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 spontaneous contractility of the epididymis in the rat was recorded in vivo and the effects of the neurohypophyseal hormones were studied. Oxytocin (50 muU and 500 muU/100 g body weight) produced a progressive increase in tonus together with an increase in amplitude and frequency of the contractions. Vasopressin (100 muU and 1000 muU/100 g body weight) showed similar effects. No differences were apparent at the doses studied.
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PMID:The 'in vivo' effects of oxytocin and vasopressin on spontaneous contractility of the rat epididymis. 1 18

The effects of norepinephrine, phentalamine, oxytocin, vasopressin, several prostaglandins, and indomethacin on the spontaneous motility of isolated guinea pig cauda epididymidis were explored. Phentolamine and indomethacin reduced the isometric peak tension of spontaneous epididymal contractions. Phentolamine also depressed the frequency. Both findings suggest that catecholamines and endogenous prostaglandins are in some way regulators of the spontaneous motility of the cauda epididymidis. Norepinephrine resulted in the development of a distinct, sustained, tonic contraction without phasic activity, whereas prostaglandins E1, E2, and F2 alpha elicited a tonic increase accompanied by frequent, superimposed, phasic contractions. Both oxytocin and vasopressin comparably enhanced epididymal motility, producing contractile responses similar to those observed with prostaglandins. Since the epididymal contractions can influence the time spent by spermatozoa in passing through the ductus epididymidis, the above-mentioned compounds could play an important role in spermatozoal transport via modulation of epididymal contractile activity. In addition, such naturally occurring substances might regulate the release of sperm from the last portion of the epididymis into the ductus deferens.
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PMID:Physiologic and pharmacologic studies on the motility of isolated guinea pig cauda epididymidis. 80 41

Neurohypophysial hormones stimulate the motility of tunica albuginea, epididymis, and vas deferens acting through oxytocin (OT) and V1 vasopressin receptors. To test the hypothesis that these hormones are involved also in the regulation of seminal vesicle physiology, we studied binding of [3H]OT and [3H] arginine vasopressin ([3H]AVP) to porcine seminal vesicle membranes. Neurohypophysial hormones bind to two different classes of sites. The first class shows low capacity (35 fmol per mg of protein) and a very high affinity (Kd less than 1 nM) for both the labeled ligands. The second class is characterized by a high capacity (2000 fmol per mg of protein) and a high affinity for AVP (Kd approximately equal to 2.5 nM), whereas OT has 160 times lower affinity. Lysine vasopressin and the V1 antagonist [1-deaminopenicillamine, 2-(O-methyl)tyrosine]Arg8-vasopressin compete with high affinity with [3H]AVP binding, whereas the V2 agonist [1-deamino,4-valine]D-Arg8-vasopressin (dVDAVP) is 110 times less potent than AVP. The OT agonist [Thr4,Gly7]OT and the OT antagonist [1(beta-mercapto-beta, beta-cyclopentamethylene propionic acid), 2-(O-ethyl)tyrosine, 8-ornithine]vasotocin failed to affect [3H]AVP binding. These findings seem to suggest that AVP interacts with the V1 vasopressin isoreceptor in porcine seminal vesicle membranes. However, AVP stimulates adenylate cyclase activity in a dose-dependent fashion with an EC50 of 14 nM, whereas OT or dVDAVP has no effect at 100 nM. Moreover, a well-characterized V1 vasopressin antagonist, [1-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid),2-(O-methyl)tyrosine]Arg8-vasopressin [d(CH2)5Tyr(Me)AVP], competes with [3H]AVP binding with an IC50 of 0.17 microM. These pharmacological properties are distinct from the previously described V1 and V2 vasopressin receptors and indicate the presence of a new class of AVP receptors. Although this vasopressin isoreceptor shares some pharmacological characteristics with the V1 (pressor) isoreceptor, it has low affinity for the V1 antagonist d(CH2)5-Tyr(Me)AVP and is linked to the adenylate cyclase system. The extremely high density of AVP receptors in porcine seminal vesicles (2 pmol per mg of protein) is comparable to the density of V2 vasopressin receptors in porcine renal medulla, suggesting a physiological role for vasopressin in the seminal vesicle.
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PMID:Identification and characterization of a vasopressin isoreceptor in porcine seminal vesicles. 294 37

The neurohypophysial hormones oxytocin (OT) and vasopressin (VP) are involved in the regulation of the contractility of the male genital tract in several animal species. We investigated the presence of specific binding sites for [3H]OT and [3H]arginine VP (AVP) in membranes prepared from tunica albuginea, epididymis, and vas deferens from prepubertal pigs 2-16 weeks of age. Membranes were incubated with [3H]OT and [3H]AVP in the presence or absence of the corresponding unlabeled peptides. Binding equilibrium was reached in 60 min at 22 C. Millimolar concentrations of Mg2+ increased the specific binding of both ligands. Analysis of families of self- and cross-displacement curves using the computer program LIGAND clearly demonstrated that two classes of binding sites were present in all tissues investigated. The first class of sites, designated the OT site, shows high affinity for OT, AVP, lysine vasopressin, arginine vasotocin, the selective OT agonists [Thr4,Gly7]OT and [Asu1,6]OT, and the OT antagonists derived from ornithine vasotocin (OVT), namely d(CH2)5Tyr(Et)OVT and dEt2OVT. The second class of sites, designated the VP site, shows high affinity for AVP, lysine vasopressin, arginine vasotocin, and the selective V1 antagonist d(CH2)5Tyr(Me)AVP. The V2 agonist [1-deamino,4-valine]8-D-AVP shows low affinity for both sites. Isotocin, desglycinamide [Arg-8]AVP and tocinoic acid were ineffective in displacing [3H]AVP or [3H]OT. The highest density of OT receptors was found in tunica albuginea and epididymis, whereas the highest density of AVP receptors was found in vas deferens. Adenylate cyclase was not activated in any of the tissues studied by concentrations of AVP or OT up to 100-fold greater than their Kd values. This is the first demonstration and pharmacological characterization of specific OT and V1 VP receptors in the tunica albuginea, epididymis, and vas deferens. The recent demonstration of high local concentration of neurohypophysial hormones in the gonads of several mammals support a physiological role of these OT and VP receptors in regulation of the motility of the male genital tract.
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PMID:Identification and characterization of two classes of receptors for oxytocin and vasopressin in porcine tunica albuginea, epididymis, and vas deferens. 302 94

Evidence suggests that systemic oxytocin (OT) causes contractions of the prostate gland during ejaculation in eutherians, although functional OT receptors in this tissue have not been identified. Male marsupials secrete mesotocin (MT) from the pituitary and have relatively large, muscular prostate glands, so we examined MT receptors (MTRs) in the reproductive tract of the male tammar wallaby at the mRNA and protein level. We first obtained a partial (588 base pair) sequence of the tammar MTR cDNA that showed high homology to eutherian OT receptors (74-77%) and low homology to vasopressin receptors (38-52%). Analysis by reverse transcription-polymerase chain reaction demonstrated MTR mRNA in the adult, juvenile, and pouch young prostate and epididymis, but not testis. MTR transcripts were observed in the smooth muscle layers surrounding the urethral lumen and in the fibromuscular capsule. There was a single high-affinity 125I-D(CH2)5[Tyr(Me)2, Tyr4, Orn8, Tyr-NH29]-vasotocin (125I-OTA) binding site in the adult prostate. Competitive binding assays revealed identical ligand-binding profiles to the myometrium MTR (OTA > OT = MT > arginine vasopressin [AVP] antagonist > AVP). A lower-affinity 125I-OTA-binding site was present in the testis, with ligand-binding profiles indicating binding to vasopressin receptors. MTR concentrations in the prostate were 8-fold lower than concentrations in the myometrium. Our data demonstrate the presence of an MTR gene and functional receptor protein in the prostate gland, but not the testis, of the tammar. Localization of MTRs to the smooth muscle fibers in the capsule and surrounding the urethral lumen suggests a contractile function for MT during ejaculation.
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PMID:Mesotocin receptor gene and protein expression in the prostate gland, but not testis, of the tammar wallaby, Macropus eugenii. 978 Mar 15

This study was performed to determine whether oxytocin or vasopressin affect the transport of spermatozoa from the epididymis of rams in vivo. Under general anaesthesia, cannulae were inserted into each ductus deferens and passed into the cauda epididymis of 24 Oxford Down cross rams and the luminal fluid was collected at 10 min intervals for 2-3 h. Animals were divided into seven groups and received either (i) 2 ml 0.9% saline, (ii) 10 micrograms oxytocin, (iii) 100 micrograms oxytocin, (iv) 100 micrograms oxytocin antagonist, (v) 300 micrograms oxytocin antagonist followed by 100 micrograms oxytocin, (vi) 100 micrograms vasopressin, or (vii) 100 micrograms vasopressin followed by 100 micrograms oxytocin, all by i.v. injection. The mass of fluid and number of spermatozoa in each 10 min sample was measured and the motility of the spermatozoa was assessed. Treatment with saline did not affect the mass or the number of spermatozoa in the fluid collected. Oxytocin at 10 micrograms significantly increased both the output of fluid and the number of spermatozoa by twofold. Oxytocin at 100 micrograms produced a greater increase in both fluid output and the number of spermatozoa within 10 min of administration of the peptide. Treatment with oxytocin antagonist had no immediate effect, but subsequently caused a significant reduction in both fluid output and the number of spermatozoa. Pretreatment with oxytocin antagonist inhibited the stimulatory effect of oxytocin. Vasopressin did not increase the number or concentration of spermatozoa in the fluid and appeared to decrease fluid output. No significant changes in the morphology or motility of the spermatozoa collected was observed in any of the samples. These data demonstrate that oxytocin has specific actions on the epididymis to increase sperm transport. They indicate that local oxytocin may be involved in regulating basal contractility of the cauda epididymidis and that augmentation by the peptide in the peripheral circulation, as occurs around the time of ejaculation, may promote a significant increase in the transport of spermatozoa into the vas deferens and ejaculate.
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PMID:Effects of oxytocin and vasopressin on sperm transport from the cauda epididymis in sheep. 1069 Jan 97

Aquaporin 2 (AQP2), the vasopressin-regulated water channel, was originally identified in renal collecting duct principal cells. However, our recent description of AQP2 in the vas deferens indicated that this water channel may have extra-renal functions, possibly related to sperm concentration in the male reproductive tract. In this study, we have examined the regulation and membrane insertion pathway of AQP2 in the vas deferens. The amino acid sequence of vas deferens AQP2 showed 100% identity to the renal protein. AQP2 was highly expressed in the distal portion (ampulla) of the vas deferens, but not in the proximal portion nearest the epididymis. It was concentrated on the apical plasma membrane of vas deferens principal cells, and very little was detected on intracellular vesicles. Protein expression levels and cellular localization patterns were similar in normal rats and vasopressin-deficient Brattleboro homozygous rats, and were not changed after 36 h of dehydration, or after 3 days of vasopressin infusion into Brattleboro rats. AQP2 was not found in apical endosomes (labeled with Texas Red-dextran) in vas deferens principal cells, indicating that it is not rapidly recycling in this tissue. Finally, vasopressin receptors were not detectable on vas deferens epithelial cell membranes using a [(3)H]vasopressin binding assay. These data indicate that AQP2 is a constitutive apical membrane protein in the vas deferens, and that it is not vasopressin-regulated in this tissue. Thus AQP2 contains targeting information that can be interpreted in a cell-type-specific fashion in vivo.
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PMID:Aquaporin 2 is a vasopressin-independent, constitutive apical membrane protein in rat vas deferens. 1075 27

Contractions of seminiferous tubules and epididymal duct walls promote spermiation and sperm transfer, and they are thought to be stimulated by the related peptides oxytocin and vasopressin. This study tested the hypothesis that if oxytocin and/or vasopressin play a physiological role in sperm shedding and transport, then local or circulating concentrations of these peptides would increase during puberty. Testes, epididymides, and trunk blood of sheep at stages during the first spermatogenic wave were collected, and radioimmunoassay measured significant increases in testicular and epididymal oxytocin during spermatogenesis. No changes were measured in circulating oxytocin or in local or circulating vasopressin. Localization and synthesis was investigated by immunohistochemistry and Western blot analysis employing antibodies recognizing epitopes of either oxytocin, oxytocin-associated neurophysin, vasopressin, or vasopressin-associated neurophysin. Marked expression of both oxytocin and its associated neurophysin in testicular Leydig and epididymal principal cells was seen, and weak neurophysin immunoreactivity was also identified in Sertoli cells. The intercellular distribution of oxytocin varied between regions of the epididymis, suggesting several roles for oxytocin. Vasopressin synthesis was not apparent in either tissue. These results confirm the presence and development of paracrine oxytocinergic systems in the ram testis and epididymis of ram during puberty while questioning the physiological importance of vasopressin.
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PMID:Oxytocin and vasopressin expression in the ovine testis and epididymis: changes with the onset of spermatogenesis. 1090 49

Molecular misreading is a novel process that causes mutations in neuronal transcripts. It is defined as the inaccurate conversion of genomic information from DNA into nonsense transcripts and the subsequent translation into mutant proteins. As a result of dinucleotide deletions (delta GA, delta GU, delta CU) in and around GAGAG motifs in mRNA the reading frame shifts to the +1 frame, and subsequently the so-called +1 proteins are synthetized. +1 Proteins have a wild-type NH2 terminus and from the site of the dinucleotide deletion onwards an aberrant, nonfunctional COOH terminus. Molecular misreading was found in the rat vasopressin gene associated with diabetes insipidus and in the human genes linked to Alzheimer's disease (AD), that is, beta-amyloid precursor protein (beta APP) and ubiquitin-B (UBB). Moreover, beta APP+1 and UBB+1 proteins accumulate in the neuropathological hallmarks of AD. Inasmuch as these +1 proteins were also found in elderly, nondemented control patients, but not in younger ones (< 72 years), molecular misreading may act as a factor that becomes manifest in aged people. A hotspot for dinucleotide deletions is GAGAG motifs. Because statistically an average of 2.1 GAGAG motifs per gene can be expected, other genes expressed in other tissues may undergo molecular misreading as well. Indeed, we recently detected +1 proteins in proliferating cells present in tissues such as the liver, epididymis, parotid gland, and neuroblastoma cell lines. Therefore, molecular misreading can be regarded as a general biological source of transcript errors that may be involved in cellular derangements in numerous age-related pathologic conditions apart from Alzheimer's disease.
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PMID:Molecular misreading. A new type of transcript mutation in gerontology. 1091 66

+1 Frame-shifted proteins such as amyloid precursor protein(+1) and ubiquitin-B(+1) have been identified in the neuropathological hallmarks of Alzheimer's disease. These frameshifts are caused by dinucleotide deletions in GAGAG motifs of messenger RNA encoded by genes that have maintained the unchanged wild-type DNA sequence. This process is termed 'molecular misreading'. A key question is whether this process is confined to neurons or whether it could also occur in non-neuronal cells. A transgenic mouse line (MV-B) carrying multiple copies of a rat vasopressin minigene as a reporter driven by the MMTV-LTR promotor was used to screen non-neuronal tissues for molecular misreading by means of detection of the rat vasopressin(+1) protein and mutated mRNA. Molecular misreading was demonstrated to occur in several organs (e.g., epididymis and the parotid gland) where transgenic vasopressin expression is abundant, but its penetrance is variable both between and within tissues. This implies that non-neural tissues too, could be affected by cellular derangements caused by molecular misreading.
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PMID:Molecular misreading in non-neuronal cells. 1092 94


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