RESUMEN
It has been shown that extracellular glycosaminoglycans (GAGs) limit the gene transfer by cationic lipids and polymers. The purpose of this study was to clarify how interactions with anionic GAGs (hyaluronic acid and heparan sulfate) modify the cellular uptake and distribution of lipoplexes and polyplexes. Experiments on cellular DNA uptake and GFP reporter gene expression showed that decreased gene expression can rarely be explained by lower cellular uptake. In most cases, the cellular uptake is not changed by GAG binding to the lipoplexes or polyplexes. Reporter gene expression is decreased or blocked by heparan sulfate, but it is increased by hyaluronic acid; this suggests that intracellular factors are involved. Confocal microscopy experiments demonstrated that extracellular heparan sulfate and hyaluronic acid are taken into cells both with free and DNA-associated carriers. We conclude that extracellular GAGs may alter both the cellular uptake and the intracellular behavior of the DNA complexes.
Asunto(s)
Técnicas de Transferencia de Gen , Glicosaminoglicanos/fisiología , Liposomas/química , Adyuvantes Inmunológicos/farmacología , Medios de Contraste/farmacología , ADN/metabolismo , ADN/farmacocinética , Citometría de Flujo , Fluoresceína/farmacología , Genes Reporteros , Terapia Genética/métodos , Proteínas Fluorescentes Verdes , Heparitina Sulfato/farmacología , Ácido Hialurónico/farmacología , Proteínas Luminiscentes/metabolismo , Proteínas Luminiscentes/farmacocinética , Microscopía Confocal , Plásmidos/metabolismo , Unión Proteica , TransfecciónRESUMEN
OBJECTIVE: To monitor the concentration of markers of cartilage and synovium metabolism in the knee (stifle) joint synovial fluid of young beagles subjected to immobilisation and subsequent remobilisation. METHODS: The right hind limb of 17 dogs was immobilised in flexion for 11 weeks. Simultaneously, the contralateral left knee was exposed to increased weight bearing. The remobilisation period lasted 50 weeks. Litter mates served as controls. The concentration in joint lavage fluid of interleukin 1alpha (IL1alpha) was measured by immunoassay, the activity of phospholipase A(2) (PLA(2)) was determined by an extraction method, chondroitin sulphate (CS) concentration by precipitation with Alcian blue, hyaluronan (HA) by an ELISA-like assay using biotinylated HA-binding complexes, matrix metalloproteinase 3 (MMP-3), and tissue inhibitor of metalloproteinases 1 (TIMP-1) by sandwich ELISA, and synovitis was scored by light microscopy. RESULTS: Synovitis or effusion was absent in all experimental and control groups. Immobilisation decreased the joint lavage fluid levels of IL1alpha (p<0.05), TIMP (p< 0.05), and the concentration of CS down to 38% (p<0.05) in comparison with untreated litter mates with normal weight bearing. Immobilisation did not affect the activity of PLA(2), or the concentration of MMP-3 or HA in synovial fluid. Joint remobilisation restored the decreased concentrations of markers to control levels. Increased weight bearing did not change the concentrations of markers in comparison with the control joints with normal weight bearing. CONCLUSIONS: 11 weeks' joint immobilisation decreased the concentration of markers of cartilage and synovium metabolism in the synovial fluid, and remobilisation restored the concentrations to control levels. The changes in joint metabolism induced by immobilisation, as reflected by the markers, are thus different from those found in osteoarthritis, where increased levels of these markers are associated with enhanced degradation and synthesis. These findings suggest that the change induced in joint metabolism by immobilisation is reversible in its early stages.
Asunto(s)
Cartílago Articular/metabolismo , Inmovilización/fisiología , Líquido Sinovial/metabolismo , Animales , Biomarcadores/análisis , Sulfatos de Condroitina/metabolismo , Perros , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Interleucina-1/metabolismo , Movimiento/fisiología , Sinovitis/etiología , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Soporte de Peso/fisiologíaRESUMEN
Eighteen peptide-oligonucleotide phosphorothioate conjugates were prepared in good yield and thoroughly characterized with electrospray ionization mass spectra. When applied to the living cells, conjugates exhibiting membrane translocation and nuclear localization properties displayed efficient intracellular penetration but failed to show any serious antisense effect. Studies on the intracellular distribution of the fluorescein-labeled conjugates revealed their trapping in endosomes.
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Núcleo Celular/química , Oligonucleótidos/química , Oligopéptidos/química , Compuestos Organotiofosforados/química , Membrana Celular/química , Reactivos de Enlaces Cruzados , Disulfuros/química , Electroforesis en Gel de Poliacrilamida , Fluoresceína-5-Isotiocianato , Expresión Génica/genética , Hidrólisis , Luciferasas/biosíntesis , Luciferasas/genética , Espectrometría de Masas , Microscopía Confocal , Oligonucleótidos/síntesis química , Oligonucleótidos/metabolismo , Oligonucleótidos Antisentido/síntesis química , Oligonucleótidos Antisentido/química , Oligopéptidos/síntesis química , Oligopéptidos/metabolismo , Compuestos Organotiofosforados/síntesis química , Compuestos Organotiofosforados/metabolismo , Ribonucleasa HRESUMEN
The amygdaloid complex and hippocampal formation mediate functions involving emotion and memory. To investigate the connections that regulate the interactions between these regions, we injected the anterograde tracer Phaseolus vulgaris-leucoagglutinin into various divisions of the lateral, basal, and accessory basal nuclei of the rat amygdala. The heaviest projection to the entorhinal cortex originates in the medial division of the lateral nucleus which innervates layer III of the ventral intermediate and dorsal intermediate subfields. In the basal nucleus, the heaviest projection arises in the parvicellular division and terminates in layer III of the amygdalo-entorhinal transitional subfield. In the accessory basal nucleus, the parvicellular division heavily innervates layer V of the ventral intermediate subfield. The most substantial projection to the hippocampus originates in the basal nucleus. The caudomedial portion of the parvicellular division projects heavily to the stratum oriens and stratum radiatum of CA3 and CA1. The accessory basal nucleus projects to the stratum lacunosum-moleculare of CA1. The subiculum receives a substantial input from the caudomedial parvicellular division. The parasubiculum receives dense projections from the caudal portion of the medial division of the lateral nucleus, the caudomedial parvicellular division of the basal nucleus, and the parvicellular division of the accessory basal nucleus. Our data show that select nuclear divisions of the amygdala project to the entorhinal cortex, hippocampus, subiculum, and parasubiculum in segregated rather than overlapping terminal fields. These data suggest that the amygdaloid complex is in a position to modulate different stages of information processing within the hippocampal formation.
Asunto(s)
Amígdala del Cerebelo/anatomía & histología , Hipocampo/anatomía & histología , Ratas Wistar/anatomía & histología , Amígdala del Cerebelo/fisiología , Animales , Transporte Axonal , Calbindinas , Corteza Entorrinal/anatomía & histología , Corteza Entorrinal/fisiología , Hipocampo/fisiología , Inmunohistoquímica , Masculino , Modelos Neurológicos , Proteínas del Tejido Nervioso/análisis , Vías Nerviosas/fisiología , Neuronas/citología , Neuronas/fisiología , Fitohemaglutininas , Ratas , Proteína G de Unión al Calcio S100/análisisRESUMEN
OBJECTIVE: To further our understanding of the pathogenesis of chondromalacia of the patella (CM), we have studied the release into knee joint fluid and serum, obtained from patients with CM, of molecules associated with the metabolism of joint cartilage matrix and synovium. METHODS: Interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), stromelysin-1 (MMP-3), interstitial collagenase (MMP-1), tissue inhibitor for metalloproteinases-1 (TIMP-1), phospholipase activity A2 (PLA2), hyaluronan (HA), aggrecan fragments (AGN) and antigenic keratan sulfate (KS) were quantified in knee joint lavage fluid from 96 patients with CM; KS and HA also was measured in serum. Chondromalacia was graded on a scale of I to IV according to Outerbridge (1961). The histopathology of the synovial membrane close to the patellofemoral joint was evaluated. Control samples were obtained from nine patients with knee pain presenting with arthroscopically normal knee joints. RESULTS: The concentrations of MMP-3, MMP-1 and TIMP-1 proteins in joint lavage fluid were increased in advanced (grade IV) CM, compared with controls. Levels of MMP-1 in lavage fluid correlated with the severity of CM (r = 0.38, P < 0.01) and MMP-1 and MMP-3 concentrations correlated with each other (r = 0.45, P < 0.001). TIMP-1 was elevated in grade IV CM compared with grades II and III CM (P < 0.02, P < 0.01). Interleukins (IL-1 alpha, IL-1 beta and IL-6) showed no significant change in CM. The lavage fluid level of PLA2 increased with the severity of CM (r = 0.40, P < 0.001). Serum KS was higher in CM IV than in controls (P = 0.05), while lavage fluid KS concentration was elevated in CM I (P = 0.04). There were no differences in the lavage fluid levels of AGN and HA between the different study groups. Synovium showed slight or moderate histological signs of inflammation in 9% of CM patients. CONCLUSION: The changes in the release and activity of these marker molecules from serum and synovial fluid may reflect changes in the metabolism of articular cartilage and synovium in CM, that are consistent with those observed in early-stage tibiofemoral cartilage changes in OA.
Asunto(s)
Enfermedades de los Cartílagos/metabolismo , Cartílago Articular/metabolismo , Proteínas de la Matriz Extracelular , Articulación de la Rodilla , Membrana Sinovial/metabolismo , Adulto , Agrecanos , Biomarcadores/análisis , Biomarcadores/sangre , Enfermedades de los Cartílagos/sangre , Colagenasas/análisis , Femenino , Humanos , Ácido Hialurónico/análisis , Interleucina-1/análisis , Interleucina-6/análisis , Sulfato de Queratano/análisis , Lectinas Tipo C , Masculino , Metaloproteinasa 1 de la Matriz , Metaloproteinasa 3 de la Matriz/análisis , Fosfolipasas A/análisis , Fosfolipasas A2 , Inhibidores de Proteasas/análisis , Proteoglicanos/análisis , Líquido Sinovial/química , Inhibidor Tisular de Metaloproteinasa-1/análisisRESUMEN
We determined the concentration of markers in cartilage and synovium metabolism in the synovial fluid (SF) of the knee of young beagle dogs with slowly progressive osteoarthrosis. Osteoarthrosis (OA) was induced by a tibial 30 degrees valgus osteotomy to the right hindlimb of 16 dogs. The contralateral knee served as control. The animals were killed 7 (group I) and 18 months (group II) after operation. The levels in SF of chondroitin sulfate (CS), tissue inhibitor of metalloproteinases (TIMP-1), stromelysin (MMP-3), hyaluronan (HA), and the activity of phospholipase A2 enzyme (PLA2) were assayed. The first microscopic signs of cartilage degeneration were observed 7 months postoperatively and the lesions became more severe, including osteophyte formation during the following 11 months. The synovial fluid level of MMP-3 was higher (p = 0.04) at both time-points in the knee joint of the operated hindlimb than in the contralateral joint. On the operated side, 7 months postoperatively, synovial fluid PLA2 activity was higher (p = 0.02) than in the contralateral knee joint, but not 18 months postoperatively. The SF level of TIMP-1 was higher (p = 0.04) in the operated joint than in the contralateral joint 18 months after operation. The molar ratio of MMP-3 to TIMP-1 was higher (p = 0.001) in group II than in group I. The changes observed in the concentration of synovial fluid markers in this slowly progressive canine OA model suggest that activation of an inflammation-related process occurs at an early stage of the OA disease induced by unilateral tibial valgus osteotomy.
Asunto(s)
Cartílago Articular/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , Osteoartritis/metabolismo , Osteotomía , Fosfolipasas A/metabolismo , Líquido Sinovial/metabolismo , Tibia/cirugía , Animales , Biomarcadores , Progresión de la Enfermedad , Perros , Femenino , Ácido Hialurónico/metabolismo , Fosfolipasas A2 , Inhibidor Tisular de Metaloproteinasa-1/metabolismoRESUMEN
STUDY DESIGN: Group II phospholipase A2 enzyme activity was studied biochemically and immunohistochemically in tissue samples from disc prolapses, degenerated discs, and macroscopically normal discs. In parallel, phospholipase A2 and inflammatory cells were studied by indirect immunocytochemistry. OBJECTIVES: To compare phospholipase A2 activity in normal discs and abnormal discs by an identical assay for phospholipases A2, and to compare the occurrence of inflammatory cells with phospholipase A2 activity and immunoreactivity. SUMMARY OF BACKGROUND DATA: It has been suggested that a high phospholipase A2 enzyme activity in herniated disc tissue could be significant in abnormal states such as sciatica and discogenic pain. No comparison between healthy disc tissue and samples of abnormal discs (degenerated or herniated) has been carried out. In particular, an identical assay for phospholipase A2 for such tissue samples, supported by immunohistochemical staining data, has never been applied in parallel to normal and abnormal disc tissue, and neither have such results been compared with the demonstration of inflammatory cells. METHODS: Group II phospholipase A2 enzyme activity was determined, in parallel, using an identical assay for tissue samples from 11 macroscopically normal discs, 33 disc herniations, and six discs showing degeneration by discography. For determination of phospholipase A2 enzyme activity, a radioassay using 1-palmitoyl-2-(1-14C)linoleoyl-L-3-phosphatidylethanolamine as the phospholipid substrate was used. Total tissue DNA as an estimate of total tissue cell number was measured in parallel with phospholipase A2 activity. All tissue samples also were studied by indirect immunocytochemistry, locating phospholipase A2 and T and B lymphocytes. RESULTS: Neither degenerated nor herniated disc tissue samples demonstrated a higher phospholipase A2 activity than control disc tissue samples. Average phospholipase A2 activity was actually higher in the control samples than in herniated disc samples (Mann-Whitney test, P < 0.001), possibly a result of a higher total DNA (P < 0.005). The observed level of phospholipase A2 activity was lower than that of inflammatory human synovial fluid. Neither was there marked immunoreactivity for phospholipase A2, which was observed in chondrocytes in areas of cartilage and occasional disc cells, supporting the biochemical results. Lymphocytes were more numerous only in herniated disc samples (15%), and their presence showed little overlap with phospholipase A2 immunoreactivity. CONCLUSIONS: Synovial-type (Group II) phospholipase A2 enzyme activity is not particularly high in disc tissue and does not appear to be higher in herniated or degenerated discs than control disc tissue. Immunoreactivity to phospholipase A2 is seen only occasionally and is strong only when cartilage tissue is present. Neither are inflammatory lymphocytes commonly observed.
Asunto(s)
Linfocitos B/enzimología , Desplazamiento del Disco Intervertebral/enzimología , Disco Intervertebral/enzimología , Fosfolipasas A/metabolismo , Linfocitos T/enzimología , Adulto , Anciano , Discitis/enzimología , Femenino , Humanos , Inmunohistoquímica , Desplazamiento del Disco Intervertebral/patología , Masculino , Persona de Mediana Edad , Fosfolipasas A2RESUMEN
Phospholipase A2 (PLA2) taken from human seminal plasma and purified about 1450-fold was injected into rabbits to prepare polyclonal antibodies. The antiserum produced and the IgG purified from the antiserum were used to compare the immunohistochemical localization of PLA2 in the human male reproductive system with that in the bull. In Western blot analyses, the polyclonal antibodies cross-reacted with purified PLA2s from human seminal plasma, bovine Cowper's glands and with partly purified PLA2 from bovine seminal vesicle fluid. On the other hand, purified PLA2s from Crotalus adamanteus venom, bovine pancreas or from bovine prostate were not recognized by the polyclonal antibodies. With an indirect peroxidase technique, PLA2 was localized in the epithelial cells of the human prostate and bovine seminal vesicles as well as in the fibrous connective tissue of bovine Cowper's gland. Indirect peroxidase staining also gave an immunoreaction in the enlarged acrosomes of round spermatids in the human testis. Using an indirect immunofluorescence method, ejaculated human spermatozoa revealed an immunoreaction which was not uniform, and the reaction was restricted to the middle piece and the acrosomal and postacrosomal regions. In conclusion, human seminal plasma, spermatozoa and prostate PLA2s were immunohistochemically related to those from bovine Cowper's gland, seminal vesicles and seminal fluid.
Asunto(s)
Genitales Masculinos/enzimología , Fosfolipasas A/metabolismo , Animales , Glándulas Bulbouretrales/enzimología , Bovinos , Reacciones Cruzadas , Humanos , Inmunohistoquímica , Masculino , Fosfolipasas A/inmunología , Fosfolipasas A2 , Próstata/enzimología , Semen/enzimología , Vesículas Seminales/enzimología , Especificidad de la Especie , Espermatozoides/enzimologíaRESUMEN
To study the expression of hyaluronan in male reproductive organs and the origin of seminal plasma hyaluronan, we stained various parts of the bull reproductive tract for hyaluronan using a biotinylated probe derived from cartilage proteoglycan (bHABC). The potential loss of hyaluronan during tissue processing was checked with a novel technique by blotting frozen tissue sections on nitrocellulose and staining the blots with bHABC. In the same tissues the CD44 receptor was visualized by Hermes 1 antibody. The testes showed only traces of hyaluronan, whereas both the epithelium and the connective tissue of seminal vesicle, prostate, Cowper's gland, and epididymis were positive in bHABC staining. Hyaluronan was localized on the basolateral surfaces of these epithelial cells. The secretions inside the seminal vesicle and in the ducts of prostate and Cowper's gland were HA-positive, whereas the luminal contents of seminiferous tubules and epididymis were unstained both in paraffin sections and in the in situ blocks. The data indicate that hyaluronan in seminal plasma originates from the accessory sex glands. The co-localization of CD44 with hyaluronan in the basolateral surfaces of the accessory gland epithelia and its absence from other epithelia with little or no hyaluronan supports its role as a hyaluronan receptor.
Asunto(s)
Glándulas Bulbouretrales/química , Ácido Hialurónico/análisis , Próstata/química , Vesículas Seminales/química , Animales , Proteínas Portadoras/análisis , Bovinos , Tejido Conectivo/química , Receptores de Hialuranos , Inmunohistoquímica , Masculino , Proteoglicanos/análisis , Receptores de Superficie Celular/análisis , Receptores Mensajeros de Linfocitos/análisisRESUMEN
A fraction from bovine seminal vesicle fluid that initiated acrosome reaction of bovine epididymal spermatozoa in vitro in the presence of heparin was prepared by sequential chromatographies on heparin-Sepharose, gel filtration (Superose 12) and reversed phase chromatography (ProRPC). Sequence analysis of the separated fraction showed that it contained the major protein (PDC-109) with 100% homology. This fraction contained also Ca(2+)-dependent phospholipase A2-like activity which hydrolysed phosphatidylethanolamine and phosphatidylcholine with 14C-labelled linoleic (lino-PE, lino-PC) or arachidonic acid (ara-PE, ara-PC) at sn-2 position. This protein was not detected in N-terminal sequence analysis. Lysophosphatidylcholine, lysophosphatidylethanolamine, and p-bromophenacyl bromide (p-BPB) inhibited this lipolytic activity. Sulfoglycolipid (Seminolipid) had inhibitory effect at concentrations above 0.1 mM but activated slightly the enzyme at lower concentrations. Boiling destroyed acrosome initiating activity in the separated fraction.
Asunto(s)
Acrosoma/fisiología , Semen/química , Semen/fisiología , Vesículas Seminales/fisiología , Espermatozoides/fisiología , Acrosoma/efectos de los fármacos , Animales , Calcio/farmacología , Bovinos , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Heparina/metabolismo , Heparina/farmacología , Humanos , Masculino , Peso Molecular , Fosfolipasas A/aislamiento & purificación , Fosfolipasas A/metabolismo , Fosfolipasas A/farmacología , Fosfolipasas A2 , Especificidad por SustratoRESUMEN
Approximately 1,100-fold purified phospholipase A2 (PLA2) from bovine prostate was injected into rabbit to prepare polyclonal antibodies. Antibodies produced showed specific immunoprecipitation only with the purified enzyme, as well as with homogenate of bovine prostatic tissue. By Western blot analysis or by immunodiffusion test, no cross-reactivity with PLA2 purified from human seminal plasma, bovine pancreas, Crotalus adamanteus venom, or with partially purified PLA2 from bovine seminal vesicle fluid or Cowper's glands was observed. Using the indirect peroxidase technique, PLA2 was localized in the cytoplasm of bovine prostatic epithelial cells. By immunogold microscopy, this enzyme was directly visualized inside the lysosomes, as well as in the endoplasmic reticulum of the glandular epithelial cells. Enzyme activity was localized in two principal subcellular sites: the mitochondria and lysosome-enriched fraction, and in the microsomal fraction.
Asunto(s)
Fosfolipasas A/biosíntesis , Próstata/enzimología , Animales , Western Blotting , Glándulas Bulbouretrales/enzimología , Bovinos , Núcleo Celular/enzimología , Reacciones Cruzadas , Epitelio/enzimología , Humanos , Inmunodifusión , Inmunohistoquímica , Lisosomas/enzimología , Masculino , Microscopía Inmunoelectrónica , Microsomas/enzimología , Mitocondrias/enzimología , Fosfolipasas A/análisis , Fosfolipasas A/aislamiento & purificación , Fosfolipasas A2 , Próstata/ultraestructura , Semen/enzimología , Testículo/enzimologíaRESUMEN
Phospholipase A2 (PLA2) was purified from bovine prostate by ammonium sulphate precipitation and fractionation by anion exchange chromatography, chromatofocusing and gel filtration. The purified enzyme was Ca(2+)-dependent and had a pH-optimum of 8.0. Ba2+, Fe2+, Hg2+, Mg2+, Pb2+, Sr2+ and Zn2+ as well as lysophosphatidylcholine, lysophosphatidylethanolamine and p-bromophenacyl bromide (p-BPB) inhibited the enzyme strongly. The enzyme had an estimated molecular weight of 12,000 +/- 1,000 daltons on SDS-PAGE. Isoelectric focusing showed one PLA2 activity-containing band at pl 5.3. The purified enzyme hydrolysed linoleic acid at the sn-2 position of phosphatidylcholine and phosphatidylethanolamine with high selectivity, compared to arachidonic acid.
Asunto(s)
Fosfolipasas A/aislamiento & purificación , Próstata/enzimología , Animales , Bovinos , Lipólisis , Masculino , Fosfolipasas A/metabolismo , Fosfolipasas A2 , Especificidad por SustratoRESUMEN
1. Approximately 150-fold purified phospholipase A2 (PLA2) from bovine seminal vesicle fluid was injected into rabbit to prepare antibodies. 2. Produced antisera blocked PLA2 activity in bovine seminal plasma, seminal vesicles and its fluid and it gave single precipitation lines with the same samples. No cross-reactivity was detected with other reproductive tissues of bull as well as human seminal plasma. 3. Using indirect peroxidase technique PLA2 was localized in the apical part of epithelia cells of the bull seminal vesicle and also some minor immunohistochemical reactions were observed in the tubular lumen. Indirect peroxidase staining gave weak or no reaction at all to seminal vesicles of immature bulls. This suggests that the enzyme may be under hormonal control. 4. By indirect immunofluorescence method ejaculated spermatozoa of bull revealed immunoreaction which was not uniform and it was restricted to the middle piece, acrosome as well as postacrosomal region, but no specific immunostaining could be found on the surface of the epididymal spermatozoa. 5. Enzyme visualization by immunoelectron microscopic labelling showed a predominant localization in membrane particles inside the lumen of bovine seminal vesicle but some gold particles were also seen in granules, larger vacuoles and in cytoplasm of epithelia cells.
Asunto(s)
Membrana Celular/enzimología , Fosfolipasas A/análisis , Vesículas Seminales/enzimología , Espermatozoides/enzimología , Animales , Western Blotting , Bovinos , Reacciones Cruzadas , Eyaculación , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Masculino , Microscopía Inmunoelectrónica , Fosfolipasas A2 , Espermatozoides/ultraestructuraRESUMEN
1. Human seminal plasma and posterior lobe of prostate was found to have phospholipase A2 (PLA2) activity hydrolysing phosphatidylethanolamine with 14C-labelled linoleic and arachidonic acid. 2. A negative relationship was between sperm count and PLA2 activity in human seminal plasma. 3. The purified PLA2 from human seminal plasma showed high affinity to heparin, sensitivity toward p-bromophenacyl bromide, Pb2+, dithioerythritol and EDTA and it was activated by Ca2+ and Mn2+. 4. The purified PLA2 had alkaline pH optimum (7.5-10.0) and pI-value of 5.3. In SDS-PAGE enzyme preparation resulted in two bands with mol. wt of 14,000 and 16,000.
Asunto(s)
Fosfolipasas A/metabolismo , Semen/enzimología , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Humanos , Masculino , Peso Molecular , Fosfolipasas A/química , Fosfolipasas A/aislamiento & purificación , Fosfolipasas A2 , Próstata/enzimologíaRESUMEN
Phospholipase A2 (PLA2) activity was measured in the reproductive organs of adult male rats. Phosphatidylethanolamine and phosphatidylcholine labelled with 14C linoleic (lino-PE, lino-PC) and arachidonic acid (ara-PE, ara-PC) at the 2-position were used as substrates. Lino-PE was hydrolysed most strongly by homogenates of the distal cauda epididymis but the testis, vas deferens and caput and corpus epididymis also contained hydrolytic activity. Ara-PC and lino-PC were hydrolysed by homogenates of the cauda epididymis and testis. No hydrolysis of ara-PE was detected using homogenates of reproductive tissues. Chromatofocusing of testis homogenate resulted in the appearance of two active forms of PLA2 with different pl-values (6.5 and 5.6) when lino-PE was used as substrate. Maximum activities of both enzymes with 1 mM Ca2+ were observed at pH 9.5. These isoenzymes have marked differences in response to Cu2+, N-ethylmaleimide and p-bromophenacyl bromide (p-BPB). Cu2+ and N-ethylmaleimide had almost no effect on PLA2 activity with a pl value of 6.5, but inhibited the other isoenzyme strongly; the latter was almost more resistant to p-bromophenacyl bromide. Both enzymes hydrolysed lino-PE most strongly. Chromatofocusing of an homogenate of cauda epididymis also revealed two isoenzymes of PLA2 with different pl-values (6.0 and 5.0). The latter form was resistant to p-bromophenacyl bromide but was more sensitive to Triton X-100 and sodium deoxycholate than was other isoenzyme. The pH optimum of the isoenzyme with a pl value of 6.0 ranged from 6.25 to 8.75 whilst the other isoenzyme was most active at pH 8.0-8.75.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Epidídimo/metabolismo , Isoenzimas/metabolismo , Fosfolipasas A/metabolismo , Testículo/metabolismo , Animales , Cromatografía , Lipólisis , Masculino , Fosfolipasas A2 , Ratas , Ratas Endogámicas , Testículo/enzimologíaRESUMEN
1. Phospholipase A2 activities were studied in the reproductive organs, seminal plasma and spermatozoa of adult bulls. 2. Phosphatidylethanolamine and phosphatidylcholine with 14C-labelled linoleic (lino-PE, lino-PC) or arachidonic acid (ara-PE, ara-PC) at sn-2 position as well as a fluorescent derivative (4-pyrenylbutyric acid) of phosphatidylcholine (PPC) were used as substrates. 3. The radioactive substrates were hydrolysed most strongly by homogenates of the prostate and Cowper's gland, but also seminal vesicle and its secretory fluid, seminal plasma and ejaculated spermatozoa contained hydrolytic activity. The fluorescence substrate was most strongly hydrolysed by homogenates of ampulla and seminal vesicle as well as its secretory fluid, seminal plasma and ejaculated spermatozoa. 4. Seminal plasma and seminal vesicle fluid contained a Ca2(+)-independent enzyme (enzyme I), which hydrolysed only PPC, while another Ca2(+)-dependent enzyme (enzyme II) hydrolysed only the radioactive substrates. 5. Both enzymes were purified from the seminal vesicle fluid and their biochemical properties were analysed. In SDS-PAGE enzyme I preparation resulted in two major bands with molecular weights of 16,000 and 60,000 in equal quantities and minor band at 15,000. The binding of the enzyme I to Con A-Sepharose indicated that it is a glycoprotein and it had multiple pI-values from 3.75 to 5.0. Enzyme II gave in SDS-PAGE two closely located bands with molecular weights of about 15,000 and 16,000 (major band). Isoelectric focusing showed one band at pI 4.7. Both enzymes appear to bind to spermatozoa at ejaculation but their function remains to be shown.
Asunto(s)
Genitales Masculinos/enzimología , Fosfolipasas A/metabolismo , Semen/enzimología , Espermatozoides/enzimología , Animales , Glándulas Bulbouretrales/enzimología , Bovinos , Cromatografía , Hidrólisis , Cinética , Masculino , Especificidad de Órganos , Fosfolipasas A/aislamiento & purificación , Fosfolipasas A2 , Próstata/enzimología , Vesículas Seminales/enzimología , Especificidad por SustratoRESUMEN
The bovine seminal plasma is formed mainly by secretions of epididymis and the glandular epithelia in ampulla, seminal vesicles, prostate and Cowper's glands. The contribution of each organ to the hydrolytic enzyme activities (glycosidases, exopeptidases, phospholipases) of the bull seminal plasma has been analyzed and is reviewed in this paper with special emphasis on the role of the accessory glands. Seminal vesicles seem to have a major role in the secretion of seminal plasma acid alpha-glucosidase, acid alpha-mannosidase and beta-N-acetylhexosaminidase, aminopeptidase A, dipeptidyl peptidase II and IV and gamma-glutamyl transpeptidase as well as Ca(2+)-dependent and Ca(2+)-independent phospholipases A2 with distinct substrate specificities, a choline-specific phospholipase C and a Co2+ (Mn2+)-activated sphingomyelinase. The enzyme pattern in the ampulla closely resembled that of the seminal vesicles and obviously contributes to the seminal plasma level of these hydrolases. The bull prostate and Cowper's glands contained a strong Ca(2+)-dependent phospholipase A2 activity. However, these glands may not contribute to the seminal plasma PLA2 activity. At ejaculation the epididymal spermatozoa are exposed to these enzymes. They may have a specific affinity to sugar, peptide or phospholipid residues at distinct sites of the sperm surface. These enzymes may also participate in the digestion of various other semen components to create a suitable milieu for the emitted spermatozoa.