RESUMEN
BACKGROUND: Expression of the VLDL receptor, primarily in macrophages, has been confirmed in human and rabbit atherosclerotic lesions. The high binding affinity of the VLDL receptor for remnant particles implicates the VLDL receptor pathway in the foam cell formation mechanism in macrophages. This study investigates the effect of interferon (IFN)-gamma on VLDL receptor expression in phorbol-12-myristate-13-acetate (PMA)-treated THP-1, HL-60 macrophages, and human monocyte-derived macrophages. METHODS AND RESULTS: THP-1 cells were induced to differentiate into macrophages by PMA treatment. IFN-gamma was added to the medium, and expression of the VLDL receptor was determined. (125)I-beta-VLDL degradation study and oil red O staining were examined. In THP-1 macrophages, VLDL receptor protein expression decreased at 2 days after PMA treatment but increased at 3 days and increased up to 5 days. Scavenger receptor proteins, which were not originally present, appeared at 3 days after PMA treatment. IFN-gamma inhibited VLDL receptor expression in a dose-and time-dependent manner in macrophages. However, no inhibitory effect was observed in monocytes. Moreover, IFN-gamma receptor mRNA increased during differentiation to macrophages. (125)I-beta-VLDL degradation study and oil red O staining showed that IFN-gamma significantly inhibited foam cell formation after the uptake of beta-VLDL. LDL receptor-related protein (LRP) and LDL receptor mRNAs were not expressed in macrophages. In PMA-treated HL-60 macrophages and human monocyte-derived macrophages, IFN-gamma also inhibited VLDL receptor expression and foam cell formation by beta-VLDL. CONCLUSIONS: VLDL receptor expression is upregulated during monocyte-macrophage differentiation. IFN-gamma inhibits VLDL receptor expression and foam cell formation only in macrophages. Remnant particles induce macrophage foam cell formation through the VLDL receptor pathway.
Asunto(s)
Células Espumosas , Interferón gamma/farmacología , Macrófagos/efectos de los fármacos , Receptores de LDL/fisiología , Diferenciación Celular/fisiología , Células Espumosas/fisiología , Expresión Génica/efectos de los fármacos , Células HL-60 , Complejo Antigénico de Nefritis de Heymann , Humanos , Macrófagos/citología , Macrófagos/metabolismo , Glicoproteínas de Membrana/biosíntesis , Monocitos/citología , Receptores de LDL/biosíntesis , Células Tumorales CultivadasRESUMEN
Detection of shallow slow earthquakes offers insight into the near-trench part of the subduction interface, an important region in the development of great earthquake ruptures and tsunami generation. Ocean-bottom monitoring of offshore seismicity off southern Kyushu, Japan, recorded a complete episode of low-frequency tremor, lasting for 1 month, that was associated with very-low-frequency earthquake (VLFE) activity in the shallow plate interface. The shallow tremor episode exhibited two migration modes reminiscent of deep tremor down-dip of the seismogenic zone in some other subduction zones: a large-scale slower propagation mode and a rapid reversal mode. These similarities in migration properties and the association with VLFEs strongly suggest that both the shallow and deep tremor and VLFE may be triggered by the migration of episodic slow slip events.
RESUMEN
A UDP-glucuronyltransferase isoform glucuronizes phenolic xenobiotics such as 4-nitrophenol, and an isoform glucuronizing 4-hydroxybiphenyl has also been found in rat liver. We purified a UDP-glucuronyltransferase isoform glucuronizing 4-hydroxybiphenyl from bovine liver microsomes by solubilization with 0.7% sodium cholate followed by three column chromatographic separations using DEAE-Toyopearl 650S, UDP-hexanolamine Sepharose 4B, and hydroxyapatite. The purified bovine liver 4-hydroxybiphenyl UDP-glucuronyltransferase (named Bovine 4HBGT) had glucuronidation activities toward 4-hydroxybiphenyl and 4-methylumbelliferone but had little activity toward 4-nitrophenol and 1-naphthol. The apparent molecular mass of Bovine 4HBGT was 54,000 Da on SDS-PAGE, and this was decreased to 50,000 Da by digestion with endo-beta-N-acetylglucosaminidase H. These data suggest that Bovine 4HBGT consists of a 50,000 Da polypeptide and a high mannose type oligosaccharide chain(s) of about 4,000 Da. The NH2-terminal sequence of GT-3 was GKVLVWPVDFSXWINI. These properties of Bovine 4HBGT were very similar to those of rat UDP-glucuronyltransferase glucuronizing xenobiotics. However, the NH2-terminal sequence of Bovine 4HBGT had higher homology with that of rat liver 4-hydroxybiphenyl UDP-glucuronyltransferase than with that of rat liver 4-nitrophenol UDP-glucuronyltransferase.
Asunto(s)
Glucuronosiltransferasa/aislamiento & purificación , Microsomas Hepáticos/enzimología , Secuencia de Aminoácidos , Animales , Compuestos de Bifenilo/metabolismo , Catálisis , Bovinos , Cromatografía Liquida , Electroforesis en Gel de Poliacrilamida , Glucuronosiltransferasa/metabolismo , Himecromona/metabolismo , Masculino , Datos de Secuencia Molecular , Naftoles/metabolismo , Nitrofenoles/metabolismo , Homología de Secuencia de Aminoácido , Especificidad por SustratoRESUMEN
A 52-year-old female, who had undergone nephrectomy and ileocystostomy for right-renal tuberculosis and contracted bladder 19 years earlier was seen with anemia and metabolic acidosis. Radiographic findings demonstrated that the patient suffered from a giant vesical calculus. Cystolithotomy was performed and the removed calculus weighed 460 g. Of the 66 cases of giant vesical calculus weighing more than 200 g reported in our country only 7 were in females.
Asunto(s)
Íleon/cirugía , Yeyuno/cirugía , Cálculos de la Vejiga Urinaria/etiología , Vejiga Urinaria/cirugía , Anastomosis Quirúrgica/efectos adversos , Femenino , Humanos , Persona de Mediana Edad , Nefrectomía , Tuberculosis Renal/cirugía , Cálculos de la Vejiga Urinaria/cirugíaRESUMEN
Clinical significance of serum immunosuppressive acid protein (IAP) was evaluated on the basis of experience on 55 patients with genitourinary malignant disease and 49 control patients. Although the measurement of serum level of IAP is not good enough to diagnose early stage of cancer, patients with 800 micrograms/ml or more of serum IAP can be suspected to have malignant diseases. With the exception of prostatic cancer, both mean serum level and positive rate of IAP were higher in patients with high stage of disease than in those with low stage. Furthermore, on an individual basis, serum level of IAP was elevated with the progress of malignant tumor and was reduced with effective treatment. Thus, serum IAP is considered as a valuable nonspecific tumor marker in monitoring clinical course of genitourinary malignant diseases except for cancer of the prostate. In patients with advanced prostatic cancer, no definite correlation was seen between serum IAP and stage of disease, histopathological finding or serum prostatic acid phosphatase.
Asunto(s)
Biomarcadores de Tumor/sangre , Proteínas de Neoplasias/sangre , Neoplasias Urogenitales/diagnóstico , Adulto , Anciano , Femenino , Humanos , Masculino , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Pronóstico , Neoplasias de la Próstata/sangre , Neoplasias Urogenitales/patología , Neoplasias Urogenitales/terapiaRESUMEN
A 7-year-old girl was hospitalized with urinary incontinence. Intravenous pyelography showed the dilatation of upper segment of the right kidney, in which slight radioisotopic accumulation was detected on renal scintigraphy with 99mTc-DMSA. On computerized tomographic (CT) scan, a cystic mass shadow occupied the retroperitoneal space. During surgery, the right kidney was found to be completely duplicated and the ectopic ureter opened in Vestibule vaginae accompanied with midureteral stricture. The ectopic ureter was incised above the strictural site and anastomosed with the ureter of the lower segment. Although approximately 700 cases of ectopic ureter have been reported in Japan, congenital midureteral stricture accompanying ectopic ureter is extremely rare.
Asunto(s)
Uréter/anomalías , Obstrucción Ureteral/congénito , Niño , Constricción Patológica , Femenino , Humanos , Riñón/anomalías , Obstrucción Ureteral/complicaciones , Incontinencia Urinaria/etiologíaRESUMEN
OBJECTIVE: We studied on the efficacy of prostate specific antigen density (PSAD) for the detection of prostate cancer among patients with intermediate serum PSA levels. MATERIALS AND METHODS: Transrectal ultrasonography (TRUS) and transrectal prostate biopsy were performed in 103 patients whose PSA levels were 10 ng/ml or less despite positive digital rectal examination(DRE) or whose PSA levels were intermediate (4 to 10 ng/ml). Prostate volume was determined by TRUS and PSAD was calculated (serum PSA divided by volume of entire prostate volume). The rate of positive biopsy was compared with PSAD (more than 0.15 versus less than 0.15), DRE (positive versus negative) and patient's age (more than 61 versus 60 or less). RESULTS: The overall cancer detection rate was 43.7% in this study. There was no apparent correlation between patient's age and cancer detection rate when the patient's age was more than 61. DRE itself was not effective for the detection of prostate cancer in the patients whose PSA level was 10 ng/ml or less. Independent of DRE findings, the rate of positive biopsy was double in the patients whose PSAD was more than 0.15, compared with the patients whose PSAD was less than 0.15. CONCLUSIONS: For the early detection of prostate cancer, PSA density may be useful in the selection of patients for transrectal prostate biopsy.
Asunto(s)
Biomarcadores de Tumor/sangre , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/diagnóstico , Anciano , Eficiencia , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
We examined the involvement of the renin-angiotensin system in the maintenance of hypertension of the rat with congenital hydronephrosis having no urinary tract obstruction. The congenital hydronephrosis rat (HNR) had a significantly higher systolic blood pressure (181 +/- 9.5 mm Hg in the male bilateral hydronephrosis rat, BHN, at 13 weeks of age, n = 10) than control Wistar-Imamichi rats (126 +/- 5.8 mm Hg). The plasma renin activity and plasma angiotensin-II concentration of BHN were decreased to 20.1 and 24.6% of those of control rats, respectively. There was a negative correlation between plasma angiotensin-II concentration and blood pressure. In addition, the effect of captopril and indomethacin on the high blood pressure of BHNs was similar to that of human low-renin essential hypertension. These findings suggest that the renin-angiotensin system activity was markedly lowered and that the involvement of the system in the maintenance of hypertension in HNRs is small.
Asunto(s)
Hidronefrosis/congénito , Hipertensión Renal/etiología , Sistema Renina-Angiotensina/fisiología , Angiotensina II/sangre , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Antihipertensivos/uso terapéutico , Captopril/uso terapéutico , Inhibidores de la Ciclooxigenasa/uso terapéutico , Hidronefrosis/complicaciones , Hidronefrosis/fisiopatología , Hipertensión Renal/tratamiento farmacológico , Indometacina/uso terapéutico , Masculino , Ratas , Ratas Wistar , Renina/sangreRESUMEN
Duplex stability measured by the melting temperature (Tm) of the duplex between oligodeoxynucleotide whose one phosphate linkage is replaced by thiophosphate and its complementary DNA/RNA. The resultant Tm values were higher for Sp isomer than Rp isomer when DNA was a target. When RNA was a target, however, Rp isomers of 5'-dGCTsTCG-3' and 5'-dGCAsTCG-3' had higher stability than Sp isomers. NMR and CD spectra obtained for the duplexes of such isomers exhibited only small difference for the base protons around the phosphorothioate linkage and could not account for the difference in Tm. Temperature dependent NMR spectra showed broadening for the AH8 proton signal of Rp and for the TH6 proton resonance of Sp. This characteristic broadening may be indicative of the different melting behavior of the duplexes of the isomers.
Asunto(s)
ADN/química , ARN/química , Tionucleótidos/química , Dicroismo Circular , Espectroscopía de Resonancia Magnética , Estructura Molecular , Conformación de Ácido Nucleico , Oligodesoxirribonucleótidos/química , Soluciones , TemperaturaRESUMEN
We present herein the case of a 34-year-old man in whom obstructive jaundice was found to be caused by an impacted detached cholesterol polyp. A cholecystectomy with exploration of the common bile duct was performed after ultrasonography showed cholesterol polyps and stones in the gallbladder. Intraoperative cholangioscopy demonstrated an impacted cholesterol polyp at the distal end of the common bile duct which appeared to be detached from the gallbladder. To our knowledge, this is the first report of an impacted detached cholesterol polyp causing obstructive jaundice.
Asunto(s)
Colestasis Extrahepática/etiología , Colesterol , Conducto Colédoco , Neoplasias de la Vesícula Biliar/complicaciones , Pólipos/complicaciones , Adulto , Colangiopancreatografia Retrógrada Endoscópica , Colecistectomía , Colelitiasis/complicaciones , Colestasis Extrahepática/diagnóstico por imagen , Endoscopía , Vesícula Biliar/patología , Neoplasias de la Vesícula Biliar/patología , Neoplasias de la Vesícula Biliar/cirugía , Humanos , Masculino , Pólipos/patología , Pólipos/cirugíaRESUMEN
Oligodeoxycytidine phosphorothioate (PS-dCn, n = chain length), known to show virus inhibition ability by a mechanism other than the antisense one when n approximately 20, was explored for its solution structure by circular dichroism (CD) and ultraviolet (UV) absorption spectroscopy. For PS-dC4, when the strand concentration was higher than 10 microM, the respective 288-nm positive and 265-nm negative peaks appeared in the CD spectra at slightly acidic pHs and 0 degree C in the absence of salt, which is indicative of a four-stranded structure (namely, the i-motif). Strand concentration-dependent CD spectroscopy indicated that intermolecular association is responsible for this i-motif. The formation or i-motif was also characterized by UV absorption spectroscopy, in which the dissociation of this structure caused a sharp increase in the absorbance at 275 nm and a decrease at 305 nm. By plotting this change, the Tn values were estimated to be ca. 11 and 13 degrees C at 20 and 50 microM strand concentrations, respectively. Stability of the i-motif was compared between PS-dC, P-chiral diastereoisomers, and the Sp configuration produced a more stable structure than Rp. PS-dC20 was also investigated at physiological temperature, and the respective 288-nm positive and 265-nm negative peaks appeared at slightly acidic pH: it has been suggested that intermolecular folding was predominant above ca. 1 microM and that intramolecular folding dominated at low strand concentrations such as 0.05 microM. Gel-filtration chromatography and nondenaturing gel electrophoresis provided the supporting data for the four-stranded folding of PS-dC20.
Asunto(s)
Nucleótidos de Desoxicitosina/química , Oligodesoxirribonucleótidos/química , Tionucleótidos/química , Cromatografía en Gel , Dicroismo Circular , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Soluciones , Espectrofotometría Ultravioleta , TermodinámicaRESUMEN
We examined the responses on blood pressure when the renal vasoactive system such as renin-angiotensin-aldosterone system (RAAS) and kallikrein-kinin system (KKS) was activated by dietary salt restriction in the congenitally bilateral hydronephrotic rat (BHN). In a low salt diet (LS)-normotensive and normal kidney control rats after 8 weeks from initiating dietary salt restriction, the plasma sodium concentration (PNa) was retained at a level similar to that in the normal diet (ND)-control rats, and plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary kallikrein activity (UKA) were about 1.8-, 9.4-and 1.7-fold higher, respectively, than those in the ND-control rats. In addition, LS-control rats had a significantly (p < 0.001) high systolic blood pressure (163 +/- 2.0 mm Hg) compared with that (136 +/- 5.8) of ND-control rats. These results suggest that the activated renal vasoactive system acted for not only sodium retention but also for elevation of blood pressure in LS-control rats. In LS-BHN at week 8, PNa was also retained at a nearly normal level. However, the renal vasoactive system activation for sodium retention was higher than that of LS-control rats; that is, increase of PRA, PAC and UKA were about 3.8-, 24.7-and 10.0-fold, respectively, than in ND-BHN. The higher activation of RAAS, nevertheless, does not affect blood pressure in BHN; that is, both hypertension of BHN fed LS and ND developed similarly. These findings suggest that dietary salt restriction could markedly activate the renal vasoactive system for sodium retention without elevating blood pressure in BHN different from control rats.
Asunto(s)
Presión Sanguínea/fisiología , Dieta Hiposódica , Hidronefrosis/fisiopatología , Circulación Renal/fisiología , Aldosterona/sangre , Animales , Frecuencia Cardíaca/fisiología , Hidronefrosis/congénito , Hidronefrosis/dietoterapia , Calicreínas/orina , Masculino , Ratas , Renina/sangre , Sodio/sangre , Sodio/orina , Equilibrio Hidroelectrolítico/fisiologíaRESUMEN
1. The regulation of angiotensin II (AII) receptor subtypes was studied in peripheral tissues of 20 week old male spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) rats. 2. AII receptor binding was determined by a quantitative in vitro autoradiography using [125I]-[Sar1,Ile8]AII as a ligand on the kidney, adrenal gland, thoracic aorta and heart. CV-11974, a specific AT1 receptor antagonist, and CGP42112B, a specific AT2 antagonist, were used in competition with [125I]-[Sar1,Ile8]AII to differentiate AT1 and AT2 receptor binding. 3. The relative abundance of each subtype was very similar between SHR and WKY rats. In both strains of rats, the adrenal cortex contained predominantly AT1 receptors, while AT2 receptors predominated in the adrenal medulla. The kidney contained exclusively AT1 receptors over glomeruli, proximal tubules and outer medulla. AT1 receptors were predominant in the thoracic aorta and heart. 4. As for relative receptor density, important differences were observed between SHR and WKY rats. In SHR, the adrenal cortex, outer medulla of the kidney, and heart displayed higher AT1 receptor density than WKY rats. 5. These results indicate that the expression of AT1 receptors is differently regulated in some important targets of AII in SHR, and suggest that the altered regulation of AT1 receptor presented in this study should be relevant to the pathophysiological features of SHR.
Asunto(s)
Angiotensina II/metabolismo , Hipertensión/genética , Hipertensión/metabolismo , Receptores de Angiotensina/genética , Glándulas Suprarrenales/efectos de los fármacos , Glándulas Suprarrenales/metabolismo , Angiotensina I/metabolismo , Antagonistas de Receptores de Angiotensina , Animales , Autorradiografía , Bencimidazoles/farmacología , Compuestos de Bifenilo , Corazón/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/metabolismo , Masculino , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Miocardio/metabolismo , Oligopéptidos/farmacología , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Tetrazoles/farmacologíaRESUMEN
Inhibition of angiotensin (Ang) II type 1 (AT1) receptors in various target tissues of adult Sprague-Dawley rats was studied after single oral administration of TCV-116. The effects of TCV-116 on Ang II-receptor binding were assessed by quantitative in vitro autoradiography using 125I-[Sar1,Ile8]Ang II as a ligand. Four hours after the administration of TCV-116 (1 mg/kg), Ang II-receptor binding was markedly inhibited in the kidney (20% of control), adrenal cortex (27%), thoracic aorta (57%), heart (55%) and testis (76%) where AT1 receptors predominate. In the brain, orally administered TCV-116 produced a significant inhibition of binding both to the circumventricular organs (38%), which are devoid of the blood-brain barrier (BBB), and to the discrete regions within the BBB such as the paraventricular hypothalamic nucleus (48%), nucleus of the solitary tract (60%). Twenty-four hours after the administration, Ang II-receptor binding had partly recovered to approximately 50-85% of control levels. In contrast, throughout the experimental period, Ang II-receptor binding was little affected in sites where Ang II type 2 (AT2) receptors predominate such as the adrenal medulla and the nucleus of the inferior olive. These data indicate that orally administered TCV-116 specifically binds to AT1 receptors both in peripheral tissues and the central nervous system.
Asunto(s)
Antagonistas de Receptores de Angiotensina , Antihipertensivos/farmacología , Bencimidazoles/farmacología , Compuestos de Bifenilo/farmacología , Barrera Hematoencefálica/fisiología , Tetrazoles/farmacología , Administración Oral , Animales , Antihipertensivos/metabolismo , Autorradiografía , Bencimidazoles/metabolismo , Compuestos de Bifenilo/metabolismo , Masculino , Unión Proteica , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2 , Receptores de Angiotensina/clasificación , Receptores de Angiotensina/metabolismo , Tetrazoles/metabolismo , Distribución TisularRESUMEN
NMR analysis of d(C4T) showed the slow exchange between two distinct tetramers (each fully symmetric) in solution. For one tetramer, NOE cross-peak patterns characteristic of an i-motif structure (H1'-H1' and H6-H1'/H1'-H6) were observed between C1 and T5, indicating that this tetramer takes a completely intercalated conformation where the T5 residue is stacked on the C1.C1(+) pair of the other duplex (S-form). The other was found to be a tetramer in which one of the duplexes is shifted by one nucleotide unit (R-form), resulting in nonstacking 3' end thymidine residues and an equal number of stacked C.C+ pairs to that of the S-form. The same spectral features were observed for d(C3T) but neither for d(TC3) nor d(TC4), indicative of the critical role of the position of the thymidine residue in the tetrad isomerization. From NMR denaturation profiles, the S-forms were found to be more stable than the R-forms, and the linear relationship between the logarithm of the equilibrium constant (K = [tetramer]/[single]4) and the inverse of temperature (1/T) was confirmed for both forms, indicating conformity to the two-state transition model. Both enthalpy and entropy values of the formation of the S-form from four single strands were more negative than those of the R-form. The enthalpy term should contribute to the stabilization of the S-forms at low temperatures. The difference of the free energy values [DeltaG degrees(S-form) - DeltaG degrees(R-form)] was found to be -2.1 and -2.7 kJ.mol-1 at 20 degreesC for d(C4T) and d(C3T), respectively, explaining the higher stability of the S-forms. With increasing temperature, these two topologies were found to comparably exist at equilibrium in solution with slow exchange via dissociation to the single strands. A biological role of this topological isomerization is also suggested.
Asunto(s)
Citidina/química , Conformación de Ácido Nucleico , Composición de Base , Secuencia de Bases , Cromatografía en Gel , Dicroismo Circular , Resonancia Magnética Nuclear Biomolecular/métodos , Oligodesoxirribonucleótidos/química , Soluciones , Temperatura , TermodinámicaRESUMEN
Angiotensin II (Ang II) receptors were labelled by in vitro autoradiography using 125I-[Sar1,Ile8]Ang II as a ligand in the kidney, adrenal gland, thoracic aorta, and hindbrain of adult spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Ang II receptors were differentiated into subtypes by susceptibility to subtype 1 (AT1) and subtype 2 (AT2) antagonists. In both rat strains, the adrenal cortex contained predominantly AT1 receptors, while AT2 receptors predominated in the adrenal medulla. The kidney contained exclusively AT1 receptors in glomeruli, proximal tubules, and the outer medulla. AT1 receptors were predominant in the thoracic aorta. The nucleus of the solitary tract (NTS), dorsal motor nucleus of the vagus (DM10), area postrema, and spinal trigeminal nucleus (Sp5) contained exclusively AT1 receptors, whereas the nucleus of the inferior olive contained AT2 receptors predominantly. Significant differences in receptor density were observed between SHR and WKY. The adrenal cortex, renal outer medulla, NTS, DM10, and Sp5 displayed higher AT1 receptor density in SHR than in WKY. These results indicate that expression of AT1 receptors is regulated differently in important targets of Ang II in SHR, and suggest that altered regulation of AT1 receptor expression may be relevant to the pathogenesis of hypertension in SHR.
Asunto(s)
Hipertensión/metabolismo , Ratas Endogámicas SHR/metabolismo , Receptores de Angiotensina/análisis , Glándulas Suprarrenales/ultraestructura , Angiotensina II/análogos & derivados , Angiotensina II/metabolismo , Animales , Aorta Torácica/ultraestructura , Autorradiografía , Radioisótopos de Yodo , Riñón/ultraestructura , Masculino , Ratas , Ratas Endogámicas WKY , Receptores de Angiotensina/clasificación , Receptores de Angiotensina/metabolismo , Rombencéfalo/ultraestructuraRESUMEN
Angiotensin II (AT2) has been implicated in the growth and/or differentiation of its target tissues. In the present study, testicular AT2 receptor and its subtypes in hypophysectomized rats were examined using quantitative in vitro autoradiography and Northern blot analysis in an attempt to determine possible involvement of pituitary hormones in their expression. Prepubescent (3 weeks of age) male Sprague-Dawley rats underwent hypophysectomy or sham operation. From 10 days thereafter, they were treated with vehicle, growth hormone, human chorionic gonadotrophin or human menopausal gonadotrophin for 10 days. Testicular AT2 receptors were labelled with 125I-[Sar1,Ile8] AT2 and differentiated into its subtypes (AT1 and FAT2) according to their susceptibility to AT1 (losartan, 5 microM) and AT2 (CGP42112B, 1 microM) antagonists. Hypophysectomy led to a marked increase in AT2 receptor concentration (sham-operated rats: 0.7 +/- 0.2 fmol/mg protein, hypophysectomized rats: 2.5 +/- 0.6 fmol/mg protein, mean +/- SEM, n = 11-12, p < 0.01) with predominant occurrence of AT1 receptors. Both human chorionic gonadotrophin and human menopausal gonadotrophin decreased testicular AT2 receptor concentration, whereas growth hormone did not affect AT2 receptor expression. Northern blot analysis revealed both testicular AT1 and AT2 receptor mRNA expression to be significantly increased after hypophysectomy and reduced by gonadotrophin treatment. These results suggest that the expression of testicular AT2 receptors is regulated by pituitary gonadotrophins and that AT2 may play a role in testicular growth and/or differentiation.
Asunto(s)
Angiotensina II/metabolismo , Hipófisis/fisiología , Receptores de Angiotensina/metabolismo , Testículo/metabolismo , Animales , Peso Corporal , Expresión Génica , Humanos , Hipofisectomía , Masculino , Tamaño de los Órganos , ARN Mensajero , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2 , Receptores de Angiotensina/genéticaRESUMEN
Expression of testicular angiotensin II (AT2) receptors in Sprague-Dawley rats at various stages of development (1 and 5 days, 2, 3, 4 and 7 weeks postnatal) were studied by in vitro autoradiography and Northern blot analysis. The receptors were labelled with 125I-[Sar1, Ile8]AT2 and differentiated into two subtypes according to their susceptibility to AT1 (losartan, 5 microM) or AT2 (PD123319, 5 microM) antagonist. Total AT2 receptor binding in the testis was highest at 1 day of age (8.12 +/- 0.35 fmol/mg protein, mean +/- secEM, n = 8) and decreased gradually thereafter (5 days: 6.9 +/- 0.41, 2 weeks: 2.85 +/- 0.10, 3 weeks: 1.64 +/- 0.19, 4 weeks: 0.76 +/- 0.09, 6 weeks: 0.77 +/- 0.09 fmol/mg protein, n = 8-11). AT2 receptor binding was strikingly abundant in 1-day-old rat testis (6.98 +/- 0.34 fmol/mg protein), while considerably less AT1 receptor binding (1.46 +/- 0.19 fmol/mg protein) was observed. The relative amounts of each subtype did not change for the first 3 weeks but the 4-week-old rat testis contained almost exclusively AT1 receptors (0.63 +/- 0.05 fmol/mg protein). Northern blot analysis showed that mRNA expression of both AT1 and AT2 types decreased with age. Microscopic emulsion autoradiography was undertaken to clarify the localization of binding. At 10 days of age, both AT1 and AT2 receptors were present in the interstitial area, whereas seminiferous tubules contained mainly AT2 receptors. At 7 weeks of age, no significant binding was observed in the seminiferous tubule and the interstitial area contained AT1 receptors exclusively. These results demonstrate expression of AT2 receptors in the rapidly growing testis and suggest that change in the levels of AT2 receptor subtypes may be relevant to development and/or growth of the testis.
Asunto(s)
Angiotensina II/metabolismo , Receptores de Angiotensina/metabolismo , Testículo/metabolismo , Animales , Autorradiografía , Femenino , Expresión Génica , Radioisótopos de Yodo , Masculino , ARN Mensajero , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2 , Testículo/crecimiento & desarrolloRESUMEN
The duplex structures of the stereoregulated phosphorothioate DNAs, [R(p),R(p)]- and [S(p),S(p)]-[d(GC(ps)T(ps)ACG)] (ps, phosphorothioate; PS-DNA), with their complementary RNA have been investigated by combined use of (1)H NMR and restrained molecular dynamics calculation. Compared to those obtained for the unmodified duplex structures (PO-DNA.RNA), the NOE cross-peak intensities are virtually identical for the PS-DNA.RNA hybrid duplexes. The structural analysis on the basis of the NOE restraints reveals that all of the three DNA.RNA duplexes take a A-form conformation and that there is no significant difference in the base stacking for the DNA.RNA hybrid duplexes. On the other hand, the NOE cross-peak intensities of the protons around the central T(ps)A step of the PS-DNA.DNA duplexes are apparently different from those of PO-DNA. DNA. The chemical shifts of H8/6 and H1' at the T(ps)A step are also largely different among PS-DNA.DNAs and PO-DNA.DNA, suggesting that the DNA.DNA structure is readily changed by the introduction of the phosphorothioate groups to the central T(p)A step. The structure calculations indicate that all of these DNA.DNA duplexes are B-form although there exist some small differences in helical parameters between the [R(p),R(p)]- and [S(p),S(p)]PS-DNA.DNA duplexes. The melting temperatures (T(m)) were determined for all of the duplexes by plotting the chemical shift change of isolated peaks as a function of temperature. For the PS-DNA.RNA hybrid duplexes, the [S(p),S(p)] isomer is less stable than the [R(p),R(p)] isomer while this trend is reversed for the PS-DNA.DNA duplexes. Consequently, although the PS-DNA.RNA duplexes take the similar A-form structure, the duplex stability is different between PS-DNA.RNA duplexes. The stability of the DNA.RNA duplexes may not be governed by the A-form structure itself but by some other factors such as the hydration around the phosphorothioate backbone, although the T(m) difference of the DNA.DNA duplexes could be explained by the structural factor.
Asunto(s)
ADN/química , Ácidos Nucleicos Heterodúplex/química , Tionucleótidos/química , Calor , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido Nucleico , Oligodesoxirribonucleótidos/química , ARN Complementario/química , Estereoisomerismo , Relación Estructura-Actividad , Temperatura , TermodinámicaRESUMEN
AIM: We assessed the prolonged dysfunction of the left atrial appendage caused by paroxysmal atrial fibrillation. METHODS AND RESULTS: Transesophageal echocardiography with intravenous albumin-microspheres (Albunex, 0.2 ml/kg) was performed in 100 consecutive patients (44 patients in sinus rhythm without previous paroxysmal atrial fibrillation: 13 patients in sinus rhythm who had had previous episodes of paroxysmal atrial fibrillation; and 43 patients with sustained atrial fibrillation). We compared the left atrial appendage ejection fraction and degree of opacification in the left atrial appendage with Albunex in the groups. Patients with previous paroxysmal atrial fibrillation had lower left atrial appendage ejection fractions than patients in sinus rhythm without paroxysmal atrial fibrillation (33 +/- 14 vs. 47 +/- 14%, p < 0.001). More than half of the patients (7/13 [54%]) with previous paroxysmal atrial fibrillation showed delayed and incomplete opacification of the left atrial appendage with Albunex. CONCLUSION: We conclude that paroxysmal atrial fibrillation causes left atrial appendage stunning, at least in some patients.