title: The action of heavy metals on the gametes of the marine mussel, Mytilus edulis (L.)--I. Copper-induced uncoupling of respiration in the unfertilized egg.
abstract: The direct addition of Cu2+ to unfertilized eggs of Mytilus edulis results in a stimulation of respiration with maximal stimulation occurring at a Cu2+ concentration of ca 0.5 mM. By contrast, the addition of Zn2+ has no effect on egg respiration. The uncoupler CCCP produces a 5/6 fold stimulation of egg respiration but the addition of ADP leads to only a small release of respiration. In contrast, sperm respiration is unaffected by Cu2+, inhibited by Zn2+ and CCCP produces only a small respiratory stimulation. The addition of Cu2+ to respiring Mytilus mantle tissue mitochondria produces an initial stimulation of State 4 oxidation which is then followed by a progressive inhibition. It is suggested that respiration in the unfertilized egg may be inhibited by a high ATP/ADP ratio in the cytosol. Respiration can, therefore, be released by either the addition of a H+-translocating uncoupler or by Cu2+ which may act by stimulating mitochondrial K+ influx.
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000187:drug effects* / Q000378:metabolism; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology*; D005260:Female; D008297:Male; D010063:Ovum / Q000187:drug effects* / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism; D015032:Zinc / Q000494:pharmacology
chemical_list: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D003300:Copper; D015032:Zinc