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33172. Role of (E)-β-farnesene in systematic aphid prey location by Episyrphus balteatus larvae (Diptera: Syrphidae)
- Creator:
- Francis, Frédéric, Martin, Thbaut, Lognay, Georges , and Haubruge, Eric
- Type:
- article, model:article, and TEXT
- Subject:
- Syrphidae, infochemical, (E)-b-farnesene, Episyrphus balteatus, larvae, prey localisation, and olfactometer
- Language:
- English
- Description:
- The foraging behaviour of beneficials such as aphidophagous predators depend largely on volatile compounds emitted by potential preys. Even if polyphagous predatory species are considered, all the potential preys are not systematically localised and accepted. In this work, chemical cues from different aphids and plants, each alone or in association, were studied to elucidate their role in prey location. Using a four-arm olfactometer, attraction of combinations of three aphid (Megoura viciae, Acyrthosiphon pisum and Aphis fabae) and one plant (Vicia faba) species for Episyrphus balteatus larvae was observed. Predatory hoverfly larvae were attracted by all tested stimuli in the presence of aphids, whatever the species. Whole or crushed aphids and also aphids on bean plant parts were attractive to syrphid larvae, but the host plant alone did not present any infochemical role for E. balteatus. Identification and quantification of the volatile releases from aphid and plant species, alone or in association, were performed using SPME and GC-MS methods. Aphid alarm pheromone, (E)-β-farnesene, was found in the volatile pattern of each aphid and was tested for its role as an effective kairomone for the hoverfly.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
33173. Role of 5-HT2 receptors family in the allergy-induced increased aorta contractile responses to 5-HT
- Creator:
- Campos-Bedolla, Patricia, Torrejón-González, Emmanuel Gilberto, Mendoza-Mejía, Dinora, Vargas, Mario H., Segura-Medina, Patricia, Carbajal, Verónica, Rodríguez-Márquez, Aniller, and Martínez-Silva, Ana Valeria
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- 5-HT2 receptors, asthma model, thoracic aorta, serotonin, and vascular smooth muscle
- Language:
- English
- Description:
- Asthma poses an increased risk for cardiovascular disorders, suggesting that allergy, which is an underlying process in asthma, causes atypical functioning of organs other than lungs. In a previous study in a guinea pig asthma model, we concluded that allergic sensitization increased aorta contractile responses to 5-HT. To further characterize these responses, here we explored the role of the 5-HT2 receptors family. We found that TCB-2 (5-HT2A agonist) and WAY161503 (5-HT2C agonist) induced aorta contractions resembling those elicited by 5-HT but less intense (~43 % and ~25 %, respectively). In these experiments, aortas from sensitized guinea pigs showed increased contractions to TCB-2, but not to WAY161503. In turn, MDL 100907 (5-HT2A antagonist) and RS-102221 (5-HT2C antagonist) caused a notably and a mild reduction of the 5-HT-induced contractions, respectively, with no differences seen between sensitized and non-sensitized tissues. BW723C86 (5-HT2B agonist) did not induce contractile responses and RS-127445 (5-HT2B antagonist) did not modify the contractile responses to 5-HT. In nonsensitized aortas, the pattern of protein expression of receptors was 5HT2B>5-HT2A=5-HT2C, which did not change in sensitized animals. In conclusion, we found that allergic sensitization increased the aorta contractile responses to 5-HT, partly mediated by enhanced responses of 5-HT2A receptors, which was unrelated to changes in the expression of these receptors.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33174. Role of afferent sensory neurones in gastric injury/protection
- Creator:
- Rybárová, S., Kočišová, M., and Mirossay, L.
- Type:
- article, model:article, and TEXT
- Subject:
- substance P, capsaicin, prostaglandins, gastric injury, gastric blood flow, nitric oxide, and motility
- Language:
- English
- Description:
- The role of afferent sensory neurones in gastric mucosal protection is discussed. The principal effects of substance P and capsaicin on gastric motility and mucosal blood flow are taken in correlation with gastric mucosal injury. It seems likely that the protective effect of sensory neuropeptides is dependent on gastric mucosal blood flow and is mediated through the nitric oxide-generating system and partly the prostaglandins. The interaction between these two systems and the primordial effect of one of them on gastric mucosal blood flow and mucosal integrity after neuropeptide release is still not clear.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33175. Role of bank vole (Myodes glareolus) personality on tick burden (Ixodes spp.)
- Creator:
- Perez, Grégoire
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- behavioural profiling, small mammals, parasite aggregation, and video analyses
- Language:
- English
- Description:
- Parasitism among individuals in a population often varies more than expected by chance only, leading to parasite aggregation, which is a parameter of paramount importance in parasite population dynamics and particularly in vector-borne epidemiology. However, the origin of this phenomenon is yet not fully elucidated. An increasing body of literature has demonstrated that individuals vary consistently in their behaviour, which is referred to as animal personality. Such behavioural variation could potentially lead to different encounter rates with parasites. To test this hypothesis, the relationship between personality and burden with ticks (Ixodes spp.) in the bank vole, Myodes glareolus (Schreber), was assessed. Wild rodents (eight females and 18 males) were live-trapped, identified, sexed, weighted, and inspected for ticks. Behavioural profiling was then performed using standardised tests measuring activity/exploration and boldness with a combination of automatically and manually recorded behavioural variables summarised using multivariate analyses. The resulting personality descriptors and questing tick variables were used as explanatory variables in negative binomial generalised linear models of tick burden and Bayesian simulations were performed to better estimate coefficients. Tick burden was associated to body mass and sex, but not to personality descriptors, which was mainly associated to activity/exploration. These results are discussed regarding the complex relationships among individual personality, physiological status, space use and health status.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33176. Role of brain angiotensin AT1 receptor in the carbachol-induced natriuresis and expression of nNOS in the locus coeruleus and proximal convoluted tubule
- Creator:
- Wang, M., Jiang, C. L., Wang, C. Y., and Yao, Q. Y.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, biochemie, physiology, biochemistry, AT1 receptor, neuronová syntáza oxidu dusnatého, karbachol, locus coeruleus, neuronal nitrix oxide synthase, carbachol, proximal convoluted tubule, 14, and 612
- Language:
- English
- Description:
- Central administration of losartan effectively blocked the increase of blood pressure and drinking response induced by angiotensin II (Ang II) or carbachol. However, the relationship between angiotensin AT1 receptors and the natriuresis induced by brain cholinergic stimuli is still not clear. The purpose of the study is to reveal the role of brain angiotensin AT1 receptor in the carbachol-induced natriuresis and expression of neuronal nitric oxide synthase (nNOS) in the locus coeruleus (LC) and proximal co nvoluted tubule (PCT). Our results indicated that 40 min after in tracerebroventricular (ICV) injection of carbachol (0.5 μg), urinary sodium excretion was significantly increased to 0.548±0.049 μmol·min-1·100 g-1. Immunohistochemistry showed that carbachol induced an increase of neuronal nitric oxide synthase immunoreactivity (nNOS-IR) in the LC and renal proximal tubular cells. After pretreatment with losartan (20 μg), carbachol-induced urinary sodium excretion was reduced to 0.249±0.067 μmol·min-1·100 g-1. The same was true for carbachol-induced increase of nNOS-IR in the LC and PCT. The present data suggest that ICV cholinergic stimulation could induce a natriuresis and upregulate the activity of nNOS in the LC and PCT. The blockade of AT1 receptors might downregulate the effects induced by carbachol in the LC and PCT. Consequently, we provide a new evidence that brain angiotensinergic pathway and NO-dependent neural pathway contribute to the natriuresis following brain cholinergic stimulation and thus play an important role in the regulation of fluid homeostasis. Furthermore, the final effect of nitric oxide on proximal tubular sodium reabsorption participated in the natriuresis induced by brain cholinergic stimulation., M. Wang, C. L. Jiang, C. Y. Wang, Q. Y. Yao., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33177. Role of calcium in luteinization stimulator-enhanced progesterone production of porcine cranulosa cells
- Creator:
- Danišová, A., Scsuková, S., Matulová, L., Orlický, J., and Kolena, J.
- Type:
- article, model:article, and TEXT
- Subject:
- follicular fluid, calcium blockers, progesterone, cGMP, and granulosa cells
- Language:
- English
- Description:
- Intrafollicular luteinization stimulator was shown to be secreted by granulosa cells in culture with stimulatory effects on differentiation of immature granulosa cells. The purpose of this study was to evaluate the role of calcium ions in luteinization stimulator-enhanced luteinization process of granulosa cells. We examined the direct effect of ionophore A23187, voltage-sensitive Ca2+-channel blockers verapamil, nimodipine, nifedipine, niludipine and calmodulin antagonist trifluoroperazine on progesterone and cGMP levels in 3-day culture of small granulosa cells. It was shown that the dihydropyridine derivatives of calcium blocker drugs (nimodipine, nifedipine, niludipine) and calmodulin antagonist (trifluoroperazine) in the micromolar range, significantly suppressed FSH-induced progesterone synthesis and cGMP accumulation in granulosa cells. On the contrary, phenylalkylamine calcium blocker verapamil and calcium ionophore A23187 had different effects on both processes. Calcium ionophore A23187 markedly enhanced cGMP formation, but simultaneously inhibited the FSH-induced progesterone synthesis. Verapamil at lower concentrations (10 jutA) stimulated and at higher concentrations (50 ptA) inhibited the formation of cGMP. To evaluate the role of extra- and intracellular calcium in luteinization stimulator-enhanced progesterone production by small granulosa cells, the effects of indicative agents on stimulatory activity of follicular fluid from large follicles, granulosa cells-conditioned media and granulosa cell extracts were tested. While verapamil is shown to be a less potent modulator, administration of other calcium antagonists as well as ionophore A23187 caused a significant decrease in stimulatory action of follicular fluid from large follicles, granulosa cells-conditioned media and extracts. These findings indicate that the stimulatory action of luteinization stimulator depends on the transport of calcium ions through voltage- sensitive calcium channels and is modulated by alteration of intracellular calcium levels.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33178. Role of complement regulatory proteins CD46, CD55 and CD59 in reproduction
- Creator:
- Frolíková, Michaela, Stopková, Romana, Antalíková, Jana, Johnson, Peter M., Stopka, Pavel, and Dvořáková-Hortová, Kateřina
- Type:
- article, model:article, and TEXT
- Subject:
- CD46, CD55, CD59, sperm, rodent, and human
- Language:
- English
- Description:
- In humans, CD46 has been detected on the acrosomal membrane in sperm, in contrast to widespread surface expression on somatic cells where it plays a key role in the protection from complement attack. In rodents, CD46 is expressed solely on the acrosomal membrane of mature sperm and their immediate precursors, spermatids. A monoclonal antibody against the short consensus repeat (SCR1) ectodomain of CD46 blocks binding of human sperm to zona-free oocytes in vitro. However, CD46-knockout mice are fertile and have an accelerated spontaneous acrosome reaction. Wild-caught field mice (Apodemus) also exhibit a rapid acrosome reaction and CD46 is not expressed in Apodemus sperm. CD46 may, therefore, play a role in stabilization of the acrosomal membrane. Two other complement regulatory proteins, CD55 and CD59, are localized on the plasma membrane of mammalian sperm. In human sperm, CD55 and CD59 are expressed also on the inner acrosomal membrane. It remains to be clarified what is the role of CD46, CD55 and CD59 during fertilization and what are the advantages of not expressing CD46 in field mice sperm.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33179. Role of copper for human organism
- Creator:
- Ghazaryan, Sedrak
- Format:
- braille, electronic resource, remote, and elektronický zdroj
- Type:
- model:article, article, Text, statistics, and TEXT
- Subject:
- měď--farmakologie--fyziologie--chemie--metabolismus, fyziologie, antiflogistika, antitumorózní látky, antibakteriální látky, radioprotektivní látky, tělo lidské, dospělí, dítě, předškolní dítě, lidé, kojenec, and novorozenec
- Language:
- English
- Description:
- The review focuses on a very peculiar aspect of the application of copper containing biologically active compounds of different chemical classes as have shown at the last scientific researches in the field of Cu (II) chelates, chelates possess have a higher activity of the same sort, than their mother compounds. The presented material shows essentially important qualities of Cu (II) containing compounds in biological aspect and has an interest for chemists, biochemists and pharmacologists., Sedrak Ghazaryan, and Literatura
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
33180. Role of cytochrome c oxidase nuclear-encoded subunits in health and disease
- Creator:
- Čunátová, Kristýna, Reguera, David Pajuelo, Houštěk, Josef, Mráček, Tomáš, and Pecina, Petr
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- Mitochondria, OXPHOS, cytochrome c oxidase, nuclearencoded subunits, and mitochondrial disease
- Language:
- English
- Description:
- Cytochrome c oxidase (COX), the terminal enzyme of mitochondrial electron transport chain, couples electron transport to oxygen with generation of proton gradient indispensable for the production of vast majority of ATP molecules in mammalian cells. The review summarizes current knowledge of COX structure and function of nuclear-encoded COX subunits, which may modulate enzyme activity according to various conditions. Moreover, some nuclear-encoded subunits possess tissue-specific and development-specific isoforms, possibly enabling fine-tuning of COX function in individual tissues. The importance of nuclearencoded subunits is emphasized by recently discovered pathogenic mutations in patients with severe mitopathies. In addition, proteins substoichiometrically associated with COX were found to contribute to COX activity regulation and stabilization of the respiratory supercomplexes. Based on the summarized data, a model of three levels of quaternary COX structure is postulated. Individual structural levels correspond to subunits of the i) catalytic center, ii) nuclear-encoded stoichiometric subunits and iii) associated proteins, which may constitute several forms of COX with varying composition and differentially regulated function.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public