IN VIVO METABOLISM OF ETHANOL AT HIGH AND LOW CONCENTRATIONS

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

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99mTc-Sn-Pyrophosphate Complexes, an Investigation of its Possible Structures

Nuklearmedizin ◽

10.1055/s-0038-1624863 ◽

1974 ◽

Vol 13 (03) ◽

pp. 252-257 ◽

Cited By ~ 1

Author(s):

K. Rörvik - Schümichen ◽

G. Hoffmann ◽

C. Schümichen

Keyword(s):

In Vivo Distribution ◽

Low Concentrations ◽

Distribution Studies

SummaryAt least two different 99mTc-Sn-pyrophosphate complexes are formed, as it is shown by comparative in vivo distribution studies: A 2 : 2 Sn : pyrophosphate complex is predominant at higher concentrations. Only this complex shows bone seeking properties. A 2 : 1 Sn : pyrophosphate complex exists only at low concentrations. This complex shows no deposition in bone but in the kidneys. Which complex is predominant depends on the pyrophosphate concentration in the equilibrium. Both complexes are rapidly excreted by the kidneys.

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Rational Design, Synthesis and Biological Evaluation of Novel Derivatives Based on in vivo Metabolism of Natural Product β-elemene

Letters in Drug Design & Discovery ◽

10.2174/1570180814666171108093021 ◽

2018 ◽

Vol 15 (8) ◽

pp. 905-912 ◽

Cited By ~ 1

Author(s):

Renren Bai ◽

Xiaokang Jie ◽

Eric Salgado ◽

Jian Sun ◽

Yao Zhu ◽

...

Keyword(s):

Natural Product ◽

Rational Design ◽

Biological Evaluation ◽

In Vivo Metabolism ◽

Design Synthesis ◽

Synthesis And Biological Evaluation

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Fighting Bisphenol A-Induced Male Infertility: The Power of Antioxidants

Antioxidants ◽

10.3390/antiox10020289 ◽

2021 ◽

Vol 10 (2) ◽

pp. 289

Author(s):

Joana Santiago ◽

Joana V. Silva ◽

Manuel A. S. Santos ◽

Margarida Fardilha

Keyword(s):

Male Infertility ◽

Bisphenol A ◽

Sperm Concentration ◽

In Vivo Studies ◽

Sperm Dna Damage ◽

Testicular Cells ◽

Low Concentrations ◽

Sperm Dna ◽

Male Reproductive Health

Bisphenol A (BPA), a well-known endocrine disruptor present in epoxy resins and polycarbonate plastics, negatively disturbs the male reproductive system affecting male fertility. In vivo studies showed that BPA exposure has deleterious effects on spermatogenesis by disturbing the hypothalamic–pituitary–gonadal axis and inducing oxidative stress in testis. This compound seems to disrupt hormone signalling even at low concentrations, modifying the levels of inhibin B, oestradiol, and testosterone. The adverse effects on seminal parameters are mainly supported by studies based on urinary BPA concentration, showing a negative association between BPA levels and sperm concentration, motility, and sperm DNA damage. Recent studies explored potential approaches to treat or prevent BPA-induced testicular toxicity and male infertility. Since the effect of BPA on testicular cells and spermatozoa is associated with an increased production of reactive oxygen species, most of the pharmacological approaches are based on the use of natural or synthetic antioxidants. In this review, we briefly describe the effects of BPA on male reproductive health and discuss the use of antioxidants to prevent or revert the BPA-induced toxicity and infertility in men.

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Characterization of Distinctive In Vivo Metabolism between Enhancing and Non-Enhancing Gliomas Using Hyperpolarized Carbon-13 MRI

Metabolites ◽

10.3390/metabo11080504 ◽

2021 ◽

Vol 11 (8) ◽

pp. 504

Author(s):

Seunggwi Park ◽

Hashizume Rintaro ◽

Seul Kee Kim ◽

Ilwoo Park

Keyword(s):

Metabolic Imaging ◽

Metabolic Profiles ◽

Rodent Models ◽

In Vivo Metabolism ◽

Hyperpolarized 13C ◽

Noninvasive Assessment ◽

Diffuse Midline Glioma ◽

Mr Spectroscopic Imaging

The development of hyperpolarized carbon-13 (13C) metabolic MRI has enabled the sensitive and noninvasive assessment of real-time in vivo metabolism in tumors. Although several studies have explored the feasibility of using hyperpolarized 13C metabolic imaging for neuro-oncology applications, most of these studies utilized high-grade enhancing tumors, and little is known about hyperpolarized 13C metabolic features of a non-enhancing tumor. In this study, 13C MR spectroscopic imaging with hyperpolarized [1-13C]pyruvate was applied for the differential characterization of metabolic profiles between enhancing and non-enhancing gliomas using rodent models of glioblastoma and a diffuse midline glioma. Distinct metabolic profiles were found between the enhancing and non-enhancing tumors, as well as their contralateral normal-appearing brain tissues. The preliminary results from this study suggest that the characterization of metabolic patterns from hyperpolarized 13C imaging between non-enhancing and enhancing tumors may be beneficial not only for understanding distinct metabolic features between the two lesions, but also for providing a basis for understanding 13C metabolic processes in ongoing clinical trials with neuro-oncology patients using this technology.

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