EGF modulates phosphoinositide levels in ovarian granulosa cells stimulated by luteinizing hormone
✍ Scribed by C. J. Hubbard
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 683 KB
- Volume
- 160
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
Hamster granulosa cells were exposed to epidermal growth factor (EGF) and luteinizing hormone (LH) to study cross-talk between second messenger pathways involving tyrosine kinase, CAMP, and phosphoinositides. Granulosa cells from ovarian preovulatory follicles of PMSG-primed hamsters were incubated with various additives in serum-free medium. LH, but not EGF, stimulated inositol phosphate (IP) accumulation; however, when combined with LH, EGF inhibited IP accumulation in a manner that was concentration dependent for both LH and EGF. The inhibitory effects of EGF were significantly reduced by the tyrosine kinase inhibitor genistein and by pertussis toxin suggesting a role for tyrosine kinase and an inhibitory G-protein (GJ in this system. EGF stimulated an increase in CAMP, but it does not appear to modulate LH-stimulated IP levels via CAMP.