BINDING OF TRITIATED METHYLATED LUTEINIZING HORMONE TO BOVINE CORPUS LUTEUM RECEPTORS

1976 ◽  
Vol 83 (2) ◽  
pp. 393-401 ◽  
Author(s):  
M. Paloma de la Llosa-Hermier ◽  
Claude Hermier ◽  
Pedro de la Llosa
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Inhibitory Activity ◽  
Significant Inhibition ◽  
Corpora Lutea ◽  
Reductive Methylation ◽  
Binding Properties ◽  
Bovine Corpus Luteum ◽  
Binding Inhibition

ABSTRACT The binding of luteinizing hormone (LH) to cow corpora lutea homogenates was studied using a tritium labelled hormone obtained by reductive methylation. The KD observed was 0.9 10−10 m and the number of sites was the equivalent of 0.4 10−15 moles per mg of wet tissue. The influence of the pH and temperature was examined. HCG and LH produced the same binding inhibition curves as did unlabelled methylated LH, suggesting that the binding properties of the derivative used for labelling LH were similar to those of native LH. The inhibitory activity of the subunits was extremely low (α-LH: 4%, β-LH: 1%). No significant inhibition was observed in the case of FSH or prolactin.

CYCLISCHE SCHWANKUNGEN DER AKTIVITÄTEN VON HYDROXYSTEROID-DEHYDROGENASEN IM CORPUS LUTEUM DES RINDES

1972 ◽  
Vol 69 (2) ◽  
pp. 369-384
Author(s):  
H. Brandau ◽  
L. Brandau ◽  
G. Mutzke
Keyword(s):  
Enzyme Activity ◽  
Corpus Luteum ◽  
Enzyme Activities ◽  
Optical Method ◽  
Activity Patterns ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpora Lutea ◽  
Bovine Corpus Luteum ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT In the bovine corpora lutea periodical activities of the Δ53β-, 3β-, 17β-and 20β-hydroxysteroid dehydrogenase (OHSDH) as well as activities of glyceraldehyde-3-phosphate- and glucose-6-phosphate dehydrogenase were measured quantitatively and the alterations throughout the different stages of the cycle were studied. After homogenization of the tissue and fractionate centrifugation the enzyme activities were determined by a standardized optical method. The activities of the Δ53β-, and 3β- and 17β-OHSDH increase slowly during the first 7 days of the cycle, the maximum is reached abruptly on the 12th to 13th day of the cycle. After a striking reduction the activities decline continually to the 19th to 21st day reaching the values detected at the beginning of the cycle. The 20β-OHSDH increases slowly to the maximum on the 15th day of the cycle. Activities of the 3α-OHSDH were obtained only inconsistently. The behaviour of the activities of G6PDH was nearly identical with that of the 3β-OHSDH, while the GAPDH shows only little fluctuations of its activities. The obtained enzyme activity patterns of the maturating and high functional corpus luteum correspond to the well-known data of the biosynthetic function of the bovine corpus luteum. The changes of the amounts of progesterone and 20β-progesterol agree with the course of the activities of the 3β- resp. 20β-OHSDH.

scholarly journals Luteinizing hormone regulates the phosphorylation and localization of the mitochondrial effector dynamin‐related protein‐1 (DRP1) and steroidogenesis in the bovine corpus luteum

2020 ◽  
Vol 34 (4) ◽  
pp. 5299-5316
Author(s):  
Michele R. Plewes ◽  
Xiaoying Hou ◽  
Heather A. Talbott ◽  
Pan Zhang ◽  
Jennifer R. Wood ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Related Protein ◽  
Bovine Corpus Luteum

β-Carotene and protein complex found in microsomal membranes of bovine corpora lutea

1996 ◽  
Vol 1996 ◽  
pp. 69-69
Author(s):  
AJ Holt ◽  
RG Rodway ◽  
JBC Findlay ◽  
HS Sands ◽  
DN Batchelder
Keyword(s):  
Corpus Luteum ◽  
High Performance ◽  
Gel Filtration ◽  
Biological Action ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Bovine Corpus Luteum ◽  
Microsomal Membranes ◽  
Ruminant Animals ◽  
Β Carotene

The role of β-carotene in the fertility of ruminant animals has long been acknowledged (Friesecke, 1978). Initially this was thought to be due to its action as a vitamin A precursor but recently β-carotene itself has been considered responsible for improving reproductive performance (Hurley & Doane, 1989). The mechanism by which β-carotcne acts is unclear, but as its concentration in the corpus luteum was typically found to be 70μg per gram of tissue, its biological action is probably exerted in this area.β-Carotene has been studied in the bovine corpus luteum using Raman spectroscopy, high performance liquid chromatography (HPLC) and gel filtration chromatography. The structure of β-carotene produces a characteristic Raman spectrum and by utilising an imaging technique, photographs of isolated luteal cells were obtained indicating the regions of β-carotene within them. Differential centrifugation was used to obtain pure subcellular fractions of luteal cells.

scholarly journals Prolactin independent rescue of mouse corpus luteum life span: identification of prolactin and luteinizing hormone target genes

2009 ◽  
Vol 297 (3) ◽  
pp. E676-E684 ◽  
Author(s):  
Anne Bachelot ◽  
Julie Beaufaron ◽  
Nathalie Servel ◽  
Cécile Kedzia ◽  
Philippe Monget ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Ovarian Function ◽  
De Novo ◽  
Embryo Implantation ◽  
Receptor Expression ◽  
Corpora Lutea ◽  
Mrna Expression Profiling

The corpus luteum (CL) plays a central role in the maintenance of pregnancy in rodents, mainly by secreting progesterone. Female mice lacking prolactin (PRL) receptor (R) are sterile due to a failure of embryo implantation, which is a consequence of decreased luteinizing hormone (LH) receptor expression in the CL and inadequate levels of progesterone. We attempted to treat PRLR−/− females with human chorionic gonadotropin (hCG) and showed a de novo expression of LHR mRNA in the corpora lutea. Binding analysis confirmed that the LHR in hCG-treated PRLR−/− animals was functional. This was accompanied with increased expression of steroidogenic enzymes involved in progesterone synthesis. Despite these effects, no embryo implantation was observed because of high expression of 20α-hydroxysteroid dehydrogenase. To better appreciate the molecular mechanisms underlying maintenance of the CL, a series of mRNA expression-profiling experiments was performed on isolated corpora lutea of PRLR−/− and hCG-treated PRLR−/− mice. This approach revealed several novel candidate genes with potentially pivotal roles in ovarian function, among them, p27, VE-cadherin, Pten, and sFRP-4, a member of the Wnt/frizzled family. This study showed the differential role of PRL and LH in CL function and identified new targets of these hormones in luteal cells.

SUPERFUSION IN VITRO IN THE STUDY OF OVARIAN STEROIDOGENESIS

1975 ◽  
Vol 64 (1) ◽  
pp. 163-173 ◽  
Author(s):  
JOHN WATSON ◽  
J. T. S. LEASK
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Transient Increase ◽  
Corpora Lutea ◽  
Ovarian Steroidogenesis ◽  
Steroid Secretion ◽  
Regulatory Factors ◽  
Prolonged Response

SUMMARY A method for the continuous superfusion of porcine corpus luteum tissue is described which readily allows both the introduction of regulatory factors to the incubating tissue, and sampling of the tissue. Oestrogen (principally oestradiol) and progestin (principally progesterone) can be measured for up to 24 h in the superfusate from corpora lutea of all ages, and the secretion of both steroids is stimulated by the addition of luteinizing hormone. The pattern of response of both steroids to a pulse of gonadotrophin was similar in that a rapid transient increase in secretion occurred followed some time later by a secondary and more prolonged response. A second pulse of gonadotrophin introduced 6 h after the first also stimulated steroid secretion, indicating that during superfusion in vitro the porcine corpus luteum does not become refractory to the steroidogenic effect of gonadotrophin.

Induction of ovulation during anoestrus in two breeds of sheep with multiple injections of LH alone or in combination with FSH

1986 ◽  
Vol 111 (1) ◽  
pp. 181-190 ◽  
Author(s):  
J. M. Wallace ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Corpora Lutea ◽  
Preovulatory Follicle ◽  
Treatment Timing ◽  
Multiple Injections ◽  
Induction Of Ovulation ◽  
Preovulatory Follicles ◽  
Identical Manner ◽  
Hormonal Priming

ABSTRACT The gonadotrophic requirements for the induction of ovulation and formation of a viable corpus luteum in two breeds of seasonally anoestrous sheep of differing fecundity was investigated. Welsh Mountain (n = 20) and Damline ewes (n = 19) were given LH or FSH either alone or in combination. Luteinizing hormone was injected i.v. at an increasing frequency for 72 h (one injection every 3 h for 24 h, one every 2 h for 24 h, and one every hour for 24 h) and FSH was injected in an identical manner for the first 36 h of treatment. Exogenous LH alone and in combination with FSH induced a preovulatory LH surge in all 19 ewes and ovulation in 18 out of 19 ewes of both breeds. However exogenous FSH alone was ineffective. The incidence of normal corpus luteum function in ewes induced to ovulate was low and not related to treatment, timing or magnitude of the LH/FSH surge. It is concluded that in both breeds studied (a) it is the infrequency of LH pulses which limits the development of preovulatory follicles during seasonal anoestrus, (b) that the requirement for FSH remains unknown, and (c) that the induction of inadequate corpora lutea during seasonal anoestrus reflects either defects in hormonal priming of the preovulatory follicle and/or inappropriate luteotrophic support after ovulation. J. Endocr. (1986) 111, 181–190

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