Adenylate compartmentation and storage in coelomic cells of the polychaete Nereis virens

1995 ◽  
Vol 198 (10) ◽  
pp. 2079-2085
Author(s):  
U Hoeger ◽  
J F Dunn ◽  
C Märker
Keyword(s):  
Cell Volume ◽  
Packed Cell Volume ◽  
Adenine Nucleotides ◽  
Nmr Studies ◽  
Nereis Virens ◽  
In Vivo Nmr ◽  
Coelomic Cells ◽  
Small Pool ◽  
High Concentrations

The concentrations of adenine nucleotides (AMP, ADP, ATP) were determined in coelomic cells (eleocytes) of the polychaete Nereis virens. In cells of immature and male animals, total ADP and AMP contents (each 10­15 µmol ml-1 packed cell volume) greatly exceeded that of ATP (0.8 µmol ml-1 packed cell volume). 31P-nuclear magnetic resonance (NMR) studies of living eleocytes showed that the high concentrations of both AMP and ADP are free in solution. Comparisons of in vivo NMR spectra with those obtained from metabolite extracts of eleocytes suggest that the adenylate pools are compartmentalized, with a large pool being in an environment with a pH<6.0 and a small pool being in a domain where pH>6.7. This indicates that eleocytes are capable of storing high concentrations of ADP and AMP without inhibiting energy metabolism by sequestering these compounds into an acidic compartment. The large acidic vacuole characteristic of eleocytes may function as this compartment.

In-vivo NMR studies of deuterium-labeled photosensitizers in mice tumor model

1993 ◽  
Author(s):  
Subbaraya Ramaprasad ◽  
Y. H. Liu ◽  
R. K. Pandey ◽  
Fuu-Yau Shiau ◽  
Kevin M. Smith
Keyword(s):  
Tumor Model ◽  
Nmr Studies ◽  
In Vivo Nmr

Mechanisms of Pi regulation of the skeletal muscle SR Ca2+ release channel

2000 ◽  
Vol 278 (3) ◽  
pp. C601-C611 ◽  
Author(s):  
Edward M. Balog ◽  
Bradley R. Fruen ◽  
Patricia K. Kane ◽  
Charles F. Louis
Keyword(s):  
Skeletal Muscle ◽  
Single Channel ◽  
Adenine Nucleotides ◽  
Muscle Fibers ◽  
Open Probability ◽  
Release Channel ◽  
High Concentrations ◽  
Channel Open Time ◽  
Stimulation Of

Inorganic phosphate (Pi) accumulates in the fibers of actively working muscle where it acts at various sites to modulate contraction. To characterize the role of Pi as a regulator of the sarcoplasmic reticulum (SR) calcium (Ca2+) release channel, we examined the action of Pi on purified SR Ca2+ release channels, isolated SR vesicles, and skinned skeletal muscle fibers. In single channel studies, addition of Pi to the cis chamber increased single channel open probability ( P o; 0.079 ± 0.020 in 0 Pi, 0.157 ± 0.034 in 20 mM Pi) by decreasing mean channel closed time; mean channel open times were unaffected. In contrast, the ATP analog, β,γ-methyleneadenosine 5′-triphosphate (AMP-PCP), enhanced P o by increasing single channel open time and decreasing channel closed time. Pi stimulation of [3H]ryanodine binding by SR vesicles was similar at all concentrations of AMP-PCP, suggesting Pi and adenine nucleotides act via independent sites. In skinned muscle fibers, 40 mM Pi enhanced Ca2+-induced Ca2+ release, suggesting an in situ stimulation of the release channel by high concentrations of Pi. Our results support the hypothesis that Pi may be an important endogenous modulator of the skeletal muscle SR Ca2+ release channel under fatiguing conditions in vivo, acting via a mechanism distinct from adenine nucleotides.

Altered brain glucose metabolism in transgenic-PFKL mice with elevated l-phosphofructokinase: in vivo NMR studies

1998 ◽  
Vol 810 (1-2) ◽  
pp. 138-145 ◽  
Author(s):  
Mira Peled-Kamar ◽  
Hadassa Degani ◽  
Peter Bendel ◽  
Ra'anan Margalit ◽  
Yoram Groner
Keyword(s):  
Glucose Metabolism ◽  
Nmr Studies ◽  
Brain Glucose ◽  
Brain Glucose Metabolism ◽  
In Vivo Nmr

scholarly journals In vivo NMR studies of the algaDunaliella salinaembedded in beads

FEBS Letters ◽  
1988 ◽  
Vol 233 (1) ◽  
pp. 124-128 ◽  
Author(s):  
M. Oren-Shamir ◽  
M. Avron ◽  
H. Degani
Keyword(s):  
Nmr Studies ◽  
In Vivo Nmr

scholarly journals Effect of Oxygen on Glucose Metabolism: Utilization of Lactate in Staphylococcus Aureus as Revealed by In Vivo NMR Studies

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58277 ◽  
Author(s):  
Maria Teresa Ferreira ◽  
Ana S. Manso ◽  
Paula Gaspar ◽  
Mariana G. Pinho ◽  
Ana Rute Neves
Keyword(s):  
Staphylococcus Aureus ◽  
Glucose Metabolism ◽  
Nmr Studies ◽  
In Vivo Nmr ◽  
Effect Of Oxygen

scholarly journals Antimalarial Activity of Nigella sativa L. Seed Extracts and Selection of Resistance in Plasmodium berghei ANKA in a Mouse Model

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Rahma Udu ◽  
Job Oyweri ◽  
Jeremiah Gathirwa
Keyword(s):  
Mouse Model ◽  
Ethyl Acetate ◽  
Cell Volume ◽  
Plasmodium Berghei ◽  
Packed Cell Volume ◽  
Antimalarial Activity ◽  
Nigella Sativa ◽  
Plasmodium Berghei Anka ◽  
Ethyl Acetate Extracts

Background. Chemotherapy plays a crucial role in malaria control. However, the main obstacle to treatment has been the rise of parasite resistance to most antimalarial drugs. Artemisinin-based combination therapies (ACTs) remain the most effective antimalarial medicines available today. However, malaria parasite tolerance to ACTs is now increasingly prevalent especially in Southeast Asia presenting the danger of the spread of ACTs resistance to other parts of the world. Consequently, this creates the need for alternative effective antimalarials. Therefore, this study sought out to determine antimalarial potential, safety, and resistance development of the extracts in a mouse model. Method. Methanolic and ethyl acetate extracts were obtained by solvent extraction. The extracts were assayed for acute toxicity in vivo. Additionally, the two extracts were evaluated for antimalarial activity in vivo against Plasmodium berghei ANKA strain by the 4-day suppressive test at 500, 250, and 125 mg/kg/day. Packed cell volume was evaluated to determine anemia manifestation. Finally, continuous drug pressure experiment at 500 mg/kg and DNA amplification via PCR were conducted. The amplicons underwent through Sanger sequencing. Results. There was no toxicity realized in the animals at 2000 mg/kg. Importantly, high parasitemia suppression of 75.52% and 75.30% using a dose of 500 mg/kg of methanolic and ethyl acetate extracts, respectively, was noted. The extracts were able to reverse packed cell volume reduction. Nigella sativa-resistant phenotype was selected as delayed parasite clearance. However, there was no change in the nucleotide sequences of PbMDR1 and PbCRT genes. Conclusion. The results provide room for future exploitation of the plant as an antimalarial.

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