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Svorc P, Svorc P, Gresova S. Sex differences, chronobiology and general anaesthesia in activities of the autonomic nervous system in rats. Exp Physiol 2023; 108:810-817. [PMID: 36951930 PMCID: PMC10988424 DOI: 10.1113/ep091143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/02/2023] [Indexed: 03/24/2023]
Abstract
NEW FINDINGS What is the topic of this review? Changes in heart rate variability in rats with sex differences and the use of different anaesthesia during light-dark cycles. What advances does it highlight? The review highlights and discusses synthesized current results in order to advance knowledge and understanding of sex differences with an emphasis on changes in the autonomic nervous system determined by heart rate variability. ABSTRACT Heart rate variability (HRV) is commonly used in experimental studies to assess sympathetic and parasympathetic activities. The belief that HRV in rodents reflects similar cardiovascular regulations in humans is supported by evidence, and HRV in rats appears to be at least analogous to that in humans, although the degree of influence of the parasympathetic division of the autonomic nervous system (ANS) may be greater in rats than in humans. Experimental studies are based on control or baseline values, on the basis of which the change in ANS activity after a given experimental intervention is assessed, but it is known that the ANS in rats is very sensitive to various stress interventions, such as the manipulation itself, and ANS activity can also differ depending on sex, the time of measurement, and whether the animals are under general anaesthesia. Thus, for correct assessment, changes in ANS activity and their relationship to the observed parameter should be based on whether ANS activity does or does not change but also to what extent the activity is already changed at the start of the experiment. Since rats are considered to be the most suitable model animal for basic cardiovascular research, in this review we point out existing differences in individual HRV frequency parameters at the start of experiments (control, baseline values), taking into account sex in relation to time of measurement and anaesthesia.
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Affiliation(s)
- Pavol Svorc
- Department of Physiology and Pathophysiology, Faculty of MedicineOstrava UniversityOstravaCzech Republic
| | - Pavol Svorc
- Department of Physiology and Pathophysiology, Faculty of MedicineOstrava UniversityOstravaCzech Republic
- Department of Physiology, Faculty of MedicineSafarik UniversityKošiceSlovak Republic
| | - Sona Gresova
- Department of Physiology, Faculty of MedicineSafarik UniversityKošiceSlovak Republic
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Naltrexone alters cardiovascular function following acute forced swimming in mice. Cardiovasc Endocrinol Metab 2022; 11:e0263. [PMID: 35441130 PMCID: PMC9010118 DOI: 10.1097/xce.0000000000000263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/28/2022] [Indexed: 11/25/2022]
Abstract
Purpose Naltrexone (NTX) is an opioid antagonist that can reverse the physiological effects of opioid receptors when bound. Opioid receptors have been found to play a role in cardiovascular (CV) function, and thus, binding of NTX may alter CV activity at rest and in response to acute and chronic exercise (EX). We hypothesized that opioid receptor blockade will alter the typical CV responses following acute EX. Methods We assessed the effects of opioid receptor blockade on CV function via echocardiography in mice following an acute bout of forced swimming (FSw), a model of rodent EX. We administered opioid receptor antagonist, NTX, or saline in mice before FSw and in the absence of an FSw perturbation. Furthermore, we assessed how NTX can influence maximal EX capacity on a rodent treadmill. Results Our data shows that NTX administration does not decrease maximal EX capacity in mice (P > 0.05). However, NTX attenuated cardiac output following FSw (FSw = 52.5 ± 2.5 ml/min vs. FSw + NTX = 32.7 ± 5.2 ml/min; P < 0.05) when compared with saline control (33.5 ± 3.8 ml/min). Further, the administration of NTX in the non-EX condition significantly (P < 0.05) reduced ejection fraction. Conclusion These data suggest that normal opioid receptor activation is necessary for typical CV function following FSw.
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Majumder R, Mohamed Nazer AN, Panfilov AV, Bodenschatz E, Wang Y. Electrophysiological Characterization of Human Atria: The Understated Role of Temperature. Front Physiol 2021; 12:639149. [PMID: 34366877 PMCID: PMC8346027 DOI: 10.3389/fphys.2021.639149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/01/2021] [Indexed: 11/13/2022] Open
Abstract
Ambient temperature has a profound influence on cellular electrophysiology through direct control over the gating mechanisms of different ion channels. In the heart, low temperature is known to favor prolongation of the action potential. However, not much is known about the influence of temperature on other important characterization parameters such as the resting membrane potential (RMP), excitability, morphology and characteristics of the action potential (AP), restitution properties, conduction velocity (CV) of signal propagation, etc. Here we present the first, detailed, systematic in silico study of the electrophysiological characterization of cardiomyocytes from different regions of the normal human atria, based on the effects of ambient temperature (5-50°C). We observe that RMP decreases with increasing temperature. At ~ 48°C, the cells lose their excitability. Our studies show that different parts of the atria react differently to the same changes in temperature. In tissue simulations a drop in temperature correlated positively with a decrease in CV, but the decrease was region-dependent, as expected. In this article we show how this heterogeneous response can provide an explanation for the development of a proarrhythmic substrate during mild hypothermia. We use the above concept to propose a treatment strategy for atrial fibrillation that involves severe hypothermia in specific regions of the heart for a duration of only ~ 200 ms.
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Affiliation(s)
- Rupamanjari Majumder
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | | | - Alexander V Panfilov
- World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov University, Moscow, Russia.,Department of Physics and Astronomy, Ghent University, Ghent, Belgium.,Laboratory of Computational Biology and Medicine, Ural Federal University, Yekaterinburg, Russia
| | - Eberhard Bodenschatz
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany.,Laboratory of Atomic and Solid-State Physics and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, United States
| | - Yong Wang
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
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Dietrichs ES, Tveita T, Smith G. Hypothermia and cardiac electrophysiology: a systematic review of clinical and experimental data. Cardiovasc Res 2020; 115:501-509. [PMID: 30544147 DOI: 10.1093/cvr/cvy305] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 12/17/2022] Open
Abstract
Moderate therapeutic hypothermia procedures are used in post-cardiac arrest care, while in surgical procedures, lower core temperatures are often utilized to provide cerebral protection. Involuntary reduction of core body temperature takes place in accidental hypothermia and ventricular arrhythmias are recognized as a principal cause for a high mortality rate in these patients. We assessed both clinical and experimental literature through a systematic literature search in the PubMed database, to review the effect of hypothermia on cardiac electrophysiology. From included studies, there is common experimental and clinical evidence that progressive cooling will induce changes in cardiac electrophysiology. The QT interval is prolonged and appears more sensitive to decreases in temperature than the QRS interval. Severe hypothermia is associated with more pronounced changes, some of which are proarrhythmic. This is supported clinically where severe accidental hypothermia is commonly associated with ventricular fibrillation or asystole. J-waves in human electrocardiogram recordings are regularly but not always observed in hypothermia. Its relation to ventricular repolarization and arrhythmias is not obvious. Little clinical data exist on efficacy of anti-arrhythmic drugs in hypothermia, while experimental data show the potential of some agents, such as the class III antiarrhythmic bretylium. It is apparent that QT-prolonging drugs should be avoided.
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Affiliation(s)
- Erik Sveberg Dietrichs
- Department of Medical Biology, Experimental and Clinical Pharmacology Research Group, UiT, The Arctic University of Norway, Tromsø, Norway.,Division of Diagnostic Services, Department of Clinical Pharmacology, University Hospital of North Norway, Tromsø, Norway
| | - Torkjel Tveita
- Department of Clinical Medicine, Anesthesia and Critical Care Research Group, UiT, The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Godfrey Smith
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
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Luppi M, Hitrec T, Di Cristoforo A, Squarcio F, Stanzani A, Occhinegro A, Chiavetta P, Tupone D, Zamboni G, Amici R, Cerri M. Phosphorylation and Dephosphorylation of Tau Protein During Synthetic Torpor. Front Neuroanat 2019; 13:57. [PMID: 31244617 PMCID: PMC6563845 DOI: 10.3389/fnana.2019.00057] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/20/2019] [Indexed: 12/30/2022] Open
Abstract
Tau protein is of primary importance for many physiological processes in neurons, where it affects the dynamics of the microtubule system. When hyperphosphorylated (PP-Tau), Tau monomers detach from microtubules and tend to aggregate firstly in oligomers, and then in neurofibrillary tangles, as it occurs in a group of neurodegenerative disorders named thauopathies. A hypothermia-related accumulation of PP-Tau, which is quickly reversed after the return to normothermia, has been shown to occur in the brain of hibernators during torpor. Since, recently, in our lab, a hypothermic torpor-like condition (synthetic torpor, ST) was pharmacologically induced in the rat, a non-hibernator, the aim of the present work was to assess whether ST can lead to a reversible PP-Tau accumulation in the rat brain. PP-Tau was immunohistochemically assessed by staining for AT8 (phosphorylated Tau) and Tau-1 (non-phosphorylated Tau) in 19 brain structures, which were chosen mostly due to their involvement in the regulation of autonomic and cognitive functions in relation to behavioral states. During ST, AT8 staining was strongly expressed throughout the brain, while Tau-1 staining was reduced compared to control conditions. During the following recovery period, AT8 staining progressively reduced close to zero after 6 h from ST. However, Tau-1 staining remained low even after 38 h from ST. Thus, overall, these results show that ST induced an accumulation of PP-Tau that was, apparently, only partially reversed to normal during the recovery period. While the accumulation of PP-Tau may only depend on the physicochemical characteristics of the enzymes regulating Tau phosphorylation, the reverse process of dephosphorylation should be actively regulated, also in non-hibernators. In conclusion, in this work a reversible and widespread PP-Tau accumulation has been induced through a procedure that leads a non-hibernator to a degree of reversible hypothermia, which is comparable to that observed in hibernators. Therefore, the physiological mechanism involved in this process can sustain an adaptive neuronal response to extreme conditions, which may however lead to neurodegeneration when particular intensities and durations are exceeded.
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Affiliation(s)
- Marco Luppi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Timna Hitrec
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Alessia Di Cristoforo
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Fabio Squarcio
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Agnese Stanzani
- Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Alessandra Occhinegro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | | | - Domenico Tupone
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, United States
| | - Giovanni Zamboni
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Roberto Amici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Matteo Cerri
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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Wang W, Hua T, Li H, Wu X, Bradley J, Peberdy MA, Ornato JP, Tang W. Decreased cAMP Level and Decreased Downregulation of β 1-Adrenoceptor Expression in Therapeutic Hypothermia-Resuscitated Myocardium Are Associated With Improved Post-Resuscitation Myocardial Function. J Am Heart Assoc 2018; 7:JAHA.117.006573. [PMID: 29572320 PMCID: PMC5907536 DOI: 10.1161/jaha.117.006573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Epinephrine administered during cardiopulmonary resuscitation (CPR) is associated with severe post‐resuscitation myocardial dysfunction. We previously demonstrated that therapeutic hypothermia reduced the severity of post‐resuscitation myocardial dysfunction caused by epinephrine; however, the relationship between myocardial adrenoceptor expression and myocardial protective effects by hypothermia remains unclear. Methods and Results Rats weighing between 450 and 550 g were randomized into 5 groups: (1) normothermic placebo, (2) normothermic epinephrine, (3) hypothermic placebo, (4) hypothermic epinephrine, and (5) sham (not subject to cardiac arrest and resuscitation). Ventricular fibrillation was induced and untreated for 8 minutes for all other groups. Hypothermia was initiated coincident with the start of CPR and maintained at 33±0.2°C for 4 hours. Placebo or epinephrine was administered 5 minutes after the start of CPR and 3 minutes before defibrillation. Post‐resuscitation ejection fraction was measured hourly for 4 hours then hearts were harvested. Epinephrine increased coronary perfusion pressure during CPR (27±6 mm Hg versus 21±2 mm Hg P<0.05). Post‐resuscitation myocardial function was impaired in the normothermic epinephrine group compared with other groups. The concentration of myocardial cAMP doubled in the normothermic epinephrine group (655.06±447.63 μmol/L) compared with the hypothermic epinephrine group (302.51±97.98 μmol/L; P<0.05). Myocardial β1‐adrenoceptor expression decreased with normothermia cardiac arrest but not with hypothermia regardless of epinephrine. Conclusions Epinephrine, administered during normothermic CPR, increased the severity of post‐resuscitation myocardial dysfunction. This adverse effect was inhibited by intra‐arrest hypothermia resuscitation. Declined cAMP with more preserved β1‐adrenoceptors in hypothermia‐resuscitated myocardium is associated with improved post‐resuscitated myocardial function in vivo.
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Affiliation(s)
- Wei Wang
- The Second Affiliated Hospital of Anhui Medical University, Hefei, China.,Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA
| | - Tianfeng Hua
- The Second Affiliated Hospital of Anhui Medical University, Hefei, China.,Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA
| | - Hao Li
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA
| | - Xiaobo Wu
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA
| | - Jennifer Bradley
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA
| | - Mary Ann Peberdy
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA.,Departments of Internal Medicine and Emergency Medicine, Virginia Commonwealth University, Richmond, VA
| | - Joseph P Ornato
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA.,Department of Emergency Medicine, Virginia Commonwealth University, Richmond, VA
| | - Wanchun Tang
- Weil Institute of Emergency and Critical Care Research, Virginia Commonwealth University, Richmond, VA .,Department of Emergency Medicine, Virginia Commonwealth University, Richmond, VA.,Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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Ferasin L, Ferasin H, Little CJL. Lack of correlation between canine heart rate and body size in veterinary clinical practice. J Small Anim Pract 2010; 51:412-8. [PMID: 20553373 DOI: 10.1111/j.1748-5827.2010.00954.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES An association between heart rate (HR) and bodyweight has been reported in dogs and it is common belief that small breeds of dog exhibit higher HR than large breeds. The first aim of this study was to test the null hypothesis that, in veterinary clinical practice, bodyweight does not affect HR measured in healthy dogs. A second objective of this investigation was to assess whether other variables, such as gender, breed morphology, age and demeanour, may have a significant effect on dog's HR measured in a clinical setting. METHODS The investigation was performed via two different studies: a retrospective analysis performed on 243 electrocardiogram recordings and a prospective study based on 153 standardised clinical examinations. RESULTS The two separate studies did not show any significant correlation between HR and bodyweight (P=0.5705 and P=0.4682, respectively). Subject's breed morphology and gender did not appear to affect HR measured under these circumstances. However, dogs under the age of one year seem to have significantly higher HRs than older dogs (P < 0.05). Finally, subject's demeanour was also found to have a significant influence on HR; lower values were recorded in relaxed dogs, and higher rates were documented in excited, nervous dogs (P < 0.05). CLINICAL SIGNIFICANCE Normal HR could be erroneously interpreted as bradycardia or tachycardia if bodyweight was to be considered a determinant factor. Instead, HR in healthy dogs undergoing routine clinical examination is related to their demeanour or age, if younger than 12 months, but does not appear to be related to bodyweight.
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Affiliation(s)
- L Ferasin
- Specialist Veterinary Cardiology Consultancy, 20 Old Bath Road, Newbury, Berkshire RG14 1QL
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Marshall JM, Willis JS. The effects of temperature on the membrane potentials in isolated atria of the ground squirrel, Citellus tridecemlineatus. J Physiol 2007; 164:64-76. [PMID: 16992131 PMCID: PMC1359285 DOI: 10.1113/jphysiol.1962.sp007002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Abstract
Using independent methods, measurements were made of the rate of oxygen consumption of quiescent rat ventricular tissue slices and of K+-arrested rabbit hearts at different temperatures. Experiments were designed such that the effect of temperature could be separated from the effect of time. The rate of oxygen consumption of both cardiac muscle preparations declined with time following cardiectomy. Likewise the rate of resting oxygen consumption of both preparations was relatively insensitive to temperature: Q10 = 1.3. By contrast, the rate of oxygen consumption of rat liver slices showed a Q10 of 2.6. The low Q10 values of the cardiac preparations do not appear to be due to an inadequate supply of oxygen. The results are in close agreement with those of myothermic studies.
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10
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Weller EB, Harris BW, Hilton FK. The effects of temperature on the isolated heart of the European starling, Sturnus vulgaris. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0300-9629(78)90039-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Schatte C, Rose C, Durrenberger J, O'Deen L, Swan H. Cold sensitivity of heart rate and succinate oxidation by myocardial homogenates from hibernating ground squirrels and diet-treated rats. Cryobiology 1977; 14:443-50. [PMID: 891234 DOI: 10.1016/0011-2240(77)90006-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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13
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Olsson SO. Comparative studies on the temperature dependence of lactic and malic dehydrogenase from a homeotherm, guinea pig (Cavia porcellus); two hibernators, hedgehog (Erinaceus europaeus) and bat (Nyctalus noctula); and two poikilotherms, frog (Rana temporaria) and cod (Gadus callarias). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1975; 51:5-18. [PMID: 1079762 DOI: 10.1016/0305-0491(75)90352-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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14
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Beltz AD, Reineke EP. Heart-rate temperature relationships. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY 1967; 23:653-9. [PMID: 6080519 DOI: 10.1016/0010-406x(67)90416-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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15
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Arnold G, Lochner W. Die Temperaturabh�ngigkeit des Sauerstoffverbrauches stillgestellter, k�nstlich perfundierter Warmbl�terherzen zwischen 34� und 4�C. Pflugers Arch 1965. [DOI: 10.1007/bf00579304] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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