Aestivation and Ionic Regulation in Two Species of Pomacea (Gastropoda, Prosobranchia)

1968 ◽  
Vol 48 (3) ◽  
pp. 569-585
Author(s):  
COLIN LITTLE
Keyword(s):  
Uric Acid ◽  
Ionic Composition ◽  
Posterior Chamber ◽  
Freshwater Gastropods ◽  
Normal Value ◽  
Weight Losses ◽  
Relative Composition ◽  
Loss Of Weight ◽  
Wet Weight ◽  
High Concentrations

1. The ionic composition of the haemolymph, and the concentrations of uric acid and protein, have been determined for the amphibious prosobranchs Pomacea lineata and P. depressa. Ionic composition of the haemolymph is similar to that of freshwater gastropods. 2. The urine is decidedly hypo-osmotic to the haemolymph, reabsorption of ions occurring in the anterior chamber of the kidney. The rate of production of urine is approximately 1 µl./g./min. at 25° C. 3. The onset of aestivation appears to be related to a loss of 20% of the normal wet weight of the tissues. The loss of weight during aestivation averages 0.009% of the initial wet weight/hr., and aestivation may continue for over 400 days. 4. During aestivation the osmotic pressure of the haemolymph may rise to twice its normal value; but this is 30 mM/l. NaCl less than that predicted from weight losses. The relative composition of the haemolymph alters little, except that the percentages of sodium and chloride increase. 5. Uric acid accumulates round the blood vessels during aestivation, especially in the lung. Relatively little accumulates in the two chambers of the kidney, and only that in the posterior chamber is excreted later. Since the volume of fluid in the posterior chamber falls to about 10% of its normal value, while the total loss of weight of the snail is about 50%, the fluid in the posterior chamber acts as a water reserve. 6. Recovery from aestivation occurs in about 24 hr., when the snails are placed in water. The posterior chamber of the kidney excretes high concentrations of uric acid during this time. 7. The characteristics of aestivation are discussed, and compared with those shown by the Pulmonata.

Natural Products and Extracts as Xantine Oxidase Inhibitors – A Hope for Gout Disease?

2020 ◽  
Vol 26 ◽  
Author(s):  
Ilkay Erdogan Orhan ◽  
Fatma Sezer Senol Deniz
Keyword(s):  
Natural Products ◽  
Uric Acid ◽  
Waste Product ◽  
Acid Synthesis ◽  
Intermediate Compound ◽  
Living System ◽  
Ginsenoside Rd ◽  
Drug Classes ◽  
Urate Crystal ◽  
High Concentrations

: Xanthine oxidase (EC 1.17.3.2) (XO) is one of the main enzymatic sources that create reactive oxygen species (ROS) in the living system. It is a dehydrogenase enzyme that performs electron transfer to nicotinamide adenine dinucleotide (NAD+ ), while oxidizing hypoxanthin, which is an intermediate compound in purine catabolism, first to xanthine and then to uric acid. XO turns into an oxidant enzyme that oxidizes thiol groups under certain stress conditions in the tissue. The last metabolic step, in which hypoxanthin turns into uric acid, is catalyzed by XO. Uric acid, considered a waste product, can cause kidney stones and gouty-type arthritis as it is crystallized, when present in high concentrations. Thus, XO inhibitors are one of the drug classes used against gout, a purine metabolism disease that causes urate crystal storage in the joint and its surroundings caused by hyperuricemia. Urate-lowering therapy include XO inhibitors that reduce uric acid production as well as uricosuric drugs that increase urea excretion. Current drugs that obstruct uric acid synthesis through XO inhibition are allopurinol, febuxostat, and uricase. However, since the side effects, safety and tolerability problems of some current gout medications still exist; intensive research is ongoing to look for new, effective, and safer XO inhibitors of natural or synthetic origins for the treatment of the disease. In the present review, we aimed to assess in detail XO inhibitory capacities of pure natural compounds along with the extracts from plants and other natural sources via screening Pubmed, Web of Science (WoS), Scopus, and Google Academic. The data pointed out to the fact that natural products, particularly phenolics such as flavonoids (quercetin, apigenin, and scutellarein), tannins (agrimoniin and ellagitannin), chalcones (melanoxethin), triterpenes (ginsenoside Rd and ursolic acid), stilbenes (resveratrol and piceatannol), alkaloids (berberin and palmatin) have a great potential for new XO inhibitors capable of use against gout disease. In addition, not only plants but other biological sources such as microfungi, macrofungi, lichens, insects (silk worms, ants, etc) seem to be the promising sources of novel XO inhibitors.

Abrogation of thrombin-induced increase in pulmonary microvascular permeability in PAR-1 knockout mice

2000 ◽  
Vol 4 (2) ◽  
pp. 137-145 ◽  
Author(s):  
STEPHEN M. VOGEL ◽  
XIAOPEI GAO ◽  
DOLLY MEHTA ◽  
RICHARD D. YE ◽  
THERESA A. JOHN ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Microvascular Permeability ◽  
Agonist Peptide ◽  
Vasoconstrictor Response ◽  
Permeability Surface ◽  
Wet Weight ◽  
Microvessel Permeability ◽  
Pulmonary Microvessels ◽  
High Concentrations ◽  
Area Product

We investigated the function of proteinase-activated receptor-1 (PAR-1) in the regulation of pulmonary microvascular permeability in response to thrombin challenge using PAR-1 knockout mice (−/−). Lungs were isolated and perfused with albumin (5 g/100 ml)-Krebs solution at constant flow (2 ml/min). Lung wet weight and pulmonary artery pressure (Ppa) were continuously monitored. We determined the capillary filtration coefficient ( Kfc) and125I-labeled albumin (BSA) permeability-surface area product (PS) to assess changes in pulmonary microvessel permeability to liquid and albumin, respectively. Normal and PAR-1-null lung preparations received in the perfusate: 1) thrombin or 2) selective PAR-1 agonist peptide (TFLLRNPNDK-NH2). In control PAR-1 (+/+) mouse lungs,125I-albumin PS and Kfcwere significantly increased over baseline (by ∼7- and 1.5-fold, respectively) within 20 min of α-thrombin (100 nM) challenge. PAR-1 agonist peptide (5 μM) gave similar results, whereas control peptide (5 μM; FTLLRNPNDK-NH2) was ineffective. At relatively high concentrations, thrombin (500 nM) or PAR-1 agonist peptide (10 μM) also induced increases in Ppaand lung wet weight. All effects of thrombin (100 or 500 nM) or PAR-1 agonist peptide (5 or 10 μM) were prevented in PAR-1-null lung preparations. Baseline measures of microvessel permeability and Ppain the PAR-1-null preparations were indistinguishable from those in normal lungs. Moreover, PAR-1-null preparations gave normal vasoconstrictor response to thromboxane analog, U-46619 (100 nM). The results indicate that the PAR-1 receptor is critical in mediating the permeability-increasing and vasoconstrictor effects of thrombin in pulmonary microvessels.

scholarly journals Nitrogenous Excretion by Embryos of the Viviparous Snake Thamnophis S. Sirtalis (L.)

1956 ◽  
Vol 33 (2) ◽  
pp. 384-393 ◽  
Author(s):  
HUGH CLARK ◽  
BETTY FLORIO SISKEN
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Dry Weight ◽  
Garter Snake ◽  
Principal Source ◽  
Wet Weight

1. The garter snake embryo excretes an estimated 2.52 mg. nitrogen, of which 1.4 mg. is recoverable from the embryonic confines. The recovered excreta consist of 16.3% uric acid, 23.4% ammonia and 60.3% urea. 2. The placenta is believed, therefore, to transmit to the mother 1.11 mg. nitrogen per embryo, and it is estimated that it transmits to the embryo approximately 45 mg. of protein as amino-acids. 3. Evidence is presented which suggests that protein may be a principal source of energy, particularly early in development. 4. Growth in terms of wet weight, dry weight, and protein is described.

scholarly journals Influence of testosterone on purine metabolism and gout

2021 ◽  
Vol 22 (3) ◽  
pp. 11-17
Author(s):  
T. S. Panevin
Keyword(s):  
Uric Acid ◽  
Sex Hormones ◽  
Metabolic Disorders ◽  
Purine Metabolism ◽  
The Body ◽  
Uric Acid Concentration ◽  
Androgen Deficiency ◽  
Inflammatory Processes ◽  
High Concentrations ◽  
Pro Inflammatory Cytokines

Many different factors are involved in the regulation of purine metabolism. An important role is played by the level of sex hormones: high concentrations of androgens lead to a higher, and estrogen – to a lower level of uric acid. However, according to the results of numerous studies, it has been shown that the effect of sex hormones is not limited only to the uric acid concentration. Sex hormones affect inflammatory processes in the body by modulating the production of pro-inflammatory cytokines and regulating the corresponding signaling pathways. Androgen deficiency can lead to obesity and metabolic disorders, which can contribute to the development and course of gout. This review examines the effect of testosterone, as well as the effect of changes in its concentration on the dynamics of purine metabolism and gout.

Changes in blood plasma during progressive dehydration

1965 ◽  
Vol 20 (6) ◽  
pp. 1136-1140 ◽  
Author(s):  
Leo C. Senay ◽  
Margaret L. Christensen
Keyword(s):  
Plasma Volume ◽  
Heat Exposure ◽  
Plasma Potassium ◽  
Plasma Sodium ◽  
Plasma Albumin ◽  
Average Decrease ◽  
Weight Losses ◽  
Potassium Plasma ◽  
High Concentrations ◽  
Male Subjects

Progressive dehydration of resting male subjects was accomplished by exposure to 43.3 C dry bulb, 29 C wet bulb for 12 hr. For control experiments, evaporative weight loss was replaced with 0.1% saline. For dehydrating subjects, the following relationships with evaporative weight losses were obtained: %Delta osmotic pressure = 1.14 (% evap wt loss) — 0.43; %Delta [Na+] = 1.37 (% evap wt loss) — 0.45; %Delta [K+] — 2.19 (% evap wt loss) — 1.29; %Delta hematocrit = 1.4 (%Delta evap wt loss) — 2.65. Comparison of dehydration with rehydration results indicated augmentation of plasma volume with fluids containing high concentrations of potassium. An average decrease in plasma volume of 13.6% (T-1824) from 2.5 to 11 hr after initial heat exposure in dehydrating subjects was accompanied by a 15.7% increase in total protein. Albumin increased 11.6% while globulin increase averaged 22.5%. Plasma protein fractions are not static during dehydration, probably due to augmentation of each protein fraction, particularly globulin. Measurement of plasma volume by T-1824 more likely indicates changes in protein concentration rather than plasma volume changes. A relationship between hematocrit changes and plasma albumin concentrations is suggested. plasma sodium; plasma potassium; plasma osmolarity; hematocrits; plasma albumin; plasma globulins Submitted on February 23, 1965

scholarly journals Xanthine Oxidase of the Clothes Moth, Tineola Bisselliella, and Some Other Insects

1955 ◽  
Vol 8 (3) ◽  
pp. 369 ◽  
Author(s):  
H Irzykiewicz
Keyword(s):  
Methylene Blue ◽  
Uric Acid ◽  
Toxic Effect ◽  
Xanthine Oxidase ◽  
Oxidase Activity ◽  
Acid Production ◽  
Fat Body ◽  
Optimum Concentration ◽  
Optimum Ph ◽  
Wet Weight

Xanthine oxidase activity in Tineola larvae averages 200� /!moles of uric acid per g whole larva (wet weight) per hr and in Tenebrio, Lucilia, Anthrenocerus, Ephestia, and Anthrenus larvae activity ranges between 13�4 and 1�3. The optimum pH for Tineola xanthine oxidase lies between pH 7�7 and 8� 0, and the optimum concentration of xanthine is at or below 1�3 X 10-3M. Methylene blue in concentrations up to 5�3 X 1O-3M has no toxic effect on this enzyme, and the lower concentrations of methylene blue have a limiting effect. Cyanide and 6-pteridyl aldehyde inhibit Tineola xanthine oxidase. The insect xanthine oxidases are demonstrated to be dehydrogenases. DPN, and pyruvate and DPN together, stimulate uric acid production by Tineola xanthine oxidase in the absence of methylene blue. In Tenebrio larvae there is a higher concentration of xanthine oxidase in the midgut and fat-body than in the remaining tissues.

Urinary excretion of prostacyclin in a rat model of uteroplacental vasculature occlusion: implications for fetal growth retardation

1996 ◽  
Vol 8 (5) ◽  
pp. 895 ◽  
Author(s):  
M Hophy ◽  
S Harel ◽  
E Yavin
Keyword(s):  
Blood Flow ◽  
Urinary Concentration ◽  
Fetal Blood ◽  
Experimental Conditions ◽  
Pregnant Rat ◽  
Flow Interruption ◽  
Lower Ability ◽  
Wet Weight ◽  
High Concentrations

An experimental model was devised in the pregnant rat to study by a combined high pressure liquid chromatography and radioimmunoassay technique the accumulation of prostanoids (PNs) in the urine after transient-complete or permanent-partial interruption of the maternal-fetal blood flow. After 8 min of complete restriction of the blood flow in the pregnant rat at 18 days of gestation, the urinary concentration of 6-keto-prostaglandin F1 alpha (6k-PGF1 alpha, the stable prostacyclin metabolite) increased from 4.97 +/- 1.27 ng mg-1 creatinine to 8.09 +/- 2.47 ng mg-1 creatinine and 13.02 +/- 4.5 ng mg-1 creatinine after the second and third post-operative day respectively. The urinary concentration of the 2,3-dinor derivative of prostacyclin reached 12.35 +/- 5.44 ng mg-1 creatinine after the second post-operative day and was reduced to 4.71 +/- 1.94 ng mg-1 creatinine after the third post-operative day. The concentration of thromboxane B2 (TxB2, the stable thromboxane A2 metabolite) increased approximately 7-fold and 13-fold over that of the control after the second and third post-operative day respectively. The urinary concentration of the 2,3-dinor derivative of TxB2 (d-TxB2) increased from about 1.42 +/- 0.3 ng mg-1 creatinine to 4.49 +/- 0.9 ng mg-1 creatinine and 7.76 +/- 2.63 ng mg-1 creatinine under the same experimental conditions. Increases in the urinary concentrations of 6k-PGF1 alpha and d-TxB2 to 94 +/- 27.76 ng mg-1 creatinine and 12.05 +/- 2.26 ng mg-1 creatinine, respectively, were observed on the second post-operative day, after the restriction time was increased to 30 min. Permanent-partial occlusion of the maternal fetal circulation resulted in excretion of PNs in the urine to similar levels produced after transient-complete restriction. High concentrations of prostacyclin (range, 0.8 ng min-1 mg-1 wet weight) were produced in vitro by uterine preparations from restricted animals after the second post-operative day. Placenta preparations from restricted animals generally exhibited a lower ability to synthesize PNS (up to 0.006 ng min-1 mg-1 wet weight) compared with uterine tissue but produced more thromboxane than their sham counterparts. The data suggest that the uterus constitutes the main source for urinary PN excretion following short episodes of maternal-fetal blood flow interruption.

scholarly journals PITUITARY AND PLASMA GONADOTROPHIN LEVELS AND SPERMATOGENESIS IN THE GOLDFISH CARASSIUS AURATUS AFTER METHALLIBURE TREATMENT

1973 ◽  
Vol 59 (3) ◽  
pp. 415-420 ◽  
Author(s):  
B. BRETON ◽  
B. JALABERT ◽  
R. BILLARD
Keyword(s):  
Carassius Auratus ◽  
Mature Male ◽  
Type B ◽  
Pretreatment Level ◽  
Goldfish Carassius Auratus ◽  
Wet Weight ◽  
High Concentrations

SUMMARY The level of gonadotrophin measured by radioimmunoassay in fully mature male goldfish was about 15 ng carp gonadotrophic hormone (c-HG)/ml plasma and 30 μg c-HG/g pituitary (wet weight). After treatment for 35 days with methallibure (added to the water at the rate of 2 p.p.m./day), the level of gonadotrophin in the blood was very low and remained at the pretreatment level in the pituitary. This suggested that releasing factor might control either synthesis or discharge of gonadotrophin from the pituitary. These results have also shown that type B spermatogonia and meiosis were gonadotrophin dependent but that the development of spermatocytes into spermatids did not require high concentrations of gonadotrophin. Spermiation was suppressed when the concentration of c-HG dropped below 10 ng/ml plasma.

Regional differences in catecholamine concentrations in bovine ovaries analysed by high-performance liquid chromatography

1991 ◽  
Vol 129 (2) ◽  
pp. 221-226 ◽  
Author(s):  
P. A. Denning-Kendall ◽  
M. L. Wild ◽  
Wathes D. C.
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Molar Ratio ◽  
Corpora Lutea ◽  
Wet Weight ◽  
High Concentrations ◽  
Highly Correlated ◽  
Very High

ABSTRACT Bovine corpora lutea and ovarian stroma were analysed by high-performance liquid chromatography for catecholamine content. High concentrations (up to 102 nmol/g wet weight) were found in both 'central' stroma, containing many blood vessels, and 'peripheral' stroma. Central stroma contained noradrenaline and some dopamine, whereas peripheral stroma contained a higher proportion of dopamine and also significant amounts of 3,4-dihydroxyphenylacetic acid (DOPAC). Occasional samples of stroma had very high amounts of dopamine, suggesting that it is stored in specific regions. Corpora lutea, although devoid of direct innervation, contained dopamine (up to 5·3 nmol/g) and noradrenaline (up to 1·2 nmol/g). The average dopamine: noradrenaline molar ratio was 1·19 : 1 and the concentrations of dopamine and noradrenaline were highly correlated (P < 0·002). The concentration of dopamine was significantly higher in the early luteal phase of the oestrous cycle than during the rest of the cycle or in pregnancy. The levels of noradrenaline and dopamine present in corpora lutea are sufficient to modulate the production of both oxytocin and progesterone by luteal cells in vitro. Journal of Endocrinology (1991) 129, 221–226

scholarly journals Spectroscopic and thermal study of bentonites from Milos Island, Greece

2013 ◽  
Vol 47 (4) ◽  
pp. 2020 ◽  
Author(s):  
A. Bourliva ◽  
K. Michailidis ◽  
C. Sikalidis ◽  
A. Filippidis
Keyword(s):  
Raw Materials ◽  
Absorption Spectrometry ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
Weight Losses ◽  
Stretching Vibration ◽  
Dioctahedral Smectite ◽  
High Concentrations ◽  
Composite Samples ◽  
Main Impurity

Bentonitic clays, currently in use in over hundred areas, are among the most important industrial raw materials. In most of the cases, bentonites predominantly consist of montmorillonite which is a 2:1 layer clay mineral formed by one alumina octahedral sheet placed between two silica tetrahedral sheets. Three bentonite composite samples (BN1, BN2, BN3) with some differences in mineralogical and chemical composition from Milos island (“Miloan”), Greece were investigated by X-ray diffraction (XRD), atomic absorption spectrometry (AAS), differential thermal analysis (DTA), thermogravimetric analysis (TG), Fourier transform infrared (FTIR) and surface area (BET) measurements techniques. Mineralogically, bentonite samples were characterized by high concentrations of smectite (>85%) and minor amounts of other clay minerals (illite and kaolinite). Nonclay minerals such as quartz, calcite and pyrite were also identified. The infrared spectrum of the bentonites also revealed the presence of dioctahedral smectite as the major component and quartz as the main impurity in all the samples. The stretching vibration at 3698cm-1 in the sample BN3 could be ascribed to kaolinite. DTA-TG curves of all samples were measured in the temperature range 75-1000oC. The total weight losses for the bentonite samples BN1, BN2 and BN3 were determined as 16.25, 12.32 and 13.35% respectively.

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