Somatostatin Dotaz Zobrazit nápovědu
Somatostatin is a hormone with broad spectrum of physiological effects. Somatostatin and its analogues are employed in the diagnosis and treatment of various clinical conditions. The article reviews the use of somatostatine and somatostatine analogues in the clinical medicine. It also comprises the overview of the basic therapeutical and diagnostic indications for somatostatine and its analogues and the theoretical basis of their use.
- MeSH
- biologické markery analýza MeSH
- lidé MeSH
- nemoci endokrinního systému diagnóza terapie MeSH
- neuroendokrinní nádory diagnóza terapie MeSH
- receptory somatostatinu metabolismus MeSH
- somatostatin * analogy a deriváty fyziologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- biologické markery MeSH
- receptory somatostatinu MeSH
- somatostatin * MeSH
Gastrin and somatostatin are enterohormones which influence several physiological processes in the gastrointestinal tract. Gastrin has a pro-malignant and pro-ulcerogenic effect, while somatostatin deficiency has a similar effect. The authors examined in their investigation the 24-hour secretion of both hormones in patients with gastric ulcer and atypical gastric conditions. They revealed a significant difference in the 24-hour somatostatin level which was higher in patients with atypical gastric conditions (p < 0.05). The finding may suggest a more intense reaction of somatostatin to malignant than to non-malignant disease. In the other compared parameters no statistically significant difference was revealed.
- MeSH
- dospělí MeSH
- gastriny krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci žaludku krev MeSH
- peptický vřed krev MeSH
- senioři MeSH
- somatostatin krev MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- gastriny MeSH
- somatostatin MeSH
- MeSH
- akromegalie farmakoterapie MeSH
- hypothalamus fyziologie MeSH
- lidé MeSH
- růstový hormon metabolismus MeSH
- somatostatin fyziologie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- růstový hormon MeSH
- somatostatin MeSH
- MeSH
- centrální nervový systém analýza účinky léků MeSH
- lidé MeSH
- pankreas účinky léků MeSH
- periferní nervy analýza MeSH
- somatostatin * analýza izolace a purifikace farmakologie MeSH
- trávicí systém účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- somatostatin * MeSH
In this study, we investigated the relationship between affinity to somatostatin receptor subtype2 (SSTR(2)) and uptake of radioactivity from a group of radiolabeled somatostatin analogues in somatostatin receptor-rich tissues of rats. Organs with a high density of somatostin receptors (namely the adrenals and pancreas bearing mainly SSTR(2); this receptor subtype is also the most abundant in somatostatin receptor-positive tumors) were chosen as markers of specific binding of the peptides in vivo. Accumulations of radioactivity in these organs 24 h and 48 h after intravenous administration of six (111)In-labeled octreotide and octreotate derivatives with predominant affinity to SSTR(2) were correlated with affinity to SSTR(2) determined in vitro (IC(50) values). For correlation between adrenal uptake of radioactivity and IC(50), the best fit for exponential dependence was found; for that of pancreas, however, linear dependence was the most suitable. In cases where the values for the peptide with affinity to SSTR subtypes 2, 3 and 5, namely (111)In-DOTA-Nal(3)-octreotide were included in the group of studied agents, substantially less correlations were obtained. Our results showed that uptake of radioactivity in tissues with a high density of somatostatin receptors correlates with somatostatin receptor affinity of receptor-specific peptides; however, other factors (the affinity to particular receptor subtypes, the overall pharmacokinetic profile in the body etc.) may contribute to this observed relationship.
- MeSH
- krysa rodu Rattus MeSH
- potkani Wistar MeSH
- receptory somatostatinu metabolismus MeSH
- somatostatin analogy a deriváty metabolismus farmakokinetika MeSH
- tkáňová distribuce MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- receptory somatostatinu MeSH
- somatostatin receptor 2 MeSH Prohlížeč
- somatostatin MeSH
- MeSH
- hypothalamus fyziologie MeSH
- lidé MeSH
- růstový hormon metabolismus MeSH
- somatostatin aplikace a dávkování analýza farmakologie MeSH
- thyreotropin metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- růstový hormon MeSH
- somatostatin MeSH
- thyreotropin MeSH
In a group consisting of 50 adults and 5 children with diagnosed or suspected medullary cancer of the thyroid, plasma somatostatin levels were measured in 77 samples with a sensitive radioimmunoassay. Only 2 patients had clearly enhanced plasma somatostatin immunoreactivity, both with highly active aggressive tumors. Other patients had plasma somatostatin levels of under 20 ng/l or undetectable ones. No evidence of response of somatostatin levels to pentagastrin stimulation was found.
- MeSH
- dítě MeSH
- dospělí MeSH
- kalcitonin krev MeSH
- karcinom krev MeSH
- lidé MeSH
- mladiství MeSH
- nádory štítné žlázy krev MeSH
- pentagastrin metabolismus MeSH
- radioimunoanalýza MeSH
- somatostatin krev MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kalcitonin MeSH
- pentagastrin MeSH
- somatostatin MeSH
UNLABELLED: Somatostatin receptor targeting is a valuable method to treat somatostatin receptor-positive tumours. In peptide receptor radionuclide therapy, it is essential to determine the highest activity that can be safely administered to the patient. As (90)Y emits no gamma rays, absorbed doses for (90)Y are usually estimated using the same peptide labelled with (111)In. The aim of the study was to determine if replacement of (90/88)Y by (111)In affects the biodistribution profile of five selected somatostatin analogues in preclinical experiments. MATERIALS AND METHODS: Radiolabelled peptides were administered intravenously to male Wistar rats. RESULTS: The peptides under study labelled either with (111)In or with (88/90)Y showed similar distribution profiles in all tissues excepting the kidney. The kidney radioactivity uptake was significantly lower for (88/90)Y-labeled peptide in comparison with the one of (111)In. CONCLUSION: We conclude that a radiation-absorbed dose after (90)Y-labelled somatostatin analogues appears to be lower than that predicted by the (111)In-labelled peptide.
- MeSH
- krysa rodu Rattus MeSH
- ledviny metabolismus MeSH
- potkani Wistar MeSH
- radioizotopy india metabolismus MeSH
- radioizotopy ytria metabolismus MeSH
- somatostatin analogy a deriváty metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- radioizotopy india MeSH
- radioizotopy ytria MeSH
- somatostatin MeSH
The somatostatin (SST) receptor family controls pituitary hormone secretion, but the distribution and specific roles of these receptors on the excitability and voltage-gated calcium signaling of hormone producing pituitary cells have not been fully characterized. Here we show that the rat pituitary gland expressed Sstr1, Sstr2, Sstr3, and Sstr5 receptor genes in a cell type-specific manner: Sstr1 and Sstr2 in thyrotrophs, Sstr3 in gonadotrophs and lactotrophs, Sstr2, Sstr3, and Sstr5 in somatotrophs, and none in corticotrophs and melanotrophs. Most gonadotrophs and thyrotrophs spontaneously fired high-amplitude single action potentials, which were silenced by SST without affecting intracellular calcium concentrations. In contrast, lactotrophs and somatotrophs spontaneously fired low-amplitude plateau-bursting action potentials in conjunction with calcium transients, both of which were silenced by SST. Moreover, SST inhibited GPCR-induced voltage-gated calcium signaling and hormone secretion in all cell types expressing SST receptors, but the inhibition was more pronounced in somatotrophs. The pattern of inhibition of electrical activity and calcium signaling was consistent with both direct and indirect inhibition of voltage-gated calcium channels, the latter being driven by cell type-specific hyperpolarization. These results indicate that the action of SST in somatotrophs is enhanced by the expression of several types of SST receptors and their slow desensitization, that SST may play a role in the electrical resynchronization of gonadotrophs, thyrotrophs, and lactotrophs, and that the lack of SST receptors in corticotrophs and melanotrophs keeps them excitable and ready to responses to stress.
- Klíčová slova
- Gonadotrophs, Lactotrophs, Pituitary, Somatostatin receptors, Somatotrophs, Thyrotrophs, Voltage-gated calcium influx,
- MeSH
- akční potenciály účinky léků MeSH
- gonadotropní buňky metabolismus účinky léků MeSH
- hypofýza * metabolismus MeSH
- krysa rodu Rattus MeSH
- potkani Wistar MeSH
- receptory somatostatinu * metabolismus genetika MeSH
- somatostatin metabolismus MeSH
- vápník metabolismus MeSH
- vápníková signalizace * účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- receptory somatostatinu * MeSH
- somatostatin receptor 5 MeSH Prohlížeč
- somatostatin MeSH
- vápník MeSH
This study was conducted to investigate somatostatin modulation of GABAA receptor binding in several rat brainstem structures, located principally in the mesencephalon, after exposure to acute immobilization stress (single 1-hour session). Animals were randomly assigned to either control or stress conditions and changes in specific binding of the GABAA receptor as labelled with TBPS were assessed by in vitro quantitative autoradiography with the aid of a computer-assisted image analysis system. Exposure to immobilization stress led to a significant increase in [35S]TBPS binding site density in the SN of stressed rats compared to controls. In the other brainstem structures analysed, specific binding of [35S]TBPS remained unchanged in stressed rats. Furthermore, the results of the present in vitro study demonstrate an alteration of the modulatory effect of somatostatin on the GABAA receptor complex in the SN of stressed rats as compared to controls. This apparent alteration of allosteric effects of GABA receptor-somatostatin in the SN of stressed rats was eliminated in the presence of 1 micromolar concentration of GABA. Taken together, these data provide the first evidence of stress-induced alteration of allosteric effects of GABA-somatostatin in the rat mesencephalon. Furthermore, they also demonstrate that the tetradecapeptide somatostatin is particularly effective in modifying the [35S]TBPS binding to the GABAA receptor in this cerebral region.
- MeSH
- alosterická regulace fyziologie MeSH
- fyziologický stres metabolismus patofyziologie MeSH
- krysa rodu Rattus MeSH
- mezencefalon fyziologie MeSH
- orgánová specificita MeSH
- potkani Wistar MeSH
- receptory GABA-A fyziologie MeSH
- somatostatin fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- receptory GABA-A MeSH
- somatostatin MeSH