W.A. Chamley

Release of Luteinizing Hormone by Oestradiol-17β and a Gonadotrophin-Releasing Hormone in Ewes Affected with Clover Disease

Sheep grazing the oestrogenic varieties of subterranean clover ( Trifolium subterraneum L.) exhibit an irreversible loss in fertility that has been associated with changes in the mec

Effect of Progesterone on the Release of Luteinizing Hormone Induced by a Synthetic Gonadotrophin-Releasing Factor in the Ewe

A synthetic decapeptide (Gn-RH) structurally identical to ‘ovine LH-releasing hormone’ was given by intra-carotid infusions (0, 0.5 and 1.5 µ g/h for 3 h) to two groups of ewes late

Luteal function in sheep with ovarian autotransplants given concurrent infusions of prolactin and prostaglandin F2α into the ovarian artery

Abstract Four experimental sheep with ovarian autotransplants were infused with prolactin (10 or 100 μg/h), into the ovarian artery, for 6 hours and then prolactin together with prostaglandin F2α (PGF2α) (5 μg/h) for a further 6 hours. A control sheep received PGF2α alone, for 6 hours on two separate occasions. Prolactin failed to overcome the luteolytic action of PGF2α in 3 of the 4 experimental sheep.

Luteal function in sheep injected with prostaglandin F2α directly into the corpus luteum

Groups of ewes received either saline or prostaglandin F2alpha (PGF2alpha) as an injection directly into the corpus luteum. Changes in circulating progesterone levels were measured as well as subsequent histological examination of the corpora lutea. Saline, or PGF2alpha given at the two lower doses (60 and 120 mug respectively), failed to suppress progesterone levels permanently, or to induce degenerative changes in the corpora lutea. Treatment with a higher dose of PGF2alpha (240 mug) was followed by a marked elevation in progesterone levels. These results are discussed in relation to reported effects of PGF2alpha arriving at the ovary via the arterial circulation.