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)

The effects of the recently described human alpha-calcitonin gene-related peptide (CGRP), human beta-CGRP and rat alpha-CGRP have been compared with those of the vasodilator sodium nitroprusside, on the rat and rabbit isolated heart. Hearts were perfused at constant flow and [Arg8]-vasopressin was used to increase coronary perfusion pressure. In the rat heart, the order of potency for evoking cumulative dose-dependent falls in perfusion pressure was human beta-CGRP greater than rat alpha-CGRP greater than human alpha-CGRP greater than sodium nitroprusside. In the same preparations the three CGRPs (but not sodium nitroprusside) elicited cumulative dose-related increases in heart rate. In the rabbit heart the order of potency for vasodilatation was rat alpha-CGRP greater than human alpha-CGRP greater than sodium nitroprusside. In marked contrast to results from the rat, neither rat alpha-CGRP nor human alpha-CGRP altered heart rate in the rabbit isolated heart. These results show that human alpha- and beta-CGRP and rat alpha-CGRP are vasodilators in the coronary vasculature, but that there is species variation as CGRP had a positive chronotropic effect in the rat heart but not in the rabbit heart.
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PMID:Human alpha- and beta-CGRP and rat alpha-CGRP are coronary vasodilators in the rat. 348 43

A tabular synopsis is presented for articles concerned with the effects of peptides on the central nervous system that appeared in the journal Peptides from 1980-1985. A table arranged alphabetically by peptide and one arranged by effects, both listing routes of injection, species, direction of change, and qualifying notes, provides easy cross-referencing of peptides and their effects. Over 80 peptides and over 135 effects are listed. The list of peptides includes, but is not limited to: ACTH, angiotensin, bombesin, bradykinin, calcitonin, casomorphin, CCK, ceruletide, CGRP, CRF, dermorphin, DSIP, dynorphin, endorphins, enkephalins, GRF, gastrin, LHRH, litorin, metkephamid, MIF-l, motilin, MSH, NPY, NT, oxytocin, ranatensin, sauvagine, substances P and K, somatostatin, TRH, VIP, vasopressin, and vasotocin. The list of effects includes, but is not limited to: aggression, alcohol, analgesia, attention, avoidance, behavior, cardiovascular regulation, catalepsy, conditioned behavior, convulsions, dopamine binding and metabolism, discrimination, drinking, EEG, exploration, feeding, fever, gastric secretion, GI motility, grooming, learning, locomotor behavior, mating, memory, neuronal activity, open field, operant behavior, rearing, respiration, satiety, scratching, seizure, sleep, stereotypy, temperature, thermoregulation and tolerance.
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PMID:Central nervous system effects of peptides, 1980-1985: a cross-listing of peptides and their central actions from the first six years of the journal Peptides. 353 8

Present evidence suggests that the renal handling of magnesium is normally a filtration-reabsorption process as evidence for secretion is unsubstantiated. Magnesium reabsorption has distinctive features when compared with that of sodium and calcium. The proximal tubule concentration of magnesium rises to levels about 1.5 times greater than the glomerular filtrate and only 20-30% of the filtered magnesium is reabsorbed in this segment. Although the fractional reabsorption of magnesium is only half that of sodium, it changes in parallel with that of sodium in response to changes in extracellular fluid volume. The major portion of filtered magnesium (some 65%) is reabsorbed in the loop of Henle and evidence indicates that the thick ascending limb is the principal segment involved in magnesium absorption. Recent observations suggests that magnesium reabsorption in the ascending limb may be voltage dependent and secondary to active sodium chloride reabsorption. The loop of Henle appears to be the major nephron site where magnesium reabsorption is regulated possibly by cAMP-mediated hormones including parathyroid hormones, calcitonin, glucagon and antidiuretic hormone. About 10% of the filtered magnesium is delivered into the distal nephron. The distal tubule reabsorbs only a small fraction of the filtered magnesium which may be regulated by the same cAMP-mediated hormones involved in control of magnesium in the loop.
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PMID:The physiology of renal magnesium handling. 354 6

The effects of different doses of Asu(1,7) eel-calcitonin, peripherally injected, on gastric secretion were studied in conscious Brattleboro rats, which are genetically deficient in vasopressin. Moreover, we evaluated the activity of this analogue on gastric ulcer formation by restraint stress. We found that 5 IU/kg Asu(1,7) eel-calcitonin decreased gastric secretion and inhibited the development of stress-induced ulcers in Brattleboro rats. These data suggest that vasopressin does not play a role in the gastrointestinal activity of Asu(1,7) eel-calcitonin.
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PMID:Inhibition of gastric secretion and stress-induced ulcers by intravenous Asu(1,7)eel-calcitonin independent of vasopressin. 362 98

We investigated by micropuncture the effects of glucagon and parathyroid hormone (PTH) on thin limbs of juxtamedullary nephrons of rats with reduced plasma concentration of endogenous glucagon, PTH, antidiuretic hormone (ADH) and calcitonin, all four hormones enhancing the adenylate-cyclase activity in the thick ascending limbs and the distal nephron. Such a hormonal depletion suppresses the corticomedullary concentration gradient, making favourable conditions for studying the influence of these hormones on the renal concentrating mechanism. Administration of glucagon (4.4 ng/min-1) or PTH (5 mU/min-1) to these hormone-deprived rats elicited the expected decrease in urinary Mg and Ca fractional excretion without modifying either fractional or absolute excretion of water. At the tip of the loop, glucagon enhanced the loop fluid osmolality by 20%, but left the delivery of water unchanged. The Na and Cl concentrations increased significantly with the osmolality, resulting in a positive correlation between the fractional delivery of either ion and the loop fluid osmolality. PTH increased the fraction of filtered phosphate delivered to the thin limbs, as expected, but, in contrast to glucagon, did not alter either the Na, Cl, or total solute fractional deliveries. The Mg, Ca and K deliveries were unaffected by glucagon and PTH. In conclusion, glucagon, which activates the cyclase system of both the medullary and cortical portion of the thick ascending limb, enhances the delivery of salt to the tip of the loop by net sodium chloride addition to the descending limb. PTH which activates the adenyl-cyclase system only in the cortical thick ascending limb cannot enhance such NaCl delivery. NaCl, when added, might therefore originate from the medullary thick ascending limb.
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PMID:Effects of glucagon and PTH on the loop of Henle of rat juxtamedullary nephrons. 371 66

The effects of synthetic human calcitonin (HCT) on water and electrolyte deliveries to the thin limbs of Henle's loop of juxtamedullary nephrons were investigated by micropuncture in the rat. To avoid undesirable interference with exogenous calcitonin, experiments were performed in hormone-deprived rats with reduced circulating calcitonin, antidiuretic hormone, parathyroid hormone and glucagon, all four of which stimulate the adenylate-cyclase activity in the thick ascending limb and the distal tubule. Administration of HCT (1.0 mU/min X 100 g body wt) to such rats significantly reduced the urinary fractional excretion rate of water, Mg, Ca and K. At the tip of the longlooped nephrons, the fractional delivery of water diminished in the presence of HCT, although the glomerular filtration rate of these nephrons was unaltered. Simultaneously, the loop fluid osmolality rose significantly. HCT, however, did not alter the fraction of total filtered solutes remaining in the thin limbs, nor the NaCl fractional delivery. As previously observed in this laboratory with dDAVP, the reduced fractional delivery of water at the hairpin turn was accompanied by a decrease in Mg and Ca deliveries in rats given HCT, indicating that the handling of these two ions along the descending limb may be linked in part to the water movements in this nephron segment. The fractional deliveries of K at the hairpin turn and in urine were significantly correlated, and both decreased in the presence of HCT. Since, as shown previously, HCT reduces the net addition of K along the superficial distal tubule, it is concluded that calcitonin inhibits the medullary recycling of K between the nephron terminal segments and the loop of Henle of juxtamedullary nephrons.
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PMID:Effects of human calcitonin on water and electrolyte movements in rat juxtamedullary nephrons: inhibition of medullary K recycling. 371 48

A chemical method has been established for the detection of carboxyl-terminally amidated peptides in tissue extracts. Tissue was homogenized in an acidic medium designed to solubilize peptides while precipitating high-molecular-weight protein. The homogenate supernatant was in turn subjected to reversed-phase extraction with C18 Sep-Pak cartridges. The eluates were fractionated by reversed-phase high-performance liquid chromatography (RP-HPLC). Individual fractions were exhaustively digested with thermolysin, derivatized with phenylisothiocyanate (PITC), and then subjected to ethyl acetate extraction under basic conditions. The phenylthiocarbamyl (PTC)-amino acid amide derivatives were selectively taken up into the organic phase, while the other digestion products remained in the aqueous phase. The organic phase was analyzed by RP-HPLC on a Pico-Tag amino acid analysis column, monitoring eluates at 254 nm. PTC-amino acid amides were identified and quantitated by comparing their elution positions and peak areas, respectively, with those of standards. Their identities were confirmed by amino acid analysis, following hydrolysis with hydriodic acid. The technique was applied to extracts of bovine posterior pituitaries and a human medullary thyroid carcinoma. Vasopressin (-Leu-Gly-amide), oxytocin (-Gly-amide), Lys1 gamma 1-melanotropin (-Phe-amide), and various acetylated and non-acetylated forms of alpha-melanotropin (-Val-amide) were identified in the posterior pituitary extract. Various forms of calcitonin (-Val-Gly-Ala-Pro-amide) were detected in the tumour extract. For vasopressin and calcitonin the thermolytic digest resulted in di- and tetra-peptides, respectively, reflecting thermolytic cleavage at more favoured sites.
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PMID:Use of Pico-Tag methodology in the chemical analysis of peptides with carboxyl-terminal amides. 373 29

Previous studies demonstrated that in rat kidney, arginine-vasopressin (AVP), glucagon (GLU), calcitonin and parathyroid hormone exert similar effects on the thick ascending limb of Henle's loop (TALH). To ascertain the physiological significance of such multiple hormonal control of TALH function, it is necessary to establish whether one hormone can exert its effect on TALH, even when other hormones are present. We therefore compared renal responses to submaximal (1 ng/min) and maximal (10 ng/min) doses of glucagon in rats deprived of endogenous AVP, GLU, calcitonin and parathyroid hormone with the responses of similar rats given a maximal dose of AVP (40 pg/min). Administration of glucagon or AVP alone reduced Mg fractional excretion, but the reduction was more marked when both hormones were given together. Consequently, their effects were additive, at submaximal and maximal doses. In the presence of AVP + glucagon, urinary osmolality was also higher than in the presence of AVP alone (Umax: 1242 +/- 49 vs. 936 +/- 50 mosmol/kg; p less than 0.001). This latter effect may indicate that AVP and glucagon also exert additive effects on Na reabsorption in the TALH.
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PMID:Additive effects of glucagon and vasopressin on renal Mg reabsorption and urine concentrating ability in the rat. 382 66

The effects of glucagon and PTH on electrolyte reabsorption in the distal tubule were investigated in rats deprived of vasopressin, calcitonin, PTH, and glucagon. Micropunctures of distal tubule, at a late and an early site of a same nephron, have been performed in 23 rats, nine control, seven infused with glucagon (5 ng X min-1 X 100 g-1 b.w.) and seven with PTH (5 mU X min-1 X 100 g-1 b.w.). The Ca and Mg reabsorptive capacity of the distal segment was increased by glucagon and by PTH. Moreover, fractional Na and Cl reabsorption was significantly higher than in control during PTH administration. A K secretion appeared during the administration of both hormones. No phosphate net transport was observed in any group. Finally, the data presented here, together with those previously reported, indicate that the increase of Ca and Mg renal reabsorption observed with glucagon and PTH results from an effect located in both Henle's loop, where the bulk of Ca and Mg is reabsorbed, and the distal tubule.
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PMID:Stimulation by glucagon and PTH of Ca and Mg reabsorption in the superficial distal tubule of the rat kidney. 398 56

We evaluated the effects of human calcitonin (hCT) on electrolyte excretion in hormone-deprived rats, that is, in the absence of endogenous parathyroid hormone, antidiuretic hormone, thyrocalcitonin and glucagon, the effects of which might have interfered with those of exogenous calcitonin. Plasma hCT levels, measured by radioimmunoassay, varied from 0 to 32 ng/ml. In these rats, hCT decreased magnesium (Mg) and calcium (Ca) excretion in a dose-dependent fashion. Maximal decreases were observed for hCT plasma concentrations comprised between 3 and 5 ng/ml, and persisted at the highest doses. Sodium, potassium, water, and total solute excretions were constant in the calcitonin concentration range explored. The same was observed for phosphate, except that slight but significant phosphaturia was elicited by the highest doses. Calcium and phosphate infusions to attenuate the fall in plasma Ca and phosphate concentration subsequent to hCT infusion, did not alter the hormonal effect on Ca and Mg excretion. hCT can therefore directly modulate Mg and Ca reabsorption by the kidney at plasma concentrations within the physiological range. The maximal effects on Mg and Ca reabsorption were obtained at plasma concentrations which are generally reached after maximal stimulation of endogenous calcitonin secretion. It is suggested that in rats, endogenous secretion of calcitonin stimulates Ca and Mg renal reabsorption without modification of sodium and phosphate excretion.
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PMID:Modulation by calcitonin of magnesium and calcium urinary excretion in the rat. 399 91


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