Growth hormone releasing factor increases growth hormone release from MtTW15 pituitary tumors

The MtTW15 pituitary tumor secretes growth hormone and prolactin. Perifusion of these dispersed MtTW15 tumor cells with 10 nM growth hormone releasing factor (GRF) increases growth hormone release without affecting prolactin release. This effect is dose-dependent between 0.001 and 0.1 nM and is blocked by 100 nM somatostatin. These findings suggest that this tumor and clones derived from it may be valuable tools in studying the cellular mechanisms of action of GRF and somatostatin.