Multiple endocrine cell types in thyroid medullary carcinoma

Summary 10 cases of thyroid medullary carcinoma (TMC) have been studied ultrastructurally and histochemically. Well differentiated calcitonin-producing C cells were present in all tumours, being prevalent in 9 cases. 5-Hydroxytryptamine (5HT) storing cells were found in two cases, somatostatin immunoreactive cells in at least 5 cases and ACTH-immunoreactive cells in 4 cases. Ultrastructurally, at least 3 types of apparently non-C cells were observed. Type 1 cells with large, poorly osmiophilic granules resembling those of gastroenteropancreatic D cells, were present in 6 cases; they appeared to correlate well with somatostatin immunoreactive cells. Type 2 cells with large osmiophilic granules were found in 5 cases; they resembled ACTH-MSH cells of the human pituitary and may correspond to the ACTH-immunoreactive cells of light microscopy. Type 3 cells with small granules and an unknown function were found in 6 cases, always in scarce number. It is concluded that TMC, although mainly made up of C cells, usually contains large proportions of other endocrine cell types.Supported in part by grant N. 75.00630.04 from the Italian National Research Council (C.N.R.). P.F. is a fellow of the Fondazione Anna Villa Rusconi, Varese     

Febrile effects of polyriboinosinic acid: polyribocytidylic acid and interferon: relationship to somatostatin in rat hypothalamus

The changes in thermoregulatory effectors produced by an injection of polyriboinosinic acid: polyribocytidylic acid (Poly I:C) or interferon were assessed and compared in control rats, in rats with hypothalamic somatostatin (SS) receptor blockade and in rats with hypothalamic SS depletion. Intrahypothalamic (i.h., 0.05–0.50 μg) or intraperitoneal (i.p., 100–600 μg) administration of Poly I:C caused a dose-related rise in colon temperature in control rats at all ambient temperatures (T_a) studied. A Poly I:C-induced fever was produced by increased metabolism at a T_a of 8 °C, whereas at 30 °C, it was caused by cutaneous vasoconstriction. At a T_a of 22 °C, the fever was caused by increased metabolism and cutaneous vasoconstriction. On the other hand, i.h. administration of SS-14 antagonist (0.1–0.5 ng) caused a dose-related fall in colon temperature at T_a of 8 °C or 22 °C. At a T_a of 8 °C, the hypothermia was caused by decreased metabolism, whereas at 22 °C, it was caused by decreased metabolism and cutaneous vasodilation. At a T_a of 30 °C, the thermoregulatory effectors were not affected by SS-14 antagonist treatment. Furthermore, the fever induced by Poly I:C or interferon was significantly reduced by pretreatment of rats with an i.p. dose of cysteamine (30 mg. kg⁻¹) or an i.h. dose of SS-14 antagonist (0.1 ng). The results indicate that a somatostatinergic pathway in rat hypothalamus may mediate the fever induced by interferon or its inducer Poly I:C.     

Ectopic ACTH secretion due to a bronchopulmonary carcinoid localized by somatostatin receptor scintigraphy

We present the case of a 65-year-old woman with an adrenocorticotropic hormone (ACTH) secreting bronchopulmonary carcinoid. This patient showed the typical long history of Cushing's syndrome, including hypokaliemia, impaired glucose tolerance, high levels of ACTH and -endorphin, and coproduction of other peptides. At the onset of clinical symptoms in 1979 an adrenal adenoma was suspected, and left-sided adrenalectomy was performed. The symptoms soon recurred, and the diagnosis of ACTH-dependent Cushing's syndrome was made. As no ACTH-secreting tumor was found, the right adrenal was resected, and the patient was followed up regularly. Fourteen years later chest roentgenography and computed tomography revealed a para-aortic pulmonary lesion, which was suspicious for a bronchopulmonary carcinoid. ACTH and -endorphin were excessively, pancreatic polypeptide slightly elevated at that time. The final diagnosis was made using somatostatin receptor scintigraphy which confirmed the hormonal activity of the suspicious lesion; no additional focus was found. This method turned out to be not only a useful additional localization technique but also a promising tool for characterization and staging of a suspected ACTH-producing carcinoid. The tumor was resected curatively, and the diagnosis was confirmed histologically.Abbreviations ACTH adrenocorticotropic hormone - DST dexamethasone suppression test - CRH corticotropin-releasing hormone - SRS somatostatin receptor scintigraphy - CT computed tomography - MRI magnetic resonance imaging     

Neuropeptide gene expression in brain is differentially regulated by midbrain dopamine neurons

Summary In situ hybridization was used to study the expression of prepro-neuropeptide Y (NPY), preprosomatostatin (SOM), preprotachykinin (PPT) and preprocholecystokinin (CCK) mRNA in caudate-putamen and frontoparietal cortex of rat brain with unilateral lesion of midbrain dopamine neurons. Neurons expressing NPY and SOM mRNA showed a similar distribution and the expression of both NPY and SOM appears to be regulated by dopamine in a similar fashion. Following a dopamine deafferentation, the numerical density of both NPY and SOM mRNA producing neurons almost doubled in the lesioned caudate-putamen with no change in the average grain density over positive neurons. Hence, in the intact caudate-putamen dopamine appears to suppress expression of these two neuropeptide genes leading to an activation of both NPY and SOM mRNA expression in many non- or low-expressing neurons when the level of dopamine is decreased. In the fronto-parietal cortex, on the other hand, dopamine appears to stimulate NPY and SOM gene expression. Thus, in the absence of dopamine about half of the NPY positive neurons disappeared. However, for SOM the number of positive neurons did not change, but rather most positive neurons appeared to have down-regulated their SOM mRNA expression. No evidence was found for a change in CCK mRNA expression by the dopamine deafferentation, while PPT mRNA expression decreased in the deafferented caudate-putamen. Consequently, dopamine exerts dissimilar effects on the expression of different neuropeptide genes, that in turn do not respond in the same way in different brain regions.     

Changes of cerebral vasoactive intestinal polypeptide-and somatostatin-like immunoreactivity induced by noise and whole-body vibration in the rat

To clarify the role of vasoactive intestinal polypeptide (VIP) and somatostatin, somatropin-release inhibiting factor, (SRIF) neurons in the response to organisms to noise or whole-body vibration stress, VIP and SRIF-like immunoreactivity were determined in various regions of the rat brain following exposure for 90 min to noise (broad band, 102 dB) or whole-body vibration (20 Hz, 4.0 g). Both noise and whole-body vibration significantly increased VIP-like immunoreactivity in the amygdala. A significant reduction of VIP like immunoreactivity in the hippocampus was induced only by whole-body vibration. On the other hand SRIF-like immunoreactivity was decreased significantly in the hypothalamus and increased significantly in the amygdala by noise and whole-body vibration, respectively. The present findings would seem to indicate that the amygdalofugal VIP neural system is involved in regulating hypothalamic and pituitary hormone secretions in non-specific reactions to stress. Responses of hippocampal VIP and the amygdalofugal SRIF to whole-body vibration stress are assumed to be activated as specific reactions to the stress.     

Effects of noradrenaline and somatostatin on basal and stimulated mucosal ion transport in the guinea-pig small intestine

Summary Noradrenaline (NA) and somatostatin (SOM) stimulate intestinal water and ion absorption and are found in mucosal nerve fibres and nerve terminals in submucous ganglia of the guinea-pig small intestine. As the main projection of submucous neurons is to the mucosa, NA and SOM might alter mucosal transport either by a direct effect on the epithelium or indirectly, by affecting submucous neurons. In this study these two possible sites of action of NA and SOM have been investigated in mucosa-submucosa preparations of guinea-pig ileum. In addition, the actions of NA and SOM on the secretory responses caused by stimulation of different populations of submucous neurons have been studied. The stimulants of secretion used were a nicotinic agonist, 1,1-dimethyl-4-phenylpiperazinium (DMPP, 10^–5 M), 5-hydroxytryptamine (5-HT, 10^–7 M) and electrical field stimulation (EFS), which activate cholinergic, noncholinergic and mixed populations of submucous secretomotor neurons, respectively.Segments of intestine were dissected free of external muscle and myenteric plexus and mounted in Ussing chambers. Short-circuit current (I _sc) was measured as an indication of net active ion transport across the tissue. NA (10^–8 M) and SOM (>10^–10 M) each caused a decrease in I _sc, indicating a net increase in ion absorption. The NA response was abolished and the magnitude of the SOM response was reduced to 20% by tetrodotoxin (10^–7 M). DMPP, 5-HT and EFS each stimulated nerves that increased I _sc and each of these responses was significantly diminished by NA and SOM; for both NA and SOM the decrease in the DMPP response was significantly greater than the decrease observed in the response to carbachol (10^–6 M). Phentolamine (10^–6 M) abolished all of the effects of NA but caused no change in the SOM effects. These studies have shown that NA and SOM cause similar changes in net ion transport, that their actions are primarily on submucous secretomotor neurons and that NA and SOM can diminish the responses to stimulation of both cholinergic and noncholinergic submucous neurons.In this tissue it is also known that SOM coexists with NA in noradrenergic nerve terminals in the submucosa. However, when applied together, NA and SOM caused no greater decrement in the carbachol and 5-HT responses than would be predicted by adding the separate effects of NA and SOM. Hence there was no obvious interaction between NA and SOM effects on mucosal transport.     

生长抑素对急性胰腺炎患者血小板参数的影响

目的　探讨血小板参数在急性水肿型胰腺炎 (AEP)和出血坏死性胰腺炎 (AHNP)中的变化特点及生长抑素 (SS)对其影响。方法　应用血细胞自动分析仪检测AEP和AHNP病人不同时期血小板计数 (PLT) ,平均血小板体积 (MPV)和血小板分布宽度 (PDW )。结果　AEP患者血小板参数无明显变化 ,1周后 ,PLT无明显升高 ,MPV和PDW有显著性升高 (P <0 .0 5 ) ;常规治疗后 ,对血小板参数无影响 ;SS治疗后 ,MPV和PDW有显著性升高 (P <0 .0 5 )。而AHNP患者PLT显著降低 (P <0 .0 5 ) ,MPV和PDW有显著性升高 (P <0 .0 5 ) ,1周后PLT显著性升高 (P <0 .0 5 ) ,但MPV和PDW无明显降低 ;常规治疗后 ,PLT升高 ,MPV、PDW均降低 (P <0 .0 5 ) ;SS治疗后PLT显著性升高 (P <0 .0 5 ) ,MPV、PDW无明显变化。结论　AEP与AHNP患者血小板参数的变化有明显不同 ,可反映病情变化。SS治疗后 ,对PLT无影响 ,但可增加血小板的活性 ,对AHNP患者有一定的治疗和预防作用     

颅脑外伤后局部脑组织中P物质和生长抑素的表达及意义

本文旨在分子水平探讨人脑外伤后神经肽的变化,为脑外伤后病理生理变化机制提供理论依据。采用免疫组织化学技术和多功能真彩色病理图像分析系统(CMIAS)对31例脑外伤患者局部脑损伤区和12例无脑损伤猝死患者相同脑区神经细胞中P物质(SP),生长抑素(SS)的表达进行了检测。结果得出脑伤患者局部伤区及周围神经细胞中SP、SS表达较尸检对照组明显减少并具时程特点。但与伤情及预后无显著关系。本实验表明SP、SS在颅脑损伤的病理生理过程中起了重要作用。     

生长抑素对奥迪括约肌运动的作用机制

目的了解徨长抑素影响败类迪括约肌运动的神经通路成分。方法建立奥迪括约股测压慢性实验动物模型,研究Ｍ受体阻断剂、α受体阻断剂、β受体阻断剂、５－ＨＴ４受体阻断剂、一氧化氮合酶抑制剂和河豚毒素对生长抑素调节奥迪括约肌运动的影响。结果阿托品、二乙胺盐酸甲酯和河豚毒素阻断生长抑素对括约肌的兴奋作用;Ｌ－精氨酸甲酯阻断生长抑素对括约肌的抑制作用。结论生长抑素通过胆碱能和５－羟色胺神经元组成的兴奋性神经通路,     

生长抑素对肝硬化食道胃底静脉曲张破裂出血作用的临床研究

目的 观察生长抑素制剂（施他宁、善得定）对于肝硬化食道胃底静脉曲张破裂出血的治疗效果,并与垂体后叶素进行比较。方法 ６４例患者随机分为垂体后叶素组（ｎ＝２１）、施他宁组（ｎ＝２０）、盖得定组（ｎ＝２３）进行治疗。结果 垂体后叶素组、施他宁组和善意得定组患者自接诊后至完全止血时的出血量,及接诊后至止血后４８小时生命 体征基本平稳时的输血量无显著性差异（Ｐ〉０．０５）。各治疗组２４小时内的止血率均为８