Animal Physiology

Animal Physiology

  • David Jacobi added an answer:
    How do you calculate how many animals are needed for hepatocyte isolation?

    I need to estimate (with power calculations) how many animals would be needed for my experiments with primary mouse hepatocytes. Assuming good yeilds. 

    David Jacobi

    Efficient isolation yields 20-30 million hepatocytes/liver after Percoll gradient.

    Typical seeding would be 0.25 million cells/mL. That would be 0.5 million / well in a 6-well plate. 

  • A. J. Escribano added an answer:
    Do you believe that CLA cause insulin resistance in dairy cows similar to monogastrics?
    It is believed that CLA in monogastrics cause insulin resistance. In dairy cows, the milk fat depression effect is well-known and it is believed that there is very limited effect on metabolic and physiological parameters.
    A. J. Escribano

    Fatty acids metabolism and nutrition is a growing field of research, and epigenetics has a lot to do with it.
    Specifically, unsaturated fatty acids seem to be on the spotlight even more than saturated ones), among other reasons, due to the economic interest of enriching animal products.
    In this sense, contradictory results can be found, as with Omega-3, so that it is timely to wait for more studies (in my opinion).


    Alfredo J. Escribano.

  • A. J. Escribano added an answer:
    What is the current status of research on CLA in ruminants?
    In the field of CLA supplementation in ruminants, it is believed that we have passed all the borders of research in the field of CLA feeding to dairy cows. Actually what we know is limited to the fact that CLA is causing milk fat depression in dairy cattle.

    What do you think about the points which are not addressed or less investigated in this area?
    A. J. Escribano

    Dear Behnam,

    It is needed to assess the efficiency of incorporation CLA in animal products so that it is sustainable. Sometimes, great efforts are made on this, obtaining poor results.

    When I say 'sustainable' I mean: feed efficiency, real need for human health (taking into account current intake of CLA and recommended dose), farms' profitability (cost-effectiveness for the farmer).

    In this regard, I would like to connect this question with one I recently made (attached).

    Interesting question, Behman.



  • Rebeca Juárez asked a question:
    What is the mechanism of action of BD1063 (antagonist of sigma 1 receptor)?


    I need know the mechanism of action BD1063. Is antagonist of sigma 1 receptor but I can't find a paper whit mechanism.

    Thanks for your time.

  • Pedram Malekpouri asked a question:
    How can I quantify the output of SwisTrack?

    I'm using the SwisTrack for fish behavior analyses. After completing all components, the software gives me a text file, including %Frame Number/ Image Center x/ Image Center y/ World Center x/ World Center y/ Area/ Orientation/ Compactness (attached file).

    I appreciate if you let me know what do they mean exactly.

    How can I use them to calculate fish swimming speed, spontaneous activity or etc?

  • Guillermo Alberto Perez Fernandez added an answer:
    Does the Autonomic Nervous System still has an effect on the Heart Rate Variability of isolated hearts?

    Langerdoff isolated hart preparation

    Guillermo Alberto Perez Fernandez

    My response is yes. Hot topic.

  • Carsten Schradin added an answer:
    Can cortisol be measured in the saliva of domestic cats?
    Does anybody have experience in measuring cortisol in the saliva of domestic cats?

    We tried some measurements (using a commercial ELISA kit to measure in human saliva), but got extremely bad double values (13-58%), making me wonder whether there is something in cat saliva that interferes.

    There is no literature on measurements of cort in cat saliva (except on small study on jaguars), but I guess others might have tried before, but also experienced significant difficulties, which never got published?
    Carsten Schradin

    We did not manage to reliably measure cort in cat saliva. Cat saliva has a very high Ph, which could be part of the problem.

  • Nicolas Bédère added an answer:
    Are there any genes related to abortion in the blood of dairy cows (WBC, RBC)?
    see above
    Nicolas Bédère


    I think you may be interested in this paper:

    • [Show abstract] [Hide abstract]
      ABSTRACT: Decline in fertility in last few decades, especially in high milk producing dairy cows, is a major concern in many countries. Fertility is a compound trait of many events leading up to successful calving and subsequent lactation. Fertility traits in cattle have relatively low heritability. Recently a number of studies have searched for genomic regions and variants associated with various reproduction traits in cattle. We constructed a systematic meta-assembly of 35 QTL studies and separately for 23 genome-wide association studies (GWAS) related to female fertility in cattle representing over 101,000 genotyped individuals. We separately compiled and discussed additional candidate gene studies, fine-mapping studies, selection signatures and other novel potential biomarkers associated with female reproduction in cattle. Despite of individual studies being low powered, inherent low heritability of fertility traits and low success of genomic selection for fertility traits, a substantial number of strong signals, causative mutations and biomarkers for fertility have been identified throughout the genome. A number of embryonic lethal mutations and haplotypes have been identified using novel approaches. These markers can be used for population screening, genomic-assisted mating plans, and can be incorporated in a marker assisted framework for genetic improvement in the fertility. The studies investigating the role of epigenomic markers are in the early stages, and may provide important biomarkers in near future. Novel approaches linking metabolomic markers, epigenetic and high resolution genome content to high quality phenotypes will assist in our understanding of the genetic architecture of complex traits underlying fertility in cattle.
      No preview · Article · Aug 2014 · Livestock Science
  • Chendi Zhang added an answer:
    Has anyone tested Zootracer (from Microsoft) for animal video tracking?
    I'm trying to install it but it seems the installation process cannot be completed. I follow all the instructions in the .txt doc but still, the .exe file does not run. Has anyone succesfully installed and tested it?
    Chendi Zhang

    It works in my computer too. According to the releasenotes of zootracer, additional files needed for operation all have 248 in their name, which may correspond to the version of 2.4.8. So you have to try OpenCV v. 2. 4. 8.

  • Julia Rowe added an answer:
    How does the isotopic ratio typically differ between avian muscle and guano?
    I have delta N15 data for seabird muscle, but what I really need is the guano. Does anyone know how much that differs?
    Julia Rowe

    Well, for anyone still interested in this question - I ran my own samples for guano and had samples for muscle. The muscle samples I had were for Wedge-tailed shearwater in Hawaii = 9.99 d15N and for the guano that I ran for Newell's Shearwater in Hawaii = 8.2 d15N.  so it is not a direct comparison but it is what I found.  Hope it helps.  

  • Suaad A. Meerkhan added an answer:
    What are the appropriate collagen levels in the testis tissue?
    Dose anybody know the collagen level in the testis of animals, specifically mice? And if there is any difference in the level between human and mice testis?
    Suaad A. Meerkhan

    Thanks Mahmoud Abdelaal

  • Deidy Azhari added an answer:
    Can anyone explain the regulation of Leptin, Orexin and NPY for metabolism and growth out in teleost?

    Can anyone explain the regulation of Leptin, Orexin and NPY for metabolism and growth out in teleost?

    Deidy Azhari

    @Mr. Asturiano: thank you very much..

    @Mr. Kelany: it is interesting

  • Toshio Murase added an answer:
    What is the current view on Hulbert's 'membrane pacemaker' theory of metabolism?
    Membrane fluidity is considered to play an important role for the regulation of cell metabolism, and dysregulation of membrane fluidity is thought to be involved in metabolic disorders and neurodegenerative diseases. What are the current opinions in this field of research?
    Toshio Murase

    I have no idea.

  • Shannon L. Cass-Calay added an answer:
    Where could I obtain Active Consumption Rates for bird and mammal species?

    I need info on Active Consumption Rates (ACR, i.e. weight of food consumed per unit time of active feeding, e.g. g/min or kg/h; see Wilmers & Stahler 2002 Canadian Journal of Zoology 80:1256-1261 for further details) for several bird and mammals species (complete list attached).

    I would very much appreciate info on: i) species' ACRs or, ii) how to infer them (from body mass, species gregariousness,...) 

    Thank you very much in advance!

    Shannon L. Cass-Calay

    A few more oldies but goodies...

    Berger, M., J. S. Hart, and O. Z. Roy. "Respiration, oxygen consumption and heart rate in some birds during rest and flight." Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology 66.2 (1970): 201-214.

    Bennettand, P. M., and P. H. Harvey. "Active and resting metabolism in birds: allometry, phylogeny and ecology." Journal of Zoology 213.2 (1987): 327-344.

    Wilmers, Christopher C., and Daniel R. Stahler. "Constraints on active-consumption rates in gray wolves, coyotes, and grizzly bears." Canadian Journal of Zoology 80.7 (2002): 1256-1261.

    Bishop, Charles M. "The maximum oxygen consumption and aerobic scope of birds and mammals: getting to the heart of the matter." Proceedings of the Royal Society of London B: Biological Sciences 266.1435 (1999): 2275-2281.

  • Ebrahim Bani Hassan added an answer:
    What is the proper method to calculate the concentration of spermatozoa?

    I want to calculated the concentration of spermatozoa collected from the epididymis knowing that I used the cell malaséz so what is the rule and the rate of dilution Applicable?

    Ebrahim Bani Hassan

    Most welcome!

  • Priyoneel Basu added an answer:
    Why control mice have increased periodicity in the circadian locomotor activity in constant darness?

    We are analyzing the locomotor activity of control mice littermates of a conditional inducible mutant mice (our control mice are Bmal1 Flox/flox). We found that the period is higher than 24h in constant darkness on those control mice. Could this be due to the mixed genetic background of the control mice?

    Priyoneel Basu

    What is the photoperiodic history, and what was the history before they got to your lab?

  • Vitthalrao Khyade added an answer:
    What is the physiological or anatomical difference between place cells and grid cells in the hippocampus?

    In the medial temporal lobe,there are specific types of neural cells such as place cells, head-direction cells, grid cells, and boundary vector cells which involved in cognitive map and spatial memory. Hippocampal “place cells” encode the rat’s location within an open environment independently of its orientation and fire in the specific position. The complementary encoding of the orientation, independently of location, is done by “head-direction cells” .I think all of them are pyramidal neurons. So Is there any physiological or anatomical difference between these kinds of cell?

    Vitthalrao Khyade

    Research Group, A.D.T. And Shardabai Pawar Mahila Mahavidyalaya, Shardanagar, Malegaon(Baramati) Dist. Pune – 413115.

    Objective: To Establish the Repository of Contributions of Eminent Scholars and  Information on Science and Culture  For The Society.                                                                   


         Fenton's reagent

    Fenton's reagent is a solution of hydrogen peroxide and an iron catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) and polychloroethylene (PCE). It was developed in the 1890s by Henry John Horstman Fenton as an analytical reagent.[1]

    Iron(II) is oxidized by hydrogen peroxide to iron(III), forming a hydroxyl radical and a hydroxide ion in the process. Iron(III) is then reduced back to iron(II) by another molecule of hydrogen peroxide, forming a hydroperoxyl radical and a proton. The net effect is a disproportionation of hydrogen peroxide to create two different oxygen-radical species, with water (H+ + OH−) as a byproduct.

    (1) Fe2+ + H2O2 → Fe3+ + HO• + OH−

    (2) Fe3+ + H2O2 → Fe2+ + HOO• + H+

    The free radicals generated by this process then engage in secondary reactions. For example, the hydroxyl is a powerful, non-selective oxidant. Oxidation of an organic compound by Fenton's reagent is rapid and exothermic and results in the oxidation of contaminants to primarily carbon dioxide and water.[2]

    Reaction (1) was suggested by Haber and Weiss in the 1930s as part of what would become the Haber–Weiss reaction.[3] Iron(II) sulfate is typically used as the iron catalyst. The exact mechanisms of the redox cycle are uncertain, and non-OH• oxidizing mechanisms of organic compounds have also been suggested. Therefore, it may be appropriate to broadly discuss Fenton chemistry rather than a specific Fenton reaction.

    In the electro-Fenton process, hydrogen peroxide is produced in situ from the electrochemical reduction of oxygen.[4]

    Fenton's reagent is also used in organic synthesis for the hydroxylation of arenes in a radical substitution reaction such as the classical conversion of benzene into phenol.

    (3) C6H6 + FeSO4 + H2O2 → C6H5OH

    A recent hydroxylation example involves the oxidation of barbituric acid to alloxane.[5] Another application of the reagent in organic synthesis is in coupling reactions of alkanes. As an example tert-butanol is dimerized with Fenton's reagent and sulfuric acid to 2,5-dimethyl-2,5-hexanediol.[6]

    Biomedical applications
    The Fenton reaction has importance in biology because it involves the creation of free radicals by chemicals that are present in vivo. Transition-metal ions such as iron and copper donate or accept free electrons via intracellular reactions and help in creating free radicals. Most intracellular iron is in ferric (+3 ion) form and must be reduced to theferrous (+2) form to take part in Fenton reaction. Since superoxide ions and transition metals act in a synergistic manner in the creation of free radical damage, iron supplementation must not be done in patients with any active infections or in general any diseases.[7]

    Henry John Horstman Fenton (18 February 1854 – 13 January 1929) was a British chemist who, in the 1890s invented Fenton's reagent,[1] a solution of hydrogen peroxide and an iron catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene (TCE) andtetrachloroethylene (PCE). Born in London, Henry Fenton was educated at Magdalen College School, King's College London and Christ's College, Cambridge.[2] He became the university demonstrator in Chemistry at Cambridge in 1878, and was University Lecturer in Chemistry from 1904 to 1924.

    1.      Fenton H.J.H. (1894). "Oxidation of tartaric acid in presence of iron". J. Chem. Soc., Trans. 65 (65): 899–911. doi:10.1039/ct8946500899.


    3.      Haber, F. and Weiss, J. (1932). "Über die Katalyse des Hydroperoxydes". Naturwissenschaften 20 (51): 948–950. doi:10.1007/BF0150471.

    4.      Juan Casado,Jordi Fornaguera,Maria I. Galan (January 2005). "Mineralization of Aromatics in Water by Sunlight-Assisted Electro-Fenton Technology in a Pilot Reactor". Environ. Sci. Technol. 39 (6): 1843–47. doi:10.1021/es0498787. PMID 15819245.

    5.      Brömme HJ, Mörke W, Peschke E (November 2002). "Transformation of barbituric acid into alloxan by hydroxyl radicals: interaction with melatonin and with other hydroxyl radical scavengers". J. Pineal Res. 33 (4): 239–47. doi:10.1034/j.1600-079X.2002.02936.x. PMID 12390507.

    6.      E. L. Jenner (1973). "α,α,α',α'-Tetramethyltetramethylene glycol". Org. Synth.; Coll. Vol. 5, p. 1026.

    7.      Robbins and Cotran (2008). Pathologic Basis of Disease - 7th edition. Elsevier. p. 16. ISBN 9780808923022.

    ----------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------              ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    Acknowledgement: Girija Girish Tambe of  Vaishnavi  Xerox helped for Collection of images in the Science Spectrum of  5 September, 2015.   All the mistakes in the collection of information from website, it’s compilation and communication belongs exclusively to :                            

       Vitthalrao B. Khyade (And not to his pace making Shardanagar). Please do excuse for the mistakes.                                                                                                                                                                                                                                


    ------------------- Dr.APIS@World.Science.   -----------------------------------------------------------------------

                                     File: Dr.APIS.5.Sept@Fenton.Reaction                                                                                                      

    Compiled for: Science Association, Shardabai Pawar Mahila Mahavidyalaya, Shardanagar (Baramati) – 413115 India.

      With the Best Compliments From:  Shardanagar (The Agro – academic Heritage of Grandsire Padmashri Dr. D. G. Alias Appasaheb Pawar).

                                                                                    All the mistakes in the collection of information from website, it’s compilation and communication ( through email ) belongs exclusively to :  Vitthalrao B. Khyade (And not to his pace making Shardanagar).                                                                                                           

  • Ricardo Augusto Mendonça Vieira added an answer:
    Does method and stage of maturity of castrating ruminants affect their growth?
    Methods such as rubber rings, burdizzo, and knives have been used in many countries. Some castrate calves, kids, and lambs at 2 weeks after birth with rubber rings, some wait for 7months and use burdizzo.
    Ricardo Augusto Mendonça Vieira

    Dear Zibani Madzonga, I have a paper that describes the long term growth of kids from birth to maturity. They were castrated with rings at the 15 days-old.

    The paper is: Araujo et alii, Journal of Agricultural Science 153(07): 1321-1340, 2015.

  • Alfredo Castro-Vazquez added an answer:
    Does anyone know if the temporal glands that are often associated with musth in elephants have any homologous structure in humans?
    Exactly what it says on the tin.
    Alfredo Castro-Vazquez

    Humans have a thickened band in the scalp skin, approximately following the hair line over the ears. Sweat from this region has a peculiar navel-like odor, but I know no reports of the presence of apocrine sweat glands in there. It may be worth investigating.

  • Eunüs S. Ali added an answer:
    How does pyruvate treatment cause blood glucose reduction in Alms1 mutant (FOZ) mice?

    In pyruvate tolerance test, by treating the FOZ mice (Fat Aussie mice) with Pyruvate (Pyruvate/Body Weight: 2g/kg), there is unpublished evidence that mice may/will be dead within the next one or two days. It was also noted that blood glucose level of mice was dramatically reduced over time. I was just wondering, what is happening in Alms1 mutant mice when they are with pyruvate treatment? Any suggestions or speculations is highly appreciated. Thanks.

    Eunüs S. Ali

    Dear Dr. Nissim, I appreciate your nice speculations.  Sincerely, Eunus

  • Charles E. Pekins added an answer:
    What are small mammal hibernators that subsist soley on body fat doing during the brief euthermic initervals?

    I have read many papers that describe the physiology and biochemistry of seasonal hibernation, including what is occurring during the periodic arousals and euthermic intervals.  I know that in species that cache food, these animals might arouse and eat food during euthermic periods, particularly in the spring.  What I don't understand is what species that rely on fat reserves are doing during the brief (< 24 hr) euthermic periods.  Are they awake and active, or do they continue to sleep albeit at a higher metabolism and body temperature?  I am mostly interested in jumping mice (Dipodidae)  but examples from any small mammals would be helpful.  thank you!

    Charles E. Pekins

    Bats that hibernate in caves in temperate areas where the temperatures may warm briefly and intermittently during the winter are known to wake, excrete wastes, leave the hibernacula, drink, eat (if insects are flying), and then return to either the same hibernacula or a different one.

    On a related note, White-nose Syndrome, which has killed millions of bats since making it to North America in 2006, causes hibernating bats to arouse in the dead of winter-except there is no food available to recover fat loss. On the surface, unusual observations occur such as many bats flying about during frigid temperatures and snow.

  • Sutarmo Vincentius Setiadji added an answer:
    Which is more common among animals, graded potentials or action potentials?

    Of species with nervous systems, which of the two is more often the main type of communication between neurons? We mostly learn about action potentials, so I've been surprised at how common graded potentials seem to be.    Are action potentials the most common, or are they mostly restricted to "higher" animals?

    Sutarmo Vincentius Setiadji

    The out put of graded potentials mostly are preparing in making action. The out put of action potential is an action. In a nerve the action is conducting umpuls. In muscle the action is contraction.

  • Oliver Henry Wearing added an answer:
    Does anyone know of any decent mathematical methods of estimating (very small) in ovo zebrafish embryo volumes/masses using length data?

    Accurately weighing individuals is problematic due to miniscule masses

    Keeping embryos in the egg is preferable, which makes determining embryo wet mass impossible (by weighing, anyway).

    Oliver Henry Wearing

    Thanks for your help, Kim. That could be really useful!

  • Sarkawt Hamad added an answer:
    Can anyone give some insight into a transient pain response (~ 45sec) from an Intraperitoneal injection of Hydroyurea (TP) Sprague Dawley rats ?

    Immediately after injection there is mobility impairment stretching and waist pinching.  This reaction lasts for about 45 seconds and then the animal regains normal posture and behaviour. 

    Dosage is 500mg/kg/bw single Ip 

    95% Pure hydroxyurea in DDH2O

    Sarkawt Hamad

    Hi Marnie

    I think you dose is too much decrease the amount, while if you need this such dose as experimental model, I prefer to prepare a mixture of it with Xylazin because it make rats more relax when you are doing experiment


  • Gheorghe Solcan added an answer:
    Can I use sweetened milk to raise blood glucose for an OGTT in rats?


    I would like to perform an OGTT in Sprague Dawley rats.

    The rats will be accustomed to sweetened milk for a behavioral experiment (novelty-induced hypophagia test) prior to the OGTT. Thus, I wondered if I can use this milk in the OGTT, as I would know the rats drink the milk without the need for gavaging. Or should the solution optimally only contain glucose?

    Alternatively, does someone know if there are sugar pellets available that I can feed the rats to even better control the amount of glucose the rat consumed?

    Thanks in advance!

    Cheers, Laura

    Gheorghe Solcan

    Dear Laura

    you may take into account the fact that in rodents oral glucose combined with some other easily digestible glucids and proteins (from milk) might induces a severe digestive dismicrobism. We VE HAD SUCH BAD EXPERIENCE IN CHINCHILAS, inducing secondary Clostridium infection

  • Peter C Hubbard added an answer:
    Has anyone any experience of electrophysiology in echinoderms?

    We are trying to characterise chemosensory systems in sea cucumbers, especially those involved in chemical communication, and would like to record from chemosensory cells (either in the papillae and/or tentacles), probably extracellular in vivo, in order to identify pheromones, but we have only found passing comments that say that the authors tried to do some recording but with no success. Initial attempts on our part were also without success; we could not even find a suitable anaesthetic. Any tips would be more than wecome!

    Peter C Hubbard

    Dear Omri,

    Thank you very much for the tip. I had seen that some people were using menthol, but it is good to know that it works with sea cucumbers. I will also be sure to give it some time to work.

    Thanks again,


  • Ram Nath Mishra added an answer:
    How can I estimate elephant age (spesifically sumatran elephant) using dung diameter?

    Conservationist, population biologist.

    Ram Nath Mishra

    Growth in the Sumatran elephant (Elephas maximus sumatranus) and age estimation based on dung diameter
    Joanne  Reilly 
     Journal of Zoology (Impact Factor: 1.95). 09/2002; 258(02):205 - 213. 
    ABSTRACT The aim of this study was to investigate age-related growth in the Sumatran elephant Elephas
    sumatranus and to use the derived relationship to determine the age structure of the wild elephant population in Way Kambas National Park (WKNP), Sumatra. Shoulder height, forefoot circumference and diameter of dung bolus were found to be related to age of captive Sumatran elephants using the Von Bertalanffy growth function. All length measurements were highly correlated with age in the Sumatran elephant and provide growth models for determining the age structure of wild populations. Female captive elephants reached their growth plateau earlier than male elephants who continued growing throughout the ages observed. There was no clear evidence of a secondary growth spurt in male elephants. The growth model relating dung diameter to age was used to predict the age structure of the wild elephant population in WKNP from dung measured along random line transects. The wild elephant population in WKNP is young and dominated by sub-adults (between 5 and 15 years of age). There are marked differences between the age structure of the population as revealed in the current survey and that reported from previous studies, suggesting that changes have occurred within the population in the intervening period. The use of dung diameter to predict age offers a robust field technique for use in situations where direct observations are limited, and the use of other age estimation methods is impractical. It is easily coupled with dung counts for estimating the size, age structure and biomass of elephant populations, and has considerable potential for investigating the effects of poaching on age structure and identifying where priority action should be directed in human–elephant conflict situations.

  • Edward Narayan added an answer:
    Would irradiating faecal samples before extracting glucocorticoid hormones affect the results of the EIA?
    For safety reasons (to kill potentially infective micro-organisms) I would like to irradiate faecal samples (from various mammalian species) before performing enzyme immunoassays for faecal glucocorticoid metabolites. I use freeze-drying, followed by a chemical extraction method (using 80% methanol) to extract the GC hormones from the faeces. I would like to do the irradiation before the freeze-drying step. I am currently using both cortisol and corticosterone EIAs on the extracts. Is the irradiation likely to affect the EIA results?

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