| Popis: |
The search for antagonistic analogs of LHRH which could form the basis of new methods of contraception (Schally and Kastin, 1971; Guillemin, 1972) met with early successes, although the potency of these analogs was low (Monahan et al., 1972; Vale et al., 1972; Guillemin et al., 1973; Coy et al., 1974; Rees et al., 1974; Vilchez-Martinez et al., 1975). For example, a dose level of 6 × 500 μg of [d-Phe2, d-Ala6]LHRH was required to inhibit ovulation in rats (Yardley et al., 1975). Developments in the antagonist field were therefore overshadowed when, starting in 1975, it was demonstrated that LHRH and its agonist analogs were capable of exerting ‘paradoxical’ antireproductive effects in doses of 0.5 μg per day or less (Oshima et al., 1975). |
