scholarly journals Effect of rate of change of luteinizing hormone concentration on in-vitro progesterone secretion within rat corpora lutea during differentiation

Reproduction ◽  
1991 ◽  
Vol 93 (2) ◽  
pp. 333-339
Author(s):  
J. C. Nulsen ◽  
J. Sullivan ◽  
J. J. Peluso
Keyword(s):  
Luteinizing Hormone ◽  
Rate Of Change ◽  
Corpora Lutea ◽  
Hormone Concentration ◽  
Progesterone Secretion ◽  
Luteinizing Hormone Concentration

A QUANTITATIVE STUDY OF GENETIC DIFFERENCES IN THE INCIDENCE OF OESTRUS, OVULATION AND PLASMA LUTEINIZING HORMONE CONCENTRATION IN THE SHEEP

1973 ◽  
Vol 58 (2) ◽  
pp. 305-317 ◽  
Author(s):  
R. B. LAND ◽  
J. PELLETIER ◽  
J. THIMONIER ◽  
P. MAULÉON
Keyword(s):  
Seasonal Variation ◽  
Luteinizing Hormone ◽  
Breeding Season ◽  
Quantitative Study ◽  
Genetic Differences ◽  
Ovulation Rate ◽  
The Other ◽  
Corpora Lutea ◽  
Hormone Concentration ◽  
Luteinizing Hormone Concentration

SUMMARY Seasonal variation in the ovulation rate and incidence of ovulation was examined in 15 Romanov and 15 Solognote ewes by endoscopy. The ovulation rate of the Romanovs was found to be related to the incidence of ovulation (r = 0·78) and to the incidence of oestrus as measured by daily teasing with aproned entire rams (r = 0·83). The ovulation rate of the Romanovs was greater than that of the Solognotes, and was 2·6 and 1·1 corpora lutea in the two breeds, respectively, in the autumn. The durations of the breeding season and of oestrus of the Romanovs exceeded those of the Solognotes. The characteristics of the preovulatory discharge of luteinizing hormone (LH) and the daily plasma LH levels were studied by radioimmunoassay in the Romanov and Solognote ewes and in ewes of the Berrichon and Berrichon × Romanov breeds. The interval between the onset of oestrus and the discharge of LH was greater in the Romanovs (17·6 h) than in the other breeds (mean = 7·5 h). The total release of LH, however, was not related to the number of corpora lutea formed.

THE OVARIAN FOLLICLE OF THE SHEEPINHIBITION OF OESTROGEN SECRETION BY LUTEINIZING HORMONE

1974 ◽  
Vol 61 (3) ◽  
pp. 455-463 ◽  
Author(s):  
R. M. MOOR
Keyword(s):  
Luteinizing Hormone ◽  
Organ Culture ◽  
Culture Medium ◽  
Ovarian Follicle ◽  
Corpora Lutea ◽  
In Vitro Techniques ◽  
Progesterone Secretion ◽  
Experimental Approaches

SUMMARY The object of this study was to test the hypothesis that levels of luteinizing hormone (LH), comparable to those circulating at oestrus, inhibit oestrogen secretion from Graafian follicles of sheep. Three experimental approaches were used. Follicles maintained in organ culture secreted high levels of oestrogen into the medium throughout a 7-day culture period; almost no progesterone was secreted under such conditions. By contrast, oestrogen secretion declined precipitously and progesterone secretion increased rapidly after the addition of LH (0·25 μg–10 μg NIH-LH-S 17/ml) to the culture medium. In experiments combining in-vivo and in-vitro techniques, follicles were obtained from sheep from which the corpora lutea had been removed 24 h previously. The large follicles explanted from these sheep secreted high levels of oestrogen throughout the 7 days in culture. Insignificant amounts of oestrogen were, however, secreted in culture by large follicles that had been explanted from sheep in which 1 mg LH had been infused between 18 and 24 h after removal of the corpus luteum. Experiments carried out entirely in vivo showed that intravenous infusion of 1 mg LH into sheep from which the corpora lutea had been removed 18 h previously prevented the ovaries from secreting, during the ensuing 22 h, the large amounts of oestrogen they would otherwise have produced. The results demonstrate that oestrogen secretion by large Graafian follicles is terminated both in vitro and in vivo by an amount of LH corresponding to that released at oestrus.

Elevated intravesicular fluid luteinizing hormone concentration in hydatidiform mole

1982 ◽  
Vol 89 (2) ◽  
pp. 160-162 ◽  
Author(s):  
R. GUNASEGARAM ◽  
K. L. PEH ◽  
A. LOGANATH ◽  
S. M. M. KARIM ◽  
S. S. RATNAM
Keyword(s):  
Luteinizing Hormone ◽  
Hydatidiform Mole ◽  
Hormone Concentration ◽  
Luteinizing Hormone Concentration
Sign in / Sign up

Export Citation Format

Share Document