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1.
J Clin Gastroenterol ; 53(5): e202-e207, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-29688916

RESUMEN

BACKGROUND AND GOALS: Gastrointestinal bleeding (GIB) is a significant complication following left ventricular assist device (LVAD) implantation. We evaluated the incidence, predictors, endoscopic findings, and outcomes of GIB in LVAD recipients. STUDY: Retrospective review of 205 adult patients undergoing HeartMate II LVAD implantation from January 2012 to June 2016. Patients were reviewed and separated into GIB (n=57; 28%) and non-GIB (n=148; 72%) groups. RESULTS: Median time to GIB was 55 (range, 3 to 730) days. The GIB group patients were older (61±12 vs. 56±13, P=0.0042), more often underwent concomitant tricuspid valve (TV) repair (16% vs. 4%, P=0.007), and a higher percentage were assigned for destination therapy (75% vs. 55%, P=0.01). Angioectasia (33%) was the most common identified cause of GIB. Median time to endoscopic intervention was 1 day. The total number of hospital readmissions after LVAD was higher in the GIB group (median of 5 vs. 3, P=0.001), as was the total number of blood products transfused after LVAD (29 vs. 13, P≤0.0001). GIB was associated with an increased risk of death (hazard ratio, 1.94; 95% confidence interval, 1.16-3.25; P=0.01) and the mortality rate during hospitalization for GIB was 11% (P=0.0004). Receiving a heart transplant was associated with a decreased hazard of death (hazard ratio, 0.40; 95% confidence interval, 0.19-0.85; P=0.016). CONCLUSIONS: Older age and destination therapy as implant strategy were found to be associated with an increased risk of GIB, consistent with previous studies. A unique finding in our study is the association of TV repair with a higher incidence of GIB. Further studies are needed to investigate possible mechanisms by which TV repair increases the incidence of GIB.


Asunto(s)
Hemorragia Gastrointestinal/epidemiología , Ventrículos Cardíacos , Corazón Auxiliar , Factores de Edad , Anticoagulantes/efectos adversos , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Nebraska/epidemiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Factores de Riesgo
2.
Catheter Cardiovasc Interv ; 92(1): 50-53, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29314555

RESUMEN

A 61-year-old man with a history of percutaneous coronary intervention (PCI) of the mid right coronary artery (RCA) with a drug eluting stent (DES), presented with non-ST segment elevation myocardial infarction. Coronary angiography demonstrated complex disease of the distal RCA as well as in-stent stenosis of the previously placed mid RCA stent. The patient underwent bifurcation PCI of the distal RCA followed by attempted intervention with a DES on the mid RCA lesion. The stent could not cross the lesion and eventually became dissociated from its delivery system. The lost stent was successfully retrieved using two different snaring systems. The procedure was terminated without further attempts for stent delivery. The patient had an uneventful recovery and underwent successful PCI of the mid RCA lesion one month later.


Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Cateterismo Cardíaco , Enfermedad de la Arteria Coronaria/terapia , Remoción de Dispositivos/métodos , Stents Liberadores de Fármacos , Migración de Cuerpo Extraño/terapia , Infarto del Miocardio sin Elevación del ST/terapia , Angioplastia Coronaria con Balón/efectos adversos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Migración de Cuerpo Extraño/diagnóstico por imagen , Migración de Cuerpo Extraño/etiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio sin Elevación del ST/diagnóstico por imagen , Infarto del Miocardio sin Elevación del ST/etiología , Diseño de Prótesis , Falla de Prótesis , Resultado del Tratamiento , Ultrasonografía Intervencional
3.
S D Med ; 71(1): 22-24, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29439300

RESUMEN

Infections are known complications of cardiovascular implantable electronic devices (CIEDs). We describe a case of a 62-year-old male who presented with pulseless electrical activity (PEA) cardiac arrest and respiratory failure. He had a history of cardiac resynchronization device and defibrillator (CRT-D) implantation for nonischemic cardiomyopathy. After resuscitation, he was found to have methicillin sensitive Staphylococcus aureus (MSSA) bacteremia on blood culture and large vegetations on the CRT-D lead and tricuspid valve found on echocardiography. The patient underwent extraction of the leads, but several large vegetations were present adherent to the tricuspid valve on intra-cardiac ultrasound (ICE). Due to comorbidities, the patient was not a candidate for surgical removal of these vegetations. Thus, he underwent percutaneous extraction of tricuspid and right atrial vegetations with the AngioVac device.


Asunto(s)
Desfibriladores Implantables/microbiología , Remoción de Dispositivos/métodos , Cardioversión Eléctrica , Infecciones Estafilocócicas/terapia , Staphylococcus aureus/aislamiento & purificación , Válvula Tricúspide/microbiología , Bacteriemia/diagnóstico , Bacteriemia/microbiología , Remoción de Dispositivos/instrumentación , Ecocardiografía , Atrios Cardíacos , Humanos , Masculino , Persona de Mediana Edad , Infecciones Estafilocócicas/diagnóstico por imagen , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Válvula Tricúspide/diagnóstico por imagen
5.
S D Med ; 70(11): 498-502, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29088521

RESUMEN

A 65-year-old male presented to the hospital with chest pain associated with recurrent syncope. He had a history of coronary artery disease and a long-standing history of smoking. While he was hospitalized, he had an episode of chest pain during which he was found to have transient ST segment elevation in the inferior leads. He was also noted to have a brief cardiac tachyarrhythmia. Coronary arteriography revealed vasospasm of the left anterior descending artery and right coronary artery, which were relieved to a significant extent after administration of intracoronary nitroglycerin. Subsequent angiograms and fractional flow reserve studies, demonstrated underlying non-obstructive coronary artery disease at the sites of spasm. No percutaneous coronary intervention was pursued. The patient was started on a calcium channel blocker on dismissal from the hospital. Upon follow up several months later, he remained free of symptoms that brought him to the hospital.


Asunto(s)
Angina Pectoris Variable/complicaciones , Dolor en el Pecho/etiología , Vasoespasmo Coronario/complicaciones , Síncope/etiología , Anciano , Angina Pectoris Variable/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Dolor en el Pecho/tratamiento farmacológico , Angiografía Coronaria , Vasoespasmo Coronario/tratamiento farmacológico , Electrocardiografía , Humanos , Masculino , Nitroglicerina/uso terapéutico , Vasodilatadores/uso terapéutico
6.
Blood Adv ; 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39093952

RESUMEN

The effect of prior inotuzumab ozogamicin (InO) treatment on brexucabtagene autoleucel (brexu-cel) outcomes remains unclear in adults with acute lymphoblastic leukemia (ALL), particularly the influence off previous InO response and the timing of administration. We conducted a retrospective multicenter analysis of 189 patients with relapsed/refractory (r/r) ALL treated with brexu-cel. Over half of the patients received InO before brexu-cel (InO-exposed). InO-exposed patients were more heavily pretreated (p= 0.02) and frequently had active marrow disease pre-apheresis (p= 0.03). Response rate and toxicity profile following brexu-cel were comparable for InO-exposed and InO-naïve; however, consolidation therapy post brexu-cel response was utilized at a higher rate in InO-naïve patients (p= 0.005). With a median follow up of 11.4 months, InO-exposed patients had inferior progression-free survival (PFS) (p=0.013) and overall survival (OS) (p=0.006) in univariate analyses; however, prior InO exposure did not influence PFS (HR 1.20, 95%CI, 0.71-2.03) in multivariate models. When InO-exposed patients were stratified according to prior InO response, InO responders had superior PFS (p=0.002) and OS (p<0.0001) relative to InO-refractory. The timing of administering InO did not affect brexu-cel outcomes, with comparable PFS (p=0.51) and OS (p=0.86) for patients receiving InO as bridging therapy or pre-apheresis. In conclusion, while InO exposure was associated with inferior survival outcomes following brexu-cel in unadjusted analyses, these associations were no longer significant in multivariate analyses, suggesting it is unlikely that InO negatively impacts brexu-cel efficacy. Our data instead imply that InO-exposed recipients of brexu-cel tend to be higher-risk patients with intrinsic adverse leukemia biology.

7.
Eur Heart J Case Rep ; 6(10): ytac383, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36237225

RESUMEN

Background: Loeys-Dietz syndrome (LDS) is a heritable disorder that presents with thoracic aortic aneurysm and/or dissection caused by a mutation in one of the transforming growth factor-B receptor or ligand genes. It is associated with widespread familial arterial aneurysm and rupture. Case summary: We present a case of a 70-year-old male with a family history of heritable thoracic aortic aneurysm disease who presented to the emergency department with chest pain. His presenting electrocardiogram was significant for ST elevation in the inferior leads with complete heart block. Computed tomography-angiography was done to rule out aortic dissection, which was negative for aortic dissection but did reveal 3.9 cm infrarenal abdominal aortic aneurysm and 2.7 cm bilateral iliac artery aneurysms. He was then taken for invasive angiography and was found to have aneurysmal dilation of the entire right coronary artery measuring up to 6 mm with 100% occlusion secondary to thrombus in the distal segment. He was found to have obstructive disease in the left anterior descending artery and first and second obtuse marginals (OMs). Genetic testing performed confirmed a pathogenic mutation in the TGFBRI gene (TGFBRI c.934G > A p.Gly312Ser) consistent with the diagnosis of LDS. Discussion: Although LDS is known to cause arterial aneurysms throughout the arterial tree, there have been no other cases of primary coronary aneurysms reported in this patient population. This case represents the first description of a patient with genetically confirmed LDS presenting with coronary artery aneurysm.

8.
JACC Case Rep ; 2(11): 1657-1661, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34317028

RESUMEN

Diagnostic coronary artery catheter knotting and kinking are uncommon but potentially catastrophic complications. Our case emphasizes the importance of avoiding this problem and provides recommendations for catheter retrieval in the unlikely event of this complication. To our knowledge, the technique used in our case has not been described before. (Level of Difficulty: Intermediate.).

9.
JACC Case Rep ; 1(4): 569-572, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34316880

RESUMEN

This is a case of a chronic left ventricular pseudoaneurysm after inferior myocardial infarction that remained clinically silent for 5 years before presenting with sudden rupture, leading to hemopericardium and cardiac tamponade. We discuss the importance of surveillance for left ventricular pseudoaneurysms, the limitations of echocardiography, and the critical role of computed tomography angiography imaging to establish the diagnosis and guide therapy. (Level of Difficulty: Beginner.).

10.
J Gen Physiol ; 125(6): 569-85, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15928403

RESUMEN

The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by the measurement of intracellular Na(+) activity ([Na(+)](i)) in polarized rat fungiform taste receptor cells (TRCs) using fluorescence imaging and by chorda tympani (CT) taste nerve recordings. CT responses were monitored during lingual stimulation with ethanol solutions containing NaCl or KCl. CT responses were recorded in the presence of Bz (a specific blocker of the epithelial Na(+) channel [ENaC]) or the vanilloid receptor-1 (VR-1) antagonists capsazepine or SB-366791, which also block the Bz-insensitive salt taste receptor, a VR-1 variant. CT responses were recorded at 23 degrees C or 42 degrees C (a temperature at which the VR-1 variant salt taste receptor activity is maximally enhanced). In the absence of permeable cations, ethanol induced a transient decrease in TRC volume, and stimulating the tongue with ethanol solutions without added salt elicited only transient phasic CT responses that were insensitive to elevated temperature or SB-366791. Preshrinking TRCs in vivo with hypertonic mannitol (0.5 M) attenuated the magnitude of the phasic CT response, indicating that in the absence of mineral salts, transient phasic CT responses are related to the ethanol-induced osmotic shrinkage of TRCs. In the presence of mineral salts, ethanol increased the Bz-insensitive apical cation flux in TRCs without a change in cell volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a transient phasic component and a sustained tonic component. Ethanol increased the Bz-insensitive NaCl CT response. This effect was further enhanced by elevating the temperature from 23 degrees C to 42 degrees C, and was blocked by SB-366791. We conclude that in the presence of mineral salts, ethanol modulates the Bz-insensitive VR-1 variant salt taste receptor.


Asunto(s)
Depresores del Sistema Nervioso Central/farmacología , Etanol/farmacología , Receptores de Droga/efectos de los fármacos , Cloruro de Sodio/farmacología , Sodio/metabolismo , Gusto/efectos de los fármacos , Amilorida/análogos & derivados , Amilorida/farmacología , Anilidas/farmacología , Animales , Capsaicina/análogos & derivados , Capsaicina/farmacología , Tamaño de la Célula/efectos de los fármacos , Nervio de la Cuerda del Tímpano/efectos de los fármacos , Cinamatos/farmacología , Citosol/efectos de los fármacos , Citosol/metabolismo , Diuréticos/farmacología , Femenino , Concentración Osmolar , Ratas , Ratas Sprague-Dawley , Receptores de Droga/antagonistas & inhibidores , Temperatura , Lengua/efectos de los fármacos , Lengua/inervación , Lengua/fisiología
11.
J Gen Physiol ; 125(6): 587-600, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15928404

RESUMEN

The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by direct measurement of intracellular Na(+) activity ([Na(+)](i)) using fluorescence imaging in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) taste nerve recordings. CT responses to KCl and NaCl were recorded in Sprague-Dawley rats, and in wild-type (WT) and vanilloid receptor-1 (VR-1) knockout mice (KO). CT responses were monitored in the presence of Bz, a specific blocker of the epithelial Na(+) channel (ENaC). CT responses were also recorded in the presence of agonists (resiniferatoxin and elevated temperature) and antagonists (capsazepine and SB-366791) of VR-1 that similarly modulate the Bz-insensitive VR-1 variant salt taste receptor. In the absence of mineral salts, ethanol induced a transient decrease in TRC volume and elicited only transient phasic CT responses. In the presence of mineral salts, ethanol increased the apical cation flux in TRCs without a change in volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a phasic component and a sustained tonic component. At concentrations <50%, ethanol enhanced responses to KCl and NaCl, while at ethanol concentrations >50%, those CT responses were inhibited. Resiniferatoxin and elevated temperature increased the sensitivity of the CT response to ethanol in salt-containing media, and SB-366791 inhibited the effect of ethanol, resiniferatoxin, and elevated temperature on the CT responses to mineral salts. VR-1 KO mice demonstrated no Bz-insensitive CT response to NaCl and no sensitivity to ethanol. We conclude that ethanol increases salt taste sensitivity by its direct action on the Bz-insensitive VR-1 variant salt taste receptor.


Asunto(s)
Depresores del Sistema Nervioso Central/farmacología , Nervio de la Cuerda del Tímpano/efectos de los fármacos , Etanol/farmacología , Receptores de Droga/efectos de los fármacos , Cloruro de Sodio/farmacología , Gusto/efectos de los fármacos , Algoritmos , Amilorida/análogos & derivados , Amilorida/farmacología , Anilidas/farmacología , Animales , Capsaicina/análogos & derivados , Capsaicina/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Polaridad Celular/fisiología , Cinamatos/farmacología , Diterpenos/farmacología , Diuréticos/farmacología , Femenino , Técnicas In Vitro , Ratones , Ratones Noqueados , Ratas , Ratas Sprague-Dawley , Receptores de Droga/antagonistas & inhibidores , Receptores de Droga/genética , Sodio/metabolismo , Estimulación Química , Umbral Gustativo/efectos de los fármacos , Temperatura , Lengua/citología , Lengua/ultraestructura
12.
J Gen Physiol ; 120(6): 793-815, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12451050

RESUMEN

Mixture interactions between sour and salt taste modalities were investigated in rats by direct measurement of intracellular pH (pH(i)) and Na(+) activity ([Na(+)](i)) in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) nerve recordings. Stimulating the lingual surface with NaCl solutions adjusted to pHs ranging between 2.0 and 10.3 increased the magnitude of NaCl CT responses linearly with increasing external pH (pH(o)). At pH 7.0, the epithelial sodium channel (ENaC) blocker, benzamil, decreased NaCl CT responses and inhibited further changes in CT responses induced by varying pH(o) to 2.0 or 10.3. At constant pH(o), buffering NaCl solutions with potassium acetate/acetic acid (KA/AA) or HCO(3)(-)/CO(2) inhibited NaCl CT responses relative to CT responses obtained with NaCl solutions buffered with HEPES. The carbonic anhydrase blockers, MK-507 and MK-417, attenuated the inhibition of NaCl CT responses in HCO(3)(-)/CO(2) buffer, suggesting a regulatory role for pH(i). In polarized TRCs step changes in apical pH(o) from 10.3 to 2.0 induced a linear decrease in pH(i) that remained within the physiological range (slope = 0.035; r(2) = 0.98). At constant pH(o), perfusing the apical membrane with Ringer's solutions buffered with KA/AA or HCO(3)(-)/CO(2) decreased resting TRC pH(i), and MK-507 or MK-417 attenuated the decrease in pH(i) in TRCs perfused with HCO(3)(-)/CO(2) buffer. In parallel experiments, TRC [Na(+)](i) decreased with (a) a decrease in apical pH, (b) exposing the apical membrane to amiloride or benzamil, (c) removal of apical Na(+), and (d) acid loading the cells with NH(4)Cl or sodium acetate at constant pH(o). Diethylpyrocarbonate and Zn(2+), modification reagents for histidine residues in proteins, attenuated the CO(2)-induced inhibition of NaCl CT responses and the pH(i)-induced inhibition of apical Na(+) influx in TRCs. We conclude that TRC pH(i) regulates Na(+)-influx through amiloride-sensitive apical ENaCs and hence modulates NaCl CT responses in acid/salt mixtures.


Asunto(s)
Nervio de la Cuerda del Tímpano/efectos de los fármacos , Líquido Intracelular/efectos de los fármacos , Cloruro de Sodio/farmacología , Sodio/fisiología , Papilas Gustativas/efectos de los fármacos , Ácidos/farmacología , Animales , Nervio de la Cuerda del Tímpano/fisiología , Femenino , Concentración de Iones de Hidrógeno , Líquido Intracelular/fisiología , Ratas , Ratas Sprague-Dawley , Canales de Sodio/fisiología , Papilas Gustativas/fisiología
14.
Case Rep Cardiol ; 2015: 835952, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26664756

RESUMEN

A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient's workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV) thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

16.
J Physiol ; 556(Pt 1): 159-73, 2004 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-14724181

RESUMEN

The role of basolateral Na(+)-H(+) exchanger isoform-1 (NHE-1) was investigated in neural adaptation of rat taste responses to acidic stimuli, by direct measurement of intracellular pH (pH(i)) in polarized taste receptor cells (TRCs) and by chorda tympani (CT) taste nerve recordings. In TRCs perfused with CO(2)/HCO(3)(-)-free solution (pH 7.4), removal of basolateral Na(+) decreased pH(i) reversibly and zoniporide, a specific NHE-1 blocker, inhibited the Na(+)-induced changes in pH(i). The spontaneous rate of TRC pH(i) recovery from NH(4)Cl pulses was inhibited by basolateral zoniporide with a K(i) of 0.33microm. Exposure to basolateral ionomycin, reversibly increased TRC Ca(2+), resting pH(i), and the spontaneous rate of pH(i) recovery from an NH(4)Cl pulse. These effects of Ca(2+) on pH(i) were blocked by zoniporide. In in vivo experiments, topical lingual application of zoniporide increased the magnitude of the CT responses to acetic acid and CO(2), but not to HCl. Topical lingual application of ionomycin did not affect the phasic part of the CT responses to acidic stimuli, but decreased the tonic part by 50% of control over a period of about 1 min. This increased adaptation in the CT response was inhibited by zoniporide. Topical lingual application of 8-CPT-cAMP increased the CT responses to HCl, but not to CO(2), and acetic acid. In the presence of cAMP, ionomycin increased sensory adaptation to HCl, CO(2), and acetic acid. Thus, cAMP and Ca(2+) independently modulate CT responses to acidic stimuli. While cAMP enhances TRC apical H(+) entry and CT responses to strong acid, an increase in Ca(2+) activates NHE-1, and increases neural adaptation to all acidic stimuli.


Asunto(s)
Ácidos/farmacología , Adaptación Fisiológica , Nervio de la Cuerda del Tímpano/fisiología , Membranas Intracelulares/metabolismo , Células Receptoras Sensoriales/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Papilas Gustativas/fisiología , Cloruro de Amonio/farmacología , Animales , Nervio de la Cuerda del Tímpano/efectos de los fármacos , AMP Cíclico/metabolismo , Electrofisiología , Guanidinas/farmacología , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Ionomicina/farmacología , Ionóforos/farmacología , Pirazoles/farmacología , Ratas , Ratas Endogámicas , Ratas Sprague-Dawley , Células Receptoras Sensoriales/efectos de los fármacos , Sodio/farmacología , Acetato de Sodio/farmacología , Intercambiador 1 de Sodio-Hidrógeno , Papilas Gustativas/citología
17.
J Neurophysiol ; 91(3): 1297-313, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14602837

RESUMEN

mRNA for two Na(+)-H(+)-exchanger isoforms 1 and 3 (NHE-1 and NHE-3) was detected by RT-PCR in fungiform and circumvallate taste receptor cells (TRCs). Anti-NHE-1 antibody binding was localized to the basolateral membranes, and the anti-NHE-3 antibody was localized in the apical membranes of fungiform and circumvallate TRCs. In a subset of TRCs, NHE-3 immunoreactivity was also detected in the intracellular compartment. For functional studies, an isolated lingual epithelium containing a single fungiform papilla was mounted with apical and basolateral sides isolated and perfused with nominally CO(2)/HCO(3)(-)-free physiological media (pH 7.4). The TRCs were monitored for changes in intracellular pH (pH(i)) and Na(+) ([Na(+)](i)) using fluorescence ratio imaging. At constant external pH, 1) removal of basolateral Na(+) reversibly decreased pH(i) and [Na(+)](i); 2) HOE642, a specific blocker, and amiloride, a nonspecific blocker of basolateral NHE-1, attenuated the decrease in pH(i) and [Na(+)](i); 3) exposure of TRCs to basolateral NH(4)Cl or sodium acetate pulses induced transient decreases in pH(i) that recovered spontaneously to baseline; 4) pH(i) recovery was inhibited by basolateral amiloride, 5-(N-methyl-N-isobutyl)-amiloride (MIA), 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), HOE642, and by Na(+) removal; 5) HOE642, MIA, EIPA, and amiloride inhibited pH(i) recovery with K(i) values of 0.23, 0.46, 0.84, and 29 microM, respectively; and 6) a decrease in apical or basolateral pH acidified TRC pH(i) and inhibited spontaneous pH(i) recovery. The results indicate the presence of a functional NHE-1 in the basolateral membranes of TRCs. We hypothesize that NHE-1 is involved in sour taste transduction since its activity is modulated during acid stimulation.


Asunto(s)
Células Quimiorreceptoras/metabolismo , Células Quimiorreceptoras/fisiología , Intercambiadores de Sodio-Hidrógeno/metabolismo , Gusto/fisiología , Algoritmos , Cloruro de Amonio/farmacología , Animales , Tampones (Química) , Membrana Celular/enzimología , Inhibidores Enzimáticos/farmacología , Concentración de Iones de Hidrógeno , Inmunohistoquímica , Cinética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/fisiología , Sodio/metabolismo , Sodio/farmacología , Intercambiador 3 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidores , Intercambiadores de Sodio-Hidrógeno/biosíntesis
18.
J Physiol ; 558(Pt 1): 147-59, 2004 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-15146042

RESUMEN

The amiloride-insensitive salt taste receptor is the predominant transducer of salt taste in some mammalian species, including humans. The physiological, pharmacological and biochemical properties of the amiloride-insensitive salt taste receptor were investigated by RT-PCR, by the measurement of unilateral apical Na+ fluxes in polarized rat fungiform taste receptor cells and by chorda tympani taste nerve recordings. The chorda tympani responses to NaCl, KCl, NH4Cl and CaCl2 were recorded in Sprague-Dawley rats, and in wild-type and vanilloid receptor-1 (VR-1) knockout mice. The chorda tympani responses to mineral salts were monitored in the presence of vanilloids (resiniferatoxin and capsaicin), VR-1 antagonists (capsazepine and SB-366791), and at elevated temperatures. The results indicate that the amiloride-insensitive salt taste receptor is a constitutively active non-selective cation channel derived from the VR-1 gene. It accounts for all of the amiloride-insensitive chorda tympani taste nerve response to Na+ salts and part of the response to K+, NH4+ and Ca2+ salts. It is activated by vanilloids and temperature (> 38 degrees C), and is inhibited by VR-1 antagonists. In the presence of vanilloids, external pH and ATP lower the temperature threshold of the channel. This allows for increased salt taste sensitivity without an increase in temperature. VR-1 knockout mice demonstrate no functional amiloride-insensitive salt taste receptor and no salt taste sensitivity to vanilloids and temperature. We conclude that the mammalian non-specific salt taste receptor is a VR-1 variant.


Asunto(s)
Amilorida/farmacología , Diuréticos/farmacología , Canales Iónicos/fisiología , Sales (Química)/farmacología , Papilas Gustativas/fisiología , Gusto/fisiología , Animales , Cationes/metabolismo , Nervio de la Cuerda del Tímpano/fisiología , Femenino , Calor , Canales Iónicos/antagonistas & inhibidores , Canales Iónicos/genética , Mamíferos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Minerales/farmacología , Ratas , Ratas Sprague-Dawley , Canales Catiónicos TRPV , Papilas Gustativas/efectos de los fármacos , Termodinámica
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