Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems.
Cell Mol Neurobiol 1992 Oct
PMID:The presence of immunoreactive vertebrate bioactive peptide substances in hemocytes of the freshwater snail Viviparus ater (Gastropoda, Prosobranchia). 136 24

The CHO-K1 cell line responds to the peptide amylin by a rapid elevation of cAMP. The related peptide calcitonin gene-related peptide (CGRP) is 100 times less potent at stimulating adenylate cyclase than is amylin. The actions of amylin at this receptor are concentration dependent and not antagonized by the CGRP antagonist CGRP-(8-37). Although these cells have receptors for calcitonin, amylin is unable to take part in any high affinity interaction with these receptors, as assessed by radioligand binding. The CHO-K1 cell line has receptors for amylin that are distinct from those for calcitonin and CGRP.
Mol Pharmacol 1992 May
PMID:Stimulation of adenylate cyclase by amylin in CHO-K1 cells. 137 16

Intramuscular hemangiomas are idiopathic lesions which are either tumoral or developmental in origin. A close association of abnormal blood vessels with nerve fibers is found and may suggest that nerves have a primary inciting role in the development of these lesions. In the current study, the number of nerve fibers in different zones around the tumors, as well as the type of neuropeptides present in these fibers, was quantitatively assessed by computer-assisted image analysis of immunohistochemical staining of histological slides. The number of nerve fibers as determined by positive staining by anti-protein S-100 antibodies was found to be elevated in the immediate vicinity of the abnormal blood vessels. The density of the nerve fibers rapidly declined with increasing distance from the hemangiomas, reaching normal values at distances of over 2 mm. Furthermore, hemangiomas contain a significantly higher number of calcitonin gene-related peptide (CGRP), substance P, and Met-enkephalin-positive fibers. The most significant rise in number is that of CGRP-positive fibers. This neuropeptide is a known mitogen, which could be responsible for the growth of the hemangiomatous blood vessels. Substance P is a nociceptive neurotransmitter and its presence can explain the pain which often accompanies even tiny intramuscular hemangiomas.
Exp Mol Pathol 1992 Jun
PMID:Neuropeptidergic innervation of intramuscular hemangiomas. 137 96

The purpose of this work was to investigate the effects of calcitonin (CT) on trophoblastic cells with respect to cAMP levels and human chorionic gonadotrophin (hCG) secretion in cultured cells from first-trimester and term placentas and in a choriocarcinoma cell line (JEG-3). The expression of the CT gene was investigated to elucidate a putative autocrine control of CT during pregnancy. The addition of salmon CT (10(-10) M and above) resulted in concentration-dependent increases in cAMP secretion by normal trophoblastic cells from term and first-trimester placentas. Moreover, CT was found to increase cAMP secretion preferentially in completely differentiated cells, i.e. after 4-7 days in culture. Addition to the culture medium of JEG-3 cells slightly increased cAMP secretion only at a concentration of 10(-8) M. The basal level of hCG in the medium was found to be higher in the first-trimester than in the term trophoblast culture, but salmon CT induced an increase in hCG secretion by term placenta cells only. CT gene expression in our experimental model was investigated to elucidate a putative autocrine control of CT action during pregnancy. It was not found to be expressed in syncytiotrophoblast cells from either first-trimester or term placenta cells by the method used. Our data demonstrate the absence of autocrine control of CT effects in trophoblastic cells, and suggest that CT is likely to exert its effect preferentially on differentiated cells.
Mol Cell Endocrinol 1992 May
PMID:Effects of calcitonin on human trophoblastic cells in culture: absence of autocrine control. 138 27

Messenger RNA for rat islet amyloid polypeptide (IAPP) has been identified not only in the pancreas but also, in lesser amounts, in preparations from the stomach and dorsal root ganglia. In the stomach, insulin mRNA was not detectable, ruling out possible contamination by pancreatic tissue. Because IAPP and calcitonin gene-related peptide (CGRP) are related and CGRP is present in both stomach and dorsal root ganglia, it was possible that 'IAPP' signals were in fact due to cross-hybridization with CGRP mRNA. A second IAPP probe was constructed which does not cross-react. This probe also detected mRNA in both tissues, confirming the expression of IAPP in both tissues. The regional distribution of IAPP mRNA in the stomach did not parallel that of gastrin mRNA. IAPP mRNA was present in the antrum, centrum and pylorus and, like gastrin, the highest amounts were in the pylorus. However, the ratio between the pylorus and centrum was 3.6:1 for IAPP and 156:1 for gastrin. The effects of dietary manipulation were determined; a period of 48 h of starvation reduced pancreatic IAPP mRNA by approximately 60%, whereas in the stomach there was no significant reduction. If the action of IAPP was hormonal, pancreas and stomach would not be acting in concert. A paracrine role for gastric IAPP therefore seems more likely.
J Mol Endocrinol 1992 Oct
PMID:Extra-pancreatic expression of the rat islet amyloid polypeptide (amylin) gene. 141 86

Calcitonin is a direct inhibitor of osteoclastic activity. Osteoclast retraction is readily induced by calcitonin and it is possible that calcitonin-induced inhibition of bone resorption is in part due to this effect. However, little is known of the mechanisms of this action. In these studies, we have investigated the intracellular signalling pathway of calcitonin-induced osteoclast retraction using cultures of freshly isolated rat osteoclasts. The spread area occupied by single Giemsa-stained rat osteoclasts was measured in vitro by a computer imaging analysis system and used as a quantitative parameter for calculating the degree of osteoclast retraction in response to various agents. Our results show that cAMP may be an important second messenger in the reaction of osteoclasts to calcitonin. Moreover, both protein kinase-A and calcium/calmodulin-dependent protein kinase are involved in the osteoclast retraction induced by this hormone, while cytoskeletal proteins are required for the process to occur.
Exp Mol Pathol 1992 Oct
PMID:Evidence that protein kinase-A, calcium-calmodulin kinase and cytoskeletal proteins are involved in osteoclast retraction induced by calcitonin. 142 55

We have analyzed the effect of extracellular stimuli on the differentiation state of the CA77 thyroid C-cell line as a model to understand the control of neural crest cell differentiation. In contrast to the endocrine C-cell phenotype, we found that CA77 cells have a neuronal phenotype characterized by laminin-induced neurites, neuronal antigens, and calcitonin gene-related peptide (CGRP) mRNA expression. Treatment with dexamethasone and retinoic acid reversibly repressed some of these neuronal characteristics to induce features more characteristic of the parental C-cells. In the case of dexamethasone treatment, there was a partial retraction and thinning of neurites, an increased number of secretory vesicles in the cell bodies, and about a 10-fold decrease in DNA synthesis. Treatment with retinoic acid alone or in combination with dexamethasone caused decreased cell adhesion and an even more extensive retraction of the neurites. Dexamethasone also biased the steady state levels of the alternatively spliced transcripts from the calcitonin/CGRP gene to favor calcitonin relative to CGRP mRNA. While retinoic acid treatment decreased both calcitonin and CGRP mRNA levels, the combination of dexamethasone and retinoic acid still yielded the increase in calcitonin relative to CGRP mRNA. These results suggest that glucocorticoids and retinoic acid may contribute to a late and reversible differentiation of thyroid C-cells by partly repressing neuronal properties.
Mol Endocrinol 1992 Feb
PMID:Neuronal properties of a thyroid C-cell line: partial repression by dexamethasone and retinoic acid. 156 64

The effects of synthetic [Asu1,7]eel calcitonin (CT) on the unidirectional inflow of Ca2+ were investigated in isolated rat liver cells by measuring the initial rate of 45Ca2+ uptake. CT increased Ca2+ inflow, with EC50 values (concentrations giving half-maximal effect) of 10(-10) M. The action of CT was in evidence within 15 s after the addition of 45Ca2+ to the cells. CT-activated Ca2+ inflow was completely blocked by the presence of the Ca2(+)-antagonist verapamil at a concentration of 10(-8) M. Meanwhile, epinephrine (10(-8) to 10(-4) M) or phenylephrine (10(-8) to 10(-4) M) increased Ca2+ inflow within 60 s after the addition of 45Ca2+ to the cells. Those hormonal effects were additively enhanced by the presence of CT (10(-8) M). Phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, increased Ca2+ inflow at a concentration of 10(-9) to 10(-5) M. The presence of CT (10(-8) M) synergistically enhanced PMA-increased Ca2+ inflow at concentrations of 10(-7) to 10(-5) M. The present results suggest that CT can stimulate the rate of Ca2+ inflow in rat liver cells.
Mol Cell Endocrinol 1991 Jan
PMID:Stimulatory effect of calcitonin on Ca2+ inflow in isolated rat hepatocytes. 164 39

Binding of 125I-calcitonin gene-related peptide (125I-CGRP) to rat cerebellum membranes and the sensitivity to guanine nucleotides of binding were investigated. Cerebellum binding sites labeled by 125I-CGRP appear to be highly specific, inasmuch as CGRP inhibited binding with an IC50 of 100 pM but other peptides were inactive or much less active in displacing 125I-CGRP from these sites. 125I-CGRP binding sites in cerebellum membranes were saturable and of high affinity. Scatchard analysis of the saturation binding data revealed a homogeneous population of binding sites, with a KD of 224 +/- 28 pM and Bmax of 131 +/- 15 fmol/mg of protein. In the presence of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) (100 microM), a single population of binding sites, with a KD of 464 +/- 77 pM and Bmax of 100 +/- 14 fmol/mg of protein, was observed. The kinetics of association of 125I-CGRP with cerebellum membranes were monophasic at all ligand concentrations tested. However, the observed association rate constant (kobs) was not dependent on [125I-CGRP] in a linear fashion in either the absence or the presence of GTP gamma S (100 microM). The kinetics of dissociation of 125I-CGRP from cerebellum membranes were multiexponential, with fast and slow dissociating components having rate constants of 0.34 +/- 0.01 and 0.025 +/- 0.001 min-1, respectively. The fast dissociating component represented 60 +/- 2% of the total specific binding sites. Dissociation of 125I-CGRP from cerebellum sites was much faster in the presence of GTP gamma S (100 microM) but still exhibited dissociation from two affinity components. The rate constants for these components of dissociation were 0.67 +/- 0.03 and 0.077 +/- 0.007 min-1, with the faster dissociating component representing 66 +/- 1% of the total specific binding sites. These findings provide the first evidence that CGRP receptors exist in multiple affinity states and that cerebellum CGRP receptors are regulated by guanine nucleotides. Our results also suggest the existence of two affinity states of the CGRP-receptor-guanine nucleotide-binding protein ternary complex.
Mol Pharmacol 1991 Jun
PMID:Multiple affinity forms of the calcitonin gene-related peptide receptor in rat cerebellum. 164 51

The distribution of cholecystokinin (CCK)-immunoreactive neurons in the central nervous system has been questioned because many antisera raised against CCK have been found to cross-react with calcitonin gene-related peptide. The use of in situ hybridization histochemistry has allowed investigators to determine which CCK-immunoreactive cells actually contain the messenger RNA (mRNA) coding for preprocholecystokinin (preproCCK), thus indicating that the peptide is synthesized in these cells. In this study, we report the distribution of preproCCK mRNA in the brainstem and spinal cord of the rat. The main findings of this study are the localization of preproCCK mRNA in motoneurons of cranial nerves IV, V, VI, VII and XII, as well as in motoneurons of the cervical and lumbrosacral levels of the spinal cord. Additionally, cells in lamina III at the cervical and lumbar enlargements contain preproCCK mRNA, suggesting that cells expressing CCK may be important in the processing of sensory information from the appendages.
Brain Res Mol Brain Res 1991 Jul
PMID:Distribution of preprocholecystokinin mRNA in motoneurons of the rat brainstem and spinal cord. 165 59


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