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1.
Neurochem Res ; 28(6): 789-96, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12718430

RESUMEN

The antibodies against omega-conotoxin GVIA (omega-CTX GVIA; N-type voltage-dependent calcium channel [VDCC] blocker) and B1Nt (N-terminal segment [residues 1-13] of BI alpha1 subunits of VDCCs) were prepared, and the selectivity for each antigen omega-CTX GVIA and B1Nt was investigated. For the antigen selectivity of anti-omega-CTX GVIA antibody against omega-CTX GVIA, ELISA, and immunoprecipitation were used. The reactions for ELISA and immunoprecipitation were observed except when antibody IgG purified by Protein A-Sepharose CL-4B from nonimmunized serum (purified NI-Ab) was used. The specific reactions were inhibited by 10 nM omega-CTX GVIA, but not by omega-CTX SVIB (N-type VDCC blocker), omega-CTX MVIIC (N- and P-type VDCC blocker), or omega-Aga IVA (P-type VDCC blocker). For the antigen selectivity of the anti-B1Nt antibody, analyses by ELISA, immunoprecipitation, and Western blotting were conducted. The reactions were observed except when NI-Ab was used. The ELISA and immunoprecipitation reactions were inhibited by the antigen peptide B1Nt, and the IC50 values were about 1.2 x 10(-8) and 1.3 x 10(-8) M, respectively. The bands of 210 and 190 kD by Western blotting of crude membranes from chick brain were also inhibited by 1 microM B1Nt. These results suggest that the antibodies prepared against omega-CTX GVIA and B1Nt in this work have high selectivity for their antigen. Therefore we assume that the antibodies against omega-CTX GVIA and B1Nt are useful tools for the analyses of the function and distribution of N-type VDCCs. The anti omega-CTX GVIA antibody must also be useful for the radioimmunoassay of omega-CTX GVIA.


Asunto(s)
Anticuerpos , Canales de Calcio Tipo N/inmunología , omega-Conotoxina GVIA/inmunología , Animales , Especificidad de Anticuerpos , Pollos , Ensayo de Inmunoadsorción Enzimática , Radioisótopos de Yodo , Cinética , Fragmentos de Péptidos/inmunología , Subunidades de Proteína , Conejos
2.
Toxicon ; 39(8): 1223-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11306134

RESUMEN

To clarify the mechanism by which the toxic abstract from Toxopneustes pileolus inhibits time-dependent (Time-dep.) Ca(2+) uptake in crude synaptosome fraction, the effective component from pedicellarial venom of the sea urchin was purified. The crude extracts were purified by a series of steps including ion exchange (DEAE-sephadex-A25 gel), gel filtration (with Superdex-2000 and Superdex-peptide columns) and reversed-phase chromatography (Sephasil-C18 column). The effective component that inhibited Time-dep. 45Ca(2+) uptake was purified and named UT841. Its IC(50) was determined to be lower than 35ng/ml. UT841 is an acidic protein with an apparent molecular weight of about 18,000. The N-terminal sequence (40 amino acids) was almost identical to that of Contractin A (a protein purified from the same kind of venom which induces smooth muscle contraction). Even though it is unclear whether or not UT841 is Contractin A, Ca(2+) mobilization in nerve cells was shown to be influenced by UT841. This investigation also revealed that a donor of nitric oxide, arachidonic acid and an inhibitor of phospholipase C selectively inhibit Time-dep. (45)Ca(2+) uptake. These results suggest that UT841 purified from sea urchin venom may affect Time-dep. (45)Ca(2+) uptake through the metabolism of some lipids and nitric oxide.


Asunto(s)
Encéfalo/efectos de los fármacos , Calcio/metabolismo , Erizos de Mar/patogenicidad , Sinaptosomas/efectos de los fármacos , Ponzoñas/toxicidad , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Pollos , Datos de Secuencia Molecular , Sinaptosomas/metabolismo , Factores de Tiempo , Ponzoñas/química
3.
Biol Trace Elem Res ; 84(1-3): 169-79, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11817687

RESUMEN

The aim of this study was to observe whether a low dosage of zinc induced mouse pancreatic injury. Dosages of zinc from 0.1 to 50 mg/kg were injected subcutaneously in mice, and plasma and pancreatic clinical parameters were observed 3-24 h after the injection. Plasma alpha-amylase activity increased 10 and 24 h after the injection of 25 or 50 mg/kg of zinc, whereas pancreatic alpha-amylase activity decreased 3 h after more than 5 mg/kg of zinc was injected. The activity recovered after 24 h except in the group injected with 50 mg/kg of zinc. The plasma glucose level did not change when less than 25 mg/kg of zinc was injected. The pancreatic zinc contents increased 3 h after more than 1 mg/kg of zinc was injected. The pancreatic metallothionein (MT) contents increased 6 h after the injection of 1 mg/kg of zinc. In addition, when more than 5 mg/kg of zinc was injected, the MT content increased at 3 h. In histochemical observations, cell damages such as fibrosis and necrosis were observed in pancreatic exocrine cells, but not in cells of Langerhans islets. From the present study, a single injection of a low dosage of zinc induces injury in pancreatic exocrine cells, but not endocrine cells.


Asunto(s)
Páncreas/efectos de los fármacos , Zinc/toxicidad , Animales , Glucemia/metabolismo , Relación Dosis-Respuesta a Droga , Inyecciones Subcutáneas , Masculino , Metalotioneína/metabolismo , Ratones , Páncreas/enzimología , Factores de Tiempo , Sulfato de Zinc/farmacología , alfa-Amilasas/metabolismo
4.
Neurochem Res ; 25(3): 335-40, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10761976

RESUMEN

The effect of Ca2+/calmodulin (CaM) on the specific binding of [125I]omega-conotoxin GVIA (125I-omega-CTX) to crude membranes from chick brain was investigated. When we examined the effects of the activation of various endogenous protein kinases on specific [125I]omega-CTX binding to crude membranes, we observed that Ca2+/CaM had an inhibitory effect regardless of whether or not the standard medium contained ATP (0.5 mM). Ca2+/CaM also had an inhibitory effect in a simple binding-assay medium containing HEPES-HCl buffer, BSA, Ca2+ and CaM, and this effect was dependent on the concentration of Ca2+. The effect of Ca2+/CaM was attenuated by the CaM antagonists W-7 and CaM-kinase II fragment (290-309). An experiment with modified ELISA using purified anti omega-CTX antibody indicated that Ca2+/CaM did not affect the direct binding of [125I]omega-CTX and CaM. These results suggest that Ca2+/CaM either directly or indirectly affects specific [125I]omega-CTX binding sites, probably N-type Ca2+ channels in crude membranes from chick whole brain.


Asunto(s)
Encéfalo/metabolismo , Bloqueadores de los Canales de Calcio/metabolismo , Calcio/metabolismo , Calmodulina/metabolismo , omega-Conotoxina GVIA/metabolismo , Animales , Canales de Calcio Tipo N/metabolismo , Pollos , Ensayo de Inmunoadsorción Enzimática , Técnicas In Vitro , Radioisótopos de Yodo , Membranas
5.
Biol Pharm Bull ; 23(3): 375-8, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10726901

RESUMEN

Semi-synthetic tetrahydroisoquinoline derivatives prepared from natural alkaloids, possess Ca2+ antagonistic properties. These derivatives significantly blocked KCl-stimulated Ca2+ uptake (In chick and rat crude nerve endings) which can be partially inhibited by the selective N-type Ca2+ channel blocker omega-conotoxin GVIA or the selective P-type Ca2+ channel blocker omega-agatoxin IVA. Moreover, PX42 (10 microM; for the tetrahydroisoquinoline compounds in this study) could inhibit the activity of calmodulin-dependent phosphodiesterase and block veratridine-induced (or tetrodotoxin-sensitive) Na+ uptake. The possible mechanism(s) of non-selective inhibition of ion channels of PX42 is discussed.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Isoquinolinas/farmacología , Terminaciones Nerviosas/efectos de los fármacos , Canales de Sodio/efectos de los fármacos , Animales , Calcio/metabolismo , Pollos , Activación del Canal Iónico , Isoquinolinas/química , Terminaciones Nerviosas/metabolismo , Hidrolasas Diéster Fosfóricas/metabolismo , Ratas , Ratas Wistar , omega-Conotoxina GVIA/farmacología
6.
Neurochem Res ; 25(12): 1629-35, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11152392

RESUMEN

The characteristics of the inhibitory effect of calcium ion (Ca2+)/calmodulin (CaM) on specific [125I]-omega-conotoxin GVIA (125I-omega-CTX) binding and on the labeling of 125I-omega-CTX to crude membranes from chick brain were investigated. The inhibitory effect of Ca2+/CaM depended on the concentrations of free Ca2+ and CaM. The IC50 values for free Ca2+ and CaM were about 2.0 x 10(-8) M and 3.0 microg protein/ml, respectively. The inhibitory effect of Ca2+/CaM was attenuated by the CaM antagonists W-7, prenylamine and CaM-kinase II fragment (290-309), but not by the calcineurin inhibitor FK506. Ca2+/CaM also inhibited the labeling of a 135-kDa band (which was considered to be part of N-type Ca2+ channel alpha1 subunits) with 125I-omega-CTX using a cross-linker. These results suggest that Ca2+/CaM affects specific 125I-omega-CTX binding sites, probably N-type Ca2+ channel alpha1 subunits, in crude membranes from chick whole brain.


Asunto(s)
Encéfalo/metabolismo , Bloqueadores de los Canales de Calcio/metabolismo , Calmodulina/farmacología , omega-Conotoxina GVIA/antagonistas & inhibidores , Animales , Animales Recién Nacidos , Calcio/metabolismo , Canales de Calcio Tipo N/efectos de los fármacos , Canales de Calcio Tipo N/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Proteínas Quinasas Dependientes de Calcio-Calmodulina/farmacología , Calmodulina/antagonistas & inhibidores , Pollos , Inhibidores Enzimáticos/farmacología , Radioisótopos de Yodo , Isoenzimas/farmacología , Masculino , Membranas/metabolismo , Fragmentos de Péptidos/farmacología , Prenilamina/farmacología , Ratas , Ratas Wistar , Sulfonamidas/farmacología
7.
Toxicon ; 37(11): 1639-43, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10482398

RESUMEN

An acidic toxic extract from the sea urchin T. pileolus inhibited time-dependent 45Ca2+ uptake in chick P2 fraction (IC50 about 10 ng/ml). This toxic extract is susceptible to trypsin. The inhibitory effect probably relate to Na+/Ca2+ exchanger.


Asunto(s)
Química Encefálica/efectos de los fármacos , Calcio/metabolismo , Pollos/metabolismo , Toxinas Marinas/farmacología , Erizos de Mar/química , Extractos de Tejidos/farmacología , Animales , Radioisótopos de Calcio , Cromatografía por Intercambio Iónico , Hidrólisis , Técnicas In Vitro , Cinética , Toxinas Marinas/química , Desnaturalización Proteica , Extractos de Tejidos/química , Tripsina
8.
Neurochem Res ; 24(8): 1059-66, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10478946

RESUMEN

The proportions of calcium (Ca2+) channel subtypes in chick or rat P2 fraction and NG 108-15 cells were investigated using selective L-, N-, P- and P/Q- type Ca2+ channel blockers. KCl-stimulated 45Ca2+ uptake by chick P2 fraction was blocked by 40-50% using N-type Ca2+ channel blockers [omega-conotoxin GVIA, aminoglycoside antibiotics and dynorphin A(1-13)], but was not inhibited by P- or P/Q-type blockers (omega-agatoxin IVA or omega-conotoxin MVIIC). On the other hand, KCl-stimulated 45Ca2+ uptake by rat P2 fraction was blocked by 30 approximately 40% using P- or P/Q-type Ca2+ channel blockers, but was not inhibited by N-type Ca2+ channel blockers. The L-type Ca2+ channel blockers 1,4-dihydropyridines, diltiazem and verapamil, but not calciseptine (CaS), inhibited both KCl-stimulated 45Ca2+ uptake and veratridine-induced 22Na+ uptake by chick or rat P2 fraction with similar IC50 values. CaS did not have any effect on 45Ca2+ uptake by either chick or rat P2 fraction. In NG108-15 cells, CaS, omega-agatoxin IVA and omega-conotoxin MVIIC, but not omega-conotoxin GVIA, inhibited KCl-stimulated 45Ca2+ uptake by 30-40%. Various combinations of these Ca2+ channel blockers had no significant additional effects in chick or rat P2 fraction or NG 108-15 cells. These findings suggest that KCl-stimulated 45Ca2+ uptake by chick or rat P2 fraction and NG 108-15 cells is a convenient and useful model for screening whether or not natural or synthetic substances have selective effects as L-, N-, P-, or P/Q- type Ca2+ channel antagonists or agonists.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/metabolismo , Animales , Calcio/metabolismo , Canales de Calcio/clasificación , Línea Celular , Pollos , Ratas , Ratas Wistar , Sodio/metabolismo , Veratridina/farmacología
9.
Biol Pharm Bull ; 22(12): 1279-83, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10746155

RESUMEN

The effects of toxic peaks (P-I, P-II and P-III eluted from Sephadex G-200 column) from the sea urchin Toxopneustes pileolus on time-dependent 45Ca2+ uptake in chick P2 fraction (crude synaptosome fraction) were studied under physiological ionic conditions. Time-dependent 45Ca2+ uptake was inhibited by P-II and P-III, but not by P-I. P-II had the greatest inhibitory effect. The inhibitory effect of P-II was not due to the inhibition of 45Ca2+ binding on P2 fraction, because P-II did not affect 45Ca2+ binding in osmotic-shocked P2 fraction. P-II did not affect KCl-stimulated 45Ca2+ uptake in P2 fraction, (Ca(2+)-Mg2+)-ATPase activity in the synaptic plasma membrane (SPM) fraction, or (Na(+)-K+)-ATPase and Mg(2+)-ATPase activities in osmotically-shocked P2 fraction. In contrast, the Na+/Ca2+ exchanger blocker 2',4'-dichlorobenzamil (DCB; 100 microM), with a poor specificity, inhibited not only time-dependent 45Ca2+ uptake but also KCl-stimulated 45Ca2+ uptake, (Ca(2+)-Mg2+)-ATPase, Mg(2+)-ATPase and (Na(+)-K+)-ATPase. Involvement of Na(+)-Ca2+ exchanger in the time-dependent 45Ca2+ uptake was ruled out, since it was not inhibited by replacement of Na+ with Li+ in reaction medium. These results suggested that the inhibition by P-II on time-dependent 45Ca2+ uptake appeared to be more specific than the commercially available Na+/Ca2+ exchanger blocker DCB, although the mechanism is not clear yet.


Asunto(s)
Encéfalo/efectos de los fármacos , Calcio/metabolismo , Erizos de Mar/química , Sinaptosomas/efectos de los fármacos , Ponzoñas/toxicidad , Animales , Encéfalo/metabolismo , Canales de Calcio/metabolismo , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , ATPasas Transportadoras de Calcio/metabolismo , Pollos , Intercambiador de Sodio-Calcio/antagonistas & inhibidores , Intercambiador de Sodio-Calcio/metabolismo , Sinaptosomas/metabolismo , Ponzoñas/aislamiento & purificación
10.
Biochim Biophys Acta ; 1325(2): 215-25, 1997 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-9168147

RESUMEN

We investigated whether the specific binding or labeling of 125I-omega-CgTX on crude membranes from chick whole brain was affected when endogenous GTP binding protein (G protein) was activated by GTP analogues, mastoparan (MP) and aluminum fluoride (AIF4-; AICl3 + NaF). Both GTPgammaS and Gpp(NH)p attenuated the inhibitory effect of selective N-type Ca channel inhibitors such as aminoglycoside antibiotics (AGs) or dynorphine (1-13)(Dyn) on specific 125I-omega-CgTX binding in a dose-dependent manner. On the other hand, the inhibitory effects of the divalent metal cations Cd2+, Co2+, Mg2+ and Mn2- on such binding were not attenuated by GTPgammaS. MP and AIF4- also attenuated the inhibitory effect of Neo on this binding similar to GTPgammaS. The attenuating effect of MP was enhanced by the presence of Mg2+ in a dose-dependent manner. However, GTP analogues, MP and AIF4-, did not affect binding or labeling without AGs or Dyn. GTPgammaS, MP and AIF4- also attenuated the specific labeling of a 215-kDa band in crude membranes with 125I-omega-CgTX using the cross-linker DSS (non-reduced condition) in the presence of Neo. These results indicate that there are direct or indirect relationships between N-type Ca channels and G proteins via binding sites for AGs or MP.


Asunto(s)
Compuestos de Aluminio/farmacología , Fluoruros/farmacología , Proteínas de Unión al GTP/metabolismo , Guanosina Trifosfato/análogos & derivados , Péptidos/metabolismo , Venenos de Avispas/farmacología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Pollos , Péptidos y Proteínas de Señalización Intercelular , Radioisótopos de Yodo , omega-Conotoxina GVIA
11.
Neurochem Res ; 21(6): 675-80, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8829139

RESUMEN

Specific binding and specific labeling of 125I-omega-CgTX were investigated in crude membranes from both subfractionated fractions and various brain areas in chick whole brain. The specific activities of the marker enzymes 2',3'-cyclic nucleotide 3'-phosphorylase, Na/K ATPase and succinic dehydrogenase in the subfractionated fractions were three- to five-fold higher than those in the P2 fraction. However, the amount of specific [125I] omega-CgTX binding in the fractions of synaptosomes and synaptic plasma membranes was only about 1.2-times higher than that in the P2 fraction. The characteristics of specific 125I-omega-CgTX labeling with disuccinimidyl suberate to the 135-kDa band were generally comparable to those of specific [125I] omega-CgTX binding sites. These results suggest that the specific binding sites of [125I] omega-CgTX were not localized the synaptosomes and synaptic plasma membranes fractions, although each fraction was well isolated from the others from which were decided by the strength of specific activity for marker enzymes.


Asunto(s)
Encéfalo/metabolismo , Bloqueadores de los Canales de Calcio/metabolismo , Venenos de Moluscos/metabolismo , Péptidos/metabolismo , Fracciones Subcelulares/metabolismo , Animales , Encéfalo/enzimología , Encéfalo/ultraestructura , Pollos , Radioisótopos de Yodo , Membranas/enzimología , Membranas/metabolismo , Ensayo de Unión Radioligante , Fracciones Subcelulares/enzimología , omega-Conotoxina GVIA
12.
Am J Kidney Dis ; 26(1): 72-9, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7611272

RESUMEN

We report a patient with anti-glomerular basement membrane disease who developed renal failure associated with systemic manifestations, including acute-phase inflammatory reactions and plasmacytosis. Renal tissue obtained by an open surgical biopsy showed circumferential cellular crescents, multinucleated giant cells, and exudation of fibrin in all glomeruli. Immunofluorescence microscopy demonstrated deposition of immunoglobulin G, C3, and membrane attack complex along glomerular capillary walls. Multinucleated giant cells were suggested to be macrophage-monocyte lineage because they were CD68 positive. Bone marrow aspiration showed an increase of plasma cells. Immunostaining showed intensive expression of interleukin-6 (IL-6) in practically every part of the renal sites involving multinucleated cells, crescents, tubules, and infiltrating cells, suggesting that one of the sources of systemically elevated IL-6 was the kidney. Serum IL-6, anti-glomerular basement membrane antibody, and acute-phase proteins were markedly elevated, and returned dramatically to the normal level after corticosteroid therapy and plasmapheresis. We believe that IL-6 played an important role in the development of many symptoms in the present case.


Asunto(s)
Anticuerpos/inmunología , Células Gigantes/patología , Glomerulonefritis/inmunología , Interleucina-6/fisiología , Glomérulos Renales/inmunología , Anciano , Anticuerpos/metabolismo , Autoanticuerpos , Membrana Basal/inmunología , Médula Ósea/patología , Complemento C3/metabolismo , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Glomerulonefritis/metabolismo , Glomerulonefritis/patología , Humanos , Inmunoglobulina G/metabolismo , Interleucina-6/metabolismo , Glomérulos Renales/patología , Células Plasmáticas/patología
13.
Neurochem Res ; 20(4): 467-73, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7651585

RESUMEN

Characteristic of [125I]omega-conotoxin (omega-CgTX) labeling using bifunctional cross linker (dithio bis[succinimidyl propionate]:DSP) was systematically investigated in crude membranes from chick whole brain. [125I]omega-CgTX specifically labeled 216 kDa as a main and 236 kDa as a minor bands in the crude membranes under non-reduced condition, but not labeled under reduced condition. We investigated the effect of various Ca channel antagonists on [125I]omega-CgTX labeling with DSP in detail, and found that there is a strong correlation between the effects of Ca channel antagonists on [125I]omega-CgTX labeling of the 216 kDa band and specific [125I]omega-CgTX binding. These results suggest that labeling of the 216 kDa band under non-reduced condition with [125I]omega-CgTX using DSP involves the specific binding sites of [125I]omega-CgTX, perhaps including one of the neuronal N-type Ca channel subunits in the crude membranes.


Asunto(s)
Encéfalo/metabolismo , Bloqueadores de los Canales de Calcio/metabolismo , Venenos de Moluscos/metabolismo , Péptidos/metabolismo , Animales , Pollos , Reactivos de Enlaces Cruzados , Radioisótopos de Yodo , Membranas/metabolismo , Unión Proteica , Succinimidas , omega-Conotoxina GVIA
14.
Biochim Biophys Acta ; 1233(1): 57-67, 1995 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-7833350

RESUMEN

Characteristics of specific 125I-omega-conotoxin GVIA (125I-omega-CgTX) binding and 125I-omega-CgTX labeling using bifunctional crosslinkers were systematically investigated in crude membranes from chick whole brain. Aminoglycosides and dynorphine A (1-13) inhibited the specific binding of 125I-omega-CgTX, but not that of the L-type calcium ion channel antagonist [3H](+)PN200-110. It seems likely that the inhibitory effect of dynorphine A (1-13) does not involve kappa-opiate receptors, based on results with the opiate receptor antagonist naloxone and the kappa-opiate receptor agonist U50488H. Spider venom, Cd2+ and La3+ inhibited the specific binding of 125I-omega-CgTX, as well as that of [3H](+)PN200-110. Various L-type Ca2+ channel antagonists did not affect the specific binding of 125I-omega-CgTX. 125I-omega-CgTX specifically labeled 135 kDa and 215 kDa bands in crude membranes under reduced and non-reduced conditions, respectively. The crosslinker disuccinimidyl suberate (DSS) yielded better 125I-omega-CgTX labeling than the other two crosslinkers tested. We investigated the effect of various Ca2+ channel antagonists on 125I-omega-CgTX labeling with DSS in detail, and found that there is a strong correlation between the effects of Ca2+ channel antagonists on 125I-omega-CgTX labeling of the 135 kDa band and specific 125I-omega-CgTX binding. These results suggest that aminoglycosides and dynorphine A (1-13) are specific inhibitors of specific 125I-omega-CgTX binding, and that labeling of the 135 kDa band with 125I-omega-CgTX using DSS involves the specific binding sites of 125I-omega-CgTX, perhaps including one of the neuronal N-type Ca2+ channel subunits in the crude membranes.


Asunto(s)
Canales de Calcio/metabolismo , Venenos de Moluscos/metabolismo , Péptidos/metabolismo , Marcadores de Afinidad , Animales , Encéfalo , Agonistas de los Canales de Calcio/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Pollos , Reactivos de Enlaces Cruzados/farmacología , Técnicas In Vitro , Indicadores y Reactivos/farmacología , Radioisótopos de Yodo , Isradipino/metabolismo , omega-Conotoxina GVIA
15.
Clin Nephrol ; 42(5): 331-6, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7851036

RESUMEN

We describe a 66-year-old man who developed renal failure related to granulomatous renal sarcoidosis without systemic manifestations. Renal failure was severe enough to require hemodialysis transiently. Renal biopsy of this patient revealed the central necrosis of the granuloma which is usually absent in sarcoid granuloma. Serum level of angiotensin converting enzyme (ACE) was not helpful for diagnosis in this patient because serum ACE level is often elevated in the condition of chronic renal failure. Immunohistochemical detection of ACE was of diagnostic value in this patient. Subsequent course in which glucocorticoid was used for therapy was consistent with the diagnosis. This is the first report of identification of ACE in renal sarcoid granuloma.


Asunto(s)
Enfermedades Renales/diagnóstico , Riñón/patología , Peptidil-Dipeptidasa A/análisis , Sarcoidosis/diagnóstico , Anciano , Biopsia , Técnica del Anticuerpo Fluorescente , Humanos , Riñón/enzimología , Enfermedades Renales/complicaciones , Enfermedades Renales/enzimología , Masculino , Microscopía Electrónica , Microscopía Fluorescente , Necrosis , Insuficiencia Renal/etiología , Sarcoidosis/complicaciones , Sarcoidosis/enzimología
16.
J Exp Med ; 180(5): 1619-27, 1994 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7525834

RESUMEN

The present work was designed to evaluate the effects of functional suppression of complement regulatory proteins in vivo. Male Wistar rats were anesthetized with Nembutal and were intravenously injected with 1 mg/kg of F(ab')2 or Fab fraction of either monoclonal antibody 5I2, which inhibits the function of rat counterpart of mouse Crry/p65, or monoclonal antibody 6D1, which inhibits the rat counterpart of CD59. Mean arterial pressure was continuously measured for 30 min. When 5I2 was injected, there was a biphasic change of mean arterial pressure, namely, the rapid increase immediately after the injection (approximately 2 min, phase 1) and the subsequent fall and slow recovery (approximately 4-30 min, phase 2). These effects were completely abrogated by pretreatment of rats with cobra venom factor. Pretreatment with carboxypeptidase inhibitor, which inhibits inactivation of anaphylatoxins C3a and C5a, induced enhanced reduction of blood pressure. Circulating leukocytes and platelets were rapidly decreased 5 min after antibody injection and became normal by 2 h. Hematocrit and erythrocyte count were continuously increased up to 2 h after injection, suggesting that there was hemoconcentration due to increased vascular permeability. Immunofluorescence study revealed binding of antibody fragments and rat C3 along the capillaries of lung, heart, and liver 5 min after injection. In contrast to 5I2, F(ab')2 fraction of 6D1, though localized to the same areas and in similar amounts, had no significant effect on the parameters measured. These data suggest that the rat counterpart of mouse Crry/p65 plays a vital role in vivo by preventing the activation of autologous complement on vascular endothelium.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos CD/fisiología , Activación de Complemento , Glicoproteínas de Membrana/fisiología , Receptores de Complemento/fisiología , Animales , Antígenos de Superficie , Presión Sanguínea , Antígenos CD59 , Permeabilidad Capilar , Complemento C3/metabolismo , Venenos Elapídicos/farmacología , Leucocitos/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratas , Ratas Wistar , Receptores de Superficie Celular , Receptores de Complemento 3b
17.
Kidney Int ; 46(1): 89-96, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7523758

RESUMEN

The kidney is an organ where complement-mediated tissue injuries take place by various stimuli. To assess how the kidney is protected from the autologous complement attack, comparative localization of decay accelerating factor (DAF), membrane cofactor protein (MCP) and 20 kDa homologous restriction factor (HRF20) was studied in the normal human kidney. Specific monoclonal antibodies to DAF, MCP and HRF20 were used for the study. Studies by immunofluorescence and immunoelectron microscopy showed that the distribution of each protein in the kidney was complementary to each other in most parts. MCP and HRF20 were clearly seen in the glomerular capillaries, while DAF was only faintly observed. Juxtaglomerular apparatus was abundant in DAF and MCP but not in HRF20. HRF20 was most strongly expressed in the peritubular capillaries where MCP was not detectable. Basolateral membranes of the proximal tubules and collecting ducts expressed MCP strongly, while there was no expression of DAF in the proximal tubules. Interestingly, both DAF and MCP, which inhibit complement activation at C3/C4 level, were not expressed in the apical portion of the tubular cells including proximal tubule brush border. In contrast, HRF20 was expressed on the apical part of the tubules. Medullary interstitium strongly expressed MCP but not DAF. Based on these observations, we conclude that each segment of the kidney is protected from the complement attack by the different combination of complement regulatory proteins. We speculate that the tubular cells might be fragile when complements are activated inside the tubular lumen, because there is no expression of complement regulatory proteins which inhibit C3 convertase.


Asunto(s)
Proteínas Inactivadoras de Complemento/análisis , Riñón/inmunología , Anticuerpos Monoclonales , Antígenos CD/análisis , Antígenos CD55 , Antígenos CD59 , Proteínas del Sistema Complemento , Técnica del Anticuerpo Fluorescente , Humanos , Riñón/ultraestructura , Proteína Cofactora de Membrana , Glicoproteínas de Membrana/análisis , Microscopía Inmunoelectrónica
18.
Jpn J Pharmacol ; 64(3): 209-12, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8022122

RESUMEN

We investigated the effects of various Ca channel agonists (Ca agonist) derived from 1,4-dihydropyridine on KCl-stimulated 45Ca uptake by differentiated and undifferentiated neuroblastoma x glioma hybrid NG108-15 cells with and without dibutyryl cAMP. Ca agonists Bay K 8644, YC-170 and CGP 28392 enhanced KCl-stimulated 45Ca uptake in differentiated NG108-15 cells, but only slightly in undifferentiated NG108-15 cells. The rank order of the enhancing effects was roughly Bay K 8644 > YC-170 > > CGP 28392. These results suggest that there is some difference between the mechanism by which these Ca agonists affect KCl-stimulated 45Ca uptake in differentiated and undifferentiated NG108-15 cells, although the nature of that difference is not clear.


Asunto(s)
Agonistas de los Canales de Calcio/farmacocinética , Calcio/farmacocinética , Células Híbridas/efectos de los fármacos , Células Híbridas/metabolismo , Bucladesina/farmacología , Radioisótopos de Calcio , Diferenciación Celular , Glioma , Humanos , Neuroblastoma , Cloruro de Potasio/farmacología , Estimulación Química , Células Tumorales Cultivadas
19.
Neurochem Res ; 18(11): 1137-44, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7902958

RESUMEN

Characteristics of specific 125I-omega-conotoxin (omega-CgTX) binding were systematically investigated in crude membranes from rat whole brain. Kd and Bmax Values for the binding were 49.7 pM and 181.5 fmol/mg of protein, respectively. The effects of various types of Ca channel antagonists on the binding were investigated. Dynorphin A (1-13), in particular, specifically inhibited 125I-omega-CgTX binding, but not that of [3H](+)PN200-110. Spider venom from Plectreurys tristes did not specifically inhibit specific binding of 125I-omega-CgTX, because the venom also inhibited the binding of [3H](+)PN200-110 to a similar degree. The amount of specific binding of 125I-omega-CgTX was less in the cerebellum than that in any other area of whole brain. The cross-linker disuccinimidyl suberate did not label with 125I-omega-CgTX and its binding sites in rat whole brain, although it did in chick whole brain, which was used as a positive control. These findings suggested that dynorphine A (1-13) was a selective blocker of omega-CgTX-sensitive Ca channels in crude membranes from rat whole brain and that omega-CgTX-sensitive Ca channels were mainly present a rat brain except cerebellum.


Asunto(s)
Encéfalo/metabolismo , Péptidos/metabolismo , Animales , Cationes , Membrana Celular/metabolismo , Reactivos de Enlaces Cruzados/farmacología , Dinorfinas/farmacología , Femenino , Radioisótopos de Yodo , Cinética , Masculino , Fragmentos de Péptidos/farmacología , Péptidos/farmacología , Proteínas Quinasas/metabolismo , Ratas , Ratas Wistar , Venenos de Araña/farmacología , Succinimidas/farmacología , omega-Conotoxina GVIA
20.
Neurochem Res ; 18(5): 625-32, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8386338

RESUMEN

The characteristics of KCl-stimulated 45Ca uptake by neuroblastoma X glioma hybrid NG108-15 cells induced to differentiate with dibutyryl cAMP (Bt2cAMP) and of PC12h pheochromocytoma cells induced to differentiate with nerve growth factor (NGF) were studied. The extent and rate of KCl-stimulated 45Ca uptake by differentiated NG108-15 cells induced with Bt2cAMP were significantly higher than those of the undifferentiated cells. However, differentiation of PC12h cells induced with NGF did not enhance their extent or rate of KCl-stimulated 45Ca uptake. The effects of Ca agonist and antagonists indicated that the characteristics of KCl-stimulated 45Ca uptake by Bt2cAMP-treated NG108-15 cells and NGF-treated PC12h cells mainly reflected those of peripheral L-type voltage-sensitive calcium channels activated by high KCl. These results suggest that differentiated neural cells did not all show an enhanced capacity for KCl-stimulated 45Ca uptake, although the characteristic patterns of differentiation (extension of neurite-like processes, etc.) and that of effect by Ca agonist or antagonists on NG108-15 cells and PC12h cells were similar.


Asunto(s)
Radioisótopos de Calcio/metabolismo , Glioma/metabolismo , Neuroblastoma/metabolismo , Células PC12/metabolismo , Cloruro de Potasio/farmacología , Animales , Bucladesina/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Cationes Bivalentes , Diferenciación Celular , Células Híbridas , Cinética , Factores de Crecimiento Nervioso/farmacología , Ratas , Células Tumorales Cultivadas
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