STUDIES ON THE TISSUE-DISPOSITION AND FATE OF [14C]STREPTOZOTOCIN WITH SPECIAL REFERENCE TO THE PANCREATIC ISLETS

1978 ◽  
Vol 89 (2) ◽  
pp. 339-351 ◽  
Author(s):  
Eva Britt Johansson ◽  
Hans Tjälve
Keyword(s):  
Pancreatic Islets ◽  
High Capacity ◽  
Whole Body ◽  
Side Chain ◽  
High Accumulation ◽  
Methyl Group ◽  
Whole Body Autoradiography ◽  
Selective Labelling ◽  
Chinese Hamsters ◽  
Tissue Disposition

ABSTRACT The tissue-disposition and fate of [14C]streptozotocin, labelled in the methyl-group of the N-nitrosomethylurea side-chain, have been studied in mice. Whole-body autoradiography, quantified by densitometric measurements, showed that the pancreatic islets had a high capacity to accumulate radioactivity after the injection of [14C]streptozotocin. Microautoradiography of the pancreas showed that centrally located cells were labelled while peripherally located cells contained a low labelling, indicating a selective labelling of the β-cells. A high radioactivity was present in the liver and the cortex of the kidney at most survival intervals. About 17 % of the radioactivity was exhaled as 14CO2 during 6 h, which shows that the methyl group of the N-nitrosomethylurea side-chain is split off. Radioactivity was shown to be incorporated in the acid-insoluble precipitate of the pancreatic islets, the liver, the kidney, and the exocrine pancreas. This may, to a varying extent, be due both to alkylating reactions and to incorporation of radioactivity in the macromolecules of the tissues via normal metabolic pathways. About 44 % of the radioactivity was excreted as unchanged [14C]streptozotocin in the urine during 24 h, while about 1 % of the radioactivity was found in the faeces. Whole-body autoradiography of [14C]streptozotocin in two Chinese hamsters and one rat also showed a high accumulation of radioactivity in the pancreatic islets in these species.

ACCUMULATION OF NICOTINE IN PANCREATIC ISLETS AND CALCITONIN-PRODUCING CELLS IN MICE AND CHICKS DEMONSTRATED BY MICRO- AND WHOLE-BODY AUTORADIOGRAPHY

1973 ◽  
Vol 58 (1) ◽  
pp. 21-NP ◽  
Author(s):  
PREMYSL SLANINA ◽  
HANS TJÄLVE
Keyword(s):  
Pancreatic Islets ◽  
Biogenic Amines ◽  
Whole Body ◽  
High Accumulation ◽  
Metabolic Studies ◽  
Whole Body Autoradiography ◽  
Parafollicular Cells ◽  
Ultimobranchial Glands ◽  
Endocrine Organs

SUMMARY By autoradiographic methods, nicotine was shown to be specifically accumulated in the pancreatic islets in mice. The results also indicated a high accumulation of nicotine in the parafollicular cells of the thyroid in mice and an accumulation was also shown in the ultimobranchial glands in chicks. Like the parafollicular cells of the thyroid in mammals, the ultimobranchial glands of birds are known to produce calcitonin. Metabolic studies with nicotine in vitro and autoradiographic studies with the main nicotine-metabolite cotinine, indicated an accumulation of unchanged nicotine (not metabolites) in the cells. The results are discussed in view of the fact that biogenic amines have been shown to be operative in these endocrine organs. It is suggested that nicotine can share common transport and/or storage mechanisms with biogenic amines in the cells. An effect of nicotine on hormone storage and/or release may take place via an interference with aminergic mechanisms in the cells.

ACCUMULATION OF ALPRENOLOL IN SOME POLYPEPTIDE HORMONE PRODUCING CELLS AND IN MELANIN-CONTAINING TISSUES

1975 ◽  
Vol 79 (1) ◽  
pp. 202-208 ◽  
Author(s):  
Premysl Slanina ◽  
Hans Tjälve
Keyword(s):  
Characteristic Feature ◽  
Pituitary Gland ◽  
Distribution Pattern ◽  
Pancreatic Islets ◽  
Adrenergic Receptor ◽  
Endocrine Cells ◽  
Whole Body ◽  
Blocking Drug ◽  
High Accumulation ◽  
Receptor Blocking

ABSTRACT The distribution of the β-adrenergic-receptor blocking drug alprenolol labelled with 3H was studied in mice by whole body autoradiography. The most characteristic feature in the distribution pattern was the accumulation in endocrine cells within the pancreatic islets, the adrenal medulla, the pituitary gland and some cells of the thyroid, presumably representing the parafollicular cells. A high accumulation was also observed in melanin-containing tissues.

DISTRIBUTION OF 14C-THIOURACIL IN THE THYROID AND THE ULTIMOBRANCHIAL GLAND OF CHICKENS STUDIED BY WHOLE-BODY AUTORADIOGRAPHY

1972 ◽  
Vol 71 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Premysl Slanina
Keyword(s):  
Whole Body ◽  
High Accumulation ◽  
Whole Body Autoradiography ◽  
Ultimobranchial Gland

ABSTRACT Whole-body autoradiography of chicks 10, 20, 240 minutes and 1 and 4 days atfer iv injection of 14C-thiouracil showed a rapid and high accumulation of radioactivity in the thyroid. The concentration of radioactivity in the thyroid was higher than in any other tissue and persisted for as long as 4 days after the injection. In contrast, the level of radioactivity in the calcitonin producing ultimobranchial gland never exceeded that of the blood, suggesting that thiouracil does not directly affect the release of calcitonin.

scholarly journals Effect of side-chain length in lignin model compound on MnO2 oxidation: comparison of oxidations between C6-C2- and C6-C1-type compounds

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shirong Sun ◽  
Tomoya Yokoyama
Keyword(s):  
Isotope Effects ◽  
Aromatic Nucleus ◽  
Side Chain ◽  
Direct Oxidation ◽  
Initial Oxidation ◽  
Methyl Group ◽  
Lignin Model Compound ◽  
Oxidation Rates ◽  
Kinetic Isotope ◽  
Lignin Model

AbstractMonomeric C6-C2-type lignin model compounds with a p-hydroxyphenyl (H), guaiacyl (G), syringyl (S), or p-ethylphenyl (E) nucleus (1-phenylethanol derivatives) were individually oxidized by MnO2 at a pH of 1.5 and room temperature. The results were compared with those of the corresponding C6-C1-type benzyl alcohol derivatives obtained in our recent report to examine the effect of the presence of the β-methyl group on the oxidation. The presence decelerated the oxidation regardless of the type of aromatic nucleus, although it did not change the order of the oxidation rates: G > S >> H > E. This deceleration results from the steric factor of the β-methyl group in the C6-C2-type compounds. The MnO2 oxidations of the corresponding C6-C2-type compounds deuterated at their α-(benzyl)positions showed that the magnitudes of the kinetic isotope effects are smaller than those observed in the oxidations of the corresponding C6-C1-type compounds, regardless of the type of aromatic nucleus. These smaller magnitudes suggest that the presence of the β-methyl group shifts the initial oxidation mode of MnO2 from direct oxidation of the benzyl position to one-electron oxidation of the aromatic nucleus. Only the S-type compounds afforded products via degradation of the aromatic nuclei.

scholarly journals Gamma-radiated immunosuppressed tumor xenograft mice can be a new ideal model in cancer research

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamid Khodayari ◽  
Saeed Khodayari ◽  
Solmaz Khalighfard ◽  
Arash Tahmasebifar ◽  
Mahboubeh Tajaldini ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
High Capacity ◽  
Xenograft Model ◽  
Tumor Xenograft ◽  
Whole Body ◽  
Cell Injection ◽  
Tumor Tissues ◽  
Post Radiation ◽  
Xenograft Models ◽  
Xenograft Mice

AbstractTumor xenograft models can create a high capacity to study human tumors and discover efficient therapeutic approaches. Here, we aimed to develop the gamma-radiated immunosuppressed (GIS) mice as a new kind of tumor xenograft model for biomedical studies. First, 144 mice were divided into the control and treated groups exposed by a medical Cobalt-60 apparatus in 3, 4, and 5 Gy based on the system outputs. Then, 144 BALB/c mice were divided into four groups; healthy, xenograft, radiation, and radiation + xenograft groups. The animals in the xenograft and radiation + xenograft groups have subcutaneously received 3 × 106 MCF-7 cells 24 h post-radiation. On 3, 7, 14, and 21 days after cell injection, the animals were sacrificed. Then, the blood samples and the spleen and tumor tissues were removed for the cellular and molecular analyses. The whole-body gamma radiation had a high immunosuppressive effect on the BALB/c mice from 1 to 21 days post-radiation. The macroscopic and histopathological observations have proved that the created clusters' tumor structure resulted in the xenograft breast tumor. There was a significant increase in tumor size after cell injection until the end of the study. Except for Treg, the spleen level of CD4, CD8, CD19, and Ly6G was significantly decreased in Xen + Rad compared to the Xen alone group on 3 and 7 days. Unlike IL-4 and IL-10, the spleen level of TGF-β, INF-γ, IL-12, and IL-17 was considerably decreased in the Xen + Rad than the Xen alone group on 3 and 7 days. The spleen expressions of the VEGF, Ki67, and Bax/Bcl-2 ratio were dramatically increased in the Xen + Rad group compared to the Xen alone on 3, 7, 14, and 21 days. Our results could confirm a new tumor xenograft model via an efficient immune-suppressive potential of the whole-body gamma radiation in mice.

scholarly journals WHOLE-BODY AUTORADIOGRAPHY OF DISTRIBUTION OF [1-14C]-2-DEOXYGLUCOSE IN MICE

1980 ◽  
Vol 13 (2) ◽  
pp. 202-210 ◽  
Author(s):  
MASAHITO WATANABE ◽  
TAKASHI KIHARA ◽  
MASAHISA SHIMADA ◽  
KIYOHISA KURIMOTO
Keyword(s):  
Whole Body ◽  
Whole Body Autoradiography
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