Preparation of isolated single cardiac cells from adult frog atrial tissue

Summary Isolated cardiac cells from bullforg atrial tissue can be readily prepared by digestion of intact fragments of atrial tissue with trypsin and collagenase. These isolated cells have dimensions of about 5 m in width and range in length from 300 m to over 500 m. Such isolated cells may prove useful for the investigation of contractile activity of cardiac muscle at the single cell level and at the sarcomere level within the single cell.This investigation was supported by U.S. Public Health Service, National Institutes of Health Grant No. HL 12426 and a Kansas Heart Association Grant-in-Aid.We wish to thank Dr.J. Sommers of Duke University Medical Center for doing electron microscopy of the isolated cells to confirm the single cell nature of the preparations.     

Chemically mediated cell-to-cell contractile activation in isolated frog atrial cardiac cells

Summary A dying single frog atrial cardiac cell liberates an unknown substance which diffuses away from the dying cell and activates contractile activity in other isolated intact single cardiac cells within the vicinity of the dying cell.This investigation was supported by US Public Health Service, National Institutes of Health Grant HL 18943 and a Kansas Heart Association Grant-In-Aid.We wish to thank Dr Alan Chapman of the Department of Anatomy for doing the scanning electron microscopy of the cardiac cells.     

An improved technique of preparing primary cultures of isolated cells from adult frog kidney

Zusammenfassung Eine verbesserte Technik zur Gewinnung der ersten Einzelschichtbildungen von Froschnierenzellen wurde entwickelt. Die Zellen werden in neuem auflösendem Nährboden isoliert und wachsen auf modifiziertem Eagle-Nährboden mit 13% Kalbsserum. Nach 10 Tagen zeigt sich stark aktives mitotisches Zellwachstum in der Kultur.     

Preparation of isolated cells from rat heart

Summary Suspensions of isolated cells from rat heart were prepared and the data for viability and yield are given. Glucose uptake by the cells was mediated by a carrier system.The technical assistance of Mr.E. T. Potter, Mr.K. D. Patel and Mr.M. Griffin is gratefully acknowledged.     

Currents through ionic channels in multicellular cardiac tissue and single heart cells

Ionic channels are elementary excitable elements in the cell membranes of heart and other tissues. They produce and transduce electrical signals. After decades of trouble with quantitative interpretation of voltage-clamp data from multicellular heart tissue, due to its morphological complexness and methodological limitations, cardiac electrophysiologists have developed new techniques for better control of membrane potential and of the ionic and metabolic environment on both sides of the plasma membrane, by the use of single heart cells. Direct recordings of the behavior of single ionic channels have become possible by using the patch-clamp technique, which was developed simultaneously. Biochemists have made excellent progress in purifying and characterizing ionic channel proteins, and there has been initial success in reconstituting some partially purified channels into lipid bilayers, where their function can be studied.     

Systematics of a leptospira strain isolated from frog

Zusammenfassung Nachweis, dass Nieren vonRana pipiens Träger pathogener Leptospiren sein können und dass in deren System mit dem neuen Leptospirenstamm eine bisher unbekannte Serogruppe aufgefunden wurde, für welche der Name ranarum vorgeschlagen wird.     

Shortening velocity of single muscle cells isolated from a molluscan smooth muscle

Summary The maximal unloaded shortening velocity (V_max) of smooth muscle cells isolated from the pedal retractor muscle ofMytilus was more than twice as large as that of the whole muscle, suggesting the presence of extracellular components which resist the contraction of the whole muscle. The V_max of the isolated cells was almost constant at cell lengths ranging between 0.5 and 0.831₀ (1₀, optimal length for tension generation) indicating that the intracellular resistance to contraction is negligible within this range of lengths.     

High shortening velocity of isolated single arterial muscle cells

Summary Surprisingly high shortening velocities (<200 msec contraction-relaxation cycles) were found in isolated vascular muscle cells cultured from rat or chick aorta. All of the small fraction of cells with such quick contractions had membrane excitation by short duration spikes, rather than the slower graded depolarization of the other cells which produced 20-fold slower contractions.This research was supported by grant HL16328 from the National Institutes of Health. I wish to thank Aurita Puga and Paige DeCino for their excellent contributions to the cell culture aspects of these experiments.     

High shortening velocity of isolated single arterial muscle cells

Surprisingly high shortening velocities (less than 200 msec contraction-relaxation cycles) were found in isolated vascular muscle cells cultured from rat or chick aorta. All of the small fraction cells with such quick contractions had membrane excitation by short duration spikes, rather than the slower graded depolarization of the other cells which produced 20-fold slower contractions.     

Ouabain potentiation of Ca release from fragmented cardiac sarcoplasmic reticulum from isolated cat heart.

The present study was performed to determine the effect of ouabain on Ca release from fragmented sarcoplasmic reticulum (FSR) isolated from cat cardiac muscles. The results clearly demonstrate that ouabain potentiates the Ca release from FSR by changing the ionic environment.     

The origin of the instantaneous elasticity in single frog muscle fibres.

High-speed cinematographic recordings of single tetanized muscle fibres during a quick decrease in length revealed that the shortening was mostly localized at the fibre segment nearest the released end of the fibre, indicating that the instantaneous elasticity may not originate from the elasticity of the cross-bridges.     

Structure of nuclear membranes isolated from brain cells

Zusammenfassung Von einer reinen Fraktion von Zellkernen aus Rattenhirn wurden Stücke der Kernmembran isoliert und nach Negativkontrastierung elektronenmikroskopisch untersucht. Dabei wurden sowohl Neuronenals auch Gliazellkerne erfasst. Die Porenhäufigkeit betrug 30–45 Poren/², d. i. etwa 13–20% der Kernoberfläche. Die Porendurchmesser lagen zwischen 68 bis 80 nm. Die auf dem Porenrand liegenden Untereinheiten des Annulus sind in einer achtstrahligen Radiärsymmetrie angeordnet. Die Ergebnisse werden in Zusammenhang mit den entsprechenden Strukturdaten aus anderen Zellen vergleichend diskutiert.

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The work was supported in part by the Deutsche Forschungsgemeinschaft.     

Ouabain potentiation of Ca release from fragmented cardiac sarcoplasmic reticulum from isolated cat heart

Summary The present study was performed to determine the effect of ouabain on Ca release from fragmented sarcoplasmic reticulum (FSR) isolated from cat cardiac muscles. The results clearly demonstrate that ouabain potentiates the Ca release from FSR by changing the ionic environment.     

Depolarizing action of K-strophantine and K-strophantoside on isolated frog skin

Résumé Après une rapide revue de la littérature, les auteurs rendent compte des résultats de leur étude sur l'action dépolarisante de la strophantine K et du strophantoside K sur la peau isolée de la grenouille. Les résultats démontrent, selon les auteurs, que la strophantine K et le strophantoside K ont la même action sur les potentiels de la peau de la grenouille que sur le myocarde. L'action dépolarisante peut être mise en corrélation avec la sortie des K⁺ions et le transport actif des Na⁺ ions dans la membrane des cellules épithéliales de la peau de la grenouille.