In Vitro: LH-RH II (chicken) occurs in low amounts throughout the brain. LH-RH II (chicken) doesn’t regulate gonadotrophin secretion in the hen directly rather than cLHRH-I.
In Vivo: LH-RH II (chicken) (10-10-10-8 mg/kg; i.v.; single dose) stimulates increases in the plasma concentrations of luteinizing hormone (LH), which are initiated within 1 min of injection in out-of-lay (OL) and incubating (I) hens but from 5 to 20 min postinjection in laying (L) hens.