Department of Poultry and Animal Sciences, Gifu University, Kakamigahara, Gifu, Japan
Fujino et al. (1972) have synthesized a nonapeptide amide with the structure, (pyro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-ethylamine, which is an analogue of LH-RH. This analogue has been shown to be more effective than LH-RH in causing the release of LH and FSH from the pituitary of rats (Fujino et al., 1972; Arimura, Vilchez-Martinez & Schally, 1974) and man (Nakano, Takekida, Kotsuji, Miyazaki & Tojo, 1974), and in inducing ovulation in rats and rabbits (Fujino et al., 1973). This paper reports a comparison of the ovulation-inducing activity in hens between synthetic LH-RH and the analogue.
The synthetic LH-RH (Eisai Co. Ltd, Tokyo, Japan) and the analogue (Takeda Chemical Industries, Tokyo, Japan) were dissolved in sterilized distilled water. They were injected into the pectoral muscle of White Leghorn hens (2·0-2·4 kg body wt, 17 months of age) which had been laying eggs in a regular