Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Local biosynthesis of the peptide hormone vasopressin is demonstrated in vitro in Leydig cells derived from rat and mouse testis. Cycloheximide-sensitive production of the nonapeptide was shown for rat Leydig cells in primary culture. A polymerase chain reaction technique demonstrated the presence of functionally constituted vasopressin mRNA in rat and mouse testis, primary mouse Leydig cells and in rat and mouse Leydig tumour cell lines (MA10, R2C). Stimulation of cells with gonadotropins, however, had no effect either on peptide production or on levels of specific mRNA. Similarly, treatment of the MA10 cell line with a phorbol ester, or with rat atriopeptin, which activate other second messenger pathways, had no influence on vasopressin mRNA levels. The results are discussed in terms of an autocrine regulatory system which would provide the cell with information about its microenvironment.
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PMID:Vasopressin biosynthesis in rodent Leydig cells. 130 84

Insulin responsiveness in the human placenta is controversial. This study evaluated insulin stimulation of alpha-aminoisobutyric acid (AIB) uptake in cultured human placental trophoblasts. Both Na(+)-dependent and -independent components of AIB uptake were present in cultured trophoblasts. Na(+)-dependent AIB uptake was significantly stimulated by insulin in a time-dependent manner, as early as 2 h, with a maximum at 12 h of continuous exposure to hormone. Insulin treatment for 4 h increased both the initial uptake rate and the final intracellular concentration. Stimulation was dependent on insulin concentration, with significant stimulation beginning at 10(-9) M. Insulin treatment increased maximum velocity but not the Michaelis constant. Approximately 75% of basal (unstimulated) AIB uptake was inhibited by 10 mM alpha-methylaminoisobutyric acid (MeAIB). The insulin-stimulated increment above basal AIB uptake was completely inhibited by 10 mM MeAIB. Cycloheximide treatment significantly reduced basal and stimulated AIB uptake, although a significant response to insulin persisted. Na(+)-dependent AIB uptake was also stimulated by glucagon, dexamethasone, and 8-bromoadenosine 3',5'-cyclic monophosphate, but not by vasopressin. This study further characterizes amino acid uptake by the human placenta and demonstrates that the Na(+)-dependent component of AIB uptake by the cultured trophoblasts is stimulated by physiological concentrations of insulin.
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PMID:Amino acid transport by the cultured human placental trophoblast: effect of insulin on AIB transport. 156 12

Vasopressin stimulates the introduction of aggregated particles, which may represent pathways for water flow, into the luminal membrane of toad urinary bladder. It is not known whether water transport pathways are degraded on removal from membrane or whether they are recycled. We examined the effect of the protein synthesis inhibitors cycloheximide and puromycin using repeated 30-min cycles of vasopressin followed by washout of vasopressin, all in the presence of an osmotic gradient, a protocol that maximizes aggregate turnover. "High dose" cycloheximide (200 micrograms/ml) inhibited flow immediately. "Low dose" cycloheximide (1 microgram/ml) did not affect initial flow; however, flow was inhibited by the fourth restimulation. On further rechallenge, inhibition persisted but did not increase. In the absence of vasopressin, inhibition did not develop. Despite the inhibition of flow in vasopressin-treated tissues, the cAMP-dependent protein kinase ratio (-cAMP/+cAMP), an index of in vivo cAMP effect, was elevated in cycloheximide-treated tissues, suggesting modulation at a distal site in the stimulatory cascade. Cycloheximide inhibited flow when 10 microM forskolin or 0.2 mM 8-BrcAMP was substituted for vasopressin in the fourth period; however, MIX (4 mM)-stimulated flow was enhanced by 1 microgram/ml cycloheximide but inhibited by 200 micrograms/ml cycloheximide. [14C]urea permeability was not inhibited by cycloheximide. Puromycin (0.5 mM) also inhibited water flow by the fourth challenge with vasopressin. The data suggest that protein synthesis inhibitors attenuate flow at a site that is distal to cAMP-dependent protein kinase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Protein synthesis inhibitors attenuate water flow in vasopressin-stimulated toad urinary bladder. 244 2

Isolated rat hepatocytes in primary monolayer culture were maintained for 18-24 h in the presence of 10% (v/v) serum and [3H]inositol. Vasopressin (100 nM) stimulated the production of inositol mono-, bis- and tris-phosphates (IP1, IP2, and IP3). Prior exposure of hepatocytes to 8-bromo cyclic AMP (8Br-cAMP; 100 microM), but not 8-bromo cyclic GMP, enhanced the vasopressin-mediated stimulation of inositol phosphate accumulation, but had no significant effect on their formation in the absence of vasopressin. The effect of the cyclic AMP analogue was mimicked by glucagon (10 nM), and was seen whether cyclic AMP or glucagon was added 5 min or 12 h before the addition of vasopressin. An 8 h incubation with dexamethasone (100 nM) enhanced the accumulation of IP3, but not that of IP2 or IP1, in the presence of 8Br-cAMP and vasopressin. Cycloheximide or actinomycin D had little effect on the vasopressin stimulation of inositol phosphate accumulation, after an 8 h incubation in the presence or absence of 8Br-cAMP.
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PMID:Exposure of cultured hepatocytes to cyclic AMP enhances the vasopressin-mediated stimulation of inositol phosphate production. 253 87

Vasopressin (VP) increases urinary concentration by signaling through the vasopressin receptor (V2R) in collecting duct principal cells. After downregulation, V2R reappears at the cell surface via an unusually slow (several hours) "recycling" pathway. To examine this pathway, we expressed V2R-green fluorescent protein (GFP) in LLC-PK1a cells. V2R-GFP showed characteristics similar to those of wild-type V2R, including high affinity for VP and adenylyl cyclase stimulation. V2R-GFP was located mainly in the plasma membrane in unstimulated cells, but it colocalized with the lysosomal marker Lysotracker after VP-induced internalization. Western blot analysis of V2R-GFP showed a broad 57- to 68-kDa band and a doublet at 46 and 52 kDa before VP treatment. After 4-h VP exposure, the 57- to 68-kDa band lost 50% of its intensity, whereas the lower 46-kDa band increased by 200%. The lysosomal inhibitor chloroquine abolished this VP effect, whereas lactacystin, a proteasome inhibitor, had no effect. Incubating cells at 20 degrees C to block trafficking from the trans-Golgi network reduced V2R membrane fluorescence, and a perinuclear patch developed. Cycloheximide reduced the intensity of this patch, showing that newly synthesized V2R-GFP contributed significantly to its appearance. Cycloheximide also inhibited the reappearance of cell surface V2R after downregulation. We conclude that after downregulation, V2R-GFP is delivered to lysosomes and degraded. Reappearance of V2R at the cell surface depends on new protein synthesis, partially explaining the long time lag needed to fully reestablish V2R at the cell surface after downregulation. This degradative pathway may be an adaptive response to allow receptor-ligand association in the hypertonic and acidic environment of the renal medulla.
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PMID:Downregulation of the vasopressin type 2 receptor after vasopressin-induced internalization: involvement of a lysosomal degradation pathway. 1567 78