Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypoglycaemia increases hepatic glucose output; insulin release is suppressed and the secretion of counter regulatory hormones enhanced. Catecholamines and glucagon seem to play a major role. The brain energy content is initially preserved, but the neuronal activity exhibits a 40-60 % decrease. Neither cerebral blood flow, nor oxygen consumption are altered. In addition to glucose, other substrates are metabolized. Cerebral edema may occur. An insulin-storage defect seems to be the main abnormality in insulinoma beta cell function. The most accurate biological tests are the insulin/glucose ratio, stimulation tests and suppression tests such as fasting and insulin-induced hypoglycaemia. Ectopic release of ACTH, HCG, HLP, glucagon or gastrin, is observed in some malignant insulinomas. When inconclusive, classic localising procedures may be effected by selective venous-blood sampling. Hypoglycaemia of extra-pancreatic tumors results from glucose hyperconsumption and decreases in glucose hepatic output, lipolysis and ketogenesis, related to secretion of insulin-like peptides NSILAs or NSILAp. Rare cases of hypoglycaemia related to insulin auto-antibodies of unknown origin have been reported. Alcoholic hypoglycemia results from diminished hepatic glycogen content, alcohol dehydrogenase pathway blockade, reduction of gluconeogenesis defect in the alcohol catabolic catalase pathway and enhancement of peripheral glucose consumption.
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PMID:[Mechanisms of spontaneous hypoglycaemia in the adult (author's transl)]. 22 19

Thirty-five patients with thalassemia major, aged 7 to 21 years, were studied to define the relationship between the pubertal development and the growth-hormone (GH) secretion during sleep, after administration of GH-releasing factor (hpGRF 1-44), and betaxolol-glucagon or arginin-insulin. Pubertal development was classified as being appropriate or delayed for chronological age. GH response to pharmacological stimuli and during sleep was not linked to the pubertal development according to the chronological age. The peak of GH secretion after GHRH injection was significantly delayed in thalassemic patients with retarded puberty. The integrated secretion of GH during the 120-min test was slightly but not significantly reduced in these patients. The prepubertal pattern of GHRH response was restored in the patients receiving substitutive therapy by HCG or testosterone. The alteration of GH response to GHRH in thalassemic patients is likely to be only due to delayed puberty and decreased endogeneous GHRH secretion since it is corrected by androgen or gonadotropin replacement.
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PMID:Growth hormone response following growth hormone releasing hormone injection in thalassemia major: influence of pubertal development. 204 23

In order to establish the extent of neuroendocrine differentiation and the occurrence of neurohormonal peptides in the neoplastic cells of prostatic carcinomas, silver-staining and immunocytochemical techniques were used. All gave satisfactory results. The incidence of the neuroendocrine cells seemed to be higher in the fresh "Bouin-fixed" biopsy specimens than in the conventionally "formalin-fixed" specimens from archival paraffin blocks. All carcinomas demonstrated argyrophil cells as an integral element of the tumour. In highly differentiated carcinomas (grade I) these cells were scattered focally, intermingled with non-argyrophil cells in typical adenocarcinomas; their incidence was estimated to be about the same as in benign prostatic hyperplasia. Most of them were immunoreactive with antisera raised against serotonin and/or TSH (thyroid stimulating hormone). In moderately and poorly differentiated (grades II-III) carcinomas, however, the argyrophil cells were more numerous and showed greater variation in growth pattern; only occasionally they displayed a typical carcinoid-like structure. Moderately and poorly differentiated carcinomas also showed a greater variation in the number and kinds of peptide immunoreactivities than the highly differentiated carcinomas. In addition to serotonin- and TSH-immunoreactive cells as the most prevalent type, now also human chorionic gonadotrophin (HCG-alpha), adrenocorticotropic hormone (ACTH), leu-enkephalin, beta-endorphin, somatostatin, glucagon and calcitonin immunoreactive cells could be found within certain tumour areas and often with a distinctly patchy distribution. In two cases, where the tumour cells in the metastases were also investigated, they were found to be both argyrophil and immunoreactive with the same antisera as those of the primary tumour. Our findings emphasise the fact that prostatic carcinomas are more complex and heterogenous than previously thought, exhibiting endocrine differentiation as an integral element of virtually all prostatic adenocarcinomas.
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PMID:Peptide-hormone- and serotonin-immunoreactive tumour cells in carcinoma of the prostate. 244 32

A 54 year old woman suffered from acromegaly due to a pancreatic islet cell tumour producing GHRH. The tumour was demonstrated on CT scan. The diagnosis was established from elevated plasma levels of GHRH, GH and prolactin, and by the lack of signs of a pituitary adenoma in trans-sphenoidal surgery. Acromegaly was cured by tumour removal. Light microscopically, the tumour showed a medullary and microlobular pattern. The cells were large and often cuspidal. Small granules were found in semi-thin sections. Small aggregations of amyloid fibres were seen, mostly around capillaries. Immunocytochemistry revealed GHRH, NSE, neurotensin, serotonin, VIP and PP. S 100 was positive only in nerve fibres. Staining for GH, ACTH, calcitonin, alpha-HCG, beta-HCG, insulin, glucagon, gastrin, substance P, bombesin and somatostatin was negative. Ultrastructure showed oval partly lobulated nuclei with small nucleoli, moderate amounts of rough endoplasmic reticulum, many free ribosomes, some large Golgi fields and small numbers of secretory granules measuring 150 nm or, in a few cells, 650 nm. Only 4 other cases of pancreatic endocrine tumours causing acromegaly by ectopic GHRH secretion are described in the literature and these were similar to our case in many respects.
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PMID:Morphology of a GHRH producing pancreatic islet cell tumour causing acromegaly. 301 79

Insulin binding was studied in rabbit semimembranosus proprius and psoas major muscles composed of slow-twitch oxidative (SO) and fast-twitch glycolytic (FG) fibers, respectively. For this purpose, we developed a technique using cryostat microtome muscle slices. Degradation of 125(I)-insulin during the incubation period was prevented by the addition of 1 mM bacitracin in the buffer. Specific binding to muscle slices plateaued by the 24 hrs. of incubation at 4 degrees C. It increased as a function of the amount of muscle, with a maximum binding occurring at about 5 mg of muscle slices. Triton X-100 has been shown to increase specific binding from a critical concentration of 10(-4) M with a maximum effect occurring at 3.3 10(-4) M. Under this condition, the binding was specific since displacement studies showed no inhibition of 125(I)-insulin binding by GH, HCG, ACTH and glucagon, whereas half maximal inhibition was achieved using 5 10(-10) M insulin, 3 10(-9) M IGF1 and 2 10(-8) M proinsulin. The analysis of the binding data yielded curvilinear Scatchard plots. The number of high affinity insulin receptors was higher in the SO muscle than in the FG muscle (4.3 +/- 0.7 vs 0.7 +/- 0.2 fmol/mg fresh muscle; P less than 0.001) with similar high affinity dissociation constants (Kd = 1.5 10(-10) M). Analogous results were obtained using muscle microsomal fractions. The differences in insulin binding might be related to the more intense metabolism of SO fibres which contract more often than FG fibres in vivo.
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PMID:Characterization of insulin binding to slices of slow and fast twitch skeletal muscles in the rabbit. 353 33

Sixteen argyrophil cell carcinomas in 59 gastric scirrhous carcinomas were examined histologically, ultrastructurally, and immunohistochemically for polypeptide hormones, CEA, lysozyme, and HCG. In nine of these 16 tumors, polypeptides such as gastrin, somatostatin, and glucagon were demonstrated. Six of these nine tumors contained all three hormones, and three of these six tumors also had argentaffin cells. In all of these 16 tumors CEA were observed. Eight of them had CEA, lysozyme, and acid mucin synchronously. Of the above six tumors containing three peptides, three produced focal HCG. Ultrastructurally, several types of secretory granules were noted. Histologically, these 16 tumors showed poorly differentiated adenocarcinomas or signet ring cell carcinomas. Macroscopically, generalized type was 11 and localized type five. No hormonal syndrome was detected in any of the patients. It was suggested that these scirrhous argyrophil cell carcinomas of the stomach with the multifunction originate from totipotent immature cells of endodermal origin.
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PMID:Scirrhous argyrophil cell carcinoma of the stomach with multiple production of polypeptide hormones, amine, CEA, lysozyme, and HCG. 617 15

A 61-year-old man with a malignant endocrine pancreatic tumour, so-called "non-functioning" islet cell tumour, is described. The tumour consisted of enterochromaffin-like cells with positive immunocytochemistry for gastrin, glucagon and VIP, but neither of these or other peptides were elevated in the circulation. Elevated serum levels of HCG-alpha and HCG-beta subunits were found. They seemed to be valuable tumour markers during cytotoxic therapy.
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PMID:HCG-alpha and HCG-beta subunits as tumour markers during therapy in a case with so-called "non-functioning" islet cell tumour. 627 Sep 88

A 60-year-old patient developed signs and symptoms of glucagonoma syndrome (dermatitis, weight loss, anemia and hypoaminoacidemia). However, diabetes mellitus was absent. Glucagonoma was suspected because of markedly elevated plasma glucagon levels and the tumor was subsequently removed by surgery. Acidethanol extraction of the tumor and immunohistochemistry provided evidence of the presence of all four islet hormones, particularly that of glucagon and pancreatic polypeptide and to a lesser extent of somatostatin and insulin. Immunohistochemistry of the tumor (but not plasma) also showed the presence of alpha-HCG. Plasma glucagon immunoreactivity consisted to a large extent (approx. 90%) of a high molecular form of glucagon, probably proglucagon. In spite of the presence of alpha-HCG - which is assumed to be a marker of malignancy - the patient has been free of recurrence for the 2 1/2 years since surgery. The increasing number of cases reported during the past few years demonstrates that the syndrome is more common than previously suspected. Glucagon secretion and its typical clinical picture may be a valuable marker of a multihormonal pancreatic tumor. In a case of suspected glucagonoma, diagnosis can be established simply by obtaining a plasma glucagon level measurement.
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PMID:[Glucagonoma syndrome in a multihormonal pancreatic tumor]. 628 78

The occurrence of endocrine cells in 350 cases of colorectal adenocarcinoma was studied by immunohistochemistry for chromogranin A (CGA). The hormone profile of endocrine tumor cells, the correlation between endocrine differentiation and presence of other colorectal epithelial-cell lineages and the prognostic relevance of endocrine differentiation in colorectal cancer were investigated. CGA-positive tumor cells were found in 30% of cases, 21% showing moderate positivity and 9.0% extensive positivity. Of CGA-positive tumors, 70% additionally produced neurohormones, mainly indigenous to normal colorectal epithelium: 55% showed immunoreactivity for glucagon-like substances, 20% for serotonin and 10% for somatostatin, PYY and HCG. No immunoreactivity was found for various neurohormones not normally produced by colorectal endocrine cells. CGA-positive tumors tended to be more aggressive than CGA-negative tumors. Especially, tumors with extensive CGA positivity showed shorter survival, which was most apparent within Dukes' stage C. In multivariate analysis, extensive CGA positivity was an independent indicator of poor prognosis. CGA immunoreactivity significantly correlated with mucin production, but not with expression of secretory component (SC), a columnar-cell marker. Mucin production significantly correlated with SC expression. Tumors positive for CGA but not for mucin and/or SC showed the worst prognosis. SC expression was a relatively favorable feature, and mucin-producing tumors showed intermediate behavior.
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PMID:Endocrine cells in colorectal adenocarcinomas: incidence, hormone profile and prognostic relevance. 810 Aug 8

The structure-stabilizing effect of homologous and heterogeneous desensitization and albumin on rat ovarian LH/hCG receptors was analyzed by thermal perturbation technique. HCG-induced down-regulation shifted the heat inactivation profile of hCG-binding sites to a temperature lower by about 7 degrees C (T50 values). In heterogeneous desensitization, which also involves uncoupling of receptors from adenylyl cyclase system, only follicle stimulating hormone (FSH) changed the stability of ovarian LH/hCG receptors. Stimulation of other hormonal receptors, which belong to the family of membrane spanning G protein-linked receptors, i.e. beta-adrenergic, glucagon, serotonin and prostaglandin E (PGE) had no effect on the stability of the LH/hCG receptor. Reduction of the stability of the LH/hCG receptor by about 3 degrees C after PGF2alpha injection to luteinized rats may be connected with specific process of luteolysis. On the other hand, albumin had a stabilizing effect on the receptor. The receptor destabilizing action of oleic acid incorporated into ovarian membranes along with calcium stimulation of endogenous phospholipase A (PLA) activity and reversal of these effects when BSA was used as fatty acid scavenger, may indicate that free fatty acids are responsible for the thermal instability of hCG-binding sites. Fluorescence quenching studies indicated that extraction of free fatty acids by albumin elevated the accessibility of fluorophores for acrylamide, and suggest that modificated lipid-protein interactions may affect the stability of the LH/hCG receptor structure.
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PMID:Hormonal modulation of structural alteration of rat ovarian luteinizing/human chorionic gonadotropin receptors. 1131 59


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