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2. Participation of electrogenic Na+-K+-ATPase in the membrane potential of earthworm body wall muscles

Creator:
Volkov, E. M., Nurullin, L. F., Ivana Švandová, Nikolsky, E. E., and František Vyskočil
Format:
print, bez média, and svazek
Type:
article, články, journal articles, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, žížaly, žáby, earthworms, frogs, Na+-K+-ATPase, resting membrane potential, ouabain, 14, and 612
Language:
English
Description:
The effect of Na+-K+-ATPase inhibitor ouabain on the resting membrane potential (Vm) was studied by glass microelectrodes in isolated somatic longitudinal muscles of the earthworm Lumbricus terrestris and compared with frog sartorius muscle. In earthworm muscle, Vm was -49 mV (inside negative) in a reference external solution with 4 mmol/l K+. The electrogenic participation of Na+-K+-ATPase was absent in solutions with very low concentrations of 0.01 mmol/l K+, higher in 4 and 8 mmol/l K+ (4-5 mV) and maximal (13 mV) in solutions containing 12 mmol/l K+ where Vm was -46 mV in the absence and -33 mV in the presence of 1x10-4 M ouabain. The electrogenic participation of Na+-K+-ATPase was much smaller in m. sartorius of the frog Rana temporaria bathed in 8 and 12 mmol/l K+. The results indicate that the Na+-K+-ATPase is an important electrogenic factor in earthworm longitudinal muscle fibres and that its contribution to Vm depends directly on the concentration of K+ in the bathing solution., E. M. Volkov, L. F. Nurullin, I. Švandová, E. E. Nikolsky, F. Vyskočil., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Příklad negativních dopadů hospodářského využívání rybníků na rozmnožování žab

Creator:
Ivan Vergner
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Zoologie, rozmnožování živočichů, žáby, rybníky, 2, and 59
Language:
Czech
Description:
Reproduction of common frog species (Bufo bufo and Rana temporaria) in commercially managed fishponds can be threa - tened due to destruction of egg clutches or early developmental stages of tadpoles. The phenomenon is described based on a monitoring of a forest fishpond in the south-eastern part of Central Bohemia. Data on the size and growth of egg clutches and tadpoles in relation to time and weather conditions are also described and Ivan Vergner.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Two new species of Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) from anuran amphibians in Pará, Brazil

Creator:
Kuzmin, Yuriy, Vasconcelos Melo, Francisco Tiago de, Silva Filho, Heriberto Figueira da, and Nascimento dos Santos, Jeannie
Format:
print, počítač, and online zdroj
Type:
model:article and TEXT
Subject:
hvízdalka, žáby, Leptodactylus, frogs, Amazonka (řeka : oblast), Jižní Amerika, Amazon River Basin, South America, taxonomy, Adelphobates, Rhabdiasidae, Anura, eastern Amazonia, 2, and 59
Language:
English
Description:
Two new lung-dwelling nematode species of the genus Rhabdias Stiles et Hassall, 1905 were discovered in Caxiuanã National Forest, Pará state, Brazil. Rhabdias galactonoti sp. n. was found in a dendrobatid frog Adelphobates galactonotus (Steindachner). The species is characterised by the regularly folded inner surface of the anterior part of the buccal capsule seen in apical view, flask-shaped oesophageal bulb and narrow, elongated tail. Rhabdias stenocephala sp. n. from two species of leptodactylid frogs, Leptodactylus pentadactylus (Laurenti) (type host) and L. paraensis (Heyer), is characterised by a narrow anterior end that is separated from the remaining body by a constriction. Both species possess six small but distinct lips, a cuticle that is inflated along the whole body, a doliiform buccal capsule separated into a longer anterior and a shallow, ring-shaped posterior part, lateral pores in the body cuticle and zones of spermatogenesis in the syngonia. Rhabdias galactonoti sp. n. is the first species of the genus found in Dendrobatidae; R. stenocephala sp. n. is the second species described from Leptodactylidae in eastern Amazonia., Yuriy Kuzmin, Francisco Tiago de Vasconcelos Melo, Heriberto Figueira da Silva Filho, Jeannie Nascimento dos Santos., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public