Gastrin-releasing peptide-like immunoreactivity in porcine follicular fluid and ovary.

Porcine follicular fluid was found to contain gastrin-releasing peptide (GRP) by radioimmunoassay. High pressure liquid chromatography of the extracted material showed two peaks of GRP immunoreactivity that closely resembled the C-terminal fragments of GRP, GRP18-27 and GRP14-27. Immunohistochemical studies revealed specific staining for GRP in the granulosa cells of adult porcine ovary. These results demonstrate the presence of substances which behave like authentic GRP-like peptides in porcine ovary and follicular fluid and suggest that these peptides may play a paracrine and/or autocrine role in the regulation of the ovarian function.