Electrocardiography in turtles

Kaplan, Harold M.; Schwartz, Clyde S.

doi:10.1016/0024-3205(63)90147-4

Cited by 16 publications

(10 citation statements)

References 6 publications

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“…Although some ECG recordings were performed in Sauropsida in general (Kaplan and Schwartz, 1963;McDonald and Heath, 1971;Blanco, 1993;Heaton-Jones and King, 1994;Anderson et al, 1999;Espino et al, 2001;Martinez-Silvestre et al, 2003;Tan et al, 2013), the information available is restricted to a few species and there are almost no comparative studies among Squamate reptiles (Mullen, 1967;Bogan Jr., 2017) to fully understand the electrophysiological function of the heart in these terrestrial ectotherms. However, with respect to ECG methodology (Einthoven, 1903), there are also some limitations of this approach for poikilotherms and ectotherms.…”

Section: Discussionmentioning

confidence: 99%

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

Kvasilová

Gregorovičová

Kundrát

et al. 2018

The Anatomical Record

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Human natural killer (HNK)‐1 antibody is an established marker of developing cardiac conduction system (CCS) in birds and mammals. In our search for the evolutionary origin of the CCS, we tested this antibody in a variety of sauropsid species (Crocodylus niloticus, Varanus indicus, Pogona vitticeps, Pantherophis guttatus, Eublepharis macularius, Gallus gallus, and Coturnix japonica). Hearts of different species were collected at various stages of embryonic development and studied to map immunoreactivity in cardiac tissues. We performed detection on alternating serial paraffin sections using immunohistochemistry for smooth muscle actin or sarcomeric actin as myocardial markers, and HNK‐1 to visualize overall staining pattern and then positivity in specific myocyte populations. We observed HNK‐1 expression of various intensity distributed in the extracellular matrix and mesenchymal cell surface of cardiac cushions in most of the examined hearts. Strong staining was found in the cardiac nerve fibers and ganglia in all species. The myocardium of the sinus venosus and the atrioventricular canal exhibited transitory patterns of expression. In the Pogona and Crocodylus hearts, as well as in the Gallus and Coturnix ones, additional expression was detected in a subset of myocytes of the (inter)ventricular septum. These results support the use of HNK‐1 as a conserved marker of the CCS and suggest that there is a rudimentary CCS present in developing reptilian hearts. Anat Rec, 302:69–82, 2019. © 2018 Wiley Periodicals, Inc.

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Section: Discussionmentioning

confidence: 99%

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

Kvasilová

Gregorovičová

Kundrát

et al. 2018

The Anatomical Record

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“…Low-voltage waves, arrhythmias in unfed animals, uncommon Q and S waves, and sex differences with the P-R interval being shorter in females have also been determined (Kaplan and Schwartz, 1963). Due to the different species and sizes and the relatively low number of individuals in one species the authors could not draw conclusions regarding the correlation between sex and ECG values.…”

Section: Discussionmentioning

confidence: 99%

“…Due to the different species and sizes and the relatively low number of individuals in one species the authors could not draw conclusions regarding the correlation between sex and ECG values. Significant differences were also described in the surgical stage of anaesthesia (Kaplan and Schwartz, 1963). A study on nine anaesthetised red-eared sliders (Trachemys scripta elegans) was performed with three cutaneous electrodes to record lead II traces.…”

Section: Discussionmentioning

confidence: 99%

Establishment of methodology for non-invasive electrocardiographic measurements in turtles and tortoises

Nógrádi

Balogh

2018

Acta Veterinaria Hungarica

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The lack of knowledge on how to perform species-specific electrocardiographic (ECG) measurements in chelonians makes ECG evaluations difficult. The aim of this study was to establish non-invasive methods for ECG sample collection in different species of non-anaesthetised chelonians, focusing on adhesive and clamp electrodes. A total of 72 turtles and tortoises from 20 species and various sizes were used for the study. Body weight ranged from 32 g to 65 kg. From the aspect of specimen fixation, dorsal recumbency proved to be the most useful. Both adhesive and clamp electrodes yielded results when applied to the plastron and skin folds. Pre-emptive results suggest an indirect correlation with plastron thickness, the presence of a hinge, habitat and measurable ECG wave amplitude. ECG wave recordings are more likely in aquatic chelonians and species with a hinge. With size the plastron also thickens, making wave detection impossible. ECG waves were detected in 41 of the 72 specimens, complete PQRST complexes in 19 animals, with the rest showing absent P waves in all leads. ECG amplitudes were below 1 mV, with an average of 0.15 mV R wave amplitude.

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“…The release of bound a-glucosidase activity had the unusual consequence of increasing the apparent total activity during growth in the absence of inducer; thus, the cryptic factor rose during reversion (27). In a strain of S. cerevisiae isolated in this laboratory, the inducible/3-glucosidase activity (determined after butanol treatment) declined during reversion by one-half per cell per division, but the specific patent activity declined at a much greater rate (28). In the case of this enzyme, whose patent activity seems to be limited by an energy-dependent, sterically specific transport system, the cryptic factor increased during reversion by more than twenty times.…”

Section: Reversion Of Catalase In Growing Yeastmentioning

confidence: 94%

“…On the other hand, the inducible ~5-galactosidase of a strain of S. cerevisiae isolated in this laboratory (28) and of a variety of strains of E. coli (Rickenberg,x14 THE JOURNAL OF GENERAL PHYSIOLOGY • VOLUME 47 " I963 cited in reference 29; Kaplan and Bonner, cited in reference 30; Holmes, Sheinin, and Crocker (31)) behaved during reversion like yeast catalase, the cryptic factor becoming unity when, or before, the basal level was attained. This was so because the patent activity declined far less during growth in the absence of inducer than did the total activity; for example, the former declined but three times and the latter about 200 times in the case of yeast catalase.…”

Section: Reversion Of Catalase In Growing Yeastmentioning

confidence: 99%

The Reversion of Catalase during Growth of Yeast in Anaerobiosis

Kaplan

1963

The Journal of General Physiology

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Growth of originally aerobic bakers' yeast under conditions of anaerobiosis caused a decrease in the total specific catalatic activity (patent plus cryptic) of one-half per generation. It is concluded that reversion of catalase was a dilution, rather than a destruction, of the intracellular enzyme. However, the specific patent (whole cell) catalase activity remained constant for one or more generations, and then declined at a considerably slower rate than did the total activity. Thus the cryptic factor diminished progressively during anaerobic growth; after seven or eight generations virtually all the catalase was patent;i.e., the cryptic factor (the ratio of total enzyme to patent enzyme) was approximately unity. At this point, the basal level of enzyme was attained, and thereafter maintained by a basal synthesis, which produced only the patent, heatstable, variety. Aerobic growth caused a significant, but much smaller, decline of both total catalase activity and of the cryptic factor. The data suggested that during reversion, the cryptic, heat-labile catalase became progressively converted to the patent, heat-resistant form. A model of these events is presented. I N T R O D U C T I O NAn inducible enzyme is one whose rate of synthesis is increased greatly by the presence of a specific inducer. Chantrenne and Courtois (1) demonstrated that yeast catalase was an inducible enzyme, and that its inducer was oxygen, or possibly hydrogen peroxide formed by reduction of oxygen by cell metabolism.When a population of previously "induced" cells is allowed to grow in absence of the inducer, the rate of synthesis of the inducible enzyme quickly falls, and the concentration of the enzyme within the growing cells is reduced to a minimum, the basal level; it is maintained at this level by a basal synthesis; that is, the low level synthesis which occurs in the absence of the specific inducer. The process whereby the high induced enzyme level becomes reduced

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Electrocardiography in turtles

Cited by 16 publications

References 6 publications

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

Establishment of methodology for non-invasive electrocardiographic measurements in turtles and tortoises

The Reversion of Catalase during Growth of Yeast in Anaerobiosis

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