ISSN:
1432-136X
Keywords:
Key words Calcium
;
Capillary electrophoresis
;
Hemolymph
;
Isopod
;
Molting
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract We analyzed the ionic composition of the hemolymph of Porcellio scaber in four different stages of the molt cycle using capillary electrophoresis and calcium selective mini- and microelectrodes. The main ions in the hemolymph were K+, Ca2+, Na+, Mg+, and Cl−. The values for total calcium obtained by means of capillary electrophoresis and calcium selective minielectrodes did not differ significantly from each other. In situ measurements of the free Ca2+ concentration ([Ca2+]) by means of calcium-selective microelectrodes indicated that Ca2+ is not bound in the hemolymph. During molt the [Ca2+] is significantly larger than during intermolt. The [Ca2+] increased by 13%, 19% and 18% during premolt, intramolt, and postmolt, respectively. The concentration of the other cations and of Cl− decreased significantly between premolt and intramolt. Thus, the rise of the [Ca2+] in the hemolymph is not due to a general increase in all ions, but rather to the resorption of cuticular calcium. Furthermore, the results suggest that K+, Na+, Mg+, and Cl−are extruded from the hemolymph during and/or after posterior ecdysis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003600050106
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