Some Observations on the Role of the Body Wall of Acanthocephalus Ranae in Lipid Uptake

1968 ◽  
Vol 48 (1) ◽  
pp. 217-225
Author(s):  
R. A. HAMMOND
Keyword(s):  
Lipid Droplets ◽  
Body Wall ◽  
The Body ◽  
Lipid Uptake ◽  
Uptake Of Nutrients ◽  
Lipid Excretion

1. Acanthocephalus ranae has been found to take up glyceryl tri[oleate-9,10-3H] solely through the surface of the trunk. The proboscis and lemnisci play no part in the uptake of this material. The large amounts of lipid present in the latter organs may be evidence of their involvement in lipid excretion. 2. Fat-soluble dyes are taken up by the animal and accumulate in lipid droplets in the lemnisci and proboscis wall. It is suggested that such dyes do not enter the animal through the surface of the proboscis, as has been suggested previously, but through the surface of the trunk. 3. The structure of the acanthocephalan body wall is discussed in relation to the uptake of nutrients.

scholarly journals EHD2 regulates adipocyte function and is enriched at cell surface–associated lipid droplets in primary human adipocytes

2019 ◽  
Vol 30 (10) ◽  
pp. 1147-1159 ◽  
Author(s):  
Björn Morén ◽  
Björn Hansson ◽  
Florentina Negoita ◽  
Claes Fryklund ◽  
Richard Lundmark ◽  
...  
Keyword(s):  
Cell Surface ◽  
Lipid Droplets ◽  
Energy Homeostasis ◽  
Lipid Uptake ◽  
Human Adipocytes ◽  
Adrenergic Stimulation ◽  
Triglyceride Accumulation ◽  
Aquaporin 7 ◽  
Interfering Rna

Adipocytes play a central role in energy balance, and dysfunctional adipose tissue severely affects systemic energy homeostasis. The ATPase EH domain–containing 2 (EHD2) has previously been shown to regulate caveolae, plasma membrane-specific domains that are involved in lipid uptake and signal transduction. Here, we investigated the role of EHD2 in adipocyte function. We demonstrate that EHD2 protein expression is highly up-regulated at the onset of triglyceride accumulation during adipocyte differentiation. Small interfering RNA–mediated EHD2 silencing affected the differentiation process and impaired insulin sensitivity, lipid storage capacity, and lipolysis. Fluorescence imaging revealed localization of EHD2 to caveolae, close to cell surface–associated lipid droplets in primary human adipocytes. These lipid droplets stained positive for glycerol transporter aquaporin 7 and phosphorylated perilipin-1 following adrenergic stimulation. Further, EHD2 overexpression in human adipocytes increased the lipolytic signaling and suppressed the activity of transcription factor PPARγ. Overall, these data suggest that EHD2 plays a key role for adipocyte function.

scholarly journals Preliminary observations on the role of the coelomic cells in food storage and transport in certain polychaetes

1957 ◽  
Vol 36 (1) ◽  
pp. 91-110 ◽  
Author(s):  
R. Phillips Dales
Keyword(s):  
Body Wall ◽  
The Body ◽  
Food Storage ◽  
Coelomic Cells ◽  
Different Parts

Determinations of the concentration of fat and glycogen in the body wall, in different parts of the gut and in the coelomic cells are described in Amphitrite and Arenicola. It is suggested that the trephocyte system constitutes a store of fat and glycogen derived from a primary store in the absorptive parts of the gut itself. In Arenicola and Nereis surplus fat is removed from the gut itself through the blood or directly by amoebocytes; the fat deposited in the epidermis and the glycogen in the peritoneum. In these worms the coelomic trephocytes are solely concerned with the maturation of the gametes. No relationship can be established between these cells and the chloragocytes. In Amphitrite and Terebella fat is stored also in the coelomic trephocytes which may derive their contents directly from the gut or from the body wall. Glycogen is stored in the trephocytes in Amphitrite, and in Arenicola in the peritoneum. Thus while large amounts of fat and glycogen are found in the trephocytes in Amphitrite, the total amount present in the body is no more than in Arenicola which lacks a well-developed trephocyte system, and in this species a larger proportion of fat and glycogen is found in the body wall.

scholarly journals The rôle of the body fluid in relation to movement in soft-bodied invertebrates I. The burrowing of Arenicola

1947 ◽  
Vol 134 (877) ◽  
pp. 431-455 ◽  
Keyword(s):  
Body Fluid ◽  
Body Wall ◽  
The Body ◽  
Coelomic Fluid ◽  
Simple Condition ◽  
Muddy Sand ◽  
Fluid System ◽  
Quantitative Results ◽  
Pressure Changes

This investigation is an attempt to obtain quantitative results on the method of functioning of the body-wall muscle-coelomic fluid system of the lugworm which was chosen as an example of a worm having this system in a relatively simple condition. Measurements of the hydrostatic pressure developed in the coelomic fluid during various phases of activity, particularly during burrowing, were recorded, and the mechanism by which pressure is differentially distributed throughout the body is discussed. The relation of pressure changes to burrowing movements is described and some calculations of the thrust which can be exerted by the worms are given. It is shown that the forces available to the worms are insufficient to allow of straight­-forward burrowing and that the ability to burrow depends on the thixotropic properties of the muddy sand in which the animals live.

Ultrastructural and cytochemical observations on the body wall of the redia of Sphaeridiotrema globulus (Rudolphi, 1819)

Parasitology ◽  
1972 ◽  
Vol 65 (3) ◽  
pp. 537-546 ◽  
Author(s):  
Trevor A. J. Reader
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membranes ◽  
Body Wall ◽  
Secretory Granules ◽  
The Body ◽  
Carbohydrate Storage ◽  
Parenchyma Cells ◽  
Membrane Bound ◽  
Cytoplasmic Processes ◽  
Uptake Of Nutrients

The ultrastructure of the body wall of the redia of Sphaeridiotrema globulus is described. The tegument, which possesses numerous microvilli, is shown to be a syncytial, cytoplasmic layer connected to underlying subtegumentary ‘cells’ by cytoplasmic processes. Between the subtegumentary ‘cells’ are located the normal parenchyma cells of the body wall, which are believed to be important in carbohydrate storage. Mitochondria, Golgi complexes, endoplasmic reticulum and beta glycogen granules are located in the tegument and subtegumentary ‘cells’. In addition, large whorled bodies and dense secretory granules appear to be formed within the subtegumentary ‘cells’ prior to their passage into the outer tegument. It is suggested that these whorled structures are contributing to the growth of the tegument. Small membrane-bound ‘vesicles’ are also seen in the tegument and some of these may be pinocytotic in nature. Following incubation, horseradish peroxidase tracer was localized within ‘vesicles’ in both the tegument, subtegumentary ‘cells’ and parenchyma cells, which indicates that the redial body wall may be important in the uptake of nutrients. Phosphatase enzymes are abundant within the tegument, particularly in association with the plasma membranes and microvilli. These enzymes, which appear to have their origin in the endoplasmic reticulum of subtegumentary cells, are believed to be associated with the uptake of nutrients through the redial tegument.

scholarly journals Role of Ca(2+) in excitation-contraction coupling in echinoderm muscle: comparison with role in other tissues

2001 ◽  
Vol 204 (5) ◽  
pp. 897-908 ◽  
Author(s):  
R.B. Hill
Keyword(s):  
Control Systems ◽  
Body Wall ◽  
Longitudinal Muscle ◽  
The Body ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Collagenous Tissue

The longitudinal muscle of the body wall of Isostichopus badionotus may be considered a model for excitation-contraction coupling in echinoderm muscle. Other echinoderm muscles are reviewed by comparison with the model. Echinoderm muscle is also of interest as a model for ‘mutable collagenous tissue’; however, in that tissue, Ca(2+) has been proposed to function both in living control systems and in regulation of non-living interstitial substance.

scholarly journals The Contractile Mechanism in Obliquely Striated Body Wall Muscle of the Earthworm, Lumbricus Terrestris

1971 ◽  
Vol 8 (2) ◽  
pp. 413-425 ◽  
Author(s):  
M. F. KNAPP ◽  
P. J. MILL
Keyword(s):  
Body Wall ◽  
Striated Muscle ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Band Width ◽  
Physiological Data ◽  
Muscle Fibres ◽  
Contraction Mechanism ◽  
Cross Links

Obliquely striated muscle fibres from the longitudinal and circular layers of the body wall of the earthworm were prepared in extended and contracted states for study in the electron microscope. Contracted fibres differ from extended ones in the following respects: (i) the I-bands are narrower, (ii) the A-bands are wider, and (iii) there are more rows of thick myofilaments in each A-band. The arrangement of the thick and thin myofilaments in interdigitating arrays and the occurrence of cross-links between the 2 types of myofilament indicate a classical sliding-filament mechanism of contraction as in cross-striated muscle, resulting in a reduction in the I-band width. The increase in the A-band width could be due to a moving apart of the myofilaments during contraction to preserve constant volume of the lattice. The third change, the increase in the number of rows of thick myofilaments in the A-band, can be explained only by a shearing of these filaments past one another in such a way as to increase the amount of their overlap. The role of the sliding-filament and shearing contraction mechanisms in bringing about the changes observed in earthworm muscle fibres is considered and the possible correlation of these mechanisms with certain physiological data is discussed. The function of the sarcoplasmic reticulum in the transmission of impulses to the interior of the fibre and/or in the control of the contraction mechanism is also discussed.

Identified cholinergic neurons R2 and LPl1 control mucus release in Aplysia

1983 ◽  
Vol 49 (4) ◽  
pp. 864-876 ◽  
Author(s):  
S. G. Rayport ◽  
R. T. Ambron ◽  
J. Babiarz
Keyword(s):  
Body Wall ◽  
Gland Cell ◽  
Cholinergic Neurons ◽  
Giant Cells ◽  
The Body ◽  
Behavioral Context ◽  
Histochemical Characterization ◽  
Stimulation Of

1. R2 and LPl1 are homologous giant cholinergic neurons in the nervous system of Aplysia with overlapping and almost symmetrical axonal trees extending over most of the body wall. In spite of much experimental study, the behavioral role of the cells has remained unknown. 2. After intrasomatic injection of R2 and LPl1 with horseradish peroxidase (HRP), the giant cell axons were traced to the periphery and found to contact subepidermal glands in the body wall exclusively. 3. The axons penetrated the glandular basal lamina, indenting the gland cell cytoplasm, and expanded into varicosities containing putative cholinergic transmissive sites. 4. Histochemical characterization of the contents of the glands showed that they contain mucus, suggesting that the giant cells control mucus release from the body wall. 5. Stimulation of R2 or LPl1 resulted in glandular discharge, as measured both by an increase in the appearance of protein and of mucus on the body wall. 6. R2 and LPl1 control mucus release from the body wall, thus providing a new system for investigations of neuroglandular control as well as a behavioral context for cellular studies using these two neurons.

The Role of Oesophageal Rhythms in the Behaviour of Arenicola Ecaudata Johnston

1951 ◽  
Vol 28 (1) ◽  
pp. 51-56
Author(s):  
G. P. WELLS ◽  
ELINOR B. ALBRECHT
Keyword(s):  
Body Wall ◽  
The Body ◽  
Rhythmic Contraction ◽  
Back Ground ◽  
Continuous Background ◽  
Mode Of Life ◽  
Nearly Continuous

1. Arenicola ecaudata differs not only in structure, but in mode of life, from A. marina. Our results indicate that there are also great differences in behaviour physiology. 2. The brainless isolated extrovert of ecaudata traces a continuous, or nearly continuous, background of activity, upon which prominent spells of vigorous rhythmic contraction appear at intervals of the order of 30-40 min. Similar spells are sometimes shown by the corresponding preparation from marina, whose characteristic f cycle can be regarded as produced by the organization of the back-ground activity of ecaudata into vigorous and regularly spaced outbursts. 3. There is little evidence of a pacemaker role of the oesophagus in ecaudata. If the movements of the extrovert and body wall are simultaneously recorded, they generally exhibit correlated outbursts of variable and fluctuating pattern, and very unlike the behaviour of the brainless extrovert. Similar outbursts are shown by the body wall after severance of its connexion with the extrovert. They are probably of central nervous origin.

scholarly journals Intricacies of Fat

2008 ◽  
Vol 88 (11) ◽  
pp. 1265-1278 ◽  
Author(s):  
Lisa Stehno-Bittel
Keyword(s):  
Cell Biology ◽  
Lipid Droplets ◽  
Normal Weight ◽  
The Body ◽  
Cellular Damage ◽  
Endocrine Organ ◽  
Fields Of Study ◽  
Large Numbers ◽  
The Brain

One of the most exciting cell biology fields of study concerns the physiology and pathology of fat. The basic assumptions once held concerning the function of adipose tissue have been shown to be oversimplified or sometimes completely wrong. Fat does more than store excess energy; it is actually the largest endocrine organ in the body, and it may be one of the most active. Adipocytes release hormones and other molecules that act on nearby tissues and travel through the vasculature to distant sites, such as the brain, skeletal muscle, and liver. Under conditions of normal weight, those signals help the body to suppress hunger, utilize glucose, and decrease the risk of cardiovascular disease. However, under conditions of obesity, the hormones (or the proteins that bind the hormones) become abnormal and can result in states of chronic inflammation leading to diabetes and heart disease. In addition, excessive fat can lead to the accumulation of lipid droplets in nonfat cells, including skeletal and cardiac muscle. Although some lipid droplets are used as an immediate source of energy for cells, large numbers of stored droplets can cause cellular damage and cell death. The purposes of this article are to review the normal and deviant signals released by fat cells, to draw a link between those signals and chronic diseases such as diabetes, and to discuss the role of exercise in reversing some of the deviant signaling perpetrated by excess fat.

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