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)

Several peptide hormones are effective when administered intranasally (in); these include oxytocin, vasopressin, insulin, glucagon, and calcitonin. With regard to GHRH and CRH, previous studies demonstrated that their bioavailability following in administration was very low. In this study we evaluated the serum GH response to 50 micrograms GHRH iv and to 700 micrograms GHRH in, the latter given alone and with 5 and 15 mg sodium-glycocholate (SGC), a surfactant, in six normal men. The bioavailability of in GHRH, calculated as net GH secretory area, was very low, and increased to 7% that of iv GHRH when SGC was used. In the same men, 50 micrograms CRH was administered both iv and in, alone and with 5 and 15 mg SGC. The bioavailability of in CRH, calculated as net cortisol secretory area, was very low and increased to 100% that of iv CRH when 15 mg SGC was used. These data indicate that the efficacy of GHRH and CRH administered in is significantly augmented by SGC.
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PMID:Effect of intranasal growth hormone-releasing hormone and corticotropin-releasing hormone administration on growth hormone and cortisol release: improved bioavailability by means of sodium-glycocholate. 249 80

Proximal tubules were prepared from rat kidney cortex by collagenase digestion and purified by Percoll gradient centrifugation. Their enrichment was estimated by comparing the specific activities of various cell-specific enzymes in homogenates of renal cortex and of the isolated tubules. The tubules were cultured in a 50:50 mixture of Dulbecco's modified Eagle's and Ham's F12 media supplemented with insulin, transferrin, epidermal growth factor, hydrocortisone, and prostaglandin E1. After 2 to 3 d an extensive outgrowth of epithelial cells developed from the attached tubules. After 5 to 7 d near confluent monolayers were obtained. Hormonal responsiveness, marker enzyme activities, and transport properties were determined to further characterize the primary cultures. The cultured cells exhibited increased cyclic AMP production in response to parathyroid hormone but not calcitonin or vasopressin, consistent with the absence of cells derived from distal and collecting tubules. The cells also retained significant levels of 25-hydroxyvitamin D3-1 alpha-hydroxylase, alkaline phosphatase, and gamma-glytamyl-transpeptidase, three enzymes that are primarily associated with the proximal tubule. The cultured epithelial cells also exhibit a Na+-dependent phosphate and glucose transport systems. Therefore, the cells retain many functional properties that are characteristic of proximal tubules. Thus, the primary cultures should be suitable for the study of processes that occur specifically within this segment of the rat nephron.
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PMID:Characterization of primary cell cultures derived from rat renal proximal tubules. 254 89

Basolateral membranes were prepared from rat renal cortex by density gradient centrifugation. Their purity was confirmed by electron microscopy and by marker enzyme enrichment. The basolateral membrane preparation was shown to be derived predominantly from the proximal renal tubule by measurement of hormone-stimulated adenylate cyclase; marked stimulation of adenylate cyclase was found with parathyroid hormone, but not with isoprenaline, antidiuretic hormone or calcitonin. A single class of specific high-affinity [3H]angiotensin II-binding site was identified in the basolateral membrane preparation which, after correction of results for tracer degradation, showed equilibrium dissociation constant of 0.23 nmol/l and binding site concentration of 485.8 fmol/mg protein. Binding sites for [3H]angiotensin II were measured in basolateral membranes prepared from rats fed diets with a low, normal or high sodium content. A trend of increased binding site density with reduced sodium intake was found which did not reach statistical significance. No effect on affinity was demonstrated. Treatment of rats on a low-sodium diet with captopril (500 mg/l drinking water) caused a significant reduction in binding site density; no effect on affinity was demonstrated. These findings suggest that the density of angiotensin II receptors at this site is altered by the activity of the renin-angiotensin system.
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PMID:[3H]angiotensin II binding to basolateral membranes from rat proximal renal tubule: effect of sodium intake and captopril. 254 61

Three clones of the pig kidney cell line LLC-PK1 were isolated and characterized with regard to morphology, growth, proximal tubule enzyme activity, sugar uptake capacity, and hormone and drug responsiveness in a defined medium. Clone N4 was similar in morphology to the wild type (WT), whereas clone F8 showed loose attachment to the substrate, formed large, sweeping domes, and had an elongated desmosome junction between cells. The third clone, F2, did not form domes and showed a marked reduction in growth rate. Cultures of WT, N4, and F8 had higher specific activities of the enzyme alkaline phosphatase and gamma-glutamyl transpeptidase at confluence relative to growing cells; however, there was no evidence of an increase in activity of either enzyme at confluence in F2. Phlorizin-sensitive alpha-methyl-D-glucoside uptake and cytochalasin B-sensitive 2-deoxy-D-glucose uptake were measured in confluent cultures grown on porous filter supports. None of the clones lacked either of the hexose transport systems, although quantitative differences were evident. N4 cells grown in a defined medium in 96-well culture plates were tested in situ for their enzyme responses to differentiation inducers, tumor promoters, and hormones. Alkaline phosphatase activity was significantly increased at confluence by serum, parathyroid hormone (PTH), and vasopressin (AVP), and was decreased by tetradecanoylphorbol acetate (TPA) and epinephrine (EPI). Glutamyl transpeptidase activity was decreased at confluence by serum, TPA, and EPI. Similar tests on alpha-methyl-D-glucoside uptake showed that serum, TPA, PTH, and AVP had no significant effect on phlorizin-sensitive uptake; however, calcitonin increased uptake by 84% (n = 18). It was concluded that LLC-PK1 clones maintained in a defined medium are useful models for studying renal cell function.
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PMID:Growth, enzyme activity, sugar transport, and hormone supplement responses in cells cloned from a pig kidney cell line LLC-PK1. 256 38

Distal bright convoluted tubules (DCTb) were microdissected from rabbit kidney cortex and cultured in a hormonally defined medium. The quality and the degree of polarization of the growing epithelia were assessed by indirect immunofluorescence studies using a monoclonal antibody raised against the apical membrane of the DCTb in situ. The cultured monolayers had a high hexokinase activity and a low gamma-glutamyl transferase activity compared with cultured proximal convoluted tubules. Adenosine 3',5'-cyclic monophosphate production was stimulated by calcitonin and insensitive to parathyroid hormone, vasopressin, and isoproterenol. Both 20- and 30-day-old cultures developed an apical-negative transepithelial potential of -3.1 and -22.3 mV, respectively. Amiloride reversibly reduced the voltage by 90% only when applied on the apical side of the monolayers. Phenamil (10(-8), 10(-6) M) had the same effect as amiloride. Calcitonin reversibly decreased the transepithelial voltage. These data support the hypothesis that, in the DCTb in primary culture, the transepithelial voltage is due to the presence of Na channels and that calcitonin modulates this transport pathway.
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PMID:Electrical properties of rabbit early distal convoluted tubule in primary culture. 256 36

The mammalian renal thick ascending limb of Henle (TAL) reabsorbs approximately 55% of the filtered magnesium; accordingly, it is the major segment involved in control of renal Mg balance. This review discusses recent evidence for passive and active transport of Mg through the paracellular and transcellular pathways of the TAL, respectively. The properties of these pathways provide a basis for understanding the factors influencing magnesium reabsorption and hormonal controls regulating Mg balance. Normally, Mg absorption is load dependent, whether delivery is altered by increasing luminal Mg concentration or increasing the flow rate into the thick ascending limb. In contrast to the luminal concentration, elevation of peritubular (plasma) Mg and Ca inhibit divalent cation absorption by mechanisms that are not entirely clear. Magnesium reabsorption in the TAL is also closely associated with NaCl absorption so that factors that influence NaCl also affect magnesium. Magnesium deficiency results in a specific and apparently intrinsic cellular adaptation to increase Mg absorption in the TAL. Our greatest understanding of hormonal controls for Mg absorption have come from recent studies using a "hormone deprived" animal model. Parathyroid hormone, calcitonin, glucagon, and antidiuretic hormone act through a common second messenger, adenosine 3',5'-cyclic monophosphate, to limit Mg excretion by enhancing active Mg transport in the TAL. The integrated actions of these hormones and possibly others provide a sensitive means of control. Clearly, recent observations, using in vivo and in vitro microperfusion studies, have altered our thinking of TAL function and indicate that Mg transport is sensitively and specifically controlled within this segment.
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PMID:Control of magnesium transport in the thick ascending limb. 264 45

An immunoblotting method to detect low-molecular-weight peptides with monoclonal antibodies that normally fail to demonstrate immunoreactivity using conventional blotting techniques is described. Detection of neurophysin, insulin, calcitonin, vasopressin, and beta-endorphin electroblotted on nitrocellulose membranes was optimized after introducing four modifications into the conventional procedure. These include renaturing the gels after sodium dodecyl sulfate electrophoresis, electroblotting the renatured gels in basic transfer buffer, fixing and/or heating the blots, and using avidin/alkaline phosphatase conjugates for antigen/antibody detection. This technique likely enables the denatured peptides to regain their native conformation and, therefore, restores antigenicity and recognition by highly structural specific monoclonal antibodies. Although the most dramatic improvement with this technique is with monoclonal antibodies, a modest improvement in sensitivity can be obtained when immunoblots are probed with polyclonal antibodies. The high resolution of this system will be useful in probing blots of partial proteolytic digests of proteins with both monoclonal and polyclonal antibodies.
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PMID:Detection of low-molecular-weight polypeptides on nitrocellulose with monoclonal antibodies. 269 85

The occurrence and distribution of peptide-containing nerve fibers to the cerebral circulation are described. Immunocytochemical studies have revealed that cerebral blood vessels are invested with nerve fibers containing neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), substance P (SP), neurokinin A (NKA), and calcitonin gene-related peptide (CGRP). In addition, there are studies reporting the occurrence of putative neurotransmitters such as cholecystokinin, dynorphin B, galanin, gastrin releasing peptide, vasopressin, neurotensin, and somatostatin. The nerves occur as a longitudinally oriented network around large cerebral arteries. There is often a richer supply of nerve fibers around arteries than veins. The origin of these nerve fibers has been studied by retrograde tracing and denervation experiments. These techniques, in combination with immunocytochemistry, have revealed a rather extensive innervation pattern. Several ganglia, such as the superior cervical ganglion, the sphenopalatine ganglion, the otic ganglion, and small local ganglia at the base of the skull, contribute to the innervation. Sensory fibers seem to derive from the trigeminal ganglion, the jugular-nodose ganglionic complex, and from dorsal root ganglia at level C2. The noradrenergic and most of the NPY fibers derive from the superior cervical ganglion. A minor population of the NPY-containing fibers contains VIP instead of NA and emanates from the sphenopalatine ganglion. The cholinergic and the VIP-containing fibers derive from the sphenopalatine ganglion, the otic ganglion, and from small local ganglia at the base of the skull. Most of the SP-, NKA-, and CGRP-containing fibers derive from the trigeminal ganglion. Minor contributions may emanate from the jugular-nodose ganglionic complex and from the spinal dorsal root ganglia. NPY is a potent vasoconstrictor in vitro and in situ. VIP, PHI, SP, NKA, and CGRP act via different mechanisms to induce cerebrovascular dilatation. The sympathetic, the parasympathetic, and the sensory systems appear to be involved in modulating cerebrovascular tone in hypertension and in conditions of threatening vasoconstriction, e.g., subarachnoid hemorrhage and migraine.
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PMID:Neuropeptides in the cerebral circulation. 270 77

The effects of the absence of various hormones (antidiuretic hormone, thyroid hormone, parathyroid hormone, and calcitonin) on proximal and distal structures were studied in diabetes insipidus (DI) Brattleboro rats. The cross-sectional area of the first segment of proximal convoluted tubules (S1) was significantly reduced in thyroparathyroidectomized (TPTX) DI rats compared with Long-Evans rats (the strain of origin of DI rats) and untreated DI rats. Administration of triiodothyronine (T3, 10 micrograms/day for 7 days) to TPTX-DI rats restored the proximal tubule structure. In the distal convoluted tubule (DCT) the cross-sectional area of the epithelium and the number of nuclei per cross-sectional area were significantly greater in untreated ADH-deficient DI rats than in the control Long-Evans rats. Daily administration of 1-desamino-8-D-arginine vasopressin (dDAVP, 500 ng/day for 3 wk) significantly reduced the size and the number of DCT cells in DI rats. Cortical micropuncture data indicated that the Na+ concentration in the fluid delivered to the DCT and the absolute amount of Na+ reabsorbed along the DCT were higher in DI than in dDAVP-treated DI rats. It is concluded that functional changes in the PCT, subsequent to chronic TPTX, are accompanied by marked alteration of the cell anatomy of this nephron segment, and that the processes that modify the Na load delivered to the DCT and the Na transport in the DCT are accompanied by structural modifications of this segment.
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PMID:A structural study of the rat proximal and distal nephron: effect of peptide and thyroid hormones. 271 59

Neurons with intrinsic pacemaker activity and presumed sympathoexcitatory function were recorded in rat tissue slices within the confines of the rostroventrolateral reticular nucleus (RVL). These cells were excited in dose-dependent fashion by arginine vasopressin (AVP, 10(8)-10(6) M) but not by oxytocin (up to 10(7) M). The effect of AVP was mimicked by the V1-selective agonist [Phe2,Orn8]vasotocin (VT) (1 microM) but not by the V2-agonist [Val4,D-Arg8]vasopressin (VP) (1.9 microM). The effect of AVP (10(-7) M) was completely blocked by SKF 101926 (10(7) M), a non-selective antagonist and by d(CH2)5[Tyr(Me)2]AVP, a V1-selective antagonist but was unaffected by the V2-selective antagonist d(CH2)5[D-Ile2,Ile4,Ala-NH2 9]AVP. These cells were also activated by thyrotropin-releasing hormone (TRH) (10(-7)-10(-6) M), calcitonin gene-related peptide (CGRP) (4 X 10(-8) M), substance P, (10(-6) M), neuropeptide Y (NPY) (10(-8) M) and inhibited by Met-enkephalin (10(-6) M) and morphine (2 mM). Corticotropin-releasing factor (CRF) (10(-7) M) and angiotensin II (10(-6) M) were ineffective. In conclusion, RVL pacemaker neurons have vasopressin receptors reminiscent of the V1 (vascular and pressor) subtype. Their pacemaking activity is modulated by low doses of several other peptides also known to produce large vasomotor effects after introduction into the cerebroventricular space.
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PMID:Effects of vasopressin and other neuropeptides on rostral medullary sympathoexcitatory neurons 'in vitro'. 275


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