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1.
Trop Anim Health Prod ; 55(2): 69, 2023 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-36749468

RESUMEN

This study aimed to determine the effects of coated cysteamine hydrochloride (CSH) and probiotics (PB) supplemented alone or in combination on feed intake, digestibility, ruminal fermentation, and blood metabolites of heifer beef cattle. Sixteen heifers (body weight = 210 ± 41 kg; age = 9 ± 2 months) were assigned according to a randomized complete block design in a 2 × 2 factorial arrangement. All animals were fed the basal diet, which contained an 82:17 concentrate-to-forage ratio, and the forage source was rice straw. The treatments were as follows: (1) 0% PB + 0 g/d CSH, (2) 0.1% PB + 0 g/d CSH, (3) 0% PB + 20 g/d CSH, and (4) 0.1% PB + 20 g/d CSH. The main effect of CSH supplementation has been found to improve feed intake (P < 0.05). There were no treatment interactions with nutrient digestibility or rumen fermentation parameters. Supplementation of CSH did not affect any of the variables evaluated, while probiotics supplementation increased DM digestibility due to the increases in CP and fiber fraction digestibility. Compared to controls and CSH, at 16 h post-feeding, heifers receiving probiotics tended (P = 0.07) to show 17% greater ruminal NH3-N concentration, but this effect was not evident at 2 h post-feeding. However, the main effects of probiotic supplementation showed a tendency to increase the number of total bacteria and fungal zoospores in the rumen at 2 h post-feeding. The blood triglyceride (BTG) concentration of heifers fed a diet supplemented with 20 g/d CSH and 0.1% probiotics was found to be greater than those fed CSH alone (P < 0.1) at 16 h post-feeding, and then, there were greater BTG concentrations than other treatments (P < 0.05) at 2 h post-feeding. In conclusion, the combination of CSH and PB did not potentiate the effects of probiotics on digestibility and rumen fermentation and had minimal effects on blood parameters.


Asunto(s)
Cisteamina , Probióticos , Bovinos , Animales , Femenino , Cisteamina/metabolismo , Cisteamina/farmacología , Fermentación , Digestión , Alimentación Animal/análisis , Suplementos Dietéticos , Dieta/veterinaria , Ingestión de Alimentos , Nutrientes , Rumen/metabolismo
2.
Anim Reprod Sci ; 249: 107186, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36638648

RESUMEN

In vitro follicle growth and oocyte maturation still has a series of limitations, since not all oocytes matured in vitro have the potential to develop in viable embryos. One of the factors associated with low oocyte quality is the generation of reactive oxygen species (ROS) during in vitro culture. Therefore, this review aims to discuss the role of non-enzymatic antioxidants in the control of oxidative stress during in vitro follicular growth, oocyte maturation and embryonic development. A wide variety of non-enzymatic antioxidants (melatonin, resveratrol, L-ascorbic acid, L-carnitine, N-acetyl-cysteine, cysteamine, quercetin, nobiletin, lycopene, acteoside, mogroside V, phycocyanin and laminarin) have been used to supplement culture media. Some of them, like N-acetyl-cysteine, cysteamine, nobiletin and quercetin act by increasing the levels of glutathione (GSH), while melatonin and resveratrol increase the expression of antioxidant enzymes and minimize oocyte oxidative stress. L-ascorbic acid reduces free radicals and reactive oxygen species. Lycopene positively regulates the expression of many antioxidant genes. Additionally, L-carnitine protects DNA against ROS-induced damage, while acteoside and laminarin reduces the expression of proapoptotic genes. Mogrosides increases mitochondrial function and reduces intracellular ROS levels, phycocyanin reduces lipid peroxidation, and lycopene neutralizes the adverse effects of ROS. Thus, it is very important to know their mechanisms of actions, because the combination of two or more antioxidants with different activities has great potential to improve in vitro culture systems.


Asunto(s)
Antioxidantes , Melatonina , Animales , Antioxidantes/farmacología , Especies Reactivas de Oxígeno/metabolismo , Melatonina/farmacología , Resveratrol/farmacología , Licopeno/farmacología , Quercetina/farmacología , Cisteamina/metabolismo , Cisteamina/farmacología , Ficocianina/metabolismo , Ficocianina/farmacología , Técnicas de Maduración In Vitro de los Oocitos/veterinaria , Estrés Oxidativo , Oocitos/fisiología , Glutatión/farmacología , Acetilcisteína/farmacología , Carnitina/metabolismo , Carnitina/farmacología , Ácido Ascórbico/farmacología , Desarrollo Embrionario
3.
J Anim Physiol Anim Nutr (Berl) ; 106(3): 471-484, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34397125

RESUMEN

In this study, high-throughput gene amplicon sequencing was used to investigate the effects of 6 treatments [2 levels of hemp seed oil (HSO) × 3 levels of cysteamine (CS)] on bacterial and fungal communities in the rumen of 30 crossbred dairy buffalo. Our results indicate that the total numbers of bacterial and fungal taxa were unaffected regardless of diet (p > 0.05), while the total number of archaea was affected (p < 0.05) by the interaction of HSO and CS. Compared with control treatment, microbial composition of archaea was strongly influenced by CS (p < 0.05), while the addition of HSO, CS or both had a weak effect on fungus and bacteria. In addition, there was a significant increase in the lactic acid content with the addition of HSO, and the addition of CS to the feed caused a significant decrease in the ratio of acetic acid to propionic acid, compared with control treatment (p < 0.05). Correlation analysis showed that Acetobacter was significantly positively correlated with the genera Pichia, Klebsiella and Acinetobacter. pH was found to have a significant effect on the methanogens, and total volatile fatty acids (VFA) had a strong correlation with Butyrivibrio. The strong influence of CS on some methanogens shows that it may have potential in the development of methane reduction interventions.


Asunto(s)
Microbiota , Rumen , Alimentación Animal/análisis , Animales , Archaea/genética , Bacterias , Búfalos , Cannabis , Cisteamina/metabolismo , Dieta/veterinaria , Suplementos Dietéticos/análisis , Ingestión de Alimentos , Femenino , Fermentación , Lactancia/fisiología , Metano/metabolismo , Extractos Vegetales , Rumen/metabolismo
5.
Poult Sci ; 97(10): 3594-3600, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-29850917

RESUMEN

This study aimed to investigate the effect of cysteamine hydrochloride (CSH) supplementation on the growth performance, opportunistic bacteria and enterotoxic markers, visceral lesions, glutathione turnover, and inflammatory factors of broilers fed diets contaminated with aflatoxin B1 (AFB1). One-day-old Arbor Acres broilers (n = 480) were randomly allocated to 4 treatments with 6 replicates of 20 chicks each for a 2 × 2 design with CSH (0 or 200 mg/kg) and AFB1 (0 or 40 µg/kg). The trial lasted for 42 d. Results showed that AFB1 negatively affected (P < 0.05) growth performance, opportunistic bacteria and enterotoxic markers, intestinal lesions, glutathione turnover, and inflammatory factors. The CSH increased (P < 0.05) feed intake and body weight gain. The enterotoxic status was relieved in the CSH treatments by reducing (P < 0.05) the populations of gut Escherichia coli, Gram-negative bacteria, serum diamine oxidase, and intestinal lesions. The CSH also increased (P < 0.05) serum reduced glutathione, glutathione s-transferases, and glutathione reductase, and decreased (P < 0.05) the mRNA levels of tumor necrosis factor-α, interleukin-6, and interleukin-1ß. Significant interactions (P < 0.05) were found on Gram-negative bacteria, diamine oxidase, and glutathione s-transferases. The results suggest that the CSH can improve glutathione turnover and reduce the risk of enterotoxic disease induced by AFB1 in broilers.


Asunto(s)
Pollos/fisiología , Cisteamina/metabolismo , Glutatión/metabolismo , Intestinos/efectos de los fármacos , Aflatoxina B1/administración & dosificación , Aflatoxina B1/toxicidad , Alimentación Animal/análisis , Animales , Pollos/crecimiento & desarrollo , Pollos/microbiología , Cisteamina/administración & dosificación , Dieta/veterinaria , Suplementos Dietéticos/análisis , Mucosa Intestinal/metabolismo , Intestinos/microbiología , Masculino , Distribución Aleatoria
6.
J Sci Food Agric ; 98(5): 1743-1750, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28859217

RESUMEN

BACKGROUND: Coated cysteamine hydrochloride (CC) was applied as a feed additive in animal production. The influence and the mechanisms of CC used as a feed additive in promoting meat quality in finishing pigs were investigated. RESULTS: Dietary CC supplementation increased (P < 0.05) the a* and H* values and reduced (P < 0.05) the L* value in the longissimus dorsi muscles at 48 h postmortem (P < 0.05). The deoxymyoglobin content was enhanced (P < 0.05) and the metmyoglobin and malondialdehyde contents were reduced (P < 0.05) in pigs fed the dietary CC. Pigs fed a dietary CC of 0.035 g kg-1 had a lower cooking loss (P < 0.05) and a higher a* (24 h) value in the longissimus dorsi muscles than pigs on control treatment. The messenger RNA expression of superoxide dismutase 1 was upregulated (P < 0.05) in the longissimus dorsi. CONCLUSION: Dietary supplementation with CC could improve antioxidant status and delay meat discoloration by improving glutathione levels and antioxidase activity after longer chill storage (for 48 h after slaughter). Dietary supplementation with CC at 0.035 g kg-1 may promote the stability of pork color by reducing oxidation. © 2017 Society of Chemical Industry.


Asunto(s)
Alimentación Animal/análisis , Cisteamina/metabolismo , Suplementos Dietéticos/análisis , Carne/análisis , Porcinos/metabolismo , Animales , Color , Femenino , Masculino , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Mioglobina/química , Mioglobina/metabolismo , Oxidación-Reducción
7.
PLoS One ; 10(9): e0139393, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26422009

RESUMEN

Dietary protein levels and cysteamine (CS) supplementation can affect growth performance and protein metabolism of pigs. However, the influence of dietary protein intake on the growth response of CS-treated pigs is unclear, and the mechanisms involved in protein metabolism remain unknown. Hence, we investigated the interactions between dietary protein levels and CS supplementation and the effects of dietary crude protein levels and CS supplementation on protein synthetic and degradative signaling in skeletal muscle of finishing pigs. One hundred twenty barrows (65.84 ± 0.61 kg) were allocated to a 2 × 2 factorial arrangement with five replicates of six pigs each. The primary variations were dietary crude protein (CP) levels (14% or 10%) and CS supplemental levels (0 or 700 mg/kg). The low-protein (LP) diets (10% CP) were supplemented with enough essential amino acids (EAA) to meet the NRC AA requirements of pigs and maintain the balanced supply of eight EAA including lysine, methionine, threonine, tryptophan, valine, phenylalanine, isoleucine, and leucine. After 41 days, 10 pigs per treatment were slaughtered. We found that LP diets supplemented with EAA resulted in decreased concentrations of plasma somatostatin (SS) (P<0.01) and plasma urea nitrogen (PUN) (P<0.001), while dietary protein levels did not affect other traits. However, CS supplementation increased the average daily gain (P<0.001) and lean percentage (P<0.05), and decreased the feed conversion ratio (P<0.05) and back fat (P<0.05). CS supplementation also increased the concentrations of plasma insulin-like growth factor 1 (IGF-1) (P<0.001), and reduced the concentrations of leptin, SS, and PUN (P<0.001). Increased mRNA abundance of Akt1 and IGF-1 signaling (P<0.001) and decreased mRNA abundance of Forkhead Box O (FOXO) 4 (P<0.01) and muscle atrophy F-box (P<0.001) were observed in pigs receiving CS. Additionally, CS supplementation increased the protein levels for the phosphorylated mammalian target of rapamycin (mTOR), eIF-4E binding protein 1, and ribosomal protein S6 kinase 1 (P<0.001). There were no interactions between dietary protein levels and CS supplementation for all traits. In conclusion, dietary protein levels and CS supplementation influenced growth and protein metabolism through independent mechanisms in pigs. In addition, LP diets supplemented with EAA did not affect growth performance and other traits except the concentrations of SS and PUN probably through maintenance of protein synthesis and degradation signaling. Moreover, CS supplementation improved growth performance by increasing plasma IGF-1 concentrations possibly through alterations of mTOR and Akt/FOXO signaling pathways in skeletal muscle of finishing pigs.


Asunto(s)
Alimentación Animal/análisis , Cisteamina/metabolismo , Dieta con Restricción de Proteínas , Proteínas en la Dieta/metabolismo , Suplementos Dietéticos , Músculo Esquelético/metabolismo , Sus scrofa , Aminoácidos Esenciales/metabolismo , Animales , Expresión Génica , Factor I del Crecimiento Similar a la Insulina/metabolismo , Redes y Vías Metabólicas , Músculo Esquelético/crecimiento & desarrollo , Biosíntesis de Proteínas , Proteolisis , ARN Mensajero/metabolismo , Porcinos , Serina-Treonina Quinasas TOR/metabolismo
8.
PLoS One ; 8(3): e58018, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23469259

RESUMEN

Although oocytes from prepubertal animals are found less competent than oocytes from adults, the underlying mechanisms are poorly understood. Using the mouse oocyte model, this paper has tested the hypothesis that the developmental potential of prepubertal oocytes is compromised due mainly to their impaired potential for glutathione synthesis. Oocytes from prepubertal and adult mice, primed with or without eCG, were matured in vitro and assessed for glutathione synthesis potential, oxidative stress, Ca(2+) reserves, fertilization and in vitro development potential. In unprimed mice, abilities for glutathione synthesis, activation, male pronuclear formation, blastocyst formation, cortical granule migration and polyspermic block were all compromised significantly in prepubertal compared to adult oocytes. Cysteamine and cystine supplementation to maturation medium significantly promoted oocyte glutathione synthesis and blastocyst development but difference due to maternal age remained. Whereas reactive oxygen species (ROS) levels increased, Ca(2+) storage decreased significantly in prepubertal oocytes. Levels of both catalytic and modifier subunits of the γ-glutamylcysteine ligase were significantly lower in prepubertal than in adult oocytes. Maternal eCG priming improved all the parameters and eliminated the age difference. Together, the results have confirmed our hypothesis by showing that prepubertal oocytes have a decreased ability to synthesize glutathione leading to an impaired potential to reduce ROS and to form male pronuclei and blastocysts. The resulting oxidative stress decreases the intracellular Ca(2+) store resulting in impaired activation at fertilization, and damages the microfilament network, which affects cortical granule redistribution leading to polyspermy.


Asunto(s)
Blastocisto/metabolismo , Glutatión/biosíntesis , Oocitos/metabolismo , Maduración Sexual/fisiología , Factores de Edad , Animales , Blastocisto/citología , Blastocisto/efectos de los fármacos , Calcio/metabolismo , Células Cultivadas , Gonadotropina Coriónica/farmacología , Medios de Cultivo , Cisteamina/metabolismo , Cisteamina/farmacología , Cistina/metabolismo , Cistina/farmacología , Combinación de Medicamentos , Técnicas de Cultivo de Embriones , Embrión de Mamíferos , Desarrollo Embrionario , Femenino , Fertilización In Vitro , Gonadotropinas Equinas/farmacología , Ratones , Oocitos/citología , Oocitos/efectos de los fármacos , Oocitos/crecimiento & desarrollo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo
9.
Res Vet Sci ; 87(3): 468-72, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19457525

RESUMEN

This study was conducted to determine the effects of cysteamine, hypotaurine and aminoacids solution (BME) on standard semen parameters, lipid peroxidation and antioxidant activities of Angora goat semen after the freeze-thawing process. Ejaculates collected from four Angora goats were evaluated and pooled at 37 degrees C. Semen samples, which were diluted with a Tris-based extender containing the antioxidants hypotaurine (5 mM) and cysteamine (5 mM), and an aminoacid solution (13%), and an extender containing no antioxidants (control), were cooled to 5 degrees C and frozen in 0.25-ml French straws in liquid nitrogen. Frozen straws were thawed individually at 37 degrees C for 20s in a water bath for evaluation. Supplementation with cysteamine, hypotaurine and BME caused significant (P<0.05) increases in sperm motility, and significant (P<0.05) decreases in total abnormality rates in comparison to the control group. While all in vitro treatments did not affect the acrosomal abnormality rates, hypotaurine and BME but not cysteamine significantly (P<0.05) increased the HOST results as compared to the control group. Supplementation with antioxidants and BME did not significantly affect MDA levels and CAT activity in comparison to the control group (P>0.05). The antioxidants hypotaurine and cysteamine decreased SOD activity when compared to the BME group and controls (P<0.001).


Asunto(s)
Aminoácidos/farmacología , Cisteamina/farmacología , Cabras/fisiología , Estrés Oxidativo , Preservación de Semen/veterinaria , Semen/efectos de los fármacos , Taurina/análogos & derivados , Aminoácidos/metabolismo , Animales , Criopreservación/métodos , Criopreservación/veterinaria , Crioprotectores , Cisteamina/metabolismo , Masculino , Semen/metabolismo , Análisis de Semen , Preservación de Semen/métodos , Taurina/metabolismo , Taurina/farmacología
10.
World J Gastroenterol ; 11(42): 6707-12, 2005 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-16425370

RESUMEN

AIM: To determine the in vivo and in vivo effects of cysteamine (CS) on expression and activity of H(+)-K(+)-ATPase of gastric mucosal cells in weaning piglets. METHODS: Eighteen litters of newborn Xinhuai piglets were employed in the in vivo experiment and allocated to control and treatment groups. From 12 d of age (D12), piglets in control group were fed basal diet, while the treatment group received basal diet supplemented with 120 mg/kg CS. Piglets were weaned on D35 in both groups. Six piglets from each group (n = 6) were slaughtered on D28 (one week before weaning), D35 (weaning), D36.5, D38, D42, and D45 (36 h, 72 h, one week and 10 d after weaning), respectively. Semi-quantitative RT-PCR was performed to determine the levels of H(+)-K(+)-ATPase mRNA in gastric mucosa. H(+)-K(+)-ATPase activity in gastric mucosa homogenate was also determined. Gastric mucosal epithelial cells from piglets through primary cultures were used to further elucidate the effect of CS on expression and activity of H(+)-K(+)-ATPase in vivo. Cells were treated for 20 h with 0.001, 0.01, and 0.1 mg/mL of CS (n = 4), respectively. The mRNA expression of H(+)-K(+)-ATPase and somatostatin (SS) as well as the H(+)-K(+)-ATPase activity were determined. RESULTS: in vivo, both mRNA expression and activity of H(+)-K(+)-ATPase in gastric mucosa of control group exhibited a trend to increase from D28 to D45, reaching a peak on D45, but did not show significant age differences. Furthermore, neither the mRNA expression nor the activity of H(+)-K(+)-ATPase was affected significantly by weaning. CS increased the mRNA expression of H(+)-K(+)-ATPase by 73%, 53%, 30% and 39% on D28 (P = 0.014), D35 (P = 0.017), D42 (P = 0.013) and D45 (P = 0.046), respectively. In accordance with the mRNA expression, H(+)-K(+)-ATPase activities were significantly higher in treatment group than in control group on D35 (P = 0.043) and D45 (P = 0.040). In vivo, CS exhibited a dose-dependent effect on mRNA expression and activity of H+-K+-ATPase. Both H(+)-K(+)-ATPase mRNA expression and activity in gastric mucosal epithelial cells were significantly elevated after 20 h of exposure to the moderate (H(+)-K(+)-ATPase expression: P=0.03; H(+)-K(+)-ATPase activity: P = 0.014) and high concentrations (H(+)-K(+)-ATPase expression: P=0.017; H(+)-K(+)-ATPase activity: P = 0.022) of CS. Significant increases in SS mRNA expression were observed to accompany the elevation of H(+)-K(+)-ATPase expression and activity induced by the moderate (P = 0.024) and high concentrations (P = 0.022) of CS. Low concentration of CS exerted no effects either on expression and activity of H(+)-K(+)-ATPase or on SS mRNA expression in cultured gastric mucosal epithelial cells. CONCLUSION: No significant changes are observed in mRNA expression and activity of H(+)-K(+)-ATPase in gastric mucosa of piglets around weaning from D28 to D45. CS increases expression and activity of gastric H(+)-K(+)-ATPase in vivo and in vivo. SS is involved in mediating the effect of CS on gastric H(+)-K(+)-ATPase expression and activity in weaning piglets.


Asunto(s)
Cisteamina/metabolismo , Mucosa Gástrica/enzimología , ATPasa Intercambiadora de Hidrógeno-Potásio/metabolismo , Destete , Animales , Células Cultivadas , Cisteamina/administración & dosificación , Dieta , Mucosa Gástrica/citología , Expresión Génica , ATPasa Intercambiadora de Hidrógeno-Potásio/genética , Porcinos
11.
Nephrology (Carlton) ; 9(2): 65-72, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15056264

RESUMEN

BACKGROUND: Aldehydes were identified in clinical solutions, including peritoneal dialysis (PD) and cryoprotection solutions, which were used to freeze cells, tissues and embryos. Aldehydes are associated with increased cellular injury and may contribute to peritoneal membrane damage that occurs in patients on peritoneal dialysis. Recently, it was demonstrated that aldehydes could be 'scavenged' from these solutions by using aminothiol compounds. Although aldehydes were removed during the scavenging process, the kinetics of scavenging and the products formed were not characterized. METHODS: Proton nuclear magnetic resonance (NMR) spectroscopy was used to investigate formaldehyde scavenging from an artificial PD solution supplemented with aminothiol compounds, cysteamine or l-cysteine. Artificial PD solutions were formulated on the basis of commercial PD solutions and consisted of 132 mmol/L NaCl, 0.25 mmol/L MgCl2, 1.25 mmol/L CaCl2, and buffered with lactate (4.0 mmol/L) and lacked d-glucose. Formaldehyde scavenging was a two-step process involving an intermediate step followed by the formation of stable thiazolidine compounds. These included the derivatives of cysteamine and l-cysteine; thiazolidine and thiazolidine-4-carboxylic acid, respectively. CONCLUSION: Scavenging with aminothiol compounds masked the destructive carbonyl group (C = O) of formaldehyde and formed a compound that has antioxidant properties. The addition of aminothiol compounds may improve the biocompatibility of commercial PD solutions.


Asunto(s)
Cisteamina/metabolismo , Cisteína/metabolismo , Soluciones para Diálisis , Formaldehído/metabolismo , Diálisis Peritoneal , Espectroscopía de Resonancia Magnética
12.
Biochem Mol Biol Int ; 41(2): 395-405, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9063580

RESUMEN

Cysteamine is oxidatively deaminated by lentil amine oxidase. It shows saturation kinetic K(m) = 9 x 10(-4) M like other substrates, but the aldehyde produced leads to loss of enzyme activity, which is restored by dialysis. When putrescine is the substrate of the amine oxidase cysteamine behaves like a competitive inhibitor, and shows Ki = 5 x 10(-5) M. The possible involvement of the oxidation of cysteamine and the inhibitory effects of thioacetaldehyde in the cystamine oxidation by amine oxidase is discussed.


Asunto(s)
Amina Oxidasa (conteniendo Cobre) , Cisteamina/metabolismo , Fabaceae/enzimología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Plantas Medicinales , Cistamina/metabolismo , Cinética , Modelos Químicos , Oxidación-Reducción , Oxígeno/metabolismo
13.
Biochemistry ; 29(1): 37-43, 1990 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-2322547

RESUMEN

The transport of exogenously supplied fluorescent analogues of aminophospholipids from the outer to inner leaflet in red blood cells (RBC) is dependent upon the oxidative status of membrane sulfhydryls. Oxidation of a sulfhydryl on a 32-kDa membrane protein by pyridyldithioethylamine (PDA) has been previously shown [Connor & Schroit (1988) Biochemistry 27, 848-851] to inhibit the transport of NBD-labeled phosphatidylserine (NBD-PS). In the present study, other sulfhydryl oxidants were examined to determine whether additional sites are involved in the transport process. Our results show that diamide inhibits the transport of NBD-PS via a mechanism that is independent of the 32-kDa site. This is shown by the inability of diamide to block labeling of the 32-kDa sulfhydryl with 125I-labeled PDA and to protect against PDA-mediated inhibition of NBD-PS transport. diamide-mediated inhibition, but not PDA-mediated inhibition, could be reversed by reduction with cysteamine or endogenous glutathione. Similarly, treatment of RBC with 5,5'-dithiobis(2-nitrobenzoic acid), which depletes endogenous glutathione and induces oxidation of endofacial proteins [Reglinski et al. (1988) J. Biol. Chem. 263, 12360-12366], inhibited NBD-PS transport in a manner analogous to diamide. Once established, the asymmetric distribution of NBD-PS could not be altered by oxidation of either site. These data indicate that a second site critical to the transport of aminophospholipids resides on the endofacial surface and suggest that the transport of aminophospholipids across the bilayer membrane of RBC depends on a coordinated and complementary process between a cytoskeletal component and the 32-kDa membrane polypeptide; both must be operative for transport to proceed.


Asunto(s)
4-Cloro-7-nitrobenzofurazano/análogos & derivados , Membrana Eritrocítica/metabolismo , Fosfatidilserinas/metabolismo , Benzoxazoles/metabolismo , Cisteamina/metabolismo , Citoesqueleto/metabolismo , Diamida/farmacología , Disulfuros/farmacología , Ácido Ditionitrobenzoico/farmacología , Glutatión/metabolismo , Humanos , Membrana Dobles de Lípidos/metabolismo , Proteínas de la Membrana/metabolismo , Oxidación-Reducción , Éteres Fosfolípidos/metabolismo , Piridinas/farmacología , Reactivos de Sulfhidrilo/farmacología
14.
Neuroendocrinology ; 41(6): 467-75, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-4080089

RESUMEN

Cysteamine (beta-mercaptoethylamine, MEA) is a naturally occurring sulfhydryl compound that depletes pituitary PRL, causes a reduction in brain and gut somatostatin (SRIF), and suppresses norepinephrine (NE) and epinephrine (EPI) synthesis by inhibition of dopamine-beta-hydroxylase (DBH). SRIF inhibits GH and TSH secretion, whereas, NE and EPI facilitate their release. The objectives of this investigation were to: (1) determine the dose-response and time course of DBH inhibition by MEA in vivo and in vitro, and correlate these findings with MEA tissue levels and (2) assess the function of SRIF and NE/EPI in regulation of episodic GH and TSH secretion using MEA. Animals were administered MEA (75-300 mg/kg, s.c.) and hypothalamic levels of dopamine (DA), NE, EPI, serotonin (5-HT) and MEA were measured by high-performance liquid chromatography (HPLC) and electrochemical detection. DBH activity was measured in vitro after exposure to MEA +/- N-ethylmaleimide (NEMI). Chronically cannulated rats were administered MEA (100 or 300 mg/Kg) and serial blood samples were removed in undisturbed animals, and after 30 min swimming stress. Cannulated rats with bilateral lesions of the ventromedial/arcuate nuclei (VMN/ARC) were administered MEA (150 mg/kg). MEA caused a dose-related decrease in NE/EPI nd in increase in DA at doses greater than or equal to 150 mg/kg. Tissue MEA was highest at 4 h (679 +/- 64 pM/mg tissue), but still measureable after 24 h. MEA inhibited DBH in vitro (95% inhibition at 10(-3) M); NEMI blocked inhibition. Stress-induced GH supression and corticosterone release were partially blocked by a low dose of MEA (100 mg/kg).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Catecolaminas/metabolismo , Cisteamina/farmacología , Dopamina beta-Hidroxilasa/antagonistas & inhibidores , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Núcleo Arqueado del Hipotálamo/fisiología , Corticosterona/sangre , Cisteamina/metabolismo , Cisteína/farmacología , Dopamina beta-Hidroxilasa/metabolismo , Hormona del Crecimiento/sangre , Hipotálamo/metabolismo , Masculino , Prolactina/sangre , Ratas , Ratas Endogámicas , Tirotropina/sangre , Núcleo Hipotalámico Ventromedial/fisiología
15.
Pediatr Res ; 19(11): 1170-4, 1985 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-4069825

RESUMEN

Cultured fibroblasts from mucolipidosis II (ML-II) patients demonstrated an elevated cystine content which increased with time in culture compared to fibroblasts from cystinotic patients or normal controls under the same conditions. In both cystinotic and ML-II cells the increased levels of cystine could be derived either from endogenous proteolysis or from in vitro supplementation of the cultured cells with cysteine-glutathione mixed disulfide. Cystine was depleted from both cell types by cysteamine. When cysteamine was replaced with complete medium, the cystine reaccumulated in both cystinotic and ML-II cells within 24 h, although a lag of 4 h was seen with ML-II cells. The intracellular location of the increased cystine in cultured fibroblasts was examined utilizing free-flow electrophoresis and found to be in the purified population of secondary lysosomes of both cystinotic and ML-II cells. White blood cell and hepatic cystine, which was greatly increased in cystinotic patients, was not elevated in ML-II patients. Compared to normal control fibroblasts the efflux of cystine from isolated granular fractions was virtually absent in cystinotic fibroblasts and considerably reduced in ML-II fibroblasts. The examination of such similarities and differences in cystine accumulation and transport in tissues from cystinotic and ML-II patients has provided some insight into the defects in these diseases.


Asunto(s)
Cistina/metabolismo , Cistinosis/metabolismo , Lisosomas/metabolismo , Mucolipidosis/metabolismo , Células Cultivadas , Cisteamina/metabolismo , Cisteína/metabolismo , Fibroblastos/metabolismo , Humanos , Leucocitos/metabolismo , Hígado/metabolismo
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