This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by HARESIGN, W. Search for Related Content PubMed Articles by HARESIGN, W.

OVARIAN RESPONSE TO SYNTHETIC LH-RH IN ANOESTROUS EWES

Department of Physiology and Environmental Studies, University of Nottingham School of Agriculture, Sutton Bonington, Loughborough, Leicestershire LE12 5RD

(Received 2nd December 1974)

Synthetic LH-releasing hormone (LH-RH) has been shown to induce release of both LH and FSH from the ovine pituitary in vivo (Jonas & co-authors, 1973; Symons, Cunningham & Saba, 1974). When administered to seasonally anoestrous Clun Forest ewes as a single intravenous injection of either 150 µg or 300 µg, the induced gonadotrophin release was sufficient to cause ovulation in 23/27 ewes (Haresign, Foster, Haynes, Crighton & Lamming, 1975). Ovulation occurred within 48 hr of injection (W. Haresign, unpublished data). However, peripheral plasma progesterone levels did not rise above basal pre-injection values in most animals after the induction of ovulation. In view of this finding the present experiment was designed to investigate whether the structures visible on the surface of the ovary after injection of LH-RH were representative