| | SLO | ENG | Piškotki in zasebnost

Večja pisava | Manjša pisava

Iskanje po katalogu digitalne knjižnice Pomoč

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju


1 - 2 / 2
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
Modeling of molecular and cellular mechanisms involved in [Ca sup 2+] signal encoding in airway myocytes
Marko Marhl, Denis Noble, Etienne Roux, 2006, pregledni znanstveni članek

Opis: In airway myocytes signal transduction via cytosolic calcium plays an important role. In relation with experimental results we review models of basic molecular and cellular mechanisms involved in the signal transduction from the myocyte stimulation to the activation of the contractile apparatus. We concentrate on mechanisms for encoding of input signals into Ca2+ signals and the mechanisms for their decoding. The mechanisms are arranged into a general scheme of cellular signaling, the so-called bow-tie architecture of signaling, in which calcium plays the role of a common media for cellular signals and links the encoding and decoding part. The encoding of calcium signals in airway myocytes is better known and is presented in more detail. Inparticular, we focus on three recent models taking into account the intracellular calcium handling and ion fluxes through the plasma membrane. Themodel of membrane conductances was originally proposed for predicting membrane depolarization and voltage-dependent Ca2+ influx triggered by initialcytosolic Ca2+ increase as observed on cholinergic stimulation. Cellular models of intracellular Ca2+ handling were developed to investigate the role of a mixed population of InsP3 receptor isoforms and the cellular environment in the occurrence of Ca2+ oscillations, and the respective role ofthe sarcoplasmic reticulum, mitochondria, and cytosolic Ca2+-binding proteins in cytosolic Ca2+ clearance. Modeling the mechanisms responsible for the decoding of calcium signals is developed in a lesser extent; however, the most recent theoretical studies are briefly presented in relation with the known experimental results.
Ključne besede: biophysics, mathematical modelling, modelling, calcium oscillations, contractions, airway smooth muscle cells, muscle cells, smooth muscles, encoding, decoding, bow-tie structures
Objavljeno v DKUM: 07.06.2012; Ogledov: 1673; Prenosov: 39
URL Povezava na celotno besedilo

Theoretical and experimental investigation of calcium-contraction coupling in airway smooth muscle
Prisca Mbikou, Aleš Fajmut, Milan Brumen, Etienne Roux, 2006, izvirni znanstveni članek

Opis: We investigated theoretically and experimentally the ▫$Ca^{2+}$▫-contraction couplingin rat tracheal smooth muscle. ▫$[Ca^{2+}]_i$▫, isometric contraction and myosin light chain (MLC) phosphorylation were measured in response to 1 mM carbachol. Theoretical modeling consisted in coupling a model of ▫$Ca^{2+}-dependent$▫ MLC kinase (MLCK) activation with a four-state model of smooth muscle contractile apparatus. Stimulation resulted in a short-time contraction obtained within 1 min, followed by a long-time contraction up to the maximal force obtained in 30 min. ML-7 and Wortmannin (MLCK inhibitors) abolished the contraction. Chelerythrine (PKC inhibitor) did not change the short-time, but reduced the long-time contraction. ▫$[Ca^{2+}]_i$▫ responses of isolated myocytes recorded during the first 90 s consisted in a fast peak, followed by a plateau phase and, in 28 % of the cells, superimposed ▫$Ca^{2+}$▫ oscillations. MLC phosphorylation was maximal at 5 s and then decreased, whereas isometric contraction followed a Hill-shaped curve. The model properlypredicts the time course of MLC phosphorylation and force of the short-time response. With oscillating ▫$Ca^{2+}$▫ signal, the predicted force does not oscillate. According to the model, the amplitude of the plateau and the frequency of oscillations encode for the amplitude of force, whereas the peak encodes for force velocity. The long-time phase of the contraction, associated with a second increase in MLC phosphorylation, may be explained, at least partially, by MLC phosphatase (MLCP) inhibition, possibly via PKC inhibition.
Ključne besede: biophysics, mathematical modelling, modelling, calcium oscillations, contractions, force development, muscle cells, smooth muscles, myosin kinase
Objavljeno v DKUM: 07.06.2012; Ogledov: 1636; Prenosov: 88
URL Povezava na celotno besedilo

Iskanje izvedeno v 0.05 sek.
Na vrh
Logotipi partnerjev Univerza v Mariboru Univerza v Ljubljani Univerza na Primorskem Univerza v Novi Gorici