A study on the localization and distribution of GnRH and its receptor in rat submaxillary glands by immunohistochemical, in situ hybridization and RT-PCR.

We investigated the rat submaxillary gland for the presence of GnRH and GnRH receptors, the localization and colocalization of GnRH, GnRH receptor and their mRNA, and studied the sequence of GnRH receptor complementary DNA (cDNA) by immunohistochemistry, in situ hybridization and RT-PCR. The results showed that GnRH and GnRH receptor immunoreactive materials were colocalized in the epithelial cells of the serous acinus and glandular duct. The GnRH and GnRH receptor mRNA hybridization signals were detected in the above cells. The sequence obtained from the RT-PCR product was identical to the published cDNA sequence of GnRH receptor in the rat pituitary. The results suggested that the rat submaxillary gland was capable of synthesizing GnRH and GnRH receptors. GnRH may be involved in the functional regulation of the submaxillary gland through autocrine or paracrine activity.