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81.
Eva Ludvigsen Carina Carlsson Eva Tiensuu Janson Stellan Sandler Mats Stridsberg 《Upsala journal of medical sciences》2015,120(3):157-168
Background
Somatostatin acts through five receptor subtypes (SSTRs 1–5). We aimed to investigate SSTRs mRNA expression and protein distribution in whole rat embryos, with special emphasis on the pancreas.Material and methods
Rat embryos were collected on embryonal days 10, 11, 12, 14, 15, 17, 19, 21, and at birth. Presence of SSTRs was investigated with RT-PCR techniques and immunohistochemistry.Results
There was no SSTR5 mRNA expression in the whole rat embryos. All SSTR1–5 proteins were observed at embryonal day 10, but the localization varied between the different subtypes. From day 11 to birth SSTRs protein presence increased with time in major structures such as skin and cartilage. It remained similar over time in the heart and liver. In the fetal pancreas mRNA expression of SSTR2 and 4 was detected at day 14, and there was an increase up to birth. Only SSTR1 protein co-localized to a higher extent with the islet hormones studied. SSTR2 was present in all islet endocrine cells except for β-cells. In contrast, the immunostaining for SSTR3–4 was co-localized with insulin and PP, and, finally, SSTR5 with glucagon and pancreatic polypeptide. In mRNA isolated from whole rat embryos SSTR1-2 and SSTR4 expression showed a peak at day 14, while SSTR3 mRNA was not present until day 15.Conclusion
The present data suggest a role for SSTRs during the development of the rat embryo. Subsequent functional studies may elucidate regulatory roles of specific SSTRs for the growth and differentiation of the pancreas as well as other organs. 相似文献82.
Berbari NF Lewis JS Bishop GA Askwith CC Mykytyn K 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(11):4242-4246
Primary cilia are ubiquitous cellular appendages that provide important yet not well understood sensory and signaling functions. Ciliary dysfunction underlies numerous human genetic disorders. However, the precise defects in cilia function and the basis of disease pathophysiology remain unclear. Here, we report that the proteins disrupted in the human ciliary disorder Bardet-Biedl syndrome (BBS) are required for the localization of G protein-coupled receptors to primary cilia on central neurons. We demonstrate a lack of ciliary localization of somatostatin receptor type 3 (Sstr3) and melanin-concentrating hormone receptor 1 (Mchr1) in neurons from mice lacking the Bbs2 or Bbs4 gene. Because Mchr1 is involved in the regulation of feeding behavior and BBS is associated with hyperphagia-induced obesity, our results suggest that altered signaling caused by mislocalization of ciliary signaling proteins underlies the BBS phenotypes. Our results also provide a potential molecular mechanism to link cilia defects with obesity. 相似文献
83.
84.
It is unknown whether glycaemic variability adds to the risk of microvascular complications of diabetes over and above the mean glucose value for a patient. We examined the effect of purposefully induced short‐term glycaemic variability on oxidative stress markers. Eleven healthy subjects underwent three sequential glycaemic states; sustained hyperglycaemia, sustained euglycaemia and variable glycaemia, using glycaemic clamps for 3 h. Twenty‐four hours urinary 8‐isoprostane‐PGF2α was measured before and after each glycaemic state to assess oxidative stress. The median and interquartile range of the urinary 8‐iso‐PGF2α in ng/24 h were (1373, 513), (996, 298) and (1227, 472) for the euglycaemic, hyperglycaemic and variable states, respectively. There was no significant difference in urinary isoprostanes between the three different states; mean ranks 20.9, 11.9 and 18.2 for the euglycaemic state, hyperglycaemic state and glycaemic variability state, respectively, p = 0.083. In conclusion, we did not see a significant increase in the urinary isoprostanes when glycaemic variability was induced under controlled conditions in healthy individuals. 相似文献
85.
Amy M. Spiegel Ming Teng Koh Nicholas M. Vogt Peter R. Rapp Michela Gallagher 《The Journal of comparative neurology》2013,521(15):3508-3523
Hippocampal interneuron populations are reportedly vulnerable to normal aging. The relationship between interneuron network integrity and age‐related memory impairment, however, has not been tested directly. That question was addressed in the present study using a well‐characterized model in which outbred, aged, male Long‐Evans rats exhibit a spectrum of individual differences in hippocampal‐dependent memory. Selected interneuron populations in the hippocampus were visualized for stereological quantification with a panel of immunocytochemical markers, including glutamic acid decarboxylase‐67 (GAD67), somatostatin, and neuropeptide Y. The overall pattern of results was that, although the numbers of GAD67‐ and somatostatin‐positive interneurons declined with age across multiple fields of the hippocampus, alterations specifically related to the cognitive outcome of aging were observed exclusively in the hilus of the dentate gyrus. Because the total number of NeuN‐immunoreactive hilar neurons was unaffected, the decline observed with other markers likely reflects a loss of target protein rather than neuron death. In support of that interpretation, treatment with the atypical antiepileptic levetiracetam at a low dose shown previously to improve behavioral performance fully restored hilar SOM expression in aged, memory‐impaired rats. Age‐related decreases in GAD67‐ and somatostatin‐immunoreactive neuron number beyond the hilus were regionally selective and spared the CA1 field of the hippocampus entirely. Together these findings confirm the vulnerability of hippocampal interneurons to normal aging and highlight that the integrity of a specific subpopulation in the hilus is coupled with age‐related memory impairment. J. Comp. Neurol. 521:3508‐3523, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
86.
Somatostatin is a peptide with a potent and broad antisecretory action, which makes it an invaluable drug target for the pharmacological management of pituitary adenomas and neuroendocrine tumors. Somatostatin receptors (SSTR1, 2A and B, 3, 4 and 5) belong to the G protein coupled receptor family and have a wide expression pattern in both normal tissues and solid tumors. Investigating the function of each SSTR in several tumor types has provided a wealth of information about the common but also distinct signaling cascades that suppress tumor cell proliferation, survival and angiogenesis. This provided the rationale for developing multireceptor-targeted somatostatin analogs and combination therapies with signaling-targeted agents such as inhibitors of the mammalian (or mechanistic) target of rapamycin (mTOR). The ability of SSTR to internalize and the development of rabiolabeled somatostatin analogs have improved the diagnosis and treatment of neuroendocrine tumors. 相似文献
87.
目的观察电针对功能性消化不良(FD)大鼠胃排空、小肠推进率及胃窦组织生长抑素(SS)含量的影响。方法将30只SD大鼠随机分为空白组、模型组、电针组,每组10只,采用夹尾刺激法配合隔日进食制备FD大鼠模型,治疗结束后,检测三组的胃排空率和小肠推进率,应用免疫组织化学法检测胃窦组织中SS的含量。结果与空白组比较,模型组大鼠胃排空和小肠推进率明显延迟(P0.01);电针组较模型组胃排空和小肠推进率增加(P0.05)。与空白组相比,模型组大鼠胃窦组织中的SS含量明显升高,电针组大鼠胃窦组织中SS含量明显降低。结论电针治疗可调节功能性消化不良模型大鼠胃窦组织SS的表达,加速胃排空,改善功能性消化不良症状。 相似文献
88.
89.
Acromegaly is a debilitating disease usually caused by a growth-hormone secreting pituitary adenoma. Therapeutic goals include
improvement of symptoms, reduction in tumor mass, biochemical normalization, and preservation of pituitary function. Treatment
options include transsphenoidal surgery, radiation, and pharmacotherapy. In view of the good cure rate, surgery remains the
therapeutic modality of choice for most patients with microadenomas or well-circumscribed macroadenomas. In contrast, >40%
of patients with invasive macroadenomas (who make up the majority of patients with acromegaly) will have residual disease
following surgery, and require additional therapeutic intervention. Somatostatin analogs result in biochemical normalization
in >60% of non-operated patients, and are well tolerated. Therefore, somatostatin analogs have emerged as a rational first-line
treatment for the appropriately selected patient with acromegaly. 相似文献
90.
Efficacy of Combined Treatment with Lanreotide and Cabergoline in Selected Therapy-Resistant Acromegalic Patients 总被引:5,自引:0,他引:5
Marzullo P Ferone D Di Somma C Pivonello R Filippella M Lombardi G Colao A 《Pituitary》1999,1(2):115-120
The aim of this study was to evaluate the efficacy of a 6-month treatment with lanreotide (LAN) (60–90 mg/month) alone and combined with cabergoline (CAB) (1.5-3 mg/week) in 10 acromegalic patients previously demonstrated to be poor responders to octreotide (OCT) (0.6 mg/day) alone and combined with quinagolide (CV) (0.6 mg/day).All patients had previously undergone unsuccessful surgery and none of them received radiotherapy. Immunohistochemistry showed intense positive GH staining in all adenomas, positive PRL staining in 5 adenomas and faint ACTH or FSH/LH positive staining in other 2 adenomas. Moderately elevated serum PRL levels (35 and 47 ng/ml) were recorded in two patients. Fasting plasma IGF-I and serum GH levels were assayed at baseline and 30, 60, 90 and 120 days after each treatment. Gallbladder ultrasonography and sellar MRI were performed before and after 6 months of OCT and LAN treatments.After OCT treatment circulating GH and IGF-I levels remained elevated in all patients, while after 3 months of combined OCT+CV treatment, serum GH levels were suppressed (below 2.5 ng/ml) in only 1 patient. Significant increase of the percent GH (83.9±4.3 vs. 70.3±5.6%, p<0.01) and IGF-I suppression (54±4.4 vs. 45.3±5.7, p<0.01) and decrease of the nadir of GH (8.5±1.2 vs. 14.6±1.9 ng/ml, p<0.01) and IGF-I (400.9±32.8 vs. 462.1±45.1 ng/ml) were obtained with the combined treatment when compared to OCT treatment alone. After a 15–30 days wash-out, circulating GH and IGF-I levels significantly increased up to pretreatment level in all patients. After 6 months of treatment with LAN, suppression of serum GH was achieved in 1 patient, but no difference in GH (66.3±6.3%) and IGF-I (43.9±4.6%) suppression was recorded in comparison to OCT treatment. After 3 months of treatment with LAN combined with CAB, suppression of serum GH and normalization of plasma IGF-I levels was achieved in 4 and 5 patients, respectively. Percent suppression of GH (88.1±2.1%) and IGF-I (57.5±2.8%) was significantly greater with the combined treatment than with LAN treatment alone. In the 7 patients with evident residual mass no change was documented by magnetic resonance imaging (MRI). None of the patients withdrew LAN+CAB treatment for poor tolerance, one patient had mild hypotension. Sludge was shown after 6 months of LAN treatment in one patient without notable change after 3 months of LAN+CAB treatment.In conclusion, the treatment with dopaminergic drugs such as CV and CAB, significantly increased the efficacy of somatostatin analogs, and can be used in combined therapy in poorly responsive patients. 相似文献