scholarly journals Sulfide metabolism and the mechanism of torpor

2021 ◽  
Vol 224 (17) ◽  
Author(s):  
Birgitte S. Jensen ◽  
Angela Fago
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Mitochondrial Respiration ◽  
Mammalian Species ◽  
Winter Season ◽  
Cold Winter ◽  
Sulfide:Quinone Oxidoreductase ◽  
Metabolic Suppression

ABSTRACT Hibernation is a powerful response of a number of mammalian species to reduce energy during the cold winter season, when food is scarce. Mammalian hibernators survive winter by spending most of the time in a state of torpor, where basal metabolic rate is strongly suppressed and body temperature comes closer to ambient temperature. These torpor bouts are regularly interrupted by short arousals, where metabolic rate and body temperature spontaneously return to normal levels. The mechanisms underlying these changes, and in particular the strong metabolic suppression of torpor, have long remained elusive. As summarized in this Commentary, increasing evidence points to a potential key role for hydrogen sulfide (H2S) in the suppression of mitochondrial respiration during torpor. The idea that H2S could be involved in hibernation originated in some early studies, where exogenous H2S gas was found to induce a torpor-like state in mice, and despite some controversy, the idea persisted. H2S is a widespread signaling molecule capable of inhibiting mitochondrial respiration in vitro and studies found significant in vivo changes in endogenous H2S metabolites associated with hibernation or torpor. Along with increased expression of H2S-synthesizing enzymes during torpor, H2S degradation catalyzed by the mitochondrial sulfide:quinone oxidoreductase (SQR) appears to have a key role in controlling H2S availability for inhibiting respiration. Specifically, in thirteen-lined squirrels, SQR is highly expressed and inhibited in torpor, possibly by acetylation, thereby limiting H2S oxidation and causing inhibition of respiration. H2S may also control other aspects associated with hibernation, such as synthesis of antioxidant enzymes and of SQR itself.

scholarly journals The relationship between fasting-induced torpor, sleep and waking in laboratory mice

SLEEP ◽  
2021 ◽  
Author(s):  
Yi-Ge Huang ◽  
Sarah J Flaherty ◽  
Carina A Pothecary ◽  
Russell G Foster ◽  
Stuart N Peirson ◽  
...  
Keyword(s):  
Body Temperature ◽  
Rem Sleep ◽  
Brain Activity ◽  
Mammalian Species ◽  
Nrem Sleep ◽  
Laboratory Mice ◽  
State Classification ◽  
Metabolic Suppression ◽  
The Relationship ◽  
Electroencephalogram Eeg

Abstract Study objectives Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor and sleep has been well-studied in seasonal hibernators, less is known about the effects of fasting-induced torpor on states of vigilance and brain activity in laboratory mice. Methods Continuous monitoring of electroencephalogram (EEG), electromyogram (EMG) and surface body temperature was undertaken in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. Results All animals showed bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of NREM sleep, REM sleep and wakefulness enabled us to perform vigilance-state classification in all cases. Consistent with previous studies, hypothermic bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing surface body temperature. During deep hypothermia, REM sleep was largely abolished, and we observed shivering-associated intense bursts of muscle activity. Conclusions Our study highlights important similarities between EEG signatures of fasting-induced torpor in mice, daily torpor in Djungarian hamsters and hibernation in seasonally-hibernating species. Future studies are necessary to clarify the effects on fasting-induced torpor on subsequent sleep.

scholarly journals Novel Role for Albumin in Innate Immunity: Serum Albumin Inhibits the Growth of Blastomyces dermatitidis Yeast Form In Vitro

2003 ◽  
Vol 71 (11) ◽  
pp. 6648-6652 ◽  
Author(s):  
Steven Giles ◽  
Charles Czuprynski
Keyword(s):  
Molecular Weight ◽  
Inhibitory Activity ◽  
Mammalian Species ◽  
Blastomyces Dermatitidis ◽  
Low Molecular Weight ◽  
Rat Serum ◽  
Yeast Form ◽  
Domain Iii

ABSTRACT In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored inhibitory activity. Inhibitory activity does not require albumin domain III and appears to involve binding of a low-molecular-weight yeast-derived growth factor.

Opioids and testicular activity in the frog, Rana esculenta

1993 ◽  
Vol 137 (1) ◽  
pp. 49-NP ◽  
Author(s):  
F. Facchinetti ◽  
A. R. Genazzani ◽  
M. Vallarino ◽  
M. Pestarino ◽  
A. Polzonetti-Magni ◽  
...  
Keyword(s):  
Physiological Activity ◽  
Mammalian Species ◽  
Rana Esculenta ◽  
Cell Degeneration ◽  
Efferent System ◽  
Naltrexone Treatment ◽  
Nucleus Infundibularis ◽  
The Brain

ABSTRACT The presence and activity of brain, pituitary and testicular β-endorphin (β-EP)-like material have been studied in the frog, Rana esculenta, using reverse-phase high-pressure liquid chromatography, coupled with radioimmunoassay and immunocytochemistry. In-vivo and in-vitro treatments with naltrexone were carried out to assess the putative physiological activity of opioid peptides. β(1–31) and (1–27), together with their acetylated forms, have been identified in brain, pituitary and testis. In particular, β-EP(1–31) concentrations peaked during July in the brain and pituitary, whilst in testes maximum concentrations were found in April and November. β-EP immunoreactivity was present in the brain within the nucleus preopticus and nucleus infundibularis ventralis while positive fibres in the retrochiasmatic regions projected to the median eminence. In the testis, interstitial cells, canaliculi of the efferent system, spermatogonia and spermatocytes showed positive immunostaining for β-EP. In intact animals, naltrexone treatment increased plasma and testicular androgen levels and this effect was confirmed in in-vitro incubations of minced testes. Naltrexone also induced a significant increase in germ cell degeneration. Our results indicated that an opioid system modulates the hypothalamus-pituitary-gonadal axis in the frog, Rana esculenta and, for the first time, we have shown that the testicular activity of a non-mammalian species may be regulated by opiates locally. Journal of Endocrinology (1993) 137, 49–57

Myosin light-chain 1 and 3 gene has two structurally distinct and differentially regulated promoters evolving at different rates

1985 ◽  
Vol 5 (11) ◽  
pp. 3168-3182
Author(s):  
E E Strehler ◽  
M Periasamy ◽  
M A Strehler-Page ◽  
B Nadal-Ginard
Keyword(s):  
Light Chain ◽  
Myosin Light Chain ◽  
Mammalian Species ◽  
In Vitro Transcription ◽  
Chain Gene ◽  
Promoter Regions ◽  
Light Chain Gene ◽  
Direct Initiation

DNA fragments located 10 kilobases apart in the genome and containing, respectively, the first myosin light chain 1 (MLC1f) and the first myosin light chain 3 (MLC3f) specific exon of the rat myosin light chain 1 and 3 gene, together with several hundred base pairs of upstream flanking sequences, have been shown in runoff in vitro transcription assays to direct initiation of transcription at the cap sites of MLC1f and MLC3f mRNAs used in vivo. These results establish the presence of two separate, functional promoters within that gene. A comparison of the nucleotide sequence of the rat MLC1f/3f gene with the corresponding sequences from mouse and chicken shows that: the MLC1f promoter regions have been highly conserved up to position -150 from the cap site while the MLC3f promoter regions display a very poor degree of homology and even the absence or poor conservation of typical eucaryotic promoter elements such as TATA and CAT boxes; the exon/intron structure of this gene has been completely conserved in the three species; and corresponding exons, except for the regions encoding most of the 5' and 3' untranslated sequences, show greater than 75% homology while corresponding introns are similar in size but considerably divergent in sequence. The above findings indicate that the overall structure of the MLC1f/3f genes has been maintained between avian and mammalian species and that these genes contain two functional and widely spaced promoters. The fact that the structures of the alkali light chain gene from Drosophila melanogaster and of other related genes of the troponin C supergene family resemble a MLC3f gene without an upstream promoter and first exon strongly suggests that the present-day MLC1f/3f genes of higher vertebrates arose from a primordial alkali light chain gene through the addition of a far-upstream MLC1f-specific promoter and first exon. The two promoters have evolved at different rates, with the MLC1f promoter being more conserved than the MLC3f promoter. This discrepant evolutionary rate might reflect different mechanisms of promoter activation for the transcription of MLC1f and MLC3f RNA.

Cold acclimation-recruited nonshivering thermogenesis: the Syrian hamster is not an exception

1995 ◽  
Vol 269 (4) ◽  
pp. R767-R774 ◽  
Author(s):  
A. Dicker ◽  
B. Cannon ◽  
J. Nedergaard
Keyword(s):  
Metabolic Rate ◽  
Cold Acclimation ◽  
Resting Metabolic Rate ◽  
High Rate ◽  
In Vivo Studies ◽  
Nonshivering Thermogenesis ◽  
Brown Adipose ◽  
Thermogenic Response

Biochemical evidence from in vitro studies of brown adipose tissue in Syrian hamsters indicates a significant degree of recruitment of the tissue as an effect of cold acclimation. However, earlier in vivo studies indicate a lack of recruitment of nonshivering thermogenesis in the intact animal as a result of cold acclimation. Because of this apparent discrepancy, the occurrence of cold acclimation-recruited nonshivering thermogenesis in hamsters was investigated. Hamsters were cold acclimated to 6 degrees C or remained at 24 degrees C (controls), and their thermogenic response was investigated in an open-circuit system at 24 degrees C. Cold acclimation resulted in a small increase in resting metabolic rate and a major increase in the thermogenic response to norepinephrine (61% increase over resting metabolic rate in controls and 156% increase in cold-acclimated animals). The absolute beta 3-specific adrenergic agonist CGP-12177 also induced a high rate of nonshivering thermogenesis, which was similarly recruited. It was concluded that, concerning the relative effect of recruitment on the capacity for nonshivering thermogenesis, the intact hamsters responded as would be predicted from in vitro experiments. Thus the hamster does not seem to constitute an exception to the general patterns described for other rodents concerning recruitment of nonshivering thermogenesis due to cold acclimation.

scholarly journals The Usefulness of Retinoic Acid Supplementation during in Vitro Oocyte Maturation for the in Vitro Embryo Production of Livestock: A Review

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 561 ◽  
Author(s):  
Abdelnour ◽  
El-Hack ◽  
Swelum ◽  
Saadeldin ◽  
Noreldin ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Mammalian Species ◽  
Antioxidant Properties ◽  
Reproductive Function ◽  
Embryonic Growth ◽  
Oxidative Damages

Retinoic acid (RA) is an indigenous metabolite and descriptive physiologically functioning constituent of vitamin A. Retinoids were documented as vital regulators for cell development and distinction, embryonic growth, and reproductive function in both male and female livestock. Previously, RA has been shown to have several positive impacts in vivo and in vitro and critically control many reproductive events, such as oocyte development, follicular growth, and early embryonic growth. In addition, RA manages apoptotic signaling and oxidative damages in cells. Recently, RA has been used widely in assisted reproductive technology fields, especially during in vitro embryo development in various mammalian species, including buffaloes, bovine, goats, sheep, pigs, and rabbits. However, the optimum concentration of RA greatly differs based on the condition of maturation media and species. Based on the obtained findings, it was generally accepted that RA enhances nuclear oocyte maturation, cleavage and maturation rates, blastocyst formation, and embryo development. As such, it possesses antioxidant properties against reactive oxygen species (ROS) and an anti-apoptotic effect through enhancing the transcription of some related genes such as superoxide dismutase, prostaglandin synthase, glutathione peroxidase, peroxiredoxins, and heme oxygenase. Therefore, the current review concludes that an addition of RA (up to 50 nM) has the potential to improve the oocyte maturation media of various species of livestock due to its antioxidant activity.

Gold Nanoparticles with Selective Antileukemic Activity In Vitro and In Vivo Target Mitochondrial Respiration

2019 ◽  
Vol 2 (6) ◽  
pp. 1800149 ◽  
Author(s):  
Ann‐Kathrin Gaiser ◽  
Susanne Hafner ◽  
Michael Schmiech ◽  
Berthold Büchele ◽  
Patrick Schäfer ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Mitochondrial Respiration ◽  
Antileukemic Activity

scholarly journals Photoperiodic regulation of prolactin secretion: changes in intra-pituitary signalling and lactotroph heterogeneity

2004 ◽  
Vol 180 (3) ◽  
pp. 351-356 ◽  
Author(s):  
JD Johnston
Keyword(s):  
Environmental Conditions ◽  
Seasonal Changes ◽  
Mammalian Species ◽  
Prolactin Secretion ◽  
Day Length ◽  
Pars Tuberalis ◽  
Photoperiodic Regulation ◽  
Pituitary Lactotroph

Many mammalian species utilise day-length (photoperiod) to adapt their physiology to seasonal changes in environmental conditions, via secretion of pineal melatonin. Photoperiodic regulation of prolactin secretion is believed to occur via melatonin-mediated changes in the secretion of a putative prolactin secretagogue, tuberalin, from the pituitary pars tuberalis. Despite the in vivo and in vitro evidence in support of this intra-pituitary signalling mechanism, the identity of tuberalin has yet to be elucidated. This paper reviews recent advances in the characterisation of tuberalin and the regulation of its secretion. Furthermore, the hypothesis that pituitary lactotroph cells display heterogeneity in their response to changing photoperiod and tuberalin secretion is examined.

324 CELL LINES DERIVED FROM MAMMALIAN PARTHENOGENETIC EMBRYOS DISPLAY ABNORMAL CHROMOSOME COMPLEMENTS AND ABERRANT CENTRIOLE NUMBER

2010 ◽  
Vol 22 (1) ◽  
pp. 318
Author(s):  
T. A. L. Brevini ◽  
G. Pennarossa ◽  
A. Vanelli ◽  
G. Tettamanti ◽  
L. Bogliolo ◽  
...  
Keyword(s):  
Cell Lines ◽  
Embryoid Body ◽  
Mammalian Species ◽  
High Rate ◽  
Primary Fibroblast ◽  
Thin Sections ◽  
Paternal Contribution ◽  
Parthenogenetic Embryos

Mature oocytes can be activated in vitro, leading to the generation of parthenotes that will develop in culture forming blastocysts morphologically indistinguishable from those derived from fertilized eggs. Parthenotes have been used as a source of pluripotent cells that show the traditional features associated with their biparental counterpart: expression of totipotency markers, telomerase activity, embryoid body formation, in vitro differentiation and, in most cases, teratoma formation. However, many aspects still need to be elucidated and, in particular, little attention has been paid to the inci- dence of aneuploidy in these cells. Limited data available for parthenotes derived from different mammalian species indicate a high rate of aneuploidy, whichis consideredtobecaused by the lackofthe paternal contribution, because alterations of the centrosome are knowntolead to multipolar spindles that, in turn, cause aneuploid cells. In this study, we analyzed the rate of aneuploidy and centriole distribution (as a marker of centrosome anomalies) in pluripotent cell lines (pSC) previously derived in our laboratory from pig parthenogenetic embryos and in primary fibroblast cultures and sections obtained from sheep parthenogenetic fetuses (n = 3) that reached 24 days of development in vivo. This protocol was chosen to separate the effect related tooocyte activation from those of the procedures used to derive pSC lines. Centriole number and distribution were assessed both by immunocy- tochemical analysis using an anti-centrin-1 antibody (1 : 200, Abcam, Cambridge, UK) and an appropriate secondary antibody, and by ultrastructural evaluation of thin sections, using a Jeol 1010 EX electron microscope (Jeol, Tokyo, Japan). Karyotyping was performed on mitotically active cells. Metaphases were fully karyotyped under a Leica HC microscope (Wetzlar, Germany). Images were then captured with a Leica DC250 digital camera and cells karyotyped using the Leica CW4000 Karyo software. The results obtained indicate that cell lines of parthenogenetic origin have, in all examined cases, an incidence of aneuploidy significantly higher than that of their respective controls. In particular, although the diploid configuration represented the modal value, the majority of the cells displayed a consistently lower number of chromosomes, between <1N (hypohaploid) and >1N to <2N (hypodiploid).This resultis possibly related toa lossofchromosomes during the mitotic process.Ahigher incidence ofmultiple centrioles was also detected, suggesting that aneuploidy may be related to the lack of paternal contribution that results in abnormal centrosome formation, incorrect control of the process of spindle rearrangement, and consequent chromosomal malsegregation.Abnormal segregation and multicentriolar distribution were not limited to parthenogenetic cell lines but was observed in parthenotes as well, indicating that culture artifacts are unlikely to be the cause. PUR 2007, PUR 2008.

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