Abstract
1. 1. Specimens of Lottia gigantea were incubated in germanium enriched seawater ( [Ge] [Si] = 0.2-783) for 1-8 days. The siliceous radulae were examined histologically. 2. 2. No visible changes, degenerations or deformations were found in all 62 experimental radulae, although germanium is known to be a competitive inhibitor of silicon. 3. 3. In high concentrations, germanium was toxic to the limpets and killed them. 4. 4. Germanium was incorporated into the radular teeth in a distribution similar to silicon. 5. 5. Two suggestions are discussed for the apparent noninhibitory result.
| Original language | English |
|---|---|
| Pages (from-to) | 137-141 |
| Number of pages | 5 |
| Journal | Comparative biochemistry and physiology. C: Comparative pharmacology |
| Volume | 83 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1986 |
| Externally published | Yes |
Bibliographical note
Funding Information:Germaniumt ransporti n limpetsi s proposedt o be more complicatedt han that found in spongeso r diatoms (the previously tested organisms).I t first crossest he covering epithelial layer, is introduced into the limpet vascular system and crosses the chitineous covering layer of the radula. Along the phaseo f the cellular transport( within gills, muscles or even within the radular gland and epithelium) additional membranesh avet o be crossedT. he possi- bility of identical transportationa nd similar meta- bolic pathwaysf or Si andG e is thereforem inimal due to the high number of variables and specialization involved in this transport. In another study, the specificityo f Ge action on spongesw as testedb y exposingn ewly developeds pongest o tin (Sn) which is the next membero f the group IV elementsin the PeriodicT able (Simpson,1 981)I.t was found that tin does not interact with the sponge silica deposition systema s does germanium( the possibility that Sn was incorporated into the spicules was not in-discussiono f ther esults,E . Winter for constructivere marks Acknowledgementt+ha-In kB . E. Volcania nd C. W. Li for vestigated)M. oreover,e veni n subcellularo rganelles and E. L. Grant for generala ssistanceS. pecialt hanksa re the transporto f Si may differ from Ge. For example, due to N. D. Holland for providings pacea nd materialsfo r Johnson and Volcani (I 978)r eportedt hat 68Ge(OH), the histological study. The work was supported by a uptakei n rat liver mitochondriaw as independento f “Rothschild” post-doctorafl ellowship. Si(OH) concentrationsa nd showedl ittle dependence on the degreeo f structural integrity of the mito- chondria.M atsumotoand Takahashi( 1976)w orked on thee ffectso f Ge on rice shootsa nd concludedt hat specific Ge-protein associations occur within the shoots.T hey proposed thatht esew erea nalogoust o Si-protein interactions.I n addition, Azam and Vol- cani (1981 ) noted somed issimilaritiesin the behavior of Ge and Si in living systemsa nd concluded that carefulc ontrols are essentialin caseso f Ge-Si inter- actions, especiallyi n multi~llular organismsw here thec omplexityo f interactioni s higher.I n conclusion, usinga ll the aboves tudies,it is proposed thGate and Si shared ifferentm etabolicp athwaysi n limpetsa nd thereforeg ermaniumh as no direct inhibitory effect on radular formation or mineralization. However, becauseo f the high concentrationso f germanium, this elementi s occasionallyt rappedin appropriate sitesi n the radular teeth.
ASJC Scopus subject areas
- Immunology
- Pharmacology