ISSN:
1615-6102
Keywords:
Nickel
;
Endocytosis
;
Motility
;
Proliferation
;
Cellular nickel content
;
Adaptation
;
Tetrahymena pyriformis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary At concentrations above 1 mM, nickel has a dose-dependent effect on the rate of food vacuole formation in cells in the growth medium, proteose peptone (PP); total inhibition of endocytosis occurs within 10 minutes in 6mM nickel. However, only a 10 times lower concentration of nickel is tolerated by starved cells in an inorganic salt medium, a difference which may be ascribed to the high binding property of nickel to organic material. In the PP medium, nickel affects cell motility by increasing the rate of movement at a concentration of 1 mM, and by causing immobilization after 30 minutes in 6mM nickel; a spontaneous, partial recovery of cell motility is seen after 3 hours in 6 mM nickel. The effects of nickel on endocytosis and cell motility are reversible after removal of nickel. Cell proliferation continues at a reduced rate in 1 mM nickel, while only 1 1/2 cell doublings are achieved in 3 mM nickel during a 72-hour exposure, and no proliferation occurs in 6mM nickel, where an increasing cell mortality is observed after 12 hours. The cell content of nickel relates initially to the external concentration of the metal; however, cells in 1 mM nickel are capable of maintaining a constant content of the metal, whereas in 3 mM, the rate of accumulation is reduced after 3 hours, and cells in 6mM nickel accumulate the metal at a constant rate. All nickel-treated cells contain small refractive granules, previously proposed as representing an ion-regulating system, and the apparent adaption ofTetrahymena to the effects of nickel may be ascribed to such a regulation of the intracellular concentration of the metal.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01293071
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