Rodent General Anesthesia Suitable for Measurement of Experimental Invasive Hemodynamics

In cases of experimentally performed invasive rodent cardiovascular measurements, selected general anesthesia for a non-recovery procedure and its proper pain control plays a fundamental role in obtaining good data recordings. Rodent anesthesia is challenging for several reasons including high metabolic rate with elevated possibility of hypothermia and hypoglycemia during the procedure, large body surface area to adjust drug medication and anticipate drug clearance. In this review article, suitable analgesia, and anesthesia to collect rodent hemodynamics is discussed with examples of commonly used methods and anesthetic combinations to assess rodent hemodynamics. In case of injectable anesthesia, hemodynamic parameters should be measured when HR and mean arterial pressure (MAP) becomes stable. If re-injection is necessary, re-evaluation of HR and MAP is crucial for data integrity. Likewise, to safeguard data quality, longitudinal collection of HRs, HR variability, MAP and body temperature should be provided. For this reason, creation of a rodent hemodynamic anesthesia protocol might be necessary. In many cases, to refine surgical anesthetic protocol suitable for hemodynamic study, pilot experiments might be required to find the correct dose, and to probe for adequacy and duration of anesthesia, anticipating technical and procedural problems. Additionally, ensuring repeatability of the hemodynamic exam, selected experimental anesthetics should not be extensively metabolized. If metabolized, the effects on central and peripheral hemodynamics (HR, pre, afterload and contractility) should be well-known and documented.

Venom Use in Eulipotyphlans: An Evolutionary and Ecological Approach

Venomousness is a complex functional trait that has evolved independently many times in the animal kingdom, although it is rare among mammals. Intriguingly, most venomous mammal species belong to Eulipotyphla (solenodons, shrews). This fact may be linked to their high metabolic rate and a nearly continuous demand of nutritious food, and thus it relates the venom functions to facilitation of their efficient foraging. While mammalian venoms have been investigated using biochemical and molecular assays, studies of their ecological functions have been neglected for a long time. Therefore, we provide here an overview of what is currently known about eulipotyphlan venoms, followed by a discussion of how these venoms might have evolved under ecological pressures related to food acquisition, ecological interactions, and defense and protection. We delineate six mutually nonexclusive functions of venom (prey hunting, food hoarding, food digestion, reducing intra- and interspecific conflicts, avoidance of predation risk, weapons in intraspecific competition) and a number of different subfunctions for eulipotyphlans, among which some are so far only hypothetical while others have some empirical confirmation. The functions resulting from the need for food acquisition seem to be the most important for solenodons and especially for shrews. We also present several hypotheses explaining why, despite so many potentially beneficial functions, venomousness is rare even among eulipotyphlans. The tentativeness of many of the arguments presented in this review highlights our main conclusion, i.e., insights regarding the functions of eulipotyphlan venoms merit additional study.

Cellular Senescence Triggers Altered Circadian Clocks With a Prolonged Period and Delayed Phases

Senescent cells, which show the permanent growth arrest in response to various forms of stress, accumulate in the body with the progression of age, and are associated with aging and age-associated diseases. Although the senescent cells are growth arrested, they still demonstrate high metabolic rate and altered gene expressions, indicating that senescent cells are still active. We recently showed that the circadian clock properties, namely phase and period of the cells, are altered with the establishment of replicative senescence. However, whether cellular senescence triggers the alteration of circadian clock properties in the cells is still unknown. In this study we show that the oxidative stress-induced premature senescence induces the alterations of the circadian clock, similar to the phenotypes of the replicative senescent cells. We found that the oxidative stress-induced premature senescent cells display the prolonged period and delayed phases. In addition, the magnitude of these changes intensified over time, indicating that cellular senescence changes the circadian clock properties. Our current results corroborate with our previous findings and further confirm that cellular senescence induces altered circadian clock properties, irrespective of the replicative senescence or the stress-induced premature senescence.

Lactate as energy substrate and its role in carcinogenesis

Introduction: Lactate is the product of the degradation of pyruvate produced in the cytoplasm. For a long time, it was believed that it was produced only in the presence of hypoxia. Several studies have shown that lactate production depends on several factors and is not only influenced by the lactic anaerobic system. In addition, large concentrations of lactate are present in neoplastic cells, even at rest, a phenomenon known as the Warburg Effect, which can occur due to the high metabolic rate of tumor cells. Objective: This study aimed to discuss the physiological aspects involved in the production, metabolism and signaling of lactate, as well as to demonstrate the new therapeutic results related to the cancer clinic. Methods: This is a literature review study. Articles were selected in the languages: Portuguese, English and Spanish, published between 2000 and 2019, in the databases: MEDline via Pubmed, Scientific Electronic Library Online (Scielo). The gray literature was verified using Google Scholar and reference list of selected articles. Results: 43 articles related to lactate were included. The searches were carried out between July and December 2019. Conclusion: Lactate is a subtract produced in aerobic and anaerobic environments, in different exercise intensities. It can be used as an energy source during and after physical exercise, in addition to acting on anabolic signals. On the other hand, it can contribute to the maintenance of an environment that favors carcinogenic proliferation. This thinking has allowed the creation of new therapies to decrease tissue damage and eradicate malignant cells.Keywords: lactic acid, neoplasm, metabolism.

Ecdysteroids are present in the blood of wild passerine birds

Ecdysteroids (arthropod molting hormones) play an important role in the development and sexual maturation of arthropods, and they have been shown to have anabolic and “energizing” effect in higher vertebrates. The aim of this study was to assess ecdysteroid diversity, levels according to bird species and months, as well as to observe the molting status of hard ticks (Acari: Ixodidae) infesting the birds. Therefore, blood samples and ticks were collected from 245 birds (244 songbirds and a quail). Mass spectrometric analyses showed that 15 ecdysteroids were regularly present in the blood samples. Molting hormones biologically most active in insects (including 20-hydroxyecdysone [20E], 2deoxy-20E, ajugasterone C and dacryhainansterone) reached different levels of concentration according to bird species and season. Similarly to ecdysteroids, the seasonal presence of affected, apolytic ticks peaked in July and August. In conclusion, this study demonstrates the presence of a broad range and high concentrations of ecdysteroids in the blood stream of wild-living passerine birds. These biologically active, anabolic compounds might possibly contribute to the known high metabolic rate of songbirds.

Invariable stoichiometry of ribosomal proteins in mouse brain tissues with aging

Across phyla, the ribosomes—the central molecular machines for translation of genetic information—exhibit an overall preserved architecture and a conserved functional core. The natural heterogeneity of the ribosome periodically phases a debate on their functional specialization and the tissue-specific variations of the ribosomal protein (RP) pool. Using sensitive differential proteomics, we performed a thorough quantitative inventory of the protein composition of ribosomes from 3 different mouse brain tissues, i.e., hippocampus, cortex, and cerebellum, across various ages, i.e., juvenile, adult, and middle-aged mouse groups. In all 3 brain tissues, in both monosomal and polysomal ribosome fractions, we detected an invariant set of 72 of 79 core RPs, RACK1 and 2 of the 8 RP paralogs, the stoichiometry of which remained constant across different ages. The amount of a few RPs punctually varied in either one tissue or one age group, but these fluctuations were within the tight bounds of the measurement noise. Further comparison with the ribosomes from a high-metabolic-rate organ, e.g., the liver, revealed protein composition identical to that of the ribosomes from the 3 brain tissues. Together, our data show an invariant protein composition of ribosomes from 4 tissues across different ages of mice and support the idea that functional heterogeneity may arise from factors other than simply ribosomal protein stoichiometry.

Functional Analysis of the Ribosomal uL6 Protein of Saccharomyces cerevisiae

The genome-wide duplication event observed in eukaryotes represents an interesting biological phenomenon, extending the biological capacity of the genome at the expense of the same genetic material. For example, most ribosomal proteins in Saccharomyces cerevisiae are encoded by a pair of paralogous genes. It is thought that gene duplication may contribute to heterogeneity of the translational machinery; however, the exact biological function of this event has not been clarified. In this study, we have investigated the functional impact of one of the duplicated ribosomal proteins, uL6, on the translational apparatus together with its consequences for aging of yeast cells. Our data show that uL6 is not required for cell survival, although lack of this protein decreases the rate of growth and inhibits budding. The uL6 protein is critical for the efficient assembly of the ribosome 60S subunit, and the two uL6 isoforms most likely serve the same function, playing an important role in the adaptation of translational machinery performance to the metabolic needs of the cell. The deletion of a single uL6 gene significantly extends the lifespan but only in cells with a high metabolic rate. We conclude that the maintenance of two copies of the uL6 gene enables the cell to cope with the high demands for effective ribosome synthesis.

Effect of Growing Groundcover Plants in a Vineyard on Dissipation of Two Neonicotinoid Insecticides

This study investigated the difference in neonicotinoids dissipation in a grape vineyard by planting different groundcovers plants, including a control bare field (CF), Arachis pintoi Krap. and Greg. (peanut field (PF)) and Clinopodium brownei (Sw.) Kuntze (mint field (MF)). After one day of pesticide spraying, the highest dinotefuran residue concentration was in 0- to 15-cm soil in the CF (0.161 mg/kg), but 30- to 45-cm and 15- to 30-cm soil in the MF and PF, respectively (0.307 and 0.033 mg/kg). Also, after four days, the highest imidacloprid residue concentration was in 0- to 15-cm soil in the CF. Imidacloprid was not retained in the 30- to 45-cm soils in the PF, but in the MF, a 0.015- and 0.011-mg/kg residue was detected in 30- to 45-cm soil in the second and third soil samplings, indicating a different distribution with different groundcover plants. The dinotefuran absorption ability was greater with A. pintoi than C. brownei, and the imidacloprid absorption ability was greater with C. brownei. Our results suggest that groundcover plants affect the dissipation of neonicotinoids differently, while A. pintoi has a high metabolic rate toward the two neonicotinoids and can increase the soil organic matter content, which is a preferable choice for a groundcover.