Ionizing radiation and somatostatin analogues are used for acromegaly treatment to achieve normalization or reduction of growth hormone hypersecretion and tumor shrinkage. In this study, we investigated a combination of somatostatin (SS14) with ionizing radiation of 60Co and its effect on reparation of radiation-induced damage and cell death of somatomammotroph pituitary cells GH3. Doses of γ-radiation 20-50 Gy were shown to inhibit proliferation and induce apoptosis in GH3 cells regardless of somatostatin presence. It has been found that the D0 value for GH3 cells was 2.5 Gy. Somatostatin treatment increased radiosensitivity of GH3 cells, so that D0 value decreased to 2.2 Gy. We detected quick phosphorylation of histone H2A.X upon irradiation by the dose 20 Gy and its colocalization with phosphorylated protein Nbs-1 in the site of double strand break of DNA (DSB). Number of DSB decreased significantly 24 h after irradiation, however, clearly distinguished foci persisted, indicating non repaired DSB, after irradiation alone or after combined treatment by irradiation and SS14. We found that SS14 alone triggers phosphorylation of Nbs1 (p-Nbs1), which correlates with antiproliferative effect of SS14. Irradiation also increased the presence of p-Nbs1. Most intensive phosphorylation of Nbs1 was detected after combined treatment of irradiation and SS14. The decrease of the number of the DSB foci 24 h after treatment shows a significant capacity of repair systems of GH3 cells. In spite of this, large number of unrepaired DSB persists for 24 h after the treatment. We conclude that SS14 does not have a radioprotective effect on somatomammotroph GH3 cells., M. Řezáčová, J. Čáp, D. Vokurková, E. Lukášová, J. Vávrová, J. Cerman, V. Mašín, N. Mazánková., and Obsahuje bibliografii a bibliografické odkazy
Early studies suggested endocrine type mother-pup interaction: 13M administered to suckling rats appeared via the urine of the suckling and mother's milk in the circulation of litter mates who were not injected with iodine; levels of thyroxin in rat milk were influenced by the status of the thyroid gland of the lactating rat. Administration of TRH (thyrotropin releasing hormone) to lactating mothers led to an appearance of unaltered hormones in the milk and stomach content of sucklings. TSH (thyroid stimulating hormone) or ACTH (adrenocorticotropic hormone) when given orogastrically to suckling rats increased thyroid hormones and corticosterone serum levels in suckling rats. Functional effects of gastrointestinal administration of insulin, bombesin (mammalian analog of gastrin-releasing peptide) and epidermal growth factor (EGF) are reviewed in detail (32 references).
Úvod: Cílem článku je představení analogu somatostatinu EDDA/HYNIC-TOC značeného 99mTechneciem (Tektrotyd), který je v České republice dostupný od roku 2011. Radiofarmakum se používá k scintigrafické lokalizaci nádorů se somatostatinovými receptory. Materiál a metoda: Na Klinice nukleární medicíny a endokrinologie v Motole jsme od září 2011 dosud vyšetřili 18 pacientů. Jednalo se o 3 pacienty s medulárním karcinomem štítné žlázy (MTC), 12 pacientů s neuroendokrinním tumorem (NET) nebo karcinoidem, 2 pacienty s podezřením na přítomnost karcinoidu a 1 pacient byl indikován pro endokrinní orbitopatii. Protokol vyšetření zahrnuje celotělové snímání a tomografickou akvizici za 4 hodiny po aplikaci 700 MBq Tektrotydu. Za 1-2 hodiny po aplikaci doplňujeme SPECT břicha. Výsledky: Patologický nález jsme pozorovali u 6 pacientů. U všech pacientů byl nález ve shodě s jinými vyšetřovacími metodami. Zobrazení nadledvin jsme pozorovali u 10 vyšetřených. Nález nebyl interpretován jako patologie, vysvětlujeme si ho dosahovaným vyšším rozlišením a zlepšenou kvalitou obrazů. U 12 pacientů bylo vyšetření negativní. Závěr: 99mTc EDDA/HYNIC-TOC (Tektrotyd) může být alternativou k užití 111In-DTPA-D-Phe1-octreotidu (Octreoscan) při vyšetřování nemocných s tumory exprimujícími somatostatinové receptory. Výhodou je větší dostupnost radiofarmaka, nižší radiační zátěž a vyšší kvalita zobrazení. K vyloučení falešně pozitivních nálezů v dutině břišní vzhledem k hepatobiliární exkreci je užitečné provádět dvě tomografická vyšetření břicha, přičemž první by mělo být provedeno mezi 1. a 2. hodinou po aplikaci., Introduction: The aim of this article is to introduce the somatostatin analog EDDA/HYNIC-TOC labeled with 99mTechnetium available in Czech Republic since 2011. This radiopharmaceutical has been used for scintigraphic localisation of tumors bearing somatostatin receptors. Material and methods: We evaluated 18 patients in our department from September 2011. There were 3 pts with medullary thyroid cancer, 12 pts with neuroendocrine tumor (NET) or carcinoid, 2 pts with suspected carcinoid and 1 pt due to endocrine orbitopathy. Imaging consists of whole-body scan and SPECT/CT performed 4 hours post injection of 700 MBq of Tektrotyd. We add an abdominal SPECT 1 to 2 hours post injection. Results: Positive findings were detected in 6 pts. It was in agreement to other diagnostic methods. We detected accumulation in the suprarenal glands in 10 pts. This was not interpreted as a pathology, we believe this detection is thanks to a better resolution and an improved image quality. 12 pts were negative. Conclusion: 99mTc EDDA/HYNIC-TOC (Tektrotyd) could be a good alternative to 111In-DTPA-D-Phe1-octreotide (Octreoscan) in evaluating patients with tumors bearing somatostatin receptors. Better availability, lower radiation and improved image quality are the advantage. Early tomographic imaging of abdomen should be done to avoid false positive findings due to nonspecific tracer accumulation., Kateřina Táborská, and Literatura 9