LH-RECEPTOR IN THE LUTEAL CELL MEMBRANES

1971 ◽  
Vol 68 (1_Supplb) ◽  
pp. S53
Author(s):  
H. Rajaniemi ◽  
T. Vanha-Perttula
Keyword(s):  
Cell Membranes ◽  
Luteal Cell ◽  
Lh Receptor

scholarly journals Corpora lutea induced by gonadotrophin-releasing hormone treatment of anoestrous Welsh Mountain ewes: reduced sensitivity to luteinizing hormone in vivo and to chorionic gonadotrophin in vitro

Reproduction ◽  
2005 ◽  
Vol 129 (1) ◽  
pp. 61-73 ◽  
Author(s):  
T A Bramley ◽  
D Stirling ◽  
G S Menzies ◽  
D T Baird
Keyword(s):  
Chorionic Gonadotrophin ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Lh Receptor ◽  
Group 4 ◽  
Progesterone Secretion ◽  
Group 3 ◽  
Gonadotrophin Releasing Hormone

Seasonally anoestrous Welsh Mountain ewes received 250 ng gonadotrophin-releasing hormone (GnRH) every 2 h, with (Group 1;n= 13) or without (Group 2;n= 14) progesterone priming for 48 h. Fourteen control ewes (Group 3) were studied during the luteal phase in the breeding season. Animals in Group 4 (n= 12) received progesterone priming followed by 250 ng GnRH at increasing frequency for 72 h, while ewes in Group 5 (n= 13) were given three bolus injections of 30 μg GnRH at 90-min intervals. All treatment regimens induced ovulation. However, only corpora lutea (CL) from ewes in Group 3 (breeding season) or Group 4 exhibited normal luteal function. Luteal luteinizing hormone (LH) receptor levels were significantly higher on day 12 than day 4, and CL from groups with adequate CL (3 and 4) had significantly higher125I-human chorionic gonadotrophin (hCG)-binding levels than the three groups with inadequate CL on day 12. LH-binding affinity was unchanged. Exogenous ovine LH (10 μg)in vivoon days 3 or 11 after ovulation induced a pulse of progesterone in ewes with adequate CL: however, ewes in Groups 1, 2 and 5 showed no significant response. Basal progesterone secretionin vitrowas significantly greater on day 4 than on day 12. Maximal steroidogenic responses of adequate and inadequate CL to hCG and to dibutyryl cyclic-3′,5′-AMP were similar at both stages of the luteal phase. However, the EC50for hCG on days 4 and 12 was 10-fold lower for groups with an adequate CL (0.1 IU hCG/ml) than for inadequate-CL groups (1 IU hCG/ml;P<0.05). Thus, in addition to the well-characterized premature sensitivity of GnRH-induced inadequate CL to endometrial luteolysin, we have shown (1) a marked decrease in total number of cells in the CL, a profound reduction in vascular surface area, and a decrease in mean large luteal cell volume (with no change in large luteal cell numbers), (2) decreased luteal LH receptor and progesterone content compared with adequate CL and (3) that CL that were becoming, or were destined to become, inadequate failed to respond to ovine LHin vivoand were 10-fold less sensitive to hCG in terms of luteal progesterone secretionin vitro.

scholarly journals Comparison of monoclonal luteinizing hormone (LH) receptor antibody and LH binding sites in vibratome sections of rat ovary by immunohistochemistry.

1989 ◽  
Vol 37 (11) ◽  
pp. 1711-1719 ◽  
Author(s):  
I Visintin ◽  
J L Luborsky
Keyword(s):  
Luteinizing Hormone ◽  
Cell Surface ◽  
Surface Membrane ◽  
Membrane Binding ◽  
Receptor Protein ◽  
Luteal Cell ◽  
Cell Surfaces ◽  
Cytoplasmic Staining ◽  
Lh Receptor ◽  
Receptor Antibody

To identify luteinizing hormone (LH) receptors, a monoclonal antibody (MAb) was produced by immunization of Balb/c mice with rat luteal cell membranes. Hybridomas, produced by a method for proteins of low antigenicity, were selected by competition with [125I]-hCG (LH) for luteal membrane binding. Conditions for analysis of LH receptor antibody (IgG2b isotype) binding by immunohistochemistry with an avidin-biotin-peroxidase complex were examined and results compared to localization of bound hCG, to detect receptors. By light microscopy, both bound hCG and the LH receptor antibody were located on luteal cell surfaces. In addition, the LH receptor antibody was associated with luteal cell cytoplasm. Cell surface membrane binding, but not cytoplasmic staining, was reduced in ovaries from rats injected with hCG. By electron microscopy, LH receptor antibody was observed in patches on luteal cell surface membranes and was associated with polysomes, small vesicles, and occasionally with discrete areas of endoplasmic reticulum. Therefore, detection of LH receptors with bound hCG may be limited to receptors found on cell surfaces, while additional LH receptors are revealed by use of a receptor antibody. The cytoplasmic LH receptor may represent stages in the processing of receptor protein. Furthermore, the methodology used in this study should be generally useful for immunohistochemistry with other MAb to receptors.

scholarly journals Luteolysis-induced changes in phase composition and fluidity of bovine luteal cell membranes.

1982 ◽  
Vol 79 (14) ◽  
pp. 4332-4336 ◽  
Author(s):  
F. Goodsaid-Zalduondo ◽  
D. A. Rintoul ◽  
J. C. Carlson ◽  
W. Hansel
Keyword(s):  
Phase Composition ◽  
Cell Membranes ◽  
Luteal Cell ◽  
Induced Changes

Induction of luteolysis by dihydrotestosterone in the pregnant rat

1981 ◽  
Vol 241 (6) ◽  
pp. E444-E448
Author(s):  
R. Sridaran ◽  
G. Gibori
Keyword(s):  
Serum Levels ◽  
Peripheral Circulation ◽  
Ovariectomized Rats ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Ovarian Vein ◽  
Serum Progesterone ◽  
Cell Content ◽  
Pregnant Rat ◽  
Lh Receptor

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. However, by day 15, complete abortion occurred in 75% of the rats, indicating that a decline in P secretion precedes abortion, To further determine whether the abortifacient action of DHT was due to its luteolytic effect, 20-cm DHT capsules were implanted subcutaneously in ovariectomized rats treated with 4 mg P and 0.5 micrograms of estradiol (E). Control rats were sham-operated and treated with empty capsules. DHT treatment induced complete abortion by day 15 only in rats with ovaries present, further indicating that DHT was not directly detrimental to the fetuses but acted on the ovaries to induce luteolysis. When DHT treatment was started on day 12, no luteolytic effect was detectable. To determine whether the effect of DHT was mediated by either a decrease in the ovarian production of E, a decline in luteal cell content of luteinizing hormone (LH) receptors or both, testosterone (T) levels in the peripheral circulation and E and P concentrations in the ovarian vein were measured on day 15 in rats implanted with two DHT pellets under the ovarian bursa on day 9. Luteal content of LH receptors was also measured on day 12 in similarly treated rats. DHT treatment had no effect on serum levels or on ovarian vein concentration of E, but induced a significant decrease in the ovarian vein levels of P. DHT also did not depress LH receptor content in corpora lutea. DHT levels in the ovaries increase significantly between days 18 and 22 of pregnancy, concomitant with the cessation of corpus luteum function. These results indicate that DHT possesses a potent luteolytic activity and could be involved in the luteolytic process in the pregnant rat.

scholarly journals Luteinizing hormone receptors are associated with non-receptor plasma membrane proteins on bovine luteal cell membranes

1998 ◽  
Vol 1371 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Deborah A Roess ◽  
Noorulhuda A Rahman ◽  
Heidi Munnelly ◽  
Bruce I Meiklejohn ◽  
Cynthia J Brady ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Luteinizing Hormone ◽  
Membrane Proteins ◽  
Cell Membranes ◽  
Hormone Receptors ◽  
Luteal Cell ◽  
Plasma Membrane Proteins ◽  
Luteinizing Hormone Receptors

Photoreceptor disk membrane substructures by means of the complementary freeze-fracture-replica methods

1978 ◽  
Vol 36 (2) ◽  
pp. 156-157
Author(s):  
A. Tonosaki ◽  
M. Yamasaki ◽  
H. Washioka ◽  
J. Mizoguchi
Keyword(s):  
Cell Membranes ◽  
Freeze Fracture ◽  
Purple Membrane ◽  
Remarkable Case ◽  
Single Face ◽  
Disk Membrane ◽  
Associated Proteins ◽  
Photoreceptor Membranes

A vertebrate disk membrane is composed of 40 % lipids and 60 % proteins. Its fracture faces have been classed into the plasmic (PF) and exoplasmic faces (EF), complementary with each other, like those of most other types of cell membranes. The hypothesis assuming the PF particles as representing membrane-associated proteins has been challenged by serious questions if they in fact emerge from the crystalline formation or decoration effects during freezing and shadowing processes. This problem seems to be yet unanswered, despite the remarkable case of the purple membrane of Halobacterium, partly because most observations have been made on the replicas from a single face of specimen, and partly because, in the case of photoreceptor membranes, the conformation of a rhodopsin and its relatives remains yet uncertain. The former defect seems to be partially fulfilled with complementary replica methods.

Introduction to Cell Membranes at Molecular Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 497-502
Author(s):  
R.J. Barrnett
Keyword(s):  
Cell Membranes ◽  
International Federation ◽  
Mountain Range ◽  
Cellular Membranes ◽  
Short History ◽  
Biological Organization ◽  
Macromolecular Assemblies ◽  
The Past

This subject, is like observing the panorama of a mountain range, magnificent towering peaks, but it doesn't take much duration of observation to recognize that they are still in the process of formation. The mountains consist of approaches, materials and methods and the rocky substance of information has accumulated to such a degree that I find myself concentrating on the foothills in the foreground in order to keep up with the advance; the edifices behind form a wonderous, substantive background. It's a short history for such an accumulation and much of it has been moved by the members of the societies that make up this International Federation. My panel of speakers are here to provide what we hope is an interesting scientific fare, based on the fact that there is a continuum of biological organization from biochemical molecules through macromolecular assemblies and cellular membranes to the cell itself. Indeed, this fact explains the whole range of towering peaks that have emerged progressively during the past 25 years.

664: CXCL12/CXCR4 Trans-Activation of HER2 in Lipid Rafts of Prostate Cancer Cell Membranes Promotes Bone Metastasis

2007 ◽  
Vol 177 (4S) ◽  
pp. 223-223
Author(s):  
Sreenivasa R. Chinni ◽  
Hamilto Yamamoto ◽  
Zhong Dong ◽  
Aaron Sabbota ◽  
Sanaa Nabha ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Bone Metastasis ◽  
Lipid Rafts ◽  
Cancer Cell ◽  
Cell Membranes ◽  
Prostate Cancer Cell

Melatonin actions in the heart; more than a hormone

2018 ◽  
Vol 1 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Darío Acuña-Castroviejo ◽  
Maria T Noguiera-Navarro ◽  
Russel J Reiter ◽  
Germaine Escames
Keyword(s):  
Cell Membranes ◽  
Myocardial Cell ◽  
Rat Tissues ◽  
Dependent Manner ◽  
Broad Distribution ◽  
Multiple Organs ◽  
High Doses ◽  
Extrapineal Melatonin ◽  
Dose Dependent ◽  
Different Doses

Due to the broad distribution of extrapineal melatonin in multiple organs and tissues, we analyzed the presence and subcellular distribution of the indoleamine in the heart of rats. Groups of sham-operated and pinealectomized rats were sacrificed at different times along the day, and the melatonin content in myocardial cell membranes, cytosol, nuclei and mitochondria, were measured. Other groups of control animals were treated with different doses of melatonin to monitor its intracellular distribution. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondria vary along the day, without showing a circadian rhythm. Pinealectomized animals trend to show higher values than sham-operated rats. Exogenous administration of melatonin yields its accumulation in a dose-dependent manner in all subcellular compartments analyzed, with maximal concentrations found in cell membranes at doses of 200 mg/kg bw melatonin. Interestingly, at dose of 40 mg/kg b.w, maximal concentration of melatonin was reached in the nucleus and mitochondrion. The results confirm previous data in other rat tissues including liver and brain, and support that melatonin is not uniformly distributed in the cell, whereas high doses of melatonin may be required for therapeutic purposes.

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