Ovulation-inducing factor (OIF) induces LH secretion from pituitary cells
O A Bogle1, M H Ratto, G P Adams
1Western College of Veterinary Medicine, University of Saskatchewan, Canada.
Animal Reproduction Science
|July 10, 2012
Summary
A newly discovered ovulation-inducing factor (OIF) in llama and alpaca seminal plasma stimulates luteinizing hormone (LH) release from pituitary cells. This finding provides insight into the reproductive mechanisms of these South American camelids.
Area of Science:
- Reproductive Biology
- Endocrinology
- Animal Science
Background:
- A substance in llama and alpaca seminal plasma induces ovulation and corpus luteum (CL) growth.
- The ovarian effects are linked to a surge in circulating luteinizing hormone (LH).
Purpose of the Study:
- To investigate if purified ovulation-inducing factor (OIF) stimulates LH release from anterior pituitary cells.
- To determine if OIF acts directly on pituitary gonadotroph cells.
Main Methods:
- Anterior pituitary cells from llamas and cattle were cultured in vitro.
- Cells were treated with either GnRH (control stimulant) or purified OIF.
- LH concentrations in culture media were measured using radioimmunoassay.
Main Results:
- Both GnRH and OIF significantly increased LH secretion compared to controls in llama and cattle pituitary cell cultures.
- A dose-dependent increase in LH secretion was observed in llama pituitary cells treated with OIF.
- OIF stimulated LH release in bovine pituitary cells, but without a dose-related effect.
Conclusions:
- OIF directly stimulates LH secretion from pituitary gonadotroph cells in vitro.
- OIF plays a role in the neuroendocrine regulation of ovulation in llamas and alpacas.
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