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The recycling of endogenous calcium across the inner membrane of incubated mitochondria consists of a passive efflux of calcium from the matrix which is compensated by an active re-uptake of this ion from the medium. Upon addition of ruthenium red which inhibits only the re-uptake. mitochondrial calcium accumulated in the medium at a rate of 3.5 nmol × min-1 × mg protein-1. The ATP balance of this experiment. measured with the help of [2-14C]pyruvate as a substrate, revealed that ruthenium red inhibited about 20% of the energy dissipation of the mitochondria. It is concluded that the calcium recycling is one of the processes related to state 4 respiration of the mitochondria. Ca/O ratios for the calcium recycling were calculated from the rates of calcium release into the medium and the concomitant decrease in the respiratory rates observed after addition of ruthenium red. When the calcium transport system was progressively inhibited with increasing concentrations of ruthenium red, the intramitochondrial ATP/ADP ratios and the rates of calcium release gradually increased up to a maximal value. whereas the Ca/O ratios concomitantly decreased. Moreover, in the presence of barely uncoupling concentrations of dinitrophenol the Ca/O ratios were larger than in the control, whereas in the presence of oligomycin they were smaller. These results indicate that the efficiency of mitochondrial calcium transport decreases when the mitochondria approach a state of a maximal energy charge. [ABSTRACT FROM AUTHOR]

The metabolism of sorbitol or glycerol in isolated liver cells from hypothyroid rats was studied in order to determine whether the rate of reducing-equivalent translocation limits hepatic metabolism in a hypometabolic state. Rates of utilization of these substrates were compared with analogous data in euthyroid animals. When a saturating concentration of sorbitol or glycerol was added to the cells, gluconeogenic rates were only 54% and 29%, respectively, of the values in cells from euthyroid rats. Reducing-equivalent translocation to O2, as well as oxygen consumption by the cells, was depressed in a similar fashion. However, addition of pyruvate, acting as a cytoplasmic hydrogen acceptor, increased the utilization of sorbitol by 1.75 μmol · g-1 · min-1 and that of glycerol by 0.50 μmol · g-1 · min-1 This maneuver restored sorbitol utilization equal to rates in controls, whereas it partially corrected the depression in glycerol metabolism resulting from hypothyroidism. It was inferred from the data that the disposal of hydrogen generated in the cytoplasm is a limiting factor in the metabolism of sorbitol or glycerol in hypothyroid animals. At the same time rates of gluconeogenesis from fructose or dihydroxyacetone, which utilize similar pathways, were not depressed. It was concluded that the enzymes of the gluconeogenic route are not responsible for the diminished metabolism of sorbitol or glycerol in hypothyroidism; rather a diminished capacity for hydrogen translocation between cell compartments results in lowered rates of substrate oxidation, and subsequently, decreased rates of gluceneogenesis. Pathways of hydrogen translocation that are depressed in hypothyroidism and responsible for the decreased utilization of sorbitol or glycerol were investigated by the use of specific inhibitors. In the hypothyroid state hydrogen translocation from each substrate was depressed by 0.91–0.96 μmol · g-1 · min-1. It was calculated that 82% and 88% of the depressed metabolism of sorbitol or glycerol, respectively, was due to decreased activity of a pathway insensitive to rotenone and sensitive to antimycin, most likely involving mitochondrial glycerol-phosphate dehydrogenase. Most of the remaining loss was attributed to a diminished capacity of shuttles which were sensitive to fluoromalate and had malate dehydrogenase as a component. These studies support the concept that thyroid hormone may play an important role in the regulation of hepatic metabolism by modulating the capacities of the shuttles which translocate reducing-equivalents between cell compartments. [ABSTRACT FROM AUTHOR]

A series of studies of progressive alterations in cell functions with hemorrhagic shock have been presented. These consist of decreases in the capability of mitochondria, alterations in mitochondrial cation content, increased Na+K-ATPase activity, depressed cell membrane transport of Na and K, decreased energy content of cells including less ATP and nonspecific hydrolysis of ADP and AMP, decreased responsiveness of the cell membrane to insulin to increase glucose uptake and increased survival when animals with hemorrhagic shock are given ATP combined with MgCl2. These studies combine with those from other laboratories allowed the development of an initial tentative hypothesis of progressive cell deterioration with shock. These studies provide: 1. Basic knowledge of the progressive alterations in cell function which occur with diminished circulation. 2. They provide for the possibility of supporting cell function in such circumstances by biochemical and pharmacological means. 3. They provide increased knowledge necessary for further developments in cryobiology and extracorporeal circulation. [ABSTRACT FROM AUTHOR]

Studies in the morphology, histochemistry, and ultrastructure of the cerebellum, with special reference to the Purkinje cell dendrites, have been undertaken in eight cases of gargoylism. The results suggest that the demonstration of ovoid swellings of the Purkinje cell dendrites by the Cajal method for the cerebellum, together with certain histochemical findings, may enable a diagnosis of mucopolysaccharidosis to be made. Possible mechanisms for the formation of these swellings are briefly discussed. [ABSTRACT FROM AUTHOR]

The low-molecular weight beta-trace protein constitutes about seven per cent of the total protein content in human cerebrospinal fluid. Within the central nervous system the protein is found predominantly in white matter and fractions enriched in glial cells. Immunofluorescence studies on sections of monkey brains show that beta-trace protein is particularly localized to cells such as astrocytes and oligodendrocytes. Significantly higher amounts of beta-trace protein are found in brain tumours derived from glial cells than in other tumours. [ABSTRACT FROM AUTHOR]

A technique is described for the detection of immunoglobulins secreted by individual lymphoid cells. Cells were cultured. in agarose gel containing dilute radio- labelled anti-immunoglobulin antibodies. The secreted immunoglobulins produced a precipitin lattice which was made visible by washing the gel, followed by autoradiography. Immunoglobulin secreting cells were surrounded by clusters, or 'galaxies' of silver grains. Galaxies did not appear in the presence of certain metabolic inhibitors, indicating that the secretion of immunoglobulin was an active process dependent upon cell metabolism. [ABSTRACT FROM AUTHOR]

Labelled maleic hydrazide (MH) was shown to be accumulated preferentially into the root-tips of young Willow roots by radiochemical analysis. A large proportion of the activity incorporated into the cell constituents was associated with RNA. MH was also bound in some way to the cell wall material. The greatest proportion of the activity was easily removed from the root tissue and thus probably occurred free within the cytoplasm and free-space. The incorporation of MH into RNA and its subsequent effects on cell metabolism via abnormal protein and enzyme synthesis is given as an explanation of the mode of action of MH. [ABSTRACT FROM AUTHOR]

Ion-stimulated stomatal opening in isolated epidermis of Commelina communis is shown to be influenced by temperature in the manner expected for a process dependent on metabolism. The effects of three metabolic inhibitors on this stomatal opening in light and darkness and two concentrations of CO[SUB2] are reported. 3-(3,4-dichlorophenyl),1,1-dimethylurea (DCMU) caused partial stomatal closure in light but this was reversed in CO[SUB2]-free conditions, suggesting that open chain photophosphorylation is not essential for stomatal opening in light. Salicylaldoxime suppressed the light-stimulated component of stomatal opening and the effect was not reversed in CO[SUB2]-free conditions. This suggests that photosystem 1 or cyclic photophosphorylation supplied the energy for ion uptake in guard cells in light. Supporting evidence comes from the finding that 2,4-dinitrophenol (DNP) also suppressed the light-stimulated component of opening. In darkness, ion-stimulated opening occurs, but to smaller apertures than in the light. This opening is insensitive to DNP treatment, suggesting that ATP from oxidative phosphorylation is not required. A possible interpretation of the results is that in darkness the energy for active transport into the guard cells is obtained from a direct linkage to the mitochondrial electron transport chain; the same could be true in light, with an additional linkage to electron transport in photosystem 1. Lack of information on the movement of specific ions means that some doubt must remain about which ions are actively transported. A comparison of the behaviour of stomata on detached and attached epidermis suggests that care is required if data from this study are to be applied to the stomatal mechanism in intact plants. [ABSTRACT FROM AUTHOR]

Active chloride uptake by cells of Chara corallina decreases as the pH of the bathing solution is increased, using a range of buffers. Superimposed on this effect, large stimulations of Cl[SUP-] uptake can be obtained by the addition of imidazole and tris buffers or ammonium sulphate. 'Stimulated' or 'normal' Cl[SUP-] influxes respond similarly to the presence of metabolic inhibitors. It is suggested that these effects are not due to changes in photosynthesis or respiration, but reflect the dependence of Cl[SUP-] transport on the pH gradient across the plasmalemma. Possible ways in which Cl[SUP-] transport might be linked to H[SUP+] or OH[SUP-] fluxes are discussed. It is proposed that the pH gradient across the plasmalemma is controlled by charge-separating reactions which produce an active H[SUP+] efflux, and that Cl[SUP-] uptake is linked to OH[SUP-] efflux by ion-exchange reactions. The metabolic implications of this scheme are discussed in detail, with reference to previous work on Characean and other plant cells. [ABSTRACT FROM AUTHOR]

Glucose and fructose fed to radish slices were taken up at different relative rates with marked accumulation of carbohydrates; a possible working mechanism is presented to explain the differential rates of uptake. Addition of iodoacetate to the sugar media decreased both the uptake of sugars and the accumulation of carbohydrates. Although there was synthesis of proteins in the presence of iodoacetate, the synthesis both in iodoacetate and in iodoacetate plus sugar was less than in the absence of iodoacetate. Sugars and iodoacetate either alone or in combination increased the rates of CO[SUB2] output; a possible explanation of the different rates observed is given. Moreover, iodoacetate increased the permeability of the cell membranes as is evident from the increased leakage of nitrogen compounds from the tissues into the media. [ABSTRACT FROM AUTHOR]

The radula-muscle in Buccinum is a group of muscle bundles, which are connected with the tooth apparatus. In the present investigation the cellular respiration and the behavior of the radula-muscle, when stimulated with certain physiologically active compounds, have been studied. In addition a brief study was made of the microscopic structure. In vitro experiments the radula-muscle shows a remarkably high oxygen consumption. Thus in the living animal the radula muscle needs a large oxygen supply. The hemoglobin of the radula muscle can presumably act for a short time as an oxygen store.

1. A proteoglycan containing about 80% chondroitin sulfate and dermatan sulfate in a ratio of 75:25 was isolated and purified from bovine arterial tissue. This proteoglycan behaved as a single compound by several criteria of homogeneity. On incubation in vitro of arterial tissue segments with [35S]sulfate under appropriate conditions the 35S-radioactivity was incorporated into the proteoglycan. 2. Degradation of the polysaccharide component of the labelled proteoglycan by testes hyaluronidase produces dermatan [35S]sulfate and a series of saccharide fragments ranging from disaccharides to decasaccharides. The tetrasaccharide fraction was found to contain iduronic acid (IduUA) as well as glucuronie acid (GlcUA), indicating a copolymeric structure of chondroitin-and dermatan-sulfate units. The IduUA/GlcUA-ratio of oligosaccharides increased with increasing chain length. The sulfate content of oligosaccharides containing either chondroitinor dermatan-sulfate units as the predominant component did not differ significantly, but the specific radioactivity of the sulfate ester groups of the dermatan-sulfate units was about three times higher than those of the chondroitin-sulfate units, thus providing evidence for a metabolic heterogeneity of these two polysaccharides. 3. The molecular weight of the proteoglycan is approximately 2 e chains which are attached to the protein by seryl and 0-threonyl glycosidic linkages. [ABSTRACT FROM AUTHOR]

1. The metabolism of pyrovate by isolated bovine-adrenal-cortex mitochondria has been studied. The rate of pyruvate oxidation depends on the availability of oxaloacetate. Oxaloacetate is formed from malate but malate cannot function in a catalytic manner in the Krebs cycle, because some is oxidised to pyruvate via malic enzyme activity with resulting diminution of the oxaloacetate pool. 2. An additional source of oxaloacetate is provided by low levels of pyruvate carboxylase. In the presence of ATP and bicarbonate, the principal initial product of pyruvate metabolism is citrate. Reducing equivalents for 11β-hydroxylation of deoxycorticosterone may be provided by oxidation of citrate. 3. When oxaloacetate is supplied by malate oxidation, the rate of citrate formation in the presence of fiuorocitrate is controlled by the rate of electron flux through either the respiratory chain or the hydroxylation chain, and is increased by addition of ADP on the one hand, or deoxycorticosterone on the other. This appears to be due to reoxidation of the pyridine nucleotides resulting in increased availability of oxaloacetate for citrate formation. Equilibration of NAD+/ NADH and NADP+/NADPH is achieved by transhydrogenase activity but this activity is not energy-linked under the conditions of these experiments. 4. In the absence of fluorocitrate, the stimulation of citrate formation brought about by initiation of llβ-hydroxylation results in increased Krebs cycle activity. In the transition from state 4 to state 3 respiration, there is an additional activation of citrate oxidation, which is interpreted to be due to activation of NAD-linked isocitrate dehydrogenase on addition of ADP. 5. Addition of both deoxycorticosterone and ADP together to the mitochondria results in inhibition of state 3 electron flux through thc respiratory chain, with concomitant inhibition of ATP formation. The rate of 1lβ-hydroxylation is not affected. Inhibition of ATP formation can be achieved by a variety of steroids and correlates with inhibition of NADH oxidase. [ABSTRACT FROM AUTHOR]

1. Studies with intact mitohondria and with soluble pyruvate dehydrogenase indicate that pyruvate and α-ketobutyrate are oxidized by the same enzyme (pyruvate dehydrogenase), while α-ketovalerate is oxidized by a different enzyme. 2. Pyruvate and α-ketobutyrate have about the same affinity for the enzyme, but pyruvate is oxidized at a much higher rate. 3. Acetyl-CoA and propionyl-CoA both behave as competitive inhibitors to CoA. The Kl for both is slightly higher than the Km for CoA. Accordingly the enzyme is only moderately inhibited by a high acetyl-CoA/CoA ratio. 4. NADH behaves mainly as a competitive inhibitor to NAD. The Kl is significantly lower than the Km for NAD. Accordingly the enzyme is strongly inhibited by a high NADH/NAD ratio. 5. The significance of these properties of the enzyme for the regulation of the activity of pyruvate dehydrogenasa in vivo is discussed. [ABSTRACT FROM AUTHOR]

The formation of polar, saturated C19steroids with a 3-keto-5α-configuration after incubation of 17β-hydroxyandrost-4-en-3-one (testosterone) with 105,000 × g microsomes of adult male rat liver was investigated. The metabolites were isolated by thin-layer chromatography and were identified as 2β-,6β-(tentatively), 7α-, and 16α-hydroxy-5α-dJhydrotestosterone by means of gas chromatography-mass spectrometry. The same compounds were also isolated after incubation with 2β-,6β-,7α-, and 16α-hydroxytestosterone, respectively. Incubation with 5α-dihydrotestosterone, however, resulted in the formation of 2βi-,7α-, and 16α-hydroxy-5α-dihydrotestosterone whereas no 6β-hydroxy-5α-dihydrotestosterone could be found. [ABSTRACT FROM AUTHOR]

Focuses on the increased incidence of drug-induced alopecia. Utilization of several agents like thallium sulphate for the treatment of several conditions; Effects of antimitotic agents on the growth of hair; Damage done by cancer chemotherapy to the growth and metabolism of hair cells.

The article discusses steroid metabolism by skin in man. The use of adrenocortical steroids and their synthetic analogues has revolutionized the treatment of certain skin conditions. The growth and development steroid hormones include the oestrogens, androgens and ecdysones. The hormones of the adrenal cortex principally cortisol and aldosterone in man, may be regarded as the regulators of cell metabolism and the transport of water and ions. It may be that up to the present aldosterone has been too expensive to justify an investigation of its possible effects on hydration of the skin.

The article provides information on the report submitted by the American Institute of Biological Sciences Inc. (AIBS) to the U.S. National Aeronautics and Space Administration (NASA) regarding the biological experimentation in a manned, orbiting laboratory from 1965 to 1967. The report tackles about the biological responses to weightlessness particularly at some four levels. These levels include the gross responses to weightlessness, the long-term results of gross gravity responses, the effect on cellular metabolism and the gross biological effects due to responses at the cellular level.

Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses the biochemistry in relation to the aetiology of acne vulgaris. Topics discussed include the metabolism of a cell, the supply of pilo-sebaceous glands, the acne equinus and acne susis, and an analysis of the urine for androgens. Estimation of basal metabolism and full blood counts might be useful laboratory procedures.

Edema is the manifestation of a disturbance of interchange between the intercapillary and interstitial fluids. Interstitial plasma forms the basis of the fluids which pass through the arterial capillaries, undergoes changes due to local cellular metabolism, and for the greater part is reabsorbed by the venous capillaries. On the other hand, substances of a coarser molecular structure and insoluble foreign bodies cannot penetrate into the blood without purification. For this reason they travel by way of the lymphatics which finally empty into the venous system not without having passed through at least one lymphatic ganglion, a sort of clearing house where such substances are partly transformed and partly retained indefinitely. Thus, interstitial plasma has a single route of entry, the arterial, and a double route of outlet, venous and lymphatic. For this reason edema corresponds to two fundamental causes: disturbance of the venous circulation, venous edema, and disturbance of the lymphatic circulation, lymphedema. Venous edema is distal, depressible, and easily reducible by recumbency. It often causes dermatitis, pigmentation and ulcers. It occurs as a result of deep valvular insufficiency, essential or postphlebitic, or as a result of venous obliteration. Rarely from the presence of a congenital or acquired arteriovenous fistula. The treatment of valvular insufficiency by deep ligation usually increases the edema. Lymphedema differs from venous edema by being less common, harder, scarcely depressible, less reducible by recumbency, and by its total or rhizomelic localization. It may be divided into congenital, essential, and secondary. In essential lymphedema the treatments indicated are lymphangioplastic surgery and delimiting cutaneous plastic surgery. Venous edema and lymphedema favor stretpococcic infections. These provoke fibrous hyperplasia of the skin, the subcutaneous cellular tissue and the aponeurosis, and at length the edema is converted into an irreversible process, totally irreducible by recumbency, which we call fibroedema, a form partly corresponding to the so-called elephantiasis. Finally, among edemas of the legs of surgical interest, may be mentioned erythrocyanoid lipedema, an orthostatic edema with adiposity of the legs forming a supramalleolar ischemia with coldness, cyanosis, and ultimately ulcers, which can be relieved by lumbar sympathectomy. [ABSTRACT FROM AUTHOR]

An attempt has been made to elucidate the mechanism of auxin action in relation to auxin regulation of nucleic acid metabolism with particular reference to nuclear DNA and RNA. Low concentrations of IAA have been found to promote the incorporation of P32 and uracil-2-C14 into RNA, and P32 and thymine-2-C14 into DNA of coconut milk nuclei. NAA-1-C14 has been shown to bind some nuclear material and the binding bas been associated with a release of nuclear RNA. The release is particularly remarkable at relatively high concentrations of auxin. Similar observations have also been made with pea internodes. The implications of the findings have been discussed in the light of recent concepts concerning the nucleic acid regulation of cell metabolism. [ABSTRACT FROM AUTHOR]

The pectin methylesterase of Avena coleoptiles is shown to be located in the free space. When coleoptiles are placed in dilute salt solutions some of the enzyme diffuses from the tissue. Estimations made from diffusion data and from fractionation in non-aqueous medium indicate that more than 90 % of the pectin methylesterase is adsorbed in vivo. It is suggested that the cell wall may contain a group of enzymes functional in cell wall metabolism. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift Für Die Gesamte Experimentelle Medizin Einschließlich Experimentelle Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article discusses the results of a research study conducted to determine the DNA metabolism of the submandibular gland in mice to better understand its proliferative activity and sensitivity to radiation damage. The study finds that an injection of tritiated thymidine stimulates mitotic division in mice.

This article discusses the results of a research study conducted to determine the response of the human gingival fibroblast-like cell (HGF) to diphenylhydantoin sodium (DPH) following exposure to X-ray radiation. The researchers seek to understand the mechanism through which DPH effects the metabolism of connective-tissue cells and increases their proliferative abilities.

Human thyroid primary, secondary and tertiary monolayer cultures with a low concentration of organ and non-organ specific antigens on the surface of their cells were incubated with different doses of phytohaemagglutinin P (PHA). PHA concentrations of 100-500 μg/ml of culture fluid were found to stimulate the appearance of organ-specific and some not specified non-organ-specific antigens that were not demonstrable in unstimulated cultures. The effect was demonstrated with the mixed haemadsorption radial diffusion disc test (MHT) with the mixed haemadsorption isotope test, and with indirect immunofluorescence tests on monolayer cultures grown on cover slips and on suspensions of cells dispersed from monolayer cultures. Whether the stimulatory-effect is due to a stimulation of some restricted cell functions or merely to a general stimulation of the cell metabolism that is known to occur, remains to be investigated. [ABSTRACT FROM AUTHOR]

Editorial. Reviews studies of the effects of calcium on cellular metabolism that may lead to clearer explanations of the phenomena of hypercalcemia. General functions of calcium in cellular activity; Finding that calcium is the coupling factor between excitation and contraction in all forms of muscle.

This article focuses on a workshop on cell controls in psoriasis. There seems to be throughout the U.S. an increasing awareness of psoriasis and the feeling that there is a need to do more about it. This workshop is a significant and valuable part of an intensifying effort to learn more add to do more about this serious and important disease. The workshop will concentrate more closely on the fundamental aspects of cell biology and metabolism, hopefully eliciting information which will be the groundwork for future research leading to the control of this serious disease. Precise data on the current prevalence, disability and economic impact of psoriasis are not available.