Chemokinesis

Cells respond to some extracellular factors such as leukotriene B (Ford-Hutchin-son et al., 1980) by increasing the locomotion rate in an undirected manner as opposed to chemotaxis. This mechanism, known as chemokinesis, is likely on purely statistical grounds to result in cells accumulating at the site of origin of this stimulus (Wilkinson, 1987). The differentiation of factors that are chemotactic from chemokinetic responses can be difficult, but this has been greatly facilitated using the Boyden chamber (Lackie, 1986). 

Amsler CD, Iken KB (2001) Chemokinesis and chemotaxis in marine bacteria and algae. In McClintock JB, Baker BJ (eds) Marine Chemical Ecology. CRC Press, Boca Raton, Florida,... 

Concentrations of 10 4-10 6 M histamine enhance neutrophil chemokinesis in response to zymosan-activated serum, casein and fMet-Leu-Phe, whereas... 

There are two distinct types of histamine receptors, H-l and H-2, with distinct pharmacological properties. There are about 2.5 x 105 H-l receptors per neutrophil, and these have a single dissociation constant of around 50 nM. Occupancy of these H-l receptors increases chemokinesis occupancy of H-2 receptors increases both chemokinesis and intracellular cAMP levels, but decreases chemotaxis and degranulation. 

Neutrophils may move at speeds of up to 20 /tm min-1 in response to chemoattractants such as denatured proteins, lipids, peptides or C5a. Movement may be defined either as chemokinesis, which is generalised (non-directional) locomotive activity, or as chemotaxis, which is orientation and directional migration up a concentration gradient. A concentration difference at opposite ends of the cell of only 1% is sufficient to activate such directional movement. However, neutrophils do not respond chemotactical-ly to static gradients of chemoattractants, and both temporal and directional changes in chemoattractant concentrations are required. 

Induction of chemokinetic ability also occurs in Alcaligenes strain M3A.60 Dimethyl sulfonio-propionate (DMSP) is an attractant for bacteria that have been induced to produce DMSP lyase. Such cells are attracted to DMSP at ecologically relevant concentrations, but uninduced cells do not respond to DMSP. Since DMSP lyase produces dimethylsulfide, which is important to global climate regulation, Zimmer-Faust et al.60 suggest that bacterial chemokinesis may play a critical role in global sulfur cycles and climate. 

Richards, K. L. and McCullough, J. (1984) A modified microchamber method for chemotaxis and chemokinesis. Immunolog. Commun. 13,46-62. 

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