Results 181 to 190 of about 7,523 (208)

Luteolysins and Mechanisms of Luteolysis

1987
A fundamentally important event in reproduction is luteolysis because without a decrease in progesterone secretion, there can be no gonadotropin-dependent ovarian differentiation and cyclic function. Until the last two decades, virtually nothing was known of the mechanisms of luteolysis or of the agents that regulate such processes.
H. R. Behrman, R. F. Aten, J. J. Ireland, L. K. Soodak, J. R. Pepperell, B. Musicki   +5 more
openaire   +1 more source

The transition between preluteolysis and luteolysis in cattle

Theriogenology, 2011
Novel characterization of the transition between preluteolysis and luteolysis was done in seven heifers. Blood samples were collected hourly and assayed for progesterone (P4), 13-14-dihydro-15-keto-PGF2α (PGFM), and estradiol (E2). The peaks of P4 oscillations were used to designate the transitional hour in each heifer.
O J, Ginther, M J, Fuenzalida, H K, Shrestha, M A, Beg   +3 more
openaire   +2 more sources

Calcium: A Cellular Mediator of Luteolysis

1984
Regression of the corpus luteum with the consequent loss of ovarian progesterone secretion appears to be an induced response which is necessary for the re-occurrence of ovulation. Conversely, prevention of corpus luteum regression is essential for the continuation of pregnancy.
Harold R. Behrman, Peter J. Albert, Steven D. Gore, Laneta J. Dorflinger   +3 more
openaire   +1 more source

Interaction between Catecholamines and Prostaglandin F2α in Human Luteolysis

Obstetrical & Gynecological Survey, 1984
Abstract. From each of 14 women undergoing laparotomy at different stages of the luteal phase of the cycle. the corpus luteum (CL) was excised, cut into pieces and incubated for 120 min. Incubations were performed in the absence and presence of hCG and prostaglandin F2α (PGF2α).
B, Bennegård, B, Dennefors, L, Hamberger   +2 more
openaire   +2 more sources

138 Characterization of partial luteolysis in mares

Journal of Equine Veterinary Science, 2015
Datawere analyzed by regression analysis and by a random effects mixedmodel. Therewere significant (P < 0.001) effects of time and assay method for the determination of progestins in the mixed model. Least squares means for progestins across the studied interval differed (P < 0.001) with P4 1⁄4 0.66 ng/mL; DHP 1⁄4 26.4 ng/ mL; ELISA progestins 1⁄4 47.9
J.C. Ferreira, D.L. Thompson, Y.L. Boakari, H.S. Canesin, L.F. Novaes Filho, C. Meira   +5 more
openaire   +1 more source

Enclomiphene induces luteolysis in the nonpregnant guinea pig

Experientia, 1989
The effect of two antiestrogens, enclomiphene and tamoxifen, on luteal function in the guinea pig was compared to that of estradiol, a known luteolysin. Enclomiphene caused premature luteolysis when administered during the early or mid-luteal phase of the cycle, but was not as potent as estradiol. Tamoxifen had no effect.
openaire   +2 more sources

Indomethacin treatment prevents prolactin-induced luteolysis in the rat

Journal of Endocrinology, 1987
ABSTRACT Adult female rats were hypophysectomized and their pituitary glands autotransplanted beneath the left kidney capsule on day 2 (day 1 was the day of ovulation). In such rats the pituitary secretes prolactin fairly constantly and the corpora lutea secrete progesterone for several months.
J E, Sánchez-Criado, K, Ochiai, I, Rothchild   +2 more
openaire   +2 more sources

Studies on Prostaglandin and Luteolysis in the Pseudopregnant Rabbit

Endocrine Research, 1990
The ability of pulsatile infusion of prostaglandin F2 alpha (PGF2 alpha) or 13, 14-dihydro prostaglandin F2 alpha to induce corpus luteum regression was examined in the pseudopregnant rabbit. Each prostaglandin was infused in 5, 1-hour pulses (1 per 6 hours) during a 25-hour period starting day 9 or 10 of pseudopregnancy.
J C, Carlson, P, Hahn, K, So, A, Chan
openaire   +2 more sources

Induction of luteolysis by dihydrotestosterone in the pregnant rat

American Journal of Physiology-Endocrinology and Metabolism, 1981
A dihydrotestosterone (DHT) pellet (4 mg) inserted under each ovarian bursa on day 9 of pregnancy induced within 24 h, a 40% decline in serum progesterone (P) concentrations in rats; a further reduction was observed on days 12 and 15. Although P levels were significantly reduced by DHT treatment, fetuses remained alive on day 12.
R, Sridaran, G, Gibori
openaire   +2 more sources

Control of pregnancy, parturition and luteolysis in marsupials

Reproduction, Fertility and Development, 1990
In most eutherian species the function of the corpus luteum (CL) is influenced by extrinsic factors and it is subordinate to the pituitary, placenta, or uterus. In contrast, in marsupials the CL is relatively autonomous. Although the pituitary is essential for the formation of the CL, thereafter the secretory activity of the CL is independent of ...
openaire   +2 more sources