Beyond GnRH, LH and FSH: the role of kisspeptin on hypothalalmic-pituitary gonadal (HPG) axis pathology and diagnostic consideration

2021 ◽  
pp. 1-20
Author(s):  
Sikandar Hayat Khan ◽  
Nayyer Chaudhry
Keyword(s):  
Diagnostic Marker ◽  
Pulse Frequency ◽  
Gonadal Steroids ◽  
Receptor Interaction ◽  
Specific Receptor ◽  
Hpg Axis ◽  
Positive Feedbacks ◽  
Chemical Agents ◽  
Diet And Lifestyle

Kisspeptin as a neuropeptide was established initially as regulator GnRH pulse frequency and intensity. Over time it was recognized that the interaction are mediated through a specific receptor GPR54, which has also been found throughout the hypothalamic-pituitary-gonadal (HPG) axis. Further insights into the mechanisms leading to triggering of kisspeptin were identified to be both negative and positive feedbacks from gonadal steroids along with various internal metabolic alterations and environmental triggers in the shape of diet and lifestyle. More so it was identified that these Kisspeptin/GPR54 receptor interaction was also influenced by endocannabinoid (eCB) system, GABA-ergic neuronal outputs (GABA) and other chemical agents. The most influencing neuronal inputs modifying the release of kisspeptin were identified as group of neurons termed “KNDy” in the ARC nuclei. Based upon these discoveries, scientist attempted to evaluate kisspeptin as diagnostic marker for various diseases including precocious puberty, puberty confirmation, hypogonadism, infertility and polycystic ovarian Continuous...

scholarly journals Adiponectin: A New Regulator of Female Reproductive System

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Kamil Dobrzyn ◽  
Nina Smolinska ◽  
Marta Kiezun ◽  
Karol Szeszko ◽  
Edyta Rytelewska ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Current Knowledge ◽  
Female Fertility ◽  
Hormonal Status ◽  
Female Reproductive System ◽  
Fertility Regulation ◽  
Hpg Axis ◽  
Chemical Agents ◽  
Growing Body

Adiponectin is the hormone that belongs to the group of adipokines, chemical agents mainly derived from the white adipose tissue. The hormone plays pleiotropic roles in the organism, but the most important function of adiponectin is the control of energy metabolism. The presence of adiponectin and its receptors in the structures responsible for the regulation of female reproductive functions, such as hypothalamic-pituitary-gonadal (HPG) axis, indicates that adiponectin may be involved in the female fertility regulation. The growing body of evidence suggests also that adiponectin action is dependent on the actual and hormonal status of the animal. Present study presents the current knowledge about the presence and role of adiponectin system (adiponectin and its receptors: AdipoR1 and AdipoR2) in the ovaries, oviduct, and uterus, as well as in the hypothalamus and pituitary, the higher branches of HPG axis, involved in the female fertility regulation.

Different Abilities of Thrombin Receptor Activating Peptide and Thrombin to Induce Platelet Calcium Rise and Full Release Reaction

1995 ◽  
Vol 74 (05) ◽  
pp. 1323-1328 ◽  
Author(s):  
Dominique Lasne ◽  
José Donato ◽  
Hervé Falet ◽  
Francine Rendu
Keyword(s):  
Essential Role ◽  
Calcium Influx ◽  
Dense Granule ◽  
Receptor Interaction ◽  
Thrombin Receptor ◽  
Release Reaction ◽  
External Calcium ◽  
Maximum Rise ◽  
Granule Release

SummarySynthetic peptides (TRAP or Thrombin Receptor Activating Peptide) corresponding to at least the first five aminoacids of the new N-terminal tail generated after thrombin proteolysis of its receptor are effective to mimic thrombin. We have studied two different TRAPs (SFLLR, and SFLLRN) in their effectiveness to induce the different platelet responses in comparison with thrombin. Using Indo-1/AM- labelled platelets, the maximum rise in cytoplasmic ionized calcium was lower with TRAPs than with thrombin. At threshold concentrations allowing maximal aggregation (50 μM SFLLR, 5 μM SFLLRN and 1 nM thrombin) the TRAPs-induced release reaction was about the same level as with thrombin, except when external calcium was removed by addition of 1 mM EDTA. In these conditions, the dense granule release induced by TRAPs was reduced by over 60%, that of lysosome release by 75%, compared to only 15% of reduction in the presence of thrombin. Thus calcium influx was more important for TRAPs-induced release than for thrombin-induced release. At strong concentrations giving maximal aggregation and release in the absence of secondary mediators (by pretreatment with ADP scavengers plus aspirin), SFLLRN mobilized less calcium, with a fast return towards the basal level and induced smaller lysosome release than did thrombin. The results further demonstrate the essential role of external calcium in triggering sustained and full platelet responses, and emphasize the major difference between TRAP and thrombin in mobilizing [Ca2+]j. Thus, apart from the proteolysis of the seven transmembrane receptor, another thrombin binding site or thrombin receptor interaction is required to obtain full and complete responses.

scholarly journals Unraveling the role of polycystin-2/inositol 1,4,5-trisphosphate receptor interaction in Ca2+signaling

2010 ◽  
Vol 3 (6) ◽  
pp. 530-532 ◽  
Author(s):  
Eva Sammels ◽  
Benoit Devogelaere ◽  
Djalila Mekahli ◽  
Geert Bultyncki ◽  
Ludwig Missiaen ◽  
...  
Keyword(s):  
Receptor Interaction ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

scholarly journals Heterologous desensitization of the cyclic AMP-independent glycogenolytic response in rat liver cells

1981 ◽  
Vol 200 (3) ◽  
pp. 509-514 ◽  
Author(s):  
B Bréant ◽  
S Keppens ◽  
H De Wulf
Keyword(s):  
Cyclic Amp ◽  
Glycogen Phosphorylase ◽  
Liver Glycogen ◽  
Receptor Interaction ◽  
Alpha Adrenergic Receptors ◽  
Rat Liver Cells ◽  
Heterologous Desensitization ◽  
Highly Correlated ◽  
Alpha Agonist

Vasopressin and alpha-adrenergic agonists are known to be potent cyclic AMP-independent Ca2+-dependent activators of liver glycogen phosphorylase. When hepatocytes are pre-incubated with increasing concentrations of vasopressin or of the alpha-agonist phenylephrine, they become progressively unresponsive to a second addition of the respective agonist. The relative abilities of six vasopressin analogues and of five alpha-agonists to activate glycogen phosphorylase and to cause subsequent desensitization are highly correlated, indicating that the same vasopressin and alpha-adrenergic receptors are involved in both responses. About 5-times-higher peptide concentrations are needed to desensitize the cells than to activate their glycogen phosphorylase, whereas the concentrations of alpha-agonists required for the desensitization are only twice those needed for the activation of phosphorylase. The desensitization is not mediated by a perturbation in the agonist-receptor interaction. It is clearly heterologous, i.e. it is not agonist-specific, and must therefore involve a mechanism common to both series of agonists. The evidence for a role of Ca2+ movements or phosphatidylinositol turnover is briefly discussed.

Role of Polyethylene Glycol Integrity in Specific Receptor Targeting of Carbon Nanotubes to Cancer Cells

Nano Letters ◽  
2009 ◽  
Vol 9 (2) ◽  
pp. 751-757 ◽  
Author(s):  
Reema Zeineldin ◽  
Marwan Al-Haik ◽  
Laurie G. Hudson
Keyword(s):  
Carbon Nanotubes ◽  
Polyethylene Glycol ◽  
Cancer Cells ◽  
Specific Receptor ◽  
Receptor Targeting

scholarly journals Analysis of the Role of N-Linked Glycosylation in Cell Surface Expression, Function, and Binding Properties of SARS-CoV-2 Receptor ACE2

2021 ◽  
Author(s):  
Raymond Rowland ◽  
Alberto Brandariz-Nuñez
Keyword(s):  
Cell Surface ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Receptor Interaction ◽  
Minimal Effect ◽  
Binding Properties ◽  
Virus Receptor

Understanding the role of glycosylation in the virus-receptor interaction is important for developing approaches that disrupt infection. In this study, we showed that deglycosylation of both ACE2 and S had a minimal effect on the spike-ACE2 interaction.

scholarly journals Role of diet and lifestyle of women suffering from breast cancer

2017 ◽  
Vol 8 (1) ◽  
pp. 100-104
Author(s):  
VIJAYSHREE PRASAD ◽  
SEEMA DEY
Keyword(s):  
Breast Cancer ◽  
Diet And Lifestyle

scholarly journals Etiology of differentiated carcinoma of the thyroid current apprehension

2003 ◽  
Vol 50 (3) ◽  
pp. 51-55
Author(s):  
Ruben Han
Keyword(s):  
Animal Experiments ◽  
Growth Control ◽  
Significant Risk ◽  
Ionising Radiation ◽  
Sodium Iodide Symporter ◽  
Chemical Agents ◽  
Tsh Secretion ◽  
Genetic And Environmental Factors

It is apparent that in the last decade carcinoma of the thyroid is becoming increasingly prevalent. The multistage complex theory of thyroid carcinogenesis is based on observations made on cohort patients studies and during animal experiments over a period of last fifty years. The process of thyroid oncogenesis is conceived to be a series of events induced by genetic and environmental factors which alter follicular cells division and growth control. These factors can be considered as initiators (chemical agents and ionising radiation) and promoters (some goitrogenes and drugs). The first class of factors induce incipient tumorigenesis while the second augments TSH secretion and radically increases tumour growth. Normally silent, intracellular proto-oncogenes (of which Ret/PTC series are the most conceived ones) can become activated by chromosomal translocations, deletions or mutations and can transform normal follicular cell into a condition of uncontrolled division and growth. The most significant known cause of thyroid carcinomas in men is exposure to external or internal ionising radiation. Beside that, long-term iodine deficiency, effects of certain chemical carcinogens, drugs and goitrogenes must be considered as significant risk factors. Possible role of sodium/iodide symporter is becoming an objective of the most recent investigations.

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