SEARCH · PubMed Health

Results for “VASOTOCIN”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

PubMed1991

Effect of a vasotocin analog on singing behavior in the canary.

Groups of juvenile and 1-year-old male canaries were treated briefly with the vasotocin (VT) analog desGly(NH2)9d(CH2)5-[Tyr(Me)2,Thr4, Orn8]VT (dGVTA) during four time intervals between September and February. The canaries received subcutaneously testosterone-containing silastic implants at the start of the VT analog treatment to assure that despite age and season differences the birds would all have comparable plasma levels of testosterone. The VT analog was administered subcutaneously (0.7 micrograms/100 microliters) during the first 3 days (3 injections daily) of chronic testosterone treatment. Observations on the singing behavior were carried out between Day 8 and Day 30 after implantation of the testosterone-filled silastic tubing. The short-term administration of the VT analog influenced the amount of singing behavior during a 30-min observation interval measured 1 to 4 weeks later. Despite age differences the effect of dGVTA held and seemed more related to season than to age. The song duration (seconds of song/30 min) was affected in a dual mode. In early autumn the VT analog enhanced song duration of testosterone-primed canaries, but the same VT analog decreased song duration in the period November/January. These results suggest that the neuropeptide VT is implicated in control of seasonal changes in singing behavior.

Age Factors↗

PubMed1991

Effect of vasotocin on locomotor activity in bullfrogs varies with developmental stage and sex.

Although neurohypophysial peptides are present in many regions of the developing and adult bullfrog (Rana catesbeiana) brain, the function of these peptides remains unclear. To investigate possible behavioral actions, we examined locomotor activity following peptide injection in bullfrogs at various developmental stages. An intraperitoneal (ip) injection of arginine vasotocin (AVT) in tadpoles (stages V, X, or XVII) produced an immediate and dose-dependent inhibition of locomotor activity. On the other hand, AVT stimulated activity when administered ip to juvenile or adult female bullfrogs, but did not influence activity in juvenile or adult males. The minimum effective dose of AVT, when injected directly into the brain of tadpoles, was 100-fold less than that observed when injected ip, suggesting a central nervous system site of action for this peptide. A vasopressin receptor antagonist (d(CH2)5[Tyr(Me)2]AVP administered ip or icv) significantly increased locomotor activity in tadpoles, compared to controls. Oxytocin, vasopressin, and AVP4-9 inhibited activity in tadpoles while mesotocin, des Gly(NH2)AVP, and pressinoic acid had no significant effect. Injection of PGF2 alpha also significantly decreased activity levels in tadpoles. However, pretreatment of tadpoles with indomethacin, a prostaglandin synthesis inhibitor, did not prevent the behavioral effects of AVT, suggesting that prostaglandin synthesis is not required for this response. In summary, AVT influenced locomotor activity in bullfrog tadpoles and female frogs. This effect shifted during development from an inhibitory action in tadpoles to a stimulatory effect in metamorphosed female frogs. The effect of AVT on juvenile and adult frog locomotion was sexually dimorphic, as this peptide altered female behavior but not male behavior.

Animals↗

PubMed1992

Sex steroids and vasotocin interact in a female amphibian (Taricha granulosa) to elicit female-like egg-laying behavior or male-like courtship.

Female egg-laying behaviors and male amplectic clasping behaviors in the rough-skinned newt (Taricha granulosa) are similar in that animals clasp an object. In the case of egg-laying, females clasp submerged inanimate objects, whereas in amplexus, males clasp conspecific females. Considering these behavioral similarities and differences, we investigated the possibility that gonadal steroids and vasotocin (AVT) interact to control egg-laying behaviors, as has been shown for the control of amplexus in Taricha males. Intact, gravid T. granulosa females injected ip with AVT, unlike those injected with saline, exhibited egg-laying behaviors and oviposition. In ovariectomy-steroid-implant studies, no saline-injected female exhibited egg-laying behaviors, whereas AVT-injected ovariectomized females exhibited egg-laying behaviors if implanted with estradiol (E2), testosterone, or dihydrotestosterone (DHT), and not if implanted with empty capsules. When given a choice between clasping aquatic vegetation or other females (amplectic clasping), following an AVT injection, unoperated and sham-operated control females and ovariectomized females with E2 implants did not preferentially clasp aquatic vegetation over other females. In contrast, AVT-injected ovariectomized females with DHT implants preferentially clasped other females. Thus, exposure of Taricha females to estrogens or androgens appears to determine whether the AVT-induced clasping is egg-laying or amplectic clasping.

Animals↗

PubMed1984

Arginine vasotocin (AVT), an alleged hormone of the mammalian pineal gland.

Arginine vasotocin has been proposed as a hormone of the mammalian pineal gland. This claim is largely based on biological and immunological results, although some chemical evidence has also been provided. Yet, more and more researchers have recently disclaimed the presence of this nonapeptide in mammalian tissue. The currently available evidence is critically reviewed exposing the dispute as a real one urgently requiring final settlement.

Amino Acid Sequence↗

PubMed1986

The plasma of pregnant women contains a novel oxytocin-vasotocin-like peptide.

Basal levels of immunoreactive oxytocin (OT) were measured in plasma of healthy pregnant women using two antisera to OT, Pitt Ab-1 and Pitt Ab-2, and an antiserum to arginine vasotocin, Tor AVT Ab. The mean (+/- SEM) level of immunoreactive OT Pitt Ab-1 was significantly higher, 7.7 +/- 0.9 microU/mL, than immunoreactive OT Pitt Ab-2, 0.9 +/- 0.2 microU/mL, P less than .001 measured in the same samples. AVT immunoreactivity in plasma of nonpregnant individuals was 0.8 +/- 0.16 pg/mL and in plasma of women in late pregnancy was 5.0 +/- 0.4 pg/mL. In four pregnant women receiving an infusion of synthetic OT (Pitocin, Parke-Davis, Morris Plains, NJ) a linear correlation was found between the dose of OT infused and the concentration of OT in plasma in samples measured with Pitt Ab-2, but no correlation was found in the same samples measured with Pitt Ab-1. Immunoreactive OT Pitt Ab-1 in plasma was not destroyed by a 60-minute incubation with pregnancy plasma. Pooled plasma from pregnant women was separated by reverse phase high pressure liquid chromatography (HPLC). OT Pitt Ab-1 and Tor AVT immunoreactivities in pregnancy plasma eluted in a position separate from synthetic OT. The differences found in levels of immunoreactive OT in the same samples of plasma measured with two antisera to OT illustrate an important reason why levels of OT in pregnant women may be reported to be variable among laboratories.

Chromatography, High Pressure Liquid↗

PubMed1987

Localization of ARG-vasopressin-like material in central neurones and mechanism of action of ARG-vasotocin on identified neurones of the snail Helix aspersa.

Immunocytochemical and electrophysiological studies were made on neurones in the suboesophageal ganglia of Helix aspersa. A group of neurones in the anterior dorsal surface of each parietal ganglion showed positive immunoreactivity to an antibody to arginine vasopressin (AVP), as did the neuropile and the nerves associated with the parietal and visceral ganglia. The only peripheral tissue to exhibit positive immunoreactivity to AVP was the optic tentacle, where positive immunoreactive fibres were present in the optic nerve and cell bodies below the retinal cell layer. Two central neurones, F1 and E13 were excited by arginine vasotocin (AVT), threshold 1-10 nM, and the ionic mechanism associated with this response was investigated. This excitation involved both sodium and calcium ions with an overall increase in resistance. In low sodium Ringer, the AVT response was greatly reduced, while in calcium-free 3 mM cobalt Ringer, the response was potentiated. Changing the external concentrations of potassium and chloride ions had no apparent effect on the response. The amplitude of the excitation induced by AVT was enhanced when the cells were hyperpolarized. Most of the other neurones tested failed to respond to AVT though the excitatory response of certain cells to acetylcholine was enhanced by 0.1 microM AVT. Excitation by 5-hydroxytryptamine was unaffected in the cells tested. This study provides further evidence for a role for an AVT-like peptide in the nervous system of Helix.

Acetylcholine↗

PubMed1989

Vasotocin improves intelligence and attention in mentally retarded children.

In mentally retarded (MR) prepubertal children, investigated both before and after six months of treatment, synthetic arginine vasotocin (AVT) (10(-6) mg/day/0.1 ml, intranasally), but not oxytocin or saline alone, significantly increased the intelligence quotient (IQ) and improved the attention parameters without affecting the short-term memory. Taking into account both the psychometric results and the clinical observations, the effects of AVT could be mainly explained by assuming the improvement of attention. Since there was a significant inverse correlation between the pretreatment levels of the IQ and attention scores and their increase after AVT, and since the AVT effects tend to be more intense in autistic children, we hypothesize that the more affected the attention mechanisms, the more they are sensitive to AVT. The present results are tentatively explained by the paradoxical sleep-enhancing properties of AVT, mechanisms by which AVT could improve the brain plasticity in MR subjects and by this, the attention performance.

Attention↗

PubMed1978

Effects of arginine vasotocin and prostaglandin E1 on the hen uterus.

In the domestic hen, the uterine portion of the oviduct responded in vitro to arginine vasotocin (AVT) and prostaglandin E1 (PGE1) at all investigated stages of the egg-laying cycle. However, the uterus was less responsive to both hormones during oviposition. The injections of these hormones provoked premature oviposition and a significant pressure increase in the uterus. In vitro and in vivo AVT was a more potent uterine stimulant than PGE1. Indomethacin, an inhibitor of prostaglandin biosynthesis, antagonized in vitro the contractor activity of AVT but not that of PGE1. Prostaglandin-like activity was demonstrated in the hen uterine tissue at the time of oviposition. It is concluded that AVT may cause uterine contractions via a prostaglandin activated mechanism.

Animals↗

PubMed1990

Arginine vasotocin-induced prostaglandin synthesis in vitro by the reproductive tract of the viviparous lizard Sceloporus jarrovi.

Two experiments were performed to determine whether arginine vasotocin (AVT) stimulates synthesis of prostaglandins (PGs) in reptilian oviducts. Homogenized oviducal tissue from female Sceloporus jarrovi in early and late pregnancy were cultured with radiolabeled (14C) prostaglandin precursor, arachidonic acid (AA). In late pregnancy, oviducts exposed to AVT exhibited a greater conversion of AA to PGF2 alpha than did controls, whereas in early pregnancy there was no difference. The conversion of AA to other prostaglandins (PGA2, PGD2, PGE2, PGI2) was not influenced by AVT. The second experiment examined whether endogenous in vitro synthesis of PGF and PGE2 from intact, pregnant oviducts was stimulated by AVT (50 ng/ml; 100 ng/ml). Both doses of AVT induced a similar, significant rise in PGF concentrations within 30 min whereas no significant increase was noted in PGE2 concentrations until 90 min after treatment. Indomethacin pretreatment blocked synthesis of both PGF and PGE2 for 30 min following AVT treatment. These data indicate that AVT induces a highly specific rise in the synthesis of PGF from the oviduct of female S. jarrovi in late pregnancy. Furthermore, the prostaglandin-stimulating effect of AVT in reptiles appears homologous with the effect of oxytocin in mammals and AVT in birds. We hypothesize that this interaction is an evolutionarily conserved relationship found in all amniote vertebrates.

Animals↗

PubMed1992

Embryonic differentiation of sexual dimorphism in vasotocin and mesotocin levels in chickens.

Chicken embryos of both sexes were injected on the tenth day of incubation with either estradiol benzoate (EB), aromatase inhibitor [1,4,6-androstatrien-3, 17-dione (ATD)], antiestrogen [tamoxifen (TAM)], antiandrogen [flutamide (FLU)], or the oil vehicle as control (C). At adulthood, at the age of 26 weeks, 10 chickens of each sex were killed and the amounts of immunoreactive arginine vasotocin (AVT) and mesotocin (MT) in the anterior hypothalamus (AHA), posterior hypothalamus (PHA), neurohypophysis (NHP), and pineal gland (PNL) were determined. Control hens had significantly more AVT in PNL and less MT in AHA and NHP than the corresponding roosters. This sexual dimorphism was affected by the embryonic treatments; TAM increased AVT in AHA of cockerels but not of hens. In both sexes, TAM and FLU increased AVT content in NYP. In males, but not in females, ATD also increased AVT content in the NHP. TAM and FLU administration to the female embryo reduced PNL AVT to the amount present in normal males. None of the treatments effected AHA MT in hens, while in cockerels TAM increased it. In females, TAM and FLU significantly increased NHP MT to the level of C males. In roosters, ATD, TAM, and FLU increased NHP MT further. In hens, but not roosters, FLU reduced MT in PNL. These results indicate that embryonic differentiation of the MT and AVT systems is affected by gonadal steroids in chickens.

Animals↗

PubMed1985

Vasotocin-like activity of cerebrospinal fluid induced by habenular lesions in cats.

The cisternal cerebrospinal fluid (CSF) samples, taken at 30, 60, 120 and 180 minutes after multiple electrolitic lesions of lateral habenular (LHB) lesions or of thalamus, performed in urethane anesthetized cats, were assayed for their antidiuretic and hydroosmotic activities before and after trypsine or thioglycollate incubation. LHB but not thalamic lesions, specifically induced the appearance of antidiuretic and hydroosmotic activities at 60 and 120 minutes. The activities decreased under the bioassays sensibilities at 180 minutes. The biological activities of the CSF samples, their ratio as well as their susceptibility to tryptic digestion and thioglycollate incubation suggest that LHB lesions induce the release of a basic peptide with a disulfide bound, indistinguishable from arginine vasotocin (AVT). Since it was previously argued that there is a pineal-habenula circuit with AVT as neuromudulator, it is advanced the hypothesis that LHB lesions interfere with an inhibitory feed-back loop between habenula and the pineal gland.

Animals↗

PubMed1992

Immunoreactive vasotocin in the zebra finch brain (Taeniopygia guttata).

UNLABELLED: The distribution of vasotocin (VT)-immunoreactive cells and fibers in the zebra finch brain was studied with immunocytochemical techniques. A large number of VT-immunoreactive cells was found in the nucleus preopticus anterior and nucleus paraventricularis. In the lateral parts of the hypothalamus diffusely organized VT-immunoreactive cells were present. Some of these cells were found close to and embedded in the optic tract. An extra-hypothalamic parvocellular cell group was found at the level of the anterior commissure in the dorsal diencephalon. VT-immunoreactive fibers and varicosities were present in a number of extrahypothalamic regions i.e. the septum, the area ventralis of Tsai, the lateral habenula, the optic tectum, the substantia grisea centralis, the nucleus tractus solitarii, the lateral medulla, the nucleus intercollicularis and in the archistriatum surrounding the nucleus robustus archistriatalis. The VT-immunostaining in the lateral septum and dorsal diencephalon showed no sex differences and can not be influenced by testosterone administration. IN CONCLUSION: the topography of the central VT-immunoreactive network is similar to that in another song bird i.e. the canary; but seasonal and testosterone-dependent changes in VT-immunostaining in the lateral septum and dorsal diencephalon are only observed in the canary.

Animals↗

PubMed1985

ACTH-releasing activity of urotensin I and ovine CRF: interactions with arginine vasotocin, isotocin and arginine vasopressin.

The release of ACTH from superfused dispersed goldfish anterior pituitary cells was examined to determine if the neurohypophyseal peptides arginine vasotocin (AVT), isotocin (IST) or arginine vasopressin (AVP) potentiate the ACTH-releasing activities of the structurally homologous peptides urotensin I (UI) or ovine corticotropin-releasing factor (CRF). The ACTH-releasing activities of the neurohypophyseal peptides and UI or CRF were additive. AVT, IST or AVP failed to potentiate the ACTH-releasing activity of UI or CRF. These results suggest that in teleost fishes neurohypophyseal peptides have intrinsic ACTH-releasing activity but, unlike mammals, do not potentiate the release of ACTH evoked by CRF, or by the piscian CRF-like peptide, UI.

Adrenocorticotropic Hormone↗

PubMed1993

Implication of central neurohypophyseal hormone receptor-mediated action in timing of reproductive events: evidence from novel observations on the effect of a vasotocin analogue on singing behaviour of the canary.

A highly discrete distribution of neurohypophyseal hormone receptors was discovered in the mammalian and avian brain. These receptors are heterogeneous. In rat brain oxytocin (OT) and V1a receptors can be distinguished which bind OT with an order of magnitude difference in affinity and which are located in discrete sites of the limbic-midbrain circuitry. In the brain of the canary low and high affinity vasotocin (VT) sites were identified; the latter putative VT receptors were found exclusively localized in the area encapsulating the nucleus robustus archistriatalis (RA). We show with recordings of singing behaviour that a VT analogue promotes the chain of seasonal events in this behaviour.

Animals↗

PubMed1988

Stimulation of sodium transport by aldosterone and arginine vasotocin in A6 cells.

The effects of aldosterone and arginine vasotocin (AVT) on transepithelial Na+ transport of cultured A6 cells were investigated. All experiments were performed with cells grown on Millicell TM culture-plate inserts for a period of 2-4 weeks in defined, serum-free medium. Omitting fetal bovine serum 2 days after seeding the cells on filters did not influence potential difference (PD) development or the hormonal responses tested. The cell layers were placed in an Ussing chamber for short-circuit current (ISC) and transepithelial conductance (G) measurements. Base-line values were (n = 93): PD, 51.0 +/- 0.2 mV (apical side negative); ISC, 14.55 +/- 0.06 microA/cm2; G, 0.306 +/- 0.001 mS/cm2. ISC and G were higher in cells pretreated with 10(-7) M aldosterone for 24 h in the incubator, when compared to controls (ISC, 28 +/- 2 vs. 16 +/- 2 microA/cm2, G, 0.41 +/- 0.04 vs. 0.26 +/- 0.01 mS/cm2, n = 5) and both remained stable for at least 6 h. In cells not treated with aldosterone, 10(-7) M AVT increased ISC within 1 min after addition, producing a maximum ISC within 15 min which then declined to baseline levels over the next 5 h. Addition of AVT to aldosterone-pretreated cells resulted in a significantly greater peak increase in ISC than in non-pretreated cells (change in ISC compared to controls: 8.1 +/- 0.4 vs. 4.9 +/- 0.4 microA/cm2, n = 5, P less than 0.001), indicating a synergistic effect. A dose-response curve for amiloride obtained in the presence of AVT showed that amiloride completely inhibits ISC. Pretreatment of the A6 cells with aldosterone for 24 h shifted the amiloride dose-response curve to the right, as expressed in a doubling of the apparent Ki value (from 0.17 +/- 0.02 to 0.33 +/- 0.04 microM). In conclusion, A6 cells grown in defined, serum-free medium express a greater than additive synergism between aldosterone and AVT in stimulating transepithelial Na+ transport.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1993

An additional arginine-vasotocin-related peptide, vasotocinyl-Gly-Lys, in Xenopus neurohypophysis.

The neurohypophysis of Xenopus and that of Ranidae and Bufonidae contain hydrin 1 (vasotocinyl-Gly-Lys-Arg) and hydrin 2 (vasotocinyl-Gly), respectively. In order to test the aldosterone-releasing activity of arginine vasotocin (AVT) and hydrin 1, purification of these peptides from an acid-extract of the neurointermediate lobe of Xenopus laevis was performed using an ODS-silica cartridge and reverse-phase and ion-exchange HPLC columns. As a result, an additional AVT-related peptide was newly found. Amino-acid analysis revealed that this peptide is vasotocinyl Gly-Lys (AVT-GK). The aldosterone-releasing activity of AVT-GK was equivalent to that of hydrin 1 (AVT-GKR) and lower than that of AVT. Like AVT and AVT-GKR, AVT-GK were effective in stimulating water flux from the isolated urinary bladder of the toad. Since AVT-GK is regarded as an intermediate between hydrin 1 and hydrin 2 in terms of its C-terminal form, it was designated hydrin 1'.

Aldosterone↗

PubMed1980

Vasotocin, melatonin and narcolepsy: possible involvement of the pineal gland in its patho-physiological mechanism.

Both the pineal nonapeptide hormone arginine vasotocin (AVT) (2.5 micrograms) administered intra-nasally and the pineal indole melatonin (50 mg) administered intravenously to three male narcoleptics (two with auxiliary symptoms and one with sleep attacks only), dramatically increased the amount of REM sleep and decreased REM sleep latency. The duration of the sleep onset REM periods in the two narcoleptics with auxiliary symptoms increased by more than 100 percent after AVT and melatonin administration. In the narcoleptic with sleep attacks only both AVT and melatonin induced REM periods at sleep onset. The hypothesis is advanced that narcolepsy represents an impairment of the melatonin-AVT control in the induction and circadian organization of REM sleep associated with an immaturity of REM triggering centers.

Adolescent↗

PubMedDate not supplied

Arginine vasotocin and renal function in the conscious dog.

The effects of arginine vasotocin (AVT), 4-6 ng/kg, on renal function and plasma prolactin (PRL) were determined in conscious American foxhounds undergoing a water diuresis. Intravenous AVT produced an antidiuresis, kaliuresis and inconsistent natriuresis, independently of changes in GFR, blood pressure, heart rate and plasma PRL.

Animals↗