Biomaterial Database

The induction of ovulation and luteal function in seasonally anoestrous ewes treated with small-dose multiple injections of Gn-RH. 1982

B J McLeod, and W Haresign, and G E Lamming

Seasonally anoestrous ewes were injected i.v. with 250, 500 or 1000 ng Gn-RH at 2-h intervals for 8 days (2 sheep/treatment). Each injection of 250 or 500 ng Gn-RH resulted in a transient rise in plasma LH concentrations. Treatment with 1000 ng Gn-RH per injection resulted in a more sustained rise in plasma LH concentrations in 1 of 2 sheep during the early part of the treatment period. A preovulatory-type LH peak occurred 17-48 h after the start of treatment in all ewes, with a second preovulatory-type peak 106-133 h later in those ewes receiving 500 or 1000 ng Gn-RH per injection. Ovulation, with subsequent normal luteal function, occurred in all sheep. However, the rise in plasma progesterone concentrations appeared to be delayed in those ewes treated with 500 or 1000 ng Gn-RH compared to ewes treated with 250 ng Gn-RH. These data suggest that the absence of ovulation during seasonal anoestrus is due to an inadequate pattern of episodic LH secretion.

UI	MeSH Term	Description	Entries
D007986	Luteinizing Hormone	A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.	ICSH (Interstitial Cell Stimulating Hormone),Interstitial Cell-Stimulating Hormone,LH (Luteinizing Hormone),Lutropin,Luteoziman,Luteozyman,Hormone, Interstitial Cell-Stimulating,Hormone, Luteinizing,Interstitial Cell Stimulating Hormone
D010060	Ovulation	The discharge of an OVUM from a rupturing follicle in the OVARY.	Ovulations
D010906	Pituitary Hormone-Releasing Hormones	Peptides, natural or synthetic, that stimulate the release of PITUITARY HORMONES. They were first isolated from the extracts of the HYPOTHALAMUS; MEDIAN EMINENCE; PITUITARY STALK; and NEUROHYPOPHYSIS. In addition, some hypophysiotropic hormones control pituitary cell differentiation, cell proliferation, and hormone synthesis. Some can act on more than one pituitary hormone.	Hormones, Pituitary Hormone Releasing,Hypophysiotropic Hormones,Hypothalamic Hypophysiotropic Hormone,Hypothalamic Releasing Factor,Hypothalamic Releasing Hormone,Hypothalamic Releasing Hormones,Hormone, Hypothalamic Hypophysiotropic,Hormones, Hypophysiotropic,Hypophysiotropic Hormone, Hypothalamic,Pituitary Hormone Releasing Hormones,Releasing Hormone, Hypothalamic
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D003338	Corpus Luteum	The yellow body derived from the ruptured OVARIAN FOLLICLE after OVULATION. The process of corpus luteum formation, LUTEINIZATION, is regulated by LUTEINIZING HORMONE.	Corpora Lutea,Lutea, Corpora
D004334	Drug Administration Schedule	Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.	Administration Schedule, Drug,Administration Schedules, Drug,Drug Administration Schedules,Schedule, Drug Administration,Schedules, Drug Administration
D004971	Estrus	The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
D005260	Female		Females
D000780	Anestrus	A state of sexual inactivity in female animals exhibiting no ESTROUS CYCLE. Causes of anestrus include pregnancy, presence of offspring, season, stress, and pathology.