Rate of Excretion of Glutamyl Polypeptide and Its Polymers in Humans

Bovarnick, Max; Fieber, Stanley S.; Bovarnick, Marianna R.; Kazlowski, Joseph

doi:10.3181/00379727-83-20323

Cited by 8 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This difficulty was overcome by sandwiching the unknown between standards and by counting samples as soon as possible after their preparation. The assay of poly-Lglutamate (PLG) is adapted from the procedure given by Bovarnide et al (12): 0.5 ml of Ringer's solution containing a known or an unknown amount of PLG is added to 1 ml of a 0.06 M NaOH-citrate buffer (pH 5.98), 1 ml of 0.1 % (w/v) safranin solution, and 2.5 ml of 0.118 M NaCl solution in a centrifuge tube. The tubes are all 4.0 g of PPO (2,5-diphenyloxazole) (Packard); 200 mg of POPOP [l ,4-bis-2-(5-phenyloxazolyl)benzene] (Packard); 60 g of naphthalene (recrystallized from alcohol, Matheson, Coleman, and Bell); 100 ml methanol (Merck); 20 ml ethylene glycol (Merck); and enough p-dioxane (purified, Fisher catalogue No.…”

Section: Assay Methodsmentioning

confidence: 99%

The Extracellular Space of Voluntary Muscle Tissues

Ling

Kromash

1967

The Journal of General Physiology

View full text Add to dashboard Cite

The volume occupied by the extracellular space has been investigated in six types of voluntary muscles: sartorius (frog), semitendinosus (frog), tibialis anticus longus (frog), iliofibularis (frog), rectus abdominis (frog), and diaphragm (rat). With the aid of four types of probe material, three of which are conventionally employed (inulin, sorbitol, sucrose) and one of which is newly introduced (poly-L-glutamate), and a different experimental method, we have demonstrated that the "true" extracellular space of frog sartorius, semitendinosus, tibialis anticus longus, and iliofibularis muscle and of rat diaphragm muscle is equal to, or probably less than, 8-9 % (v/w) of the tissue. The frog rectus muscle shows a somewhat higher ceiling value of 14 %.Living tissue consists of cells and "extracellular space." A precise knowledge of the percentage of extracellular space is essential if one is to obtain meaningful values for the concentrations of solutes or water within the cell. In the case of solutes like Na+ ion and glucose, which are usually found at lower concentrations within the cell than in the extracellular fluid, an erroneous value for the extracellular space may lead to the conclusion that these solutes are altogether absent in the cell, while in truth they are present in sizable concentrations (or vice versa). Yet published values for the extracellular space vary widely. Thus, for frog sartorius muscle the proportion of extracellular space given in the literature varies from 13% of the tissue (1-4) to as high as 35% (5-9). With this degree of uncertainty, meaningful interpretation of quantitative data on "glucose transport" or "sodium transport" in muscle tissues, as examples, is virtually impossible. Such problems are of fundamental importance in understanding the behavior of the living cell.In this communication we present results of investigations of the extracellular space of several types of voluntary muscles of amphibian and mammalian origin. Using new techniques, we have found the extracellular spaces of these tissues to be surprisingly low and constant.

show abstract

Section: Assay Methodsmentioning

confidence: 99%

The Extracellular Space of Voluntary Muscle Tissues

Ling

Kromash

1967

The Journal of General Physiology

View full text Add to dashboard Cite

show abstract

“…Dark-grown resting organisms were obtained, as described previously (32), using pH 6.8 resting medium (3). Conditions for normal light-induced chloroplast development have also been given before (33).…”

mentioning

confidence: 99%

“…This pattern is different from that of normal chloroplast constituents and more closely resembles the behavior of enzymes which are not chloroplast localized and which are found in other cellular compartments (21,22,31). Since the loss of enzyme activity takes place in complete darkness, it is not part of the light-induced sequence of events involved in plastid development and may be attributed to protein turnover which occurs in these starving cells (3). The result with W3BUL is consistent with this interpretation and suggests that during incubation on resting medium, turnover sacrifices certain proteins which are not immediately indispensable for survival and, in wild type in the light, the amino acids released are probably used to form the constituents of the photosynthetic apparatus.…”

mentioning

confidence: 99%

Studies of Sulfate Utilization of Algae

Brunold

Schiff²

1976

Plant Physiol.

View full text Add to dashboard Cite

Crude extracts of wild-type Euglena grown in the light (WTL) or in the dark (WTD) and a mutant lacking detectable plastid DNA (W3BUL) contain adenosine 5'-phosphosulfate (APS) sulfottansferase. Isotope dilution experiments indicate that adenosine 3-phosphate 5'-phosphosulfate (PAPS) sulfotransferase is absent.Thiosulfonate reductase, requiring addition of NADH or NADPH but not ferredoxin, and O-acetyl-L-serine sulfhydrylse, the two other enzymes of the bound intermediate pathway of assimilatory sulfate reduction, are also present. Increasing levels of all three enzymes were found in WTL, WTD, and W3BUL during logarithmic growth but the various activities were similar at comparable stages of growth in all three types of cell.These results show that the three enzymes are not coded in the chloroplast DNA and are not restricted to Euglena cells having fully developed chloroplasts. Consistent with this, they do not increase during light-induced chloroplast development in resting cells and are found to be enriched in the mitochondrial fraction. Further resolution of this fraction on sucrose gradients shows that the APS sulfotransferase is associated with both the microbody (glyoxysomal) and mitochondrial fractions while the thiosulfonate reductase and O-acetyl-L-serine sulfhydrylase are associated only with the mitochondria. Thus the three known enzymes of the bound pathway of assimilatory sulfate reduction are present in Eugkna mitochondrina.Although the activity of the entire bound pathway (APS to cysteine) is low in extracts, addition of dithlothreitol which releases free sulfite from the product of the APS sulfotransferase reaction, causes an increase in reduction activity indicating that a sulfite reductase is also present. It remains to be shown which reducing system is the significant one in vivo in Eugkna.A pathway of assimilatory sulfate reduction containing carrier-bound intermediates has been described for Chlorella where it appears to be the major pathway of reduction in vivo (26). This reduction pathway begins with adenosine 5'-phosphosulfate, the sulfonyl group of which is transferred via APS sulfotransferase to a carrier to form Car-S-SO3-which is then reduced to Car-S-S-by a ferredoxin-dependent thiosulfonate reductase. The thiol group is then transferred via 0-acetyl-serine sulfhydrylase to OAS to form cysteine. A (35, 37) and yeast (20, 40) where the nucleotide sulfonyl donor is PAPS.4 Sulfite reductases which reduce free sulfite to free sulfide have also been found in many organisms (23) where they have been suggested as participants in a pathway of sulfate reduction involving free inorganic intermediates. In Chlorella, however, studies with mutants suggest that the bound pathway is the physiological route of sulfate reduction in vivo with sulfite reductase participating only when free sulfite is supplied exogenously. In E. coli the separation of the two pathways is less clear since thiosulfonate reductase and sulfite reductase activities may be contained in the same molecule (37), unlik...

show abstract

“…The potentialities of glutamyl peptide polymers as plasma volume expanders have been pointed out (1)(2)(3)(4). Data were presented to demonstrate that linear glutamyl polypeptides of average molecular weight of 12-1 5,-000 were rapidly excreted in humans and dogs.…”

mentioning

confidence: 98%