Intercellular communications

Yamasaki, H., Knitovskikh, V, Mesnil, M., Cohirabano, A., Tsuda, H., and Ito, N. (1993). Gap jurictional intercellular communication and cell proliferation during rat liver carcinogenesis. Academic diss.. University of Helsinki. 

Arrhythmia is either the result of impaired conduction or altered electrical activity. However, in all arrhythmias, conduction and intercellular communication are important since arrhythmia only occurs if the altered electrical activity in one region is transduced to the whole organ. 

Cytokines are small, short-lived proteins and important mediators of local intercellular communication. They play a key role in integrating responses to a variety of stimuli in immune and inflammatory processes. By binding their cognate receptors on target cells in their immediate vicinity, these molecules participate in many important biological activities including cell proliferation, activation, death and differentiation. In... 

Fransson-Steen R, Warngard L. 1992. Inhibitory effects of endosulfan on gap junctional intercellular communication in WB-F344 rat liver cells and primary rat hepatocytes. Carcinogenesis 13(4) 657-662. 

Kenne K, Fransson-Steen R, Honkasalo S, et al. 1994. Two inhibitors of gap junctional intercellular communication, TPA and endosulfan Different effects on phosphorylation of connexin 43 in the rat liver epithelial cell line, lAR 20. Carcinogenesis 15(6) 1161-1165. 

An emerging area of interest for the physiological action of the brain of chanokine is the intercellular communication system between neuronal and ghal cells. Indeed, recent in vitro and in situ studies indicated that the chemokines together with then-receptors are constitutively expressed by glial cells and neurons in mature brain (Asensio and Campbell 1999 Cho and Miller 2002 Tran and Miller 2003 Rostene... 

CX3CL1 as Mediators of Intercellular Communication in the Nervous System... 

Another study showed that a mixture of oxidative metabolites of P-carotene, but not P-carotene, was able to increase the binding of benzo[a]pyrene to DNA. Other mixtures of P-carotene cleavage products have been shown to induce oxidative stress in vitro,exert cytotoxic and genotoxic effects, and inhibit gap junction intercellular communications. It has been suggested that these detrimental effects could possibly occur in vivo following the intake of high doses of carotenoids. 

Yeh, S.L. and Hu, M.L., Oxidized [beta]-carotene inhibits gap junction intercellular communication in the human lung adenocarcinoma cell line A549, Food Chem. Toxicol., 41, 1677, 2003. 

Ion transport processes of the cornea and the conjunctiva can play an important role in maintaining intra- and extracellular fluid homeostasis, signal transduction, and intercellular communication. As all these functions may contribute to the modulation of drug transport (see Section IV.B), it is essential that the baseline ion transport processes in the cornea and the conjunctiva be understood. 

Intercellular communication can be affected by different carotenoids and their oxidation products, and opposing effects can be observed depending on their concentrations (Stahl et al., 1998). Carotenoids play a role in the induction and stimulation of intercellular communication via gap junctions, which in turn play an important role in the regulation of cell growth, differentiation, and apoptosis (Tapiero et al., 2004). 

Trosko, J. E., C. C. Chang, B. Upham, and M. Wilson. 1998. Epigenetic toxicology as toxicant-induced changes in intracellular signalling leading to altered gap junctional intercellular communication. Toxicol Lett 102-103 71-78. 

Synapses between the autonomic postganglionic neuron and effector tissue — the neuroeffector junction — differ greatly from the neuron-to-neuron synapses discussed previously in Chapter 5 (see Table 9.1). The postganglionic fibers in the ANS do not terminate in a single swelling like the synaptic knob, nor do they synapse directly with the cells of a tissue. Instead, the axon terminals branch and contain multiple swellings called varicosities that lie across the surface of the tissue. When the neuron is stimulated, these varicosities release neurotransmitter over a large surface area of the effector tissue. This diffuse release of the neurotransmitter affects many tissue cells simultaneously. Furthermore, cardiac muscle and most smooth muscle have gap junctions between cells. These specialized intercellular communications... 

At the organism level, there are three issues that must be tackled, besides that of visual representation the first division, breaking of symmetry, and intercellular communication. The simulation forces the first cell to divide by initializing the node (gene) signifying division to 1. This ensures that the organism divides at least once. 

Models of lipid bilayers have been employed widely to investigate diffusion properties across membranes through assisted and non-assisted mechanisms. Simple monovalent ions, e.g., Na+, K+, and Cl, have been shown to play a crucial role in intercellular communication. In order to enter the cell, the ion must preliminarily permeate the membrane that acts as an impervious wall towards the cytoplasm. Passive transport of Na+ and Cl ions across membranes has been investigated using a model lipid bilayer that undergoes severe deformations upon translocation of the ions across the aqueous interface [126]. This process is accompanied by thinning defects in the membrane and the formation of water fingers that ensure appropriate hydration of the ion as it permeates the hydrophobic environment. 

Simons M, Raposo G (2009) Exosomes-vesicular carriers for intercellular communication. Curr Opin Cell Biol 21 575-581... 

Agnati,L. F.,Zoli,M.,Stromberg,I. and Fuxe,K. Intercellular communication in the brain wiring versus volume transmission. Neuroscience 69 711-726,1995. 

The function of peptides as first messengers is evolu-tionarily very old. In phylogenetic terms, neuropeptides were established very early as molecules effecting intercellular communication. In coelenterates, such as Hydra, there are many peptides used in neurotransmission, but many of the conventional neurotransmitter systems, such as acetylcholine (ACh), catecholamines and serotonin,... 

Fenvalerate inhibits intercellular communication between fibroblast cells and enhances the development of hepatocyte foci in rat liver at nonhepatotoxic dose levels. Chemicals that possess these properties are likely to be tumor promoters (Flodstrom et al. 1988). Fenvalerate alone induced no hepatotoxic effects in rat liver, as judged by transaminase activities and histology. However, some rats that were partially hepatectomized and insulted with nitrosodiethylamine — a carcinogen and tumor initiator — had significantly elevated numbers of liver foci after administrations of fenvalerate. This response suggests that fenvalerate is a potential tumor promoter (Flodstrom et al. 1988). 

As indicated above in the section on "Genotoxic Effects", it is likely that mirex and chlordecone are tumor promoters and not tumor initiators. Initiators irreversibly alter DNA by a mutation, chromosomal aberration, or other alteration. Promoters act by facilitating the proliferation of previously initiated preneoplastic cells. One of the mechanisms for promotion is believed to involve suppression of inhibitory proliferative control through inhibition of gap-junctional-mediated intercellular communication as well as enzyme induction (Trosko et al. 1983). The results of studies to evaluate the promotional activity potential of mirex in mice indicate that mirex is a mouse skin cancer promoter but exerts this toxicity through a hitherto unknown mechanism that is different from that of phorbol esters, such as TPA (Meyer et al. 1993, 1994 Moser et al. 1992, 1993). Unlike initiation, promotion is a reversible process to a point. This implies, at least in theory, that there may be justification for setting NOAELs for promoters. 

Trosko JE, Jone C, Chang CC. 1983.The role of tumor promoters on phenotypic alterations affecting intercellular communication and tumorigenesis. Ann NY Acad Sci 407 316-327. 

Tsushimoto G, Trosko JE, Chang CC, et al. 1982. Inhibition of intercellular communication by... 

Klaunig JE, Ruch RJ, DeAngelo AB, et al. 1988. Inhibition of mouse hepatocyte intercellular communication by phthalate monoesters. Cancer Lett 43 65-71. 

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