Direct Inhibition of Pituitary LH Secretion in Rats by CB-154 (2-Br-β-ergocryptine)

The effect of 2-Br-α-ergocryptine Prolactin, LH and FSH were determined by (CB-154) on pituitary response to synthetic LH-double-antibody solid-phase radioimmunoassays. RH or rat hypothalamic extract (HE) was in-Serum prolactin levels were significantly de- vestigated in ovariectomized, estrogen-proges-creased by CB-154. Although the ergot alkaloid terone-blocked rats by measuring pituitary contentid not significantly change serum FSH levels, it and serum concentration of prolactin, LH and significantly suppressed LH release induced by FSH. CB-1S4 was injected once ip at a dose of synthetic LH-RH or rat HE. This suggests that 500 µ.g/100 g body weight 2 hr before autopsy or iv injection with synthetic LH-RH or rat HE. Prolactin, LH and FSH were determined by double-antibody solid-phase radioimmunoassays. Serum prolactin levels were significantly decreased by CB-154. Although the ergot alkaloid did not significantly change serum FSH levels, it significantly suppressed LH release induced by synthetic LH-RH ...