RESUMEN
Progress in science, technology, innovation, and digital capabilities call for reassessing food science, technology, and engineering (FST&E) education and research programs. This survey targeted global professionals and students across food disciplines and nutrition. Its main objectives included assessing the status of FST&E higher education, identifying challenges and opportunities, and furnishing recommendations. Seven topics affecting the future of the FST&E curricula were evaluated by the panel as 'High' to 'Very high', namely: 'Critical thinking', followed by 'Problem-solving projects', 'Teamwork/collaboration', 'Innovation/Open innovation' and 'Multidisciplinary'. The importance of academic partnership/collaboration with the Food Industry and Nutrition Sciences was demonstrated. Significant positive roles of the food industry in collaboration and partnerships were found. Other essential food industry attributes were related to internships, education, strategy, and vision. Collaboration between FST&E and nutrition sciences indicated the high standing of this direction. The need to integrate or converge nutrition sciences and FST&E is emphasized, especially with the growing consumer awareness of health and wellness. The study provides insights into new education and learning opportunities and new topics for future curricula.
RESUMEN
This study aimed to estimate the absorption, distribution, metabolism and excretion (ADME) properties and safety of LDT5, a lead compound for oral treatment of benign prostatic hyperplasia that has previously been characterized as a multi-target antagonist of α1A-, α1D-adrenoceptors and 5-HT1A receptors. The preclinical characterization of this compound comprised the evaluation of its in vitro properties, including plasma, microsomal and hepatocytes stability, cytochrome P450 metabolism and inhibition, plasma protein binding, and permeability using MDCK-MDR1 cells. De-risking and preliminary safety pharmacology assays were performed through screening of 44 off-target receptors and in vivo tests in mice (rota-rod and single dose toxicity). LDT5 is stable in rat and human plasma, human liver microsomes and hepatocytes, but unstable in rat liver microsomes and hepatocytes (half-life of 11 min). LDT5 is highly permeable across the MDCK-MDR1 monolayer (Papp â¼32×10-6 cm/s), indicating good intestinal absorption and putative brain penetration. LDT5 is not extensively protein-bound and is a substrate of human CYP2D6 and CYP2C19 but not of CYP3A4 (half-life >60 min), and did not significantly influence the activities of any of the human cytochrome P450 isoforms screened. LDT5 was considered safe albeit new studies are necessary to rule out putative central adverse effects through D2, 5-HT1A and 5-HT2B receptors, after chronic use. This work highlights the drug-likeness properties of LDT5 and supports its further preclinical development.
Asunto(s)
Evaluación Preclínica de Medicamentos , Piperazinas/farmacología , Hiperplasia Prostática/tratamiento farmacológico , Animales , Estabilidad de Medicamentos , Femenino , Humanos , Masculino , Ratones , Permeabilidad , Piperazinas/química , Piperazinas/metabolismo , Ratas , Factores de TiempoRESUMEN
This study aimed to estimate the absorption, distribution, metabolism and excretion (ADME) properties and safety of LDT5, a lead compound for oral treatment of benign prostatic hyperplasia that has previously been characterized as a multi-target antagonist of α1A-, α1D-adrenoceptors and 5-HT1A receptors. The preclinical characterization of this compound comprised the evaluation of its in vitro properties, including plasma, microsomal and hepatocytes stability, cytochrome P450 metabolism and inhibition, plasma protein binding, and permeability using MDCK-MDR1 cells. De-risking and preliminary safety pharmacology assays were performed through screening of 44 off-target receptors and in vivo tests in mice (rota-rod and single dose toxicity). LDT5 is stable in rat and human plasma, human liver microsomes and hepatocytes, but unstable in rat liver microsomes and hepatocytes (half-life of 11 min). LDT5 is highly permeable across the MDCK-MDR1 monolayer (Papp ∼32×10-6 cm/s), indicating good intestinal absorption and putative brain penetration. LDT5 is not extensively protein-bound and is a substrate of human CYP2D6 and CYP2C19 but not of CYP3A4 (half-life >60 min), and did not significantly influence the activities of any of the human cytochrome P450 isoforms screened. LDT5 was considered safe albeit new studies are necessary to rule out putative central adverse effects through D2, 5-HT1A and 5-HT2B receptors, after chronic use. This work highlights the drug-likeness properties of LDT5 and supports its further preclinical development.
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Humanos , Animales , Masculino , Femenino , Ratones , Ratas , Evaluación Preclínica de Medicamentos , Piperazinas/farmacología , Hiperplasia Prostática/tratamiento farmacológico , Estabilidad de Medicamentos , Permeabilidad , Piperazinas/química , Piperazinas/metabolismo , Factores de TiempoRESUMEN
Angiotensins (Angs) modulate blood pressure, hydro-electrolyte composition, and antinociception. Although Ang (5-8) has generally been considered to be inactive, we show here that Ang (5-8) was the smallest Ang to elicit dose-dependent responses and receptor-mediated antinociception in the rat ventrolateral periaqueductal gray matter (vlPAG). Ang (5-8) antinociception seems to be selective, because it did not alter blood pressure or act on vascular or intestinal smooth muscle cells. The non-selective Ang-receptor (Ang-R) antagonist saralasin blocked Ang (5-8) antinociception, but selective antagonists of Ang-R types I, II, IV, and Mas did not, suggesting that Ang (5-8) may act via an unknown receptor. Endopeptidase EP 24.11 and amastatin-sensitive aminopeptidase from the vlPAG catalyzed the synthesis (from Ang II or Ang III) and inactivation of Ang (5-8), respectively. Selective inhibitors of neuronal-nitric oxide (NO) synthase, soluble guanylyl cyclase (sGC) and a non-selective opioid receptor (opioid-R) inhibitor blocked Ang (5-8)-induced antinociception. In conclusion, Ang (5-8) is a new member of the Ang family that selectively and strongly modulates antinociception via NO-sGC and endogenous opioid in the vlPAG.
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Angiotensina I/farmacología , Guanilato Ciclasa/metabolismo , Óxido Nítrico/metabolismo , Nocicepción/efectos de los fármacos , Péptidos Opioides/metabolismo , Fragmentos de Péptidos/farmacología , Sustancia Gris Periacueductal/efectos de los fármacos , Receptores Citoplasmáticos y Nucleares/metabolismo , Transducción de Señal/efectos de los fármacos , Antagonistas de Receptores de Angiotensina/farmacología , Animales , Aorta/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Frecuencia Cardíaca/fisiología , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Péptidos Opioides/antagonistas & inhibidores , Ratas , Ratas Wistar , Saralasina/farmacología , Guanilil Ciclasa Soluble , Teprotido/farmacologíaRESUMEN
Ethylene oxide is currently a dominant agent in medical device sterilization. This work intends to study the main effects and interactions of temperature, ethylene oxide concentration, and relative humidity on commercial spore strips of Bacillus subtilis, var. niger (ATCC 9372) inactivation, the most common microorganism used in controlling the efficacy of the process. Experiments were carried out using a full factorial experimental design at two levels (2(3) factorial design). Limit target exposure conditions for ethylene oxide concentration, temperature, and relative humidity were 250-1,000 mg EO/l, 40-60°C, and 50-90%, respectively. Adopting a different approach from the first-order kinetics, a Gompertz model was successfully applied in data fitting of the inactivation curves. Bacillus subtilis kinetic behavior presented a sigmoidal inactivation with an initial shoulder (λ), followed by a maximum inactivation rate (k(max)), these being model parameters. It was concluded that temperature and ethylene oxide concentration were the most significant factors and consequently, additional experiments were carried out aiming at describing the parameters' dependence on these process factors. Mathematical relations describing such dependences were successfully developed and included in the Gompertz kinetic model. The predictive ability of this integrated model was assessed, and its adequacy in predicting B. subtilis inactivation was proven.
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Bacillus subtilis/efectos de los fármacos , Desinfectantes/farmacología , Óxido de Etileno/farmacología , Modelos Biológicos , Humedad , Cinética , Viabilidad Microbiana , Esporas Bacterianas/efectos de los fármacos , Esterilización , TemperaturaRESUMEN
The regulatory function of á1B-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na+/K+-ATPase and Ca2+-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant á1B-adrenoceptor (CAMá1B-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca2+-ATPase (PMCA) expression was increased by 30 percent in CAMá1B-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) expression. Moreover, total Ca2+-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na+/K+-ATPase activity nor the expression of á1 and á2 subunit isoforms was changed in CAMá1B-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac á1B-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development.
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Animales , Masculino , Ratones , Adenosina Trifosfatasas/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Miocardio/enzimología , Receptores Adrenérgicos alfa 1/metabolismo , Señalización del Calcio/fisiología , Ratones Transgénicos , Regulación hacia ArribaRESUMEN
The regulatory function of alpha(1B)-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na(+)/K(+)-ATPase and Ca(2+)-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant alpha1B-adrenoceptor (CAMalpha(1B)-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca(2+)-ATPase (PMCA) expression was increased by 30% in CAMalpha(1B)-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA2) expression. Moreover, total Ca(2+)-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na(+)/K(+)-ATPase activity nor the expression of alpha(1) and alpha(2) subunit isoforms was changed in CAMalpha(1B)-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac alpha(1B)-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development.
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Adenosina Trifosfatasas/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Miocardio/enzimología , Receptores Adrenérgicos alfa 1/metabolismo , Animales , Señalización del Calcio/fisiología , Masculino , Ratones , Ratones Transgénicos , Regulación hacia ArribaRESUMEN
Murine Schistosoma mansoni infection is related to an increased contraction of portal vein in response to 5-hydroxytryptamine (5-HT). The present study addressed a putative alteration of ion channels and enzymes involved in vascular contraction. In control group, either inhibition of K+ channels sensitive to ATP (K(ATP)) or Ca2+ (BK(Ca)) increased 5-HT-induced contraction, but the same did not occur in infected mice. On the other hand, inhibition of p38 MAP kinase markedly decreased the vascular contraction to 5-HT in the infected mice with minor effects in the control group. Accordingly, we observed a higher density of phospho-p38 MAP kinase, that refers to the fully active state of the enzyme, in portal veins from infected mice as compared to control animals. These results suggest that the reduced function of K(ATP) and BK(Ca) channels along with an increased contribution of p38 MAP kinase contribute to the increased contraction of portal veins to 5-HT observed in murine schistosomiasis.
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Vena Porta/fisiopatología , Canales de Potasio/metabolismo , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/fisiopatología , Vasoconstricción , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Animales Recién Nacidos , Femenino , Interacciones Huésped-Parásitos , Humanos , Masculino , Ratones , Schistosoma mansoni/crecimiento & desarrollo , Esquistosomiasis mansoni/parasitología , Serotonina/farmacologíaRESUMEN
BACKGROUND AND PURPOSE: We have previously shown that melatonin inhibits bradykinin-induced NO production by endothelial cells in vitro. The purpose of this investigation was to extend this observation to an in vivo condition and to explore the mechanism of action of melatonin. EXPERIMENTAL APPROACH: RT-PCR assays were performed with rat cultured endothelial cells. The putative effect of melatonin upon arteriolar tone was investigated by intravital microscopy while NO production by endothelial cells in vitro was assayed by fluorimetry, and intracellular Ca(2+) measurements were assayed by confocal microscopy. KEY RESULTS: No expression of the mRNA for the melatonin synthesizing enzymes, arylalkylamine N-acetyltransferase and hydroxyindole-O-methyltransferase, or for the melatonin MT(2) receptor was detected in microvascular endothelial cells. Melatonin fully inhibited L-NAME-sensitive bradykinin-induced vasodilation and also inhibited NO production induced by histamine, carbachol and 2-methylthio ATP, but did not inhibit NO production induced by ATP or alpha, beta-methylene ATP. None of its inhibitory effects was prevented by the melatonin receptor antagonist, luzindole. In nominally Ca(2+)-free solution, melatonin reduced intracellular Ca(2+) mobilization induced by bradykinin (40%) and 2-methylthio ATP (62%) but not Ca(2+) mobilization induced by ATP. CONCLUSIONS AND IMPLICATIONS: We have confirmed that melatonin inhibited NO production both in vivo and in vitro. In addition, the melatonin effect was selective for some G protein-coupled receptors and most probably reflects an inhibition of Ca(2+) mobilization from intracellular stores.
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Células Endoteliales/efectos de los fármacos , Melatonina/farmacología , Arterias Mesentéricas/efectos de los fármacos , Óxido Nítrico/biosíntesis , Acetilserotonina O-Metiltransferasa/genética , Adenosina Trifosfato/farmacología , Animales , N-Acetiltransferasa de Arilalquilamina/genética , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Calcio/metabolismo , Carbacol/farmacología , Células Cultivadas , Células Endoteliales/citología , Células Endoteliales/metabolismo , Fluorometría , Expresión Génica/efectos de los fármacos , Histamina/farmacología , Masculino , Arterias Mesentéricas/fisiología , Microscopía Confocal , Microscopía por Video , NG-Nitroarginina Metil Éster/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptor de Melatonina MT2/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Vasodilatación/efectos de los fármacosRESUMEN
Schistosomiasis, an intravascular parasitic disease caused by Schistosoma mansoni, is related to alterations of murine vascular reactivity in the mesenteric bed, characterized by an impairment of the l-arginine/NO pathway and an increased potency of 5-hydroxytryptamine. The current study was performed to test the hypothesis that a similar alteration of reactivity also occurs in the aorta and to identify the mechanism behind such an increase. We found that aorta from mice infected with male S. mansoni exhibited an enhanced contraction in response to noradrenaline and 100 mM KCl. The inhibition of nitric oxide synthase increased aortic maximal contraction in response to noradrenaline in both groups, but the effect was less pronounced in infected mice than in control mice. Endothelium-dependent relaxation induced by acetylcholine was also smaller in infected mice compared to control mice, while endothelial-independent relaxation induced by sodium nitroprusside and forskolin was similar in both groups. The inhibition of voltage-dependent L-type Ca(2+) channels reduced the maximal contraction in response to noradrenaline more effectively in infected than in control mice. Conversely the inhibition of K(ATP) channels had a smaller effect in the infected group. As a conclusion, our data indicate that schistosomiasis also alters murine vascular reactivity outside the mesenteric bed, due to a partial impairment of NO signaling, a reduced contribution of K(ATP) channels and an increased Ca(2+) influx through L-type Ca(2+) channels.
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Aorta Torácica/fisiopatología , Norepinefrina/farmacología , Esquistosomiasis mansoni/fisiopatología , Vasoconstrictores/farmacología , Vasodilatación/efectos de los fármacos , Adenosina Trifosfato/metabolismo , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/metabolismo , Aorta Torácica/parasitología , Canales de Calcio Tipo L/metabolismo , Señalización del Calcio , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Masculino , Ratones , Óxido Nítrico/metabolismo , Canales de Potasio/metabolismo , Cloruro de Potasio/farmacología , Esquistosomiasis mansoni/metabolismo , Esquistosomiasis mansoni/parasitología , Vasodilatadores/farmacologíaRESUMEN
We tested the hypothesis that voltage-operated Ca2+ channels mediate an extracellular Ca2+ influx in muscle fibres from the human parasite Schistosoma mansoni and, along with Ca2+ mobilization from the sarcoplasmic reticulum, contribute to muscle contraction. Indeed, whole-cell voltage clamp revealed voltage-gated inward currents carried by divalent ions with a peak current elicited by steps to +20 mV (from a holding potential of -70 mV). Depolarization of the fibres by elevated extracellular K+ elicited contractions that were completely dependent on extracellular Ca2+ and inhibited by nicardipine (half inhibition at 4.1 microM). However these contractions were not very sensitive to other classical blockers of voltage-gated Ca2+ channels, indicating that the schistosome muscle channels have an atypical pharmacology when compared to their mammalian counterparts. Futhermore, the contraction induced by 5 mM caffeine was inhibited after depletion of the sarcoplasmic reticulum either with thapsigargin (10 microM) or ryanodine (10 microM). These data suggest that voltage-operated Ca2+ channels do contribute to S. mansoni contraction as does the mobilization of stored Ca2+, despite the small volume of sarcoplasmic reticulum in schistosome smooth muscles.
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Canales de Calcio/fisiología , Calcio/metabolismo , Schistosoma mansoni/fisiología , Animales , Cafeína/farmacología , Bloqueadores de los Canales de Calcio , Canales de Calcio/metabolismo , Electrofisiología , Potenciales de la Membrana , Contracción Muscular/efectos de los fármacos , Músculos/efectos de los fármacos , Músculos/fisiología , Técnicas de Placa-Clamp , Rianodina/farmacología , Schistosoma mansoni/metabolismo , Tapsigargina/farmacologíaRESUMEN
We previously reported that portal veins from mice infected with male Schistosoma mansoni exhibited an increased reactivity to 5-hydroxytryptamine (5-HT). Here, we extended our observations to mice infected by both male and female worms and we further investigated another constrictor agent and the mechanism(s) responsible for the enhanced maximal contraction ( E(max)). Bisexual infection increased the E(max) of 5-HT (from 0.66+/-0.06 mN.s to 1.56+/-0.38 mN.s), in a similar way to the unisexual (male) infection. Infection with male worms increased portal vein reactivity to acetylcholine, as revealed by a higher E(max) (1.03+/-0.2 mN.s) in relation to non-infected control animals ( E(max)= 0.54+/-0.08 mN.s). Sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibition with 100 nM thapsigargin reduced the E(max) of 5-HT by 35% in both tissues, discharging a deficiency of SERCA pump in infected animals. In contrast, the number of voltage-dependent Ca(2+) channels (L-type) was higher in portal veins from infected than non-infected control mice. Inhibition of Ca(2+)-activated chloride channels (Cl(Ca)) with 10 micro M niflumic acid reduced the E(max) of 5-HT in portal veins more from infected than non-infected animals (remaining tension = 60.9+/-2.2% and 70.4+/-2.3%, respectively). Histopathological analysis revealed an increased content of collagen and elastin in portal veins from male S. mansoni-infected mice, compatible with an increased intraluminal pressure. In conclusion, male S. mansoni altered portal vein physiology, increasing the E(max) of two vasoconstrictors, possibly by increasing membrane depolarisation through a more effective opening of Cl(Ca) channels, with calcium entering through L-type Ca(2+) channels.
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Vena Porta/fisiopatología , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/fisiopatología , Vasoconstricción , Acetilcolina/farmacología , Animales , Calcio/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Histocitoquímica , Masculino , Ratones , Vena Porta/citología , Vena Porta/patología , Retículo Sarcoplasmático/efectos de los fármacos , Retículo Sarcoplasmático/metabolismo , Esquistosomiasis mansoni/metabolismo , Esquistosomiasis mansoni/parasitología , Esquistosomiasis mansoni/patología , Serotonina/farmacología , Factores Sexuales , CaracolesRESUMEN
. The effects of LASSBio 294, a new 3,4-methylenedioxybenzoyl-2-thienylhydrazone, on vascular tonus were investigated in isolated rat aortic rings. 2. LASSBio 294 induced a concentration-dependent relaxation of intact rat aortic rings with an inhibitory concentration (IC(50)) of 74 microM (95% confidence limits: 59 - 92). The mechanical removal of the endothelium abolished this effect. 3. In aortic rings with intact endothelium the effect of 100 microM LASSBio 294 was not altered by the pharmacological inhibition of NOS and cyclo-oxygenase pathways with 500 microM L-NAME and 10 microM indomethacin, respectively. 4. LASSBio 294 (100 microM) was able to relax aortic rings pre-contracted with high extracellular K(+) (KCl 100 mM). 5. The relaxant effect of LASSBio 294 was fully reversed (and prevented) by the addition of 1 microM ODQ (1H-(1,2,4)oxadiazolo[4,3-a]quinoxaline-1-one), a selective inhibitor of soluble guanylate cyclase. 6. LASSBio 294 (100 microM) had no direct effect on PDE3 and PDE4 activities, however, it increased by 150% cyclic GMP content in aortic rings pre-treated with 100 microM L-NAME and 10 microM indomethacin, as did 1 microM zaprinast, a selective PDE5 inhibitor. 7. In conclusion, LASSBio 294 induced relaxation of isolated rat aorta probably by directly increasing cyclic GMP content, possibly as a consequence of PDE5 inhibition.
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Aorta Torácica/efectos de los fármacos , GMP Cíclico/metabolismo , Hidrazonas/farmacología , Tiofenos/farmacología , Vasoconstricción/efectos de los fármacos , Vasodilatadores/farmacología , 3',5'-GMP Cíclico Fosfodiesterasas/metabolismo , Animales , Aorta Torácica/metabolismo , Aorta Torácica/fisiología , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5 , Guanilato Ciclasa/antagonistas & inhibidores , Guanilato Ciclasa/metabolismo , Hidrazonas/química , Técnicas In Vitro , Indometacina/farmacología , Masculino , Estructura Molecular , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Oxadiazoles/farmacología , Prostaglandina-Endoperóxido Sintasas/efectos de los fármacos , Prostaglandina-Endoperóxido Sintasas/metabolismo , Quinoxalinas/farmacología , Ratas , Ratas Wistar , Tiofenos/químicaRESUMEN
Calcium signalling is fundamental for muscular contractility of Schistosoma mansoni. We have previously described the presence of transport ATPases (Na+,K+-ATPase and (Ca2+-Mg2+)-ATPase) and calcium channels (ryanodine receptors - RyR) involved in control of calcium homeostasis in this worm. Here we briefly review the main technics (ATPase activity, binding with specific radioligands, fluxes of 45Ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (Ca2+-Mg2+)-ATPase activity and RyR co-purified in P1 and P4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal ATPase (along with Na+,K+-ATPase) and thapsigargin-resistant (Ca2+-Mg2+)-ATPase have a distinct distribution, indicative of their plasma membrane localization. Finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in S. mansoni
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Animales , Calcio/fisiología , Homeostasis/fisiología , Schistosoma mansoni/metabolismo , ATPasa de Ca(2+) y Mg(2+)/metabolismo , Señalización del Calcio , Calcio/metabolismo , Músculo Liso/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismoRESUMEN
In chronic severe infection with Schistosoma mansoni, portal hypertension and related vascular alterations usually develop as a consequence of granolomatous response to eggs. In order to investigate a putative direct effect of worms on the reactivity of their host portal vein, mice infected only with male worms were used in the present study. An higher reactivity to 5-hydroxytryptamine (5-HT) characterized by an increase in the maximal contraction and sensitivity was observed in portal vein from infected mice compared to healthy mice. Blockade of NO-synthase with l-NAME induced a small increase in 5-HT potency in portal vein from non-infected mice without changing the amplitude of the contractions, whereas it did not alter the reactivity of veins from infected mice. The present results show that unisexual infection of mice with male S. mansoni increased the reactivity of the portal vein to 5-HT which seems to be partially related to an alteration in the nitric oxide release by endothelium.
Asunto(s)
Animales , Endotelio/parasitología , Ratones/parasitología , Vena Porta , Schistosoma mansoni , Serotonina , Esquistosomiasis mansoniRESUMEN
The ratio of (Na++K+)-ATPase (EC 3.6.1.3.) isoforms with high and low affinity for cardiac glycosides was studied in heart preparations from neonatal, 3-month and 6-month old Wistar rats. Biphasic ouabain inhibition curves of (Na++K+)-ATPase activity indicated that the relative contribution of the high-affinity process decreased from 34 percent at 9 days to 23 percent at 3 months and to 10 percent at 6 months. Scatchard plots for [3H]ouabain binding were curvillinear and indicated that the relative contribution of the high-affinity sites (Kd = 0.1-0.25 µM) decreased by about one-half between 3 months (19-24 percent, N = 2) and 6 months (9-11 percent, N = 2)