ISSN:
1573-5117
Keywords:
Hydra vulgaris
;
nematocysts
;
potassium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The spatial distribution of cations was assayed qualitatively and quantitatively in tentacular nematocytes of Hydra vulgaris in a scanning transmission electron microscope by means of x-ray microanalysis performed on 100 nm thick freeze-dried cryosections. The matrix of undischarged cysts (stenoteles, desmonemes and isorhizas) was found to contain mainly K+. In isolated nematocysts of Hydra the intracapsular potassium can be readily substituted by practically any other mono- and divalent cation (Na+, NH4 +, Mn2+, Co2+, Mg2+, Ca2+, Fe2+) all, except Fe2+, without impairing the ability of the cyst to respond to the chemical triggering with dithioerythritol or proteases. Monovalent cations increase the osmotically generated intracapsular pressure compared to divalent ions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00026528
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