Effect of adenylate cyclase stimulation on meiotic resumption and cyclic AMP content of zona-free and cumulus-enclosed bovine oocytes in vitro.

Abstract

The effect of adenylate cyclase stimulation via the components of the enzyme on nuclear maturation in bovine cumulus-enclosed and zona-free oocytes was examined. The stimulating agents were cholera toxin, pertussis toxin, forskolin, sodium fluoride and prostaglandin E2. Cyclic AMP contents were measured in cumulus-oocyte complexes, cumulus-enclosed oocytes and in zona-free oocytes after stimulation, to establish the relationship between cumulus cell and oocyte cAMP concentrations and the meiotic status of the oocyte. In cumulus-enclosed oocytes, forskolin alone and 3-isobutyl-1-methylxanthine (IBMX), at 0.5 mmol l-1, inhibited the resumption of meiosis after 8 h of culture; the other agents were without effect. After 24 h of culture, IBMX at 0.5 mmol l-1 was without effect, but at 2 mmol l-1 reduced the percentage of oocytes at the mature stage (51 versus 82% in control medium). Forskolin alone reduced the proportion of oocytes at the mature stage from 82 to 58%. Forskolin plus IBMX at 2 mmol l-1 and sodium fluoride plus IBMX at 2 mmol l-1 significantly diminished the maturation rate (6 and 17% mature oocytes, respectively). Cholera toxin (with IBMX) and forskolin (alone or with IBMX) stimulated the synthesis of high amounts of cAMP in complexes, but only forskolin had a significant effect on the cAMP contents of oocytes derived from complexes. Forskolin was more effective in zona-free oocytes than in cumulus-enclosed oocytes in inhibiting nuclear maturation (24% mature oocytes versus 73% in control medium) even after 24 h of culture; its effect was potentiated by IBMX; forskolin also stimulated cAMP synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: S Bilodeau, M A Fortier, M A Sirard
• Journal: Journal of reproduction and fertility (J Reprod Fertil) Vol. 97 Issue 1 Pg. 5-11 (Jan 1993) ISSN: 0022-4251 [Print] England
• PMID: 7681878 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adenylate Cyclase Toxin
• Virulence Factors, Bordetella
• Colforsin
• Sodium Fluoride
• Cholera Toxin
• Cyclic AMP
• Pertussis Toxin
• Adenylyl Cyclases
• Dinoprostone
• 1-Methyl-3-isobutylxanthine

Topics

• 1-Methyl-3-isobutylxanthine (pharmacology)
• Adenylate Cyclase Toxin
• Adenylyl Cyclases (metabolism)
• Animals
• Cattle
• Cell Nucleus (metabolism)
• Cells, Cultured
• Cholera Toxin (pharmacology)
• Colforsin (pharmacology)
• Cyclic AMP (metabolism)
• Dinoprostone (pharmacology)
• Female
• Meiosis (drug effects, physiology)
• Oocytes (drug effects, enzymology, physiology)
• Ovarian Follicle (physiology)
• Pertussis Toxin
• Sodium Fluoride (pharmacology)
• Stimulation, Chemical
• Virulence Factors, Bordetella (pharmacology)
• Zona Pellucida (physiology)