and a steady state was reached after 30 min. Maximal uptake occurred from a solution whose pH was 6.5. The uptake process was stereoselective and concentration dependent. In addition to the uptake, secretion of levofloxacin also occurred. These results indicate that the corneal epithelium is the site of levofloxacin transport mechanisms, mediating both absorption and secretion.


Assuntos
Anti-Infecciosos/farmacocinética , Epitélio Corneano/metabolismo , Levofloxacino , Ofloxacino/farmacocinética , Absorção , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Epitélio Corneano/citologia , Concentração de Íons de Hidrogênio , Cinética , Ofloxacino/química , Coelhos , Estereoisomerismo , Temperatura , Fatores de Tempo
18.
J Pharm Pharmacol ; 51(7): 797-801, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10467954

RESUMO

The cornea presents a formidable barrier to drug penetration. The fluoroquinolone levofloxacin, which is an effective antimicrobial agent, has the potential to be used in the topical treatment of ocular disease. Thus, we sought to characterize how levofloxacin penetrates the cornea. To perform this characterization, we measured the time dependent permeation of levofloxacin across the isolated rabbit cornea using a diffusion chamber, and compared it with antipyrine fluxes. Levofloxacin permeation into the receiver epithelial-side bathing solution (pH = 6.5) from the donor endothelial-side (pH = 7.4) reached 3.00 nmolcm(-2) cornea after 2h, whereas in the opposite direction permeation was 1.89 nmolcm(-2) cornea. Based on the temperature-dependent effects on permeation, the calculated energy of activation for permeation, Ea, was 31.3 kcal mol(-1), whereas Ea for antipyrine, a marker of diffusion, was 11.0 kcalmol(-1). The transport of levofloxacin from epithelium to endothelium was concentration-dependent and had both a linear and saturable component. Evaluation of the kinetic parameters, Jmax, apparent Km and k(d) showed that they were 38.78 pmol min(-1) cm(-2), 3.83 mM and 0.0135 microL min(-1) cm(-2), respectively. These results, coupled with the fact that levofloxacin permeation reached a maximum value at pH 6.5, suggest that levofloxacin transport across the cornea is carrier mediated. However, at present, it cannot be ascertained whether such a system is localized in either the corneal epithelial or the endothelial layer.


Assuntos
Anti-Infecciosos/farmacocinética , Proteínas de Transporte/metabolismo , Córnea/metabolismo , Levofloxacino , Ofloxacino/farmacocinética , Animais , Transporte Biológico , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Masculino , Permeabilidade , Coelhos , Temperatura
19.
Invest Ophthalmol Vis Sci ; 40(8): 1738-44, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10393043

RESUMO

PURPOSE: The purpose of this study was to characterize cyclosporin A (CsA) uptake and transport in cultured rabbit corneal epithelial cells (RCECs). METHODS: CsA uptake was evaluated by measuring time-dependent 3H-CsA accumulation in confluent RCECs. Bidirectional 3H-CsA fluxes were measured across the RCEC layers grown on Transwell-COL culture plate inserts. The anti-P-gp monoclonal antibody C219 was used in western blot analysis to probe for the presence of P-gp in these cells. RESULTS: The accumulation of 3H-CsA was time and temperature dependent. Steady state was reached by 60 minutes. The initial uptake was saturable and was suppressed as a function of increases in preloading with unlabeled CsA. This uptake process was enhanced by metabolic inhibition with either 3-O-methylglucose, MG, or 10 mM NaN3 and 3-O-MG. The largest increase was obtained with 10 mM NaN3 in combination with 3-O-MG. In their presence, uptake increased by 40%. A multidrug-resistance (MDR)-reversing agent (i.e., 500 microM verapamil, 100 microM vincristine, 100 microM progesterone, 100 microM testosterone, 500 microM quinidine, or 100 microM chlorpromazine) significantly increased 3H-CsA accumulation. The largest increase was obtained with 500 microM quinidine (i.e., 36%). Conversely, verapamil and vincristine produced the largest inhibition of 3H-CsA efflux (i.e., 19% and 28%, respectively). However, in the presence of 10 microM unlabeled CsA, 3H-CsA efflux increased. 3H-CsA flux across RCEC layers showed marked directional asymmetry. The stromal (S) to tear (T) side transcellular 3H-CsA permeability coefficient (Ptrans) was approximately seven times higher than that in the T-to-S direction. The S-to-T Ptrans was reduced by an MDR-reversing agent by up to 40%. Western blot analysis of lysates revealed a 170-kDa membrane protein band. CONCLUSIONS: These results suggest that in RCEC the tear-side-facing membrane has a P-gp-mediated drug efflux pump. In addition, there is suggestive evidence for the presence of the cytosolic protein, cyclophilin. The presence of P-gp in these cells could help protect them from being damaged by the uptake of toxic substances.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Ciclosporina/farmacocinética , Epitélio Corneano/metabolismo , Peptidilprolil Isomerase/metabolismo , 3-O-Metilglucose/farmacologia , Animais , Transporte Biológico , Western Blotting , Tamanho Celular , Células Cultivadas , Combinação de Medicamentos , Resistência a Múltiplos Medicamentos , Epitélio Corneano/citologia , Epitélio Corneano/efeitos dos fármacos , Permeabilidade , Coelhos , Azida Sódica/farmacologia , Temperatura , Fatores de Tempo
20.
J Nat Prod ; 62(2): 337-9, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10075780

RESUMO

Vibsanin E (4), a tricyclic vibsane-type diterpene, has been prepared in 50% yield from vibsanin C (2), a seven-membered ring vibsane-type diterpene by reaction with BF3.OEt2 at -78 degrees C. This chemical correlation not only established structure, including absolute configurations, but also has demonstrated a possible biosynthetic route to 4 via 2 derived from vibsanin B (1). The structure of 3-hydroxyvibsanin E (5), another example of a tricyclic seven-membered ring vibsane, isolated from the leaves of Viburnumawabuki, has been established by extensive analyses of 2D NMR data and comparison of its spectral data with those of 4.

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