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)

Proximal duodenal bicarbonate secretion is an important factor in humans and animals protecting the mucosa against acid-peptic damage. This study examined the mechanisms responsible for the central nervous system regulation of duodenal bicarbonate secretion by calcitonin gene-related peptide (CGRP) in unrestrained rats. Cerebroventricular administration of rat CGRP significantly inhibited basal duodenal bicarbonate secretion as well as the stimulatory effects of vasoactive intestinal peptide, neurotensin, a luminal PGE1 analogue, misoprostol, and hydrochloric acid. The inhibitory effects of cerebroventricular CGRP were abolished by ganglionic blockade with chlorisondamine, significantly attenuated by noradrenergic blockade with bretylium, and enhanced by vagotomy. Inhibition of duodenal bicarbonate secretion induced by CGRP coincided with significant increases in plasma norepinephrine (NE) and vasopressin concentrations. The alpha adrenergic receptor antagonist, phentolamine, and the vasopressin V1 receptor antagonist, (1-deaminopenicillamine, 2-[O-methyl]Tyr, 8-Arg)-vasopressin, given intravenously reversed the central inhibitory effect of CGRP by approximately 50% each. Pretreatment of the animals with both phentolamine and the vasopressin antagonist completely abolished the central inhibitory effect of CGRP. Peripheral vasopressin and NE significantly decreased duodenal bicarbonate secretion, and their inhibitory effects were additive and prevented by phentolamine and the vasopressin antagonist, respectively. We conclude that cerebroventricular CGRP inhibits rat duodenal bicarbonate secretion by activation of sympathetic efferents and subsequent release of NE and vasopressin that act on alpha adrenergic and vasopressin receptors, respectively.
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PMID:Cerebroventricular calcitonin gene-related peptide inhibits rat duodenal bicarbonate secretion by release of norepinephrine and vasopressin. 229

The humoral hypercalcemia of malignancy factor (also called PTH-related protein or PTHrp) has been shown to produce effects similar to PTH in the kidney, bone, and cardiovascular system. Binding of PTHrp and PTH has been characterized in renal and osseous tissues, but not in vascular tissue. We have attempted to characterize the interaction of both human PTHrp and rat PTH to renal microvessels as a model of vascular smooth muscle and in a renal tubule preparation from the same rabbit kidneys. Previous studies have shown the microvessel and tubule preparations to be distinct based upon morphological examination, differential enzyme markers, calcitonin and vasopressin-sensitive adenylate cyclase distribution, and different characteristics of guanine nucleotide and of oxidized PTH activation of the adenylate cyclases associated with the preparations. Human PTHrp and rat PTH were iodinated by standard techniques and purified by HPLC. Both ligands bound to microvessels and tubules in a saturable, specific manner, Maximal specific binding of either ligand was 65-75% in microvessels and 80-90% in renal tubules. The time courses of binding of both ligands were identical with steady state achieved within 20 min in the smooth muscle of microvessels and 15 min in the tubules at 22 C. In equilibrium competition binding experiments, bound 125I-PTHrp was displaced by both PTHrp and PTH in microvessels and tubules. Rat PTH displayed slightly higher affinity in microvessels and tubules than PTHrp. Identical results were obtained with 125I-PTH as ligand. Specificity of binding of PTHrp and PTH to both microvessels and tubules was excellent, with competition observed between the radioactive ligand and bovine and rat PTH, PTHrp, and the antagonists, [Nle8,18, Tyr34]bovine PTH and [Nle8,18, Tyr34]bovine PTH but not with several other peptides of unrelated structure. The only major difference in binding between microvessels and tubules was a smaller number of binding sites in microvessels compared to tubules. These results indicate that vascular tissue contains receptor sites for PTH and PTHrp as identified by radioligand binding techniques. These receptors are similar in characteristics to the receptors of renal tubular tissue. Both PTH and PTHrp appear to interact with the receptors of rabbit kidney microvessels and tubules.
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PMID:Binding of parathyroid hormone and parathyroid hormone-related protein to vascular smooth muscle of rabbit renal microvessels. 229 68

A possible regulatory role of calcitonin (CT) upon liver calcium content was investigated by using a Ca2+ channel blocker in thyroparathyroidectomized (TPTX) rats. In bile duct-ligated TPTX rats, liver calcium content was not significantly increased by a single ip injection of calcium chloride (4.0 mg Ca2+/100 g body weight). Administration of CT (80 MRC mU/100 g) caused a remarkable elevation of liver calcium content. This hormonal effect was inhibited by administration of verapamil (1.0 mg/100 g) or lanthanum chloride (0.4 mg/100 g), Ca2+ channel blockers. CT administration markedly increased the transport of calcium into the bile through the liver cells of TPTX rats injected ip with calcium. This increase in the bile calcium content was prevented by administration of verapamil or lanthanum chloride. Administration of epinephrine (10 micrograms/100 g), vasopressin (10 micrograms/100 g), or concanavalin A (1.0 mg/100 g) produced a significant elevation of bile calcium content; these elevations were not significantly altered by addition of verapamil (1.0 mg/100 g). These data suggest the presence of CT receptors on liver cell plasma membranes which are involved in regulation of membrane Ca2+ channels. It is proposed that CT facilitates the entry of extracellular calcium into liver cells by opening Ca2+ channels located on their plasma membranes.
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PMID:Participation of Ca2+ channel in liver calcium regulation by calcitonin in rats. 241 53

Recently it has been shown that calcitonin gene-related peptide (CGRP) and substance P (SP) are coexisting in central and peripheral nerve endings of sensory neurons. In the present study we compared the vasodepressor and plasma extravasating activity of CGRP with that of SP. Systemic administration of CGRP to pithed, vagotomized rats evoked a dose dependent, long lasting vasodilation accompanied by a parallel rise in heart rate. The tachycardic response to CGRP may indicate a direct positive chronotropic action on the heart since this effect could not be blocked by beta-adrenoceptor blockade. For any equimolar dose the hypotensive effect of CGRP was much larger than that of SP. Both, CGRP and SP, showed a more pronounced decrease in mean arterial blood pressure after elevation of basal blood pressure levels by constant infusion of either phenylephrine, arginine-vasopressin, or angiotensin II. After systemic administration in equimolar doses CGRP was much less effective in producing plasma extravasation than SP. In conclusion, at equimolar doses CGRP is 10 times more potent than SP in producing vasodilatation but it possesses less than a third of the potency of equimolar doses of SP in producing plasma extravasation.
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PMID:Cardiovascular effects of calcitonin gene-related peptide in the pithed rat: comparison with substance P. 241 96

The cAMP-dependent protein kinase from LLC-PK1 cells can be activated in vivo by calcitonin and vasopressin, or forskolin. Continuous treatment of cells with these agents results in a decrease of total cAMP-PK activity. The loss of kinase activity was enhanced when either of these three agents was incubated in the presence of isobutylmethylxanthine. Results obtained using affinity purified antibodies to the catalytic subunit show that the loss of kinase was due to specific proteolysis of this subunit.
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PMID:cAMP mediated proteolysis of the catalytic subunit of cAMP-dependent protein kinase. 241 85

The medial preoptic nucleus (MPN) is a sexually dimorphic complex with three major subdivisions. The cell-dense central (MPNc) and medial (MPNm) subdivisions are larger in male rats, while the cell-sparse lateral subdivision (MPNl) occupies a majority of the nucleus in females. In the present study we evaluated the distribution of possible monoaminergic and peptidergic cells and fibers within the MPN, as well as in adjacent regions of the medial preoptic area of the adult male rat. For this, we used an indirect immunohistochemical method with antisera to serotonin (5HT), dopamine beta-hydroxylase (DBH), tyrosine hydroxylase (TH), neuropeptide Y (NPY), cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), substance P (SP), neurotensin (NT), corticotropin-releasing factor (CRF), luteotropin-releasing hormone (LRH), somatostatin (SS), thyrotropin-releasing hormone (TRH), oxytocin (OXY), vasopressin (VAS), adrenocorticotropic hormone (1-24; ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), leucine-enkephalin (L-ENK), and calcitonin gene-related peptide (CGRP). The results suggest that cell bodies and/or fibers crossreacting with all of these putative neurotransmitters are differentially distributed within the MPN. Within the MPNm, the densest plexuses of fibers were stained with antisera to SP and NPY, while moderate densities of fibers were stained with anti-DBH, SS, CCK, CGRP, ACTH, and alpha-MSH, and only a few fibers were stained with anti-5HT, TH, NT, VAS, and L-ENK. Moderate numbers of SP- and L-ENK-immunoreactive cell bodies, and a few SS-, NT-, CRF-, and TRH-stained cell bodies were also found within the MPNm. The MPNc contained a dense plexus of CCK-immunoreactive fibers, as well as a few CRF-immunoreactive fibers. Both fiber types were localized almost exclusively to this subdivision, while most of the others studied here appeared to avoid it selectively. This suggests that there are relatively few inputs to the MPNc, and that they tend to avoid other parts of the nucleus, although moderate densities of DBH- and NPY-immunoreactive fibers were found in both the MPNm and MPNc. The MPNc contained several CCK-immunoreactive cell bodies as well as a moderate number of TRH-stained cell bodies. Both cell types were nearly completely localized to the MPNc. The major inputs to the MPNl studied here appear to be stained with antisera to 5HT and L-ENK, although moderate numbers of NT- and CRF- immunoreactive fibers were also found in this part of the nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Neurotransmitter specificity of cells and fibers in the medial preoptic nucleus: an immunohistochemical study in the rat. 242 28

To aid in characterizing adenosine receptors in renal cells, primary cultures of rabbit cortical collecting tubule (RCCT) cells were infected with an adenovirus 12-simian virus 40 hybrid, resulting in a continuous cell line. The cells, designated RCCT-28A, retained their epithelial morphology and reacted with a monoclonal antibody specific for rabbit collecting tubule. Adenosine 3',5'-cyclic monophosphate (cAMP) accumulation was stimulated by vasopressin (AVP), isoproterenol, prostaglandin E2 (PGE2), calcitonin, parathyroid hormone, and a potent adenosine A1- and A2-receptor agonist, 5'-N-ethylcarboxamidoadenosine (NECA). A more selective adenosine A1-receptor agonist, N6-cyclohexyl adenosine (CHA) inhibited basal and AVP-stimulated cAMP accumulation. Cytosolic free calcium was transiently elevated by bradykinin, PGE2, NECA, and CHA. To examine the mechanism by which adenosine analogues increase intracellular free calcium, phosphoinositide (PI) turnover was assessed in the 28A cells after labeling with myo-[3H]inositol. NECA and CHA increased [3H]inositol phosphate formation with an approximate half-maximal effective concentration of 0.1 microM for both analogues. The increase in PI turnover was blocked by the selective adenosine A1-receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine and pretreatment of the 28A cells with pertussis toxin. These results suggest that adenosine analogues increase cytosolic free calcium by stimulating PI turnover.
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PMID:Adenosine-sensitive phosphoinositide turnover in a newly established renal cell line. 247 75

We have examined the distribution pattern and the density of various neuropeptide, neurotransmitter and enzyme containing neurons in the rat medial septum and the nucleus of the diagonal band of Broca to assess their possible involvement in the septohippocampal, septocortical and septobulbar pathways. Immunohistochemical methods were combined with the retrograde transport of a protein-gold complex injected in the hippocampus, the cingulate cortex or the olfactory bulb. Cholinergic neurons were the most numerous. Galanin-positive neurons were about two or three times less numerous than cholinergic cells. Both these cell types had a similar location though the choline acetyl transferase-like immunoreactive cells extended more caudally in the horizontal limb of the nucleus of the diagonal band of Broca. Immunoreactive cells for other neuroactive substances were few (calcitonin gene-related peptide, luteinizing hormone releasing hormone. [Met]enkephalin-arg-gly-leu) or occasional (dynorphin B, vasoactive intestinal polypeptide, somatostatin, neurotensin, cholecystokinin, neuropeptide Y and substance P). No immunoreactive cells for bombesin, alpha atrial natriuretic factor, corticotropin releasing factor, 5-hydroxytryptamine, melanocyte stimulating hormone, oxytocin, prolactin, tyrosine hydroxylase or arg-vasopressin were present. Choline acetyltransferase- and galanin-like immunoreactive cells densely participate to septal efferents. Cholinergic neurons constituted the bulk of septal efferent neurons. Galanin-positive cells were 22% of septohippocampal, 8% of septocortical, and 9% of septobulbar neurons. Galanin containing septohippocampal neurons were found in the medial septum and the nucleus of the diagonal band of Broca; galanin-positive septobulbar and septocortical cells were limited to the nucleus of the diagonal band of Broca. Occasional double-labellings were noticed with some peptides other than galanin. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were the most often observed; some other projecting cells stained for vasoactive intestinal polypeptide or dynorphin B. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were observed in septohippocampal neurons; luteinizing hormone-releasing hormone and vasoactive intestinal peptide were observed in septocortical neurons and calcitonin gene-related peptide, luteinizing hormone-releasing hormone and dynorphin B were observed in septo-bulbar cells. These results show that, in addition to acetylcholine, galanin is a major cellular neuroactive substance in septal projections to the hippocampus, the cingulate cortex and the olfactory bulb. The presence of septal projecting neurons immunoreactive for other peptides shows that a variety of distinct peptides may also participate, but in a smaller number, to septal efferent pathways.
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PMID:Cholinergic and peptidergic projections from the medial septum and the nucleus of the diagonal band of Broca to dorsal hippocampus, cingulate cortex and olfactory bulb: a combined wheatgerm agglutinin-apohorseradish peroxidase-gold immunohistochemical study. 247 18

The purpose of the present study was to quantify the extent to which several peptides and serotonin coexist with substance P or somatostatin in selected lumbar dorsal root ganglia of the cat. The technique for the simultaneous visualization of two antigens by immunofluorescence was used to investigate the coexistence of neuropeptides in the lumbar dorsal root ganglia of colchicine-treated cats. Perikarya immunoreactive for calcitonin gene-related peptide, galanin, leu-enkephalin, somatostatin, and substance P were visualized in both the lumbar 5 and 6 dorsal root ganglia. In contrast, no immunoreactivity was observed for adipokinetic hormone, bombesin, dynorphin A, met-enkephalin, oxytocin, tyrosine hydroxylase, thyrotropin-releasing hormone, vasopressin, vasoactive intestinal peptide, or serotonin in either ganglion examined. Substance P coexisted with calcitonin-gene-related peptide, somatostatin, and leu-enkephalin. Somatostatin was colocalized with calcitonin gene-related peptide, leu-enkephalin, and substance P but coexisted with galanin minimally. The cell area of immunoreactive perikarya was also examined. Data concerning the cross-sectional area of immunoreactive cells indicated that somatostatin-immunoreactive perikarya were generally the largest population observed (up to approximately 6,000 microns2). Somatostatin and calcitonin gene-related peptide, as well as substance P and calcitonin gene-related peptide, coexisted in populations of cell bodies that had a smaller size (less than 2,000 microns2). These results suggest that certain peptides which coexist in the dorsal root ganglia may provide histochemical markers for functional groups of primary afferent neurons.
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PMID:Lumbar dorsal root ganglia of the cat: a quantitative study of peptide immunoreactivity and cell size. 247 1

Current understanding of the phenomenon of ectopic hormone production is largely based on a histopathological and immunocytochemical analysis of peptide hormone secreting tumours arising in non-endocrine tissues. Recent advances in the study of gene regulation show that the tissue-specific expression of genes is a highly sophisticated process and is unlikely to be disturbed by a spontaneous event such as point mutation in DNA. Study of several genes for frequently found ectopic hormones, i.e. prop-opiomelanocortin, vasopressin/neurophysin II, gastrin-releasing peptide, parathyroid hormone-related peptide, calcitonin gene-related peptide and beta-chorionic gonadotropin, suggests they are transcribed as they would be in their natural cell of origin. It is argued therefore that these data are compatible with the concept that the tumour cell of origin was capable of expressing these peptides, if only in a minor or transient manner. In one example, the ectopic ACTH syndrome, it is also necessary to explain the non-suppression of this gene's expression by elevated levels of glucocorticoids. Recent work suggests that this may result from physically present, but biologically inactive glucocorticoid receptors, a phenomenon that has occasionally been noted in hormonally inactive tumour tissue and cell lines.
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PMID:Ectopic hormone production. 247 14


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