ه‍.ش. ۱۳۸۹ آذر ۲۹, دوشنبه

dr.ahmadi

ionophores
Depatment of Zoology, Islamic Azad University, Hamedan Branch, Hamedan, Iran
S.MOHAMMADI and H.GOLMOHAMMADI

Abstract
An ionophore is a lipid-soluble molecule usually synthesized by microorganisms to transport ions across the lipid bilayer of the cell membrane. There are two broad classifications of ionophores. Chemical compounds (mobile ion carriers) that bind to a particular ion, shielding its charge from the surrounding environment, and thus facilitating its crossing of the hydrophobic interior of the lipid membrane. Channel formers that introduce a hydrophilic pore into the membrane, allowing ions to pass through while avoiding contact with the membrane's hydrophobic interior. Ionophores disrupt transmembrane ion concentration gradients, required for the proper functioning and survival of microorganisms, and thus have antibiotic properties. They are produced naturally by certain microbes and act as a defense against competing microbes. In laboratory research, ionophores are used to increase the permeability of biological membranes to certain ions. Additionally, some ionophores are used as antibiotics and/or as growth enhancing feed additives for certain feed animals such as cattle
Key words: ionophores, permeability , cell membrane, transport
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INTRODUCTION
Ionophores are antibiotics that where originally developed as coccidiostats for poultry. (Horton et al.,1992). Ionophores are a chemical compound classified as polyether antibiotics.(Hirohiko et al, 1994) Ionophores work in a number of different ways to improve growth rate and feed efficiency. Ionophores reduce protein degradation in the rumen thus aiding in post ruminal digestion (Horton, 1992). Calcium ionophore elevates angiotensin-converting enzyme in cultured bovine endothelial cells Yamuna Dasarathy (2003)

MATERIALS AND METHODS

RESULTS


DISCUSSION AND CONCLUSION
Ionophores are compounds that increase the permeability of cellular membrane barriers to ions by functioning as mobile ion carriers or channel formers. They contain hydrophobic regions conferring lipid solubility and hydrophilic ion-binding regions that delocalise the charge of the ion to shield it from the hydrophobic regions of the membrane lipid bilayer
ACKNOWLEGEMENTS
This work was supported by Islamic Azad University- Hamedan Branch and Science and Research Campus

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