scholarly journals Regulation of Luminal Acidification by the V-ATPase

Physiology ◽  
2013 ◽  
Vol 28 (5) ◽  
pp. 318-329 ◽  
Author(s):  
Sylvie Breton ◽  
Dennis Brown
Keyword(s):  
Plasma Membrane ◽  
Male Infertility ◽  
The Body ◽  
Intercalated Cells ◽  
Extracellular Acidification ◽  
Clear Cells ◽  
Physiological Processes ◽  
Key Players ◽  
Atpase Subunits ◽  
Distal Tubular Acidosis

Specialized cells in the body express high levels of V-ATPase in their plasma membrane and respond to hormonal and nonhormonal cues to regulate extracellular acidification. Mutations in or loss of some V-ATPase subunits cause several disorders, including renal distal tubular acidosis and male infertility. This review focuses on the regulation of V-ATPase-dependent luminal acidification in renal intercalated cells and epididymal clear cells, which are key players in these physiological processes.

An Ultrastructural Study of Pericytes

1968 ◽  
Vol 26 ◽  
pp. 66-67
Author(s):  
T. M. Murad ◽  
E. von Haam
Keyword(s):  
Plasma Membrane ◽  
Endothelial Cell ◽  
Basement Membrane ◽  
Blood Vessel ◽  
Vascular Endothelial Cells ◽  
Myoepithelial Cells ◽  
Capillary Blood ◽  
The Body ◽  
Capillary Blood Vessel ◽  
Outer Plasma Membrane

Pericytes are vascular satellites present around capillary blood vessels and small venules. They have been observed in almost every tissue of the body and are thought to be related to vascular smooth muscle cells. Morphologically pericytes have great similarity to vascular endothelial cells and also slightly resemble myoepithelial cells.The present study describes the ultrastructural morphology of pericytes in normal breast tissue and in benign tumor of the breast. The study showed that pericytes are ovoid or elongated cells separated from the endothelial cell of the capillary blood vessel by the basement membrane of endothelial cell. The nuclei of pericytes are often very distinctive. Although some are round, oval, or elongated, others show marked irregularity and infolding of the nuclear membrane. The cytoplasm shows mono-or bipolar extension in which the cytoplasmic organelles are located (Fig. 1). These cytoplasmic extensions embrace the capillary blood vessel incompletely. The plasma membrane exhibits multiple areas of focal condensation called hemidesmosomes (Fig. 2, arrow). A variable number of pinocytotic vesicles are frequently seen lining the outer plasma membrane. Normally pericytes are surrounded by a basement membrane which is found more consistently on the outer plasma membrane separating the pericytes from the stromal connective tissue.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Therapeutic Potential of Agonists and Antagonists of A1, A2a, A2b and A3 Adenosine Receptors

2019 ◽  
Vol 25 (26) ◽  
pp. 2892-2905 ◽  
Author(s):  
Sumit Jamwal ◽  
Ashish Mittal ◽  
Puneet Kumar ◽  
Dana M. Alhayani ◽  
Amal Al-Aboudi
Keyword(s):  
Nervous System ◽  
Therapeutic Potential ◽  
The Body ◽  
Membrane Receptors ◽  
Physiological Importance ◽  
Physiological Processes ◽  
Central Nervous Systems ◽  
Energy Consuming ◽  
Metabolic Dysfunctions ◽  
G Protein Coupled

Adenosine is a naturally occurring nucleoside and an essential component of the energy production and utilization systems of the body. Adenosine is formed by the degradation of adenosine-triphosphate (ATP) during energy-consuming processes. Adenosine regulates numerous physiological processes through activation of four subtypes of G-protein coupled membrane receptors viz. A1, A2A, A2B and A3. Its physiological importance depends on the affinity of these receptors and the extracellular concentrations reached. ATP acts as a neurotransmitter in both peripheral and central nervous systems. In the peripheral nervous system, ATP is involved in chemical transmission in sensory and autonomic ganglia, whereas in central nervous system, ATP, released from synaptic terminals, induces fast excitatory postsynaptic currents. ATP provides the energetics for all muscle movements, heart beats, nerve signals and chemical reactions inside the body. Adenosine has been traditionally considered an inhibitor of neuronal activity and a regulator of cerebral blood flow. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosinerelated drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases. This review will summarize the therapeutic potential and recent SAR and pharmacology of adenosine and its receptor agonists and antagonists.

scholarly journals Understanding sex differences in long-term blood pressure regulation: insights from experimental studies and computational modeling

2019 ◽  
Vol 316 (5) ◽  
pp. H1113-H1123 ◽  
Author(s):  
Sameed Ahmed ◽  
Rui Hu ◽  
Jessica Leete ◽  
Anita T. Layton
Keyword(s):  
Blood Pressure ◽  
Sex Differences ◽  
Computational Models ◽  
Experimental Studies ◽  
Pressure Control ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Physiological Processes ◽  
Key Players

Sex differences in blood pressure and the prevalence of hypertension are found in humans and animal models. Moreover, there has been a recent explosion of data concerning sex differences in nitric oxide, the renin-angiotensin-aldosterone system, inflammation, and kidney function. These data have the potential to reveal the mechanisms underlying male-female differences in blood pressure control. To elucidate the interactions among the multitude of physiological processes involved, one may apply computational models. In this review, we describe published computational models that represent key players in blood pressure regulation, and highlight sex-specific models and their findings.

scholarly journals Cannabinoid receptors distribution in mouse cortical plasma membrane compartments

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hajar Miranzadeh Mahabadi ◽  
Haseeb Bhatti ◽  
Robert B. Laprairie ◽  
Changiz Taghibiglou
Keyword(s):  
Plasma Membrane ◽  
Lipid Raft ◽  
Cannabinoid Receptors ◽  
Gradient Centrifugation ◽  
Brain Regions ◽  
Cb1 Receptor ◽  
The Body ◽  
Cb2 Receptor ◽  
Cortical Tissue ◽  
Ionic Detergent

AbstractThe type 1 and type 2 cannabinoid receptors (CB1 and CB2 receptors) are class A G protein-coupled receptors (GPCRs) that are activated by endogenous lipids called endocannabinoids to modulate neuronal excitability and synaptic transmission in neurons throughout the central nervous system (CNS), and inflammatory processes throughout the body. CB1 receptor is one of the most abundant GPCRs in the CNS and is involved in many physiological and pathophysiological processes, including mood, appetite, and nociception. CB2 receptor is primarily found on immunomodulatory cells of both the CNS and the peripheral immune system. In this study, we isolated lipid raft and non-lipid raft fractions of plasma membrane (PM) from mouse cortical tissue by using cold non-ionic detergent and sucrose gradient centrifugation to study the localization of CB1 receptor and CB2 receptor. Lipid raft and non-lipid raft fractions were confirmed by flotillin-1, caveolin-1 and transferrin receptor as their protein biomarkers. Both CB1 receptor and CB2 receptor were found in non-raft compartments that is inconsistent with previous findings in cultured cell lines. This study demonstrates compartmentalization of both CB1 receptor and CB2 receptor in cortical tissue and warrants further investigation of CB1 receptor and CB2 receptor compartmental distribution in various brain regions and cell types.

scholarly journals PPARs as Metabolic Sensors and Therapeutic Targets in Liver Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8298
Author(s):  
Hugo Christian Monroy-Ramirez ◽  
Marina Galicia-Moreno ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Arturo Santos ◽  
...  
Keyword(s):  
Liver Diseases ◽  
Metabolic Regulation ◽  
Structural Changes ◽  
Critical Role ◽  
The Body ◽  
Molecular Characteristics ◽  
Signal Pathways ◽  
Virus Infections ◽  
Physiological Processes ◽  
Hepatic Level

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs’ critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.

Vitamin D and sleep duration: Is there a bidirectional relationship?

2020 ◽  
Vol 41 (4) ◽  
Author(s):  
Maryam Mosavat ◽  
Aisling Smyth ◽  
Diana Arabiat ◽  
Lisa Whitehead
Keyword(s):  
Vitamin D ◽  
Sleep Duration ◽  
Vitamin D Supplementation ◽  
The Body ◽  
Bone Homeostasis ◽  
Limited Information ◽  
Physiological Processes ◽  
Vitamin D Levels ◽  
Bidirectional Relationship ◽  
Sleep Length

AbstractVitamin D contributes to numerous physiological processes within the body but primarily calcium and bone homeostasis. Emerging evidence highlights a novel role for vitamin D in maintaining and regulating optimal sleep. Sleep is a known regulator of bone health, highlighting the interconnectedness between vitamin D concentrations, sleep duration and bone metabolism. It is possible that the relationship between sleep length and vitamin D is bidirectional, with vitamin D playing a role in sleep health and conversely, sleep affecting vitamin D levels. Nevertheless, limited information on the direction of the interaction is available, and much remains to be learned concerning the complex relationship between insufficient sleep duration and vitamin D deficiency. Given the potential to implement interventions to improve sleep and vitamin D supplementation, understanding this relationship further could represent a novel way to support and improve health.

scholarly journals Potassium depletion increases proton pump (H+-ATPase) activity in intercalated cells of cortical collecting duct

2000 ◽  
Vol 279 (1) ◽  
pp. F195-F202 ◽  
Author(s):  
Randi B. Silver ◽  
Sylvie Breton ◽  
Dennis Brown
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Collecting Duct ◽  
Proton Pumps ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Acid Load ◽  
Collecting Tubules ◽  
Atpase Staining

Intercalated cells (ICs) from kidney collecting ducts contain proton-transporting ATPases (H+-ATPases) whose plasma membrane expression is regulated under a variety of conditions. It has been shown that net proton secretion occurs in the distal nephron from chronically K+-depleted rats and that upregulation of tubular H+- ATPase is involved in this process. However, regulation of this protein at the level of individual cells has not so far been examined. In the present study, H+-ATPase activity was determined in individually identified ICs from control and chronically K+-depleted rats (9–14 days on a low-K+ diet) by monitoring K+- and Na+-independent H+ extrusion rates after an acute acid load. Split-open rat cortical collecting tubules were loaded with the intracellular pH (pHi) indicator 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and pHiwas determined by using ratiometric fluorescence imaging. The rate of pHi recovery in ICs in response to an acute acid load, a measure of plasma membrane H+-ATPase activity, was increased after K+ depletion to almost three times that of controls. Furthermore, the lag time before the start of pHirecovery after the cells were maximally acidified fell from 93.5 ± 13.7 s in controls to 24.5 ± 2.1 s in K+-depleted rats. In all ICs tested, Na+- and K+-independent pHi recovery was abolished in the presence of bafilomycin (100 nM), an inhibitor of the H+-ATPase. Analysis of the cell-to-cell variability in the rate of pHi recovery reveals a change in the distribution of membrane-bound proton pumps in the IC population of cortical collecting duct from K+-depleted rats. Immunocytochemical analysis of collecting ducts from control and K+-depleted rats showed that K+-depletion increased the number of ICs with tight apical H+ATPase staining and decreased the number of cells with diffuse or basolateral H+-ATPase staining. Taken together, these data indicate that chronic K+ depletion induces a marked increase in plasma membrane H+ATPase activity in individual ICs.

FEATURES OF CALCIUM HOMEOSTASIS AND CALCIUM SIGNALING IN NEURONS

Vestnik ◽  
2021 ◽  
pp. 208-214
Author(s):  
Б.К. Кайрат ◽  
С.Т. Тулеуханов ◽  
В.П. Зинченко
Keyword(s):  
Plasma Membrane ◽  
Calcium Signaling ◽  
Calcium Binding ◽  
Intracellular Signaling ◽  
Cell Damage ◽  
Compensatory Mechanisms ◽  
Physiological Processes ◽  
Intracellular Ca ◽  
Ca Ions ◽  
Ca Homeostasis

Ионы Са являются основным мессенджером в регуляции физиологических функций клеток. Внутриклеточном пространстве ионы Ca могут свободно состоянии диффундироваться в различных частях цитоплазмы, в то же время значительное количество Ca в связанном виде накапливается в различных внутриклеточных депо или в составе кальций-связывающих белков. Регуляция физиологических процессов с ионами внутриклеточного Са происходит в диапазоне концентраций 10 М, тогда как концентрация Са во внеклеточном пространстве выше и составляет 10 М, для поддержании градиента концентраций в клетках имеются важные Са транспортирующие системы плазматической мембраны, эндоплазматического ретикулума и митохондрий. В нейронах функционируют внутриклеточные ферменты и белки плазматической мембраны для поддержания Са-гомеостаза и реализации механизмов внутриклеточной сигнализации для обеспечения жизнедеятельности в выживании клеток. Нарушение или гиперактивация одного или нескольких механизмов кальциевой сигнализации может привести к повреждению и гибели нейронов в случае отсутствия компенсаторных механизмов. Ca ions are a key messenger for the regulation of most of the physiological functions of cells. Inside the cell, Ca ions can freely diffuse in various parts of the cytoplasm, but a significant amount of Ca is also bound in various intracellular depots or in the form of calcium-binding proteins. The regulation of physiological processes by intracellular Ca ions occurs in the concentration range of 10 M, and the concentration of Ca in the extracellular space is higher and is 10 M, and to maintain this concentration gradient, cells have Ca-transporting systems of the plasma membrane, endoplasmic reticulum and mitochondria. In neurons, a large number of intracellular enzymes and plasma membrane proteins function to maintain Ca-homeostasis and implement intracellular signaling mechanisms to ensure vital activity in the survival of cells. Violation or hyperactivation of one or more mechanisms of calcium signaling can lead to cell damage and death in the absence of compensatory mechanisms.

Food supplement “carrageenan” and its effect on the organism

2020 ◽  
Author(s):  
O.E. Luneva ◽  
Keyword(s):  
Gastrointestinal Tract ◽  
Food Additives ◽  
Food Supplement ◽  
The Body ◽  
Laboratory Rats ◽  
Experimental Part ◽  
In Vivo Experiments ◽  
Physiological Processes

Food additives are positioned as harmless, although, their components affectthe physiological processes associated with the permeability of the wall of the gastrointestinal tract (GIT) and intestinal microbiota. This article describes thecarrageenan supplement and its effects on the body in in vitro and in vivo experiments. The experimental part is devoted to analysis of the intestinalmicrobiota of laboratory rats with the consumption of the carrageenan dietary supplement in the amount of about 4,4 % of the standard feed.

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