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

Thyrotropin (10 muM) inhibited the antiviral activity of interferon. When added after interferon, thyrotropin (TSH) had no effect on antiviral activity. There was also no inhibition of interferon action in cells washed with medium between incubations with TSH and interferon. 125I-Labeled TSH and 125I-labeled cholera toxin could bind to preparations of mouse L-cell plasma membranes. The binding was specific in that it was prevented by unlabeled thyrotropin or cholera toxin, but not by insulin, glucagon, prolactin, growth hormone, human chorionic gonadotropin, or luteinizing hormone. Mouse interferon inhibited 125I-labeled TSH binding to L-cell plasma membranes. The effect of mouse interferon on 125I-labeled cholera toxon binding was more complex, inhibition occurring only after an initial enhancement at low interferon concentrations. A 10-fold higher concentration of interferon was required to inhibit 125I-labeled TSH binding. Mouse interferon was also able to displace bound 125I-labeled TSH, but not bound 125I-labeled cholera toxin. The interferon interaction with cell membranes was temperature-sensitive. Human interferon could induce changes in binding of 125I-labeled TSH and 125I-labeled cholera toxin to mouse L-cell plasma membranes similar to those induced by mouse interferon. Mouse interferon induced similar changes in plasma membranes of human KB-3 cells, which are insensitive to both human and mouse interferons. In view of these results, the species specificity of interferons does not appear to reside solely at the point of the initial interaction with their binding sites.
 ...
PMID:Use of thyrotropin and cholera toxin to probe the mechanism by which interferon initiates its antiviral activity. 1 May 73

Twenty-nine women in premature labor were randomly assigned to a ritodrine (N = 14) or placebo (N = 15) treatment group. Thirteen serial blood samples were drawn during the first 12 hours of therapy by intravenous drug infusion and they were analyzed for a variety of metabolic substances. There was a significant increase in the blood glucose level in the ritodrine group after one hour and this persisted for the 12 hours of intravenous drug treatment. Plasma insulin levels similarly did not increase in the placebo but significantly rose in the ritodrine group by 30 minutes, peaked at 2 1/2 hours, and remained elevated throughout the infusion. There were no significant differences between levels of plasma glucagon, cholesterol triglyceride, human placental lactogen, or human chorionic gonadotropin in the two treatment groups. Ritodrine caused significant maternal and fetal tachycardia. Its use in women with carbohydrate abnormalities should be monitored carefully. The increased glucose levels may lead to an increased fetal weight.
 ...
PMID:The acute effects of ritodrine infusion on maternal metabolism: measurements of levels of glucose, insulin, glucagon, triglycerides, cholesterol, placental lactogen and chorionic gonadotropin. 35 1

The association of hypoglycemia and microphallus in the male neonate is presumptive evidence of congenital hypopituitarism. This was observed in four male infants with normal birth weight and length, optic discs, and intelligence, and without gross central nervous system malformations. Plasma and urinary cortisol values were low. Stimulation with metyrapone and insulin hypoglycemia failed to elicit a rise in plasma corticoids, but multiple doses of ACTH evoked a response. Growth hormone responses to arginine, insulin, sleep, L-dopa, and glucagon were uniformly less than 2.5 ng/ml. In three patients, however, length remained within 2 SD of the mean until two years of age; in one, there was a sharp decrease in growth by three months. Two patients had low plasma TSH and thyroxine concentrations within the first month of life. In the other two patients, whose thyroxine levels were measurable, intravenous administration of thyrotropin-releasing factor evoked a normal rise in plasma TSH; serum thyroxine decreased into the hypothyroid range in one after GH therapy was initiated. Plasma prolactin was normal in the first two patients receiving thyroxine replacement therapy. The other two patients had elevated baseline prolactin levels and had an augmented rise in plasma prolactin after administration of TRF. Human chorionic gonadotropin induced a 10- to 15-fold rise in plasma testosterone in the two patients tested. The changes in plasma FSH and LH after luteinizing hormone-releasing factor were either low or in the prepubertal range. In three patients, treated with testosterone enanthate intramuscularly, phallic growth occurred. In addition, all three had a transient increase in height but no acceleration of skeletal maturation. The data suggest a deficiency of hypothalamic hypophysiotropic hormones rather than a primary pituitary defect. Early recognition of this syndrome complex is critical for prompt treatment of the life-threatening cortisol deficiency. The diagnosis is more difficult in affected females because their external genitals are normal. The microphallus is a remediable manifestation of hypopituitarism.
 ...
PMID:Congenital hypopituitarism associated with neonatal hypoglycemia and microphallus: four cases secondary to hypothalamic hormone deficiencies. 118 16

The diabetic state, as well as elevated culture media glucose level (950 mg D-glucose/dL) per se, significantly retards in vitro development of mouse pre-implantation embryos from a two-cell stage to blastocyst stage; maternal insulin therapy to diabetic mice reverses this impairment. This study was undertaken to assess (1) whether less extreme elevation of the media glucose concentration would also impair development, and (2) whether elevated culture media insulin or glucagon levels would alter development. Two-cell pre-embryos were recovered from B6C3F1 mice that had been stimulated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hGG), mated, and killed 48 hours later. Pre-embryos were observed in culture at 24-hour intervals for a total of 72 hours at four glucose levels: 110 (n = 108), 220 (n = 101), 440 (n = 65), and 950 (n = 106) mg D-glucose/dL. Impairment in progression of development was noted at each time period; compared with development in 110 mg glucose/dL, the distribution of development was significantly different at 24 hours (chi 2 = 60.1, P less than .001), at 48 hours (chi 2 = 36.7, P less than .001), and at 72 hours (chi 2 = 45.1, P less than .001). Rate of development as assessed by ANOVA was also significantly reduced at increasing glucose levels (P less than .0001), with Duncan Multiple Range test demonstrating differences between development at higher glucose levels in the comparison of development in 110 mg/dL versus 440 mg/dL and 950 mg/dL, and at 220 mg/dL versus 950 mg/dL.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Dose-response effects of glucose, insulin, and glucagon on mouse pre-embryo development. 186 20

Indirect evidence has indicated that the carbohydrate moieties of the glycoprotein hormones are involved in the activation of the receptor-adenylyl cyclase system of reproductive tissues. In the present study, we have isolated the glycopeptides (GP) from human chorionic gonadotropin (hCG), the alpha-subunit of hCG, fetuin, and bovine gamma-globulin (b gamma G). These along with a number of synthetic oligosaccharides were tested for their ability to inhibit adenylyl cyclase (AC). There was less than 0.001% cross-reactivity of the GP from hCG, hCG alpha, fetuin, and b gamma G when tested in a double-antibody hCG radioimmunoassay or rat corpora lutea radioreceptor assay. The GP of fetuin, b gamma G, and the synthetic oligosaccharides did not inhibit AC activity of 2000 g corpora lutea membranes when coincubated with 100 ng of hCG/mL (ED50). However, when the GP of hCG and hCG alpha were included with intact hCG, there was a dose-related inhibition. Inhibition of cyclase activity was enhanced when the hCG GP were desialylated. This occurred without a change in the lag time of hCG activation which was calculated to be 1-1.5 min. Changing the concentration of ATP and Mg2+ did not affect the inhibitory effects of the hCG alpha GP on hCG-stimulated AC activity. Inhibition by hCG GP followed uncompetitive kinetics. The inhibition by the GP of hCG seems to be restricted to the LH/hCG-stimulatable AC system because the same dosage of hCG GP which inhibited the rat luteal AC system did not have any effect on the rat hepatocyte AC system when coincubated with glucagon or on NaF-stimulated activity in luteal membranes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Inhibition of adenylyl cyclase activity in rat corpora luteal tissue by glycopeptides of human chorionic gonadotropin and the alpha-subunit of human chorionic gonadotropin. 241 22

An 8-cm mass in the tail of the pancreas was resected from a 40-year-old man with polyarteritis nodosa. The tumor cells contained abundant, finely granular, eosinophilic cytoplasm arranged in a gyriform pattern that suggested the tumor was an oncocytoma of the endocrine pancreas. Electron microscopy confirmed that the tumor was an oncocytoma by demonstrating tumor cell cytoplasm packed with mitochondria. Ultrastructural and immunocytochemical studies confirmed the neuroendocrine nature of the tumor by demonstrating dense-core, membrane-bound structures consistent with neurosecretory granules and neuron-specific enolase immunoreactivity. No immunoreactivity for insulin, glucagon, gastrin, somatostatin, or pancreatic polypeptide was found. No human chorionic gonadotropin alpha-chain immunoreactivity was detected. The patient is well without evidence of tumor five years after operation. The apparently benign behavior of the pancreatic endocrine oncocytoma reported here is in contrast to the malignant nature of another case reported recently.
 ...
PMID:Benign oncocytic endocrine tumor of the pancreas in a patient with polyarteritis nodosa. 288 5

Vasoactive intestinal peptide (VIP) and VIPergic nerve fibers are present in the ovaries of several mammalian species, suggesting a possible ovarian action of VIP. We have investigated the direct effects of synthetic porcine VIP on rat granulosa cell steroidogenesis in vitro. The cells were obtained from immature, hypophysectomized, estrogen-primed rats, and cultured in a serum-free medium for 24 h in the absence or presence of varying amounts of VIP. Medium steroids were then determined by specific radioimmunoassay. Vasoactive intestinal peptide dose-dependently stimulated progesterone, 20 alpha-hydroxypregn-4-ene-3-one (20 alpha-OH-progesterone), and estrogen production with an approximate ED50 value of 3 X 10(-8) M. Maximum steroid production induced by VIP ranged from 15% to 28% of that seen with maximal follicle-stimulating hormone (FSH) stimulation. In contrast to the ability of FSH to induce luteinizing hormone (LH) receptor formation, treatment with VIP did not increase [125I]iodo-human chorionic gonadotropin (hCG) binding to granulosa cells. The ability of several gastrointestinal peptides, having 17-44% sequence identity to VIP, to stimulate granulosa cell steroidogenesis was also tested. The most closely related peptide, PHM-27 was less effective than VIP, and the least closely related, secretin and glucagon, were ineffective at 10(-6) M. Vasoactive intestinal peptide seems to act at least partly through cyclic 3',5'-adenosine monophosphate (cAMP)-dependent processes: addition of a phosphodiesterase inhibitor significantly potentiated the VIP stimulation of granulosa cell steroidogenesis, and VIP was capable of producing a dose- and time-dependent increase in both intracellular and medium cAMP levels. Vasoactive intestinal peptide stimulation of estrogen production seemed to be a result of increased aromatase activity. The increased progesterone production was associated with increased pregnenolone production, increased rate of conversion of pregnenolone to progesterone via 3 beta-hydroxysteroid dehydrogenase, and decreased metabolism of progesterone via 20 alpha-hydroxysteroid dehydrogenase. These results indicate that VIP exerts a specific action on granulosa cells to increase estrogen and progestin production. The observed direct effects of VIP, coupled with its identification in the ovary, suggest that VIP may be a physiologically important regulator of ovarian activity.
 ...
PMID:Vasoactive intestinal peptide: a novel stimulator of steroidogenesis by cultured rat granulosa cells. 299 97

A case of a 58-year-old woman with an unusual variant of malignant islet-cell tumor showing oncocytic features is described. Using the light microscopy technique, the tumor appeared comprised of solid nests of uniform cells with abundant, eosinophilic cytoplasm and round nuclei with granular chromatin. Ultrastructurally, the cells contained numerous abnormal mitochondria, dilated rough endoplasmic reticulum, and scattered dense-core neurosecretory granules, often associated with cytoplasmic filaments. Tumor cells were focally immunoreactive for insulin, glucagon, and somatostatin and diffusely immunoreactive for alpha 1-antitrypsin as assayed by the avidin--biotin technique. The tumor was immunonegative for human chorionic gonadotropin, gastrin, adrenocorticotropic hormone, and serotonin. The patient exhibited some of the clinical features associated with glucagonoma syndrome, including diabetes mellitus and chronic diarrhea. The tumor behaved in a malignant fashion, with widespread lymphatic involvement and bony metastases at the time of presentation. This report of an oncocytic islet-cell carcinoma supports the concept of oncocytic differentiation in islet-cell tumors in a fashion analagous to oncocytic carcinoids.
 ...
PMID:Functioning oncocytic islet-cell carcinoma. Report of a case with electron-microscopic and immunohistochemical confirmation. 300 44

Carcinoid tumors of the middle ear are rare, with only three previously reported cases. The authors report the light and electron microscopic and immunohistochemical features of two carcinoid tumors that occurred in a 34-year-old female and a 21-year-old male. Both presented with unilateral hearing loss. By light microscopic examination, both were characterized by trabecula of tall columnar cells with basal nuclei and no mitotic activity. Electron microscopic examination demonstrated large numbers of pleomorphic neurosecretory granules, perinuclear aggregates of intermediate filaments, cell junctions, and surface microvillous processes. Some cells contained intermediate filaments forming tonofilaments and lacked secretory granules. These cells stained for cytokeratin by immunoperoxidase and separated the neuroendocrine cells from the underlying basal lamina. The cells in this tumor stained for the molluscan cardioexcitatory peptide. Cells in both tumors also stained for pancreatic polypeptide. Neither case stained for lysozyme, insulin, glucagon, somatastatin, gastrin, substance P, thyroid-stimulating hormone, adrenocorticotropic hormone, Met-enkephalin, Leu-enkephalin, neuropeptide Y, peptide YY, neurotensin, Bombesin, serotonin, neuron-specific enolose, glial and neural filaments, S-100 protein, cholecystokinin, beta-endorphin, beta-human chorionic gonadotropin, luteinizing hormone/follicle-stimulating hormone, vasoactive intestinal polypeptide, prolactin or calcitonin. Carcinoid tumor of the middle ear can be distinguished from paraganglioma and middle ear adenoma.
 ...
PMID:Carcinoid tumors of the middle ear. 357 33

Polyamines are polycationic substances which are widely distributed in living organisms and have a close relation to rapid growth phenomena. We examined ornithine decarboxylase (ODC), which is the rate limiting enzyme of polyamine biosynthesis, and polyamine induction in primary cultured rat hepatocytes by various hormones which increase during pregnancy, and revealed differences in hormonal responses between adult and fetal rat hepatocytes. Thirteen hormones, including estrone, estradiol, progesterone, testosterone, human chorionic gonadotropin (HCG), cortisol, dexamethasone, insulin, glucagon, epinephrine and epidermal growth factor (EGF), were tested. Among these hormones, only insulin, dexamethasone and EGF induced ODC activity and polyamine biosynthesis, especially that of putrescine, in both adult and fetal hepatocytes. The effects of EGF were the most significant. The combined effect of insulin and dexamethasone was additive, while that of insulin and EGF was synergistic. The rate of ODC induction was higher in adult hepatocytes than in fetal hepatocytes, however, the reaction was earlier in fetal hepatocytes. These observations suggest that ODC and polyamines in the fetal stage of development are regulated by a mechanism different from that in the adult liver.
 ...
PMID:Hormonal regulation of ornithine decarboxylase and polyamines in primary cultured rat hepatocytes--differences in hormonal response between adult and fetal hepatocytes. 390 80


1 2 3 Next >>