Potentiation of the cGMP-induced guinea pig acrosome reaction by zinc.
The addition of 8 bromo cGMP (10 mM) immediately (approximately 2 min) upon suspension of Guinea pig sperm in glucose-free BWW medium induces a significant number of acrosome reactions within minutes. The simultaneous addition of micromolar concentrations of ZnCl2 (25-1000 microM) potentiates the cGMP effects. Mid-micromolar concentrations were able to dramatically increase the percentage of acrosome reactions by a factor of 6.5 over 8 bromo cGMP alone. The induction of acrosome reactions was dependent upon external Ca++, and it is suggested that in this species Zn++ functions by affecting cyclic nucleotide metabolism and/or Ca++ flux.
D000177:Acrosome / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D006168:Guinea Pigs; D008297:Male; D013094:Spermatozoa / Q000502:physiology*; D013329:Structure-Activity Relationship; D015032:Zinc / Q000494:pharmacology*
C016276:8-bromocyclic GMP; D006152:Cyclic GMP; D015032:Zinc; D002118:Calcium