Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pineal indoleamine, melatonin, has been shown to influence many physiological systems within the mammalian body. Few studies, however, have examined the influence of melatonin on renal function. This study investigated the effects of melatonin on water metabolism and renal function. Young adult male Syrian hamsters were maintained on a long photoperiod (LD 14:10) in metabolic cages. The animals received daily (1700) injections of either control vehicle or 25 micrograms of melatonin for 85 consecutive days. Melatonin administration resulted in significant increases in water consumption and urine production. Water budgets were also significantly influenced by melatonin, as were urinary osmolality, urinary sodium, and potassium concentrations, but urinary calcium concentrations were essentially unaltered. When excretion rates for sodium, potassium, and calcium were calculated, no differences were observed between the vehicle control and melatonin-treated groups. Injections of melatonin also significantly decreased plasma antidiuretic hormone (ADH). These results demonstrate that afternoon injections of melatonin can alter renal function, which may involve direct (i.e., on ADH secretion and/or thirst mechanisms) or indirect (i.e., behavioral) effects.
J Pineal Res 1992 Sep
PMID:Effects of melatonin on water metabolism and renal function in male Syrian hamsters (Mesocricetus auratus). 145 9

The effect of melatonin as well as pinealectomy on the basal and K(+)-evoked release of vasopressin and oxytocin from the neurointermediate lobes in vitro was determined. Pineal removal resulted in a diminution of vasopressin and oxytocin release from the neurointermediate lobes in vitro. Melatonin (10(-3) or 10(-6) M/l) increased vasopressin and oxytocin release from neurointermediate lobes of sham-operated rats. Nevertheless, when pinealectomized rats served as donors of the neurointermediate lobes, melatonin (10(-3) or 10(-6) M/l) increased vasopressin release under basal conditions. For the same tissue, melatonin did not affect the oxytocin release either under basal conditions or during depolarization due to excess potassium. When 10(-7) M/l melatonin was used, no changes in either vasopressin or oxytocin release were observed in vitro.
J Pineal Res 1992 Jan
PMID:Melatonin, pinealectomy, and release of neurohypophysial hormones: in vitro studies. 156 28

The distribution of nerve fibers containing immunoreactive substance P (SP), estrogen-stimulated neurophysin (ESN), nicotine-stimulated neurophysin (NSN), oxytocin (OT), and vasopressin (VP) was examined in the epithalamic area of adult male and female macaques. Perfused or immersion-fixed epithalamic tissues, sectioned, and mounted on glass slides were processed through the avidin-biotin immunofluorescence method. Fibers containing immunoreactive SP were observed in the pineal organ along the periphery, in the perivascular space, and dispersed between the pinealocytes. Fibers were often observed in the pineal stalk region, and the habenular nuclei had high concentration of immunoreactive SP. Immunoreactive ESN fibers were observed in the stria medullaris, in the lateral habenula, in the pineal stalk, and in the pineal organ. Within the pineal, fibers containing ESN were present in the perivascular space, often concentrated in the walls of blood vessels, but also dispersed between pineal cells. Fibers containing OT, NSN, and VP were also present in the macaque pineal, but in lower quantities compared with fibers containing ESN. These studies show that the pineal of subhuman primates contain nerve fibers (ESN, NSN, VP, OT) of possibly hypothalamic origin. It also has a rich supply of SP fibers, which might be of habenula origin, peripheral parasympathetic ganglia origin, or both. The functional significance of these peptidergic nerve fibers remains to be determined. However, there are indications that they might be involved in regulation of blood flow and release of secretory products from the pinealocytes.
J Pineal Res 1988
PMID:Distribution in the macaque pineal of nerve fibers containing immunoreactive substance P, vasopressin, oxytocin, and neurophysins. 245 73

The effect of melatonin on hypothalamic and neurohypophysial vasopressin and oxytocin was investigated in normal and pinealectomized rats. Pinealectomy was followed by a decrease of both vasopressin and oxytocin content in the hypothalamus and neurohypophysis. In unpinealectomized rats, melatonin decreased vasopressin and oxytocin storage in the hypothalamo-neurohypophysial system. Following pineal removal, melatonin did not augment the pinealectomy-induced decrease of vasopressin and oxytocin in the neurohypophysis; the hypothalamic storage of both neurohormones was even higher when compared with vehicle-treated animals.
J Pineal Res 1988
PMID:Hypothalamic and neurohypophysial vasopressin and oxytocin in melatonin-treated pinealectomized male rats. 322 38

Melatonin injected in a single intraperitoneal dose of 100 micrograms/100 g b.w. to euhydrated rats resulted in a decrease of neurohypophysial oxytocin content but the hypothalamic oxytocin storage as well as the hypothalamo-neurohypophysial storage of vasopressin were not changed. Following 8 d of once-daily melatonin treatment the hypothalamic and neurohypophysial oxytocin and vasopressin content was decreased. It might be therefore suggested that melatonin increases the release of neurohypophysial hormones and/or decreases their synthesis. Melatonin did not significantly modify the neurohypophysial vasopressin depletion rate in animals deprived of water up to 8 days. No consistent effects of melatonin on the decrease of hypothalamo-neurohypophysial content of oxytocin were noted under conditions of dehydration and simultaneous administration of melatonin up to 8 d.
J Pineal Res 1986
PMID:The influence of melatonin on the content of vasopressin and oxytocin in the hypothalamus and neurohypophysis in euhydrated and dehydrated male rats. 377 20

The release of progesterone, estradiol-17 beta, oxytocin, arginine-vasopressin, cAMP, and cGMP by cultured granulosa cells isolated from porcine ovaries without and in the presence of melatonin (0.001, 0.01, 0.1, 1, 10, and 100 ng/ml medium) was analyzed. It was found that melatonin is able to inhibit progesterone and stimulate estradiol secretion. Melatonin treatments significantly inhibited oxytocin release. Some inhibition of vasopressin and cAMP and significant stimulation of cGMP also resulted from melatonin treatment. The present observations suggest a direct effect of melatonin on the steroid, nonapeptide hormone, and cyclic nucleotide release from porcine ovarian cells.
J Pineal Res 1994 Oct
PMID:Direct influence of melatonin on steroid, nonapeptide hormones, and cyclic nucleotide secretion by granulosa cells isolated from porcine ovaries. 789 82

The connection between the suprachiasmatic nucleus (SCN) and the paraventricular nucleus of the hypothalamus (PVN) forms an important component of the melatonin rhythm-generating system. However, the chemical identity of this projection is not known. To test the possible implication of the SCN peptides vasopressin (VP) and vasoactive intestinal peptide (VIP) in this projection, we performed microinfusions in the PVN during the first half of the dark period and subsequently monitored resulting plasma melatonin levels. Infusions for 7 hr of either VP or VIP, but not oxytocin, caused increased plasma melatonin levels in the middle of the dark period. These observations confirm the role of the PVN in the melatonin rhythm-generating pathway and indicate that both VP and VIP released at the level of the PVN, and probably derived from the SCN, are able to influence peripheral plasma melatonin levels.
J Pineal Res 1993 Aug
PMID:Vasopressin and vasoactive intestinal peptide infused in the paraventricular nucleus of the hypothalamus elevate plasma melatonin levels. 822 45

In addition to the stimulating influence of the sympathetic system on the function of the mammalian pineal gland, neuropeptides such as neuropeptide Y, vasoactive intestinal polypeptide and arginine-vasopressin (AVP) are thought to function as modulators. Since AVP has been shown to influence pineal melatonin synthesis, the aim of the present study was to investigate the possible effects of the second hypothalamic nonapeptide oxytocin (OT), which likewise has been detected in the pineal gland. We therefore studied "synaptic" ribbon (SR) numbers, N-acetyltransferase (NAT) activity and the intracellular concentration of cyclic guanosine monophosphate (cGMP) following in vitro incubation of rat pineals in media containing OT (10(-5) M), noradrenaline (NA, 10(-5) M) or both NA and OT. Pineal glands were derived from rats of three different strains (Sprague-Dawley, Long-Evans and the AVP-deficient strain Brattleboro). Neither morphological nor biochemical analyses showed a difference between control and OT-incubated organs in any of the strains tested. In Brattleboro rats, but not in the other strains, noradrenaline slightly increased the number of SR which was not observed when NA and OT were combined. The addition of NA resulted in distinct augmentation of NAT activity and cGMP content, which were not affected by additional OT application. These results suggest that oxytocin is not crucially involved in the regulation of pineal gland function.
 ...
PMID:Lack of effect of oxytocin on the numbers of "synaptic" ribbons, cyclic guanosine monophosphate and serotonin N-acetyltransferase activity in organ-cultured pineals of three strains of rats. 826 81

Plasma concentrations of neurohypophysial hormones show clear rhythms over 24 hr which can be suppressed by exposure to constant light, an observation consistent with pineal involvement. A study has therefore been performed on the changes in the hormone levels in the hypothalamus, posterior pituitary, and plasma over 24 hr in control, pinealectomised, and sham pinealectomised animals to determine if the pineal could play a role. Water intake, urine excretion, packed cell volume, plasma osmolality, and electrolytes were also monitored. Pinealectomy had little effect on fluid balance, but after 8 weeks for oxytocin and 2 weeks for vasopressin the morning values (0700-0800) for the circulating concentrations of the hormones were significantly higher in the pinealectomized group compared with the combined sham operated and unoperated groups (pineal intact). By contrast, the pituitary vasopressin was significantly lower in the pinealectomised group. The increase in plasma oxytocin and vasopressin seen over the hours of daylight and accompanying fall in plasma osmolality seen in the pineal intact group were absent in the pinealectomised group. Similarly, the evening fall in pituitary hormone concentrations and increase in hypothalamic hormone content were absent in the pinealectomised animals. After 10 days of exposure to constant light, the fall in plasma osmolality in the pineal-intact animals over the day was no longer significant; instead a significant increase in plasma osmolality and sodium was seen in the pinealectomised group. Exposure to constant light, while altering the patterns of neurohypophysial activity in the pineal intact group, had little effect on the pinealectomised animals.
J Pineal Res 1993 Jan
PMID:The role of the pineal in the control of the daily patterns of neurohypophysial hormone secretion. 848 5

Pinealectomy has been shown to alter daily rhythms of neurohypophysial hormone release, with plasma hormone concentrations being elevated in the morning, as compared to intact rats. To determine whether pineal removal also altered the response to known stimuli of hormone release, vasopressin concentrations were measured in control, sham-operated, and pinealectomized animals during extracellular fluid hypertonicity produced by an intraperitoneal (i.p.) injection of hypertonic saline or hypovolaemia produced by an i.p. injections of polyethylene glycol. In the combined sham-operated and unoperated groups, injection of hypertonic saline produced a marked increase in plasma vasopressin concentrations from 2.18 +/- 0.28 to 7.2 +/- 1.24 pmol/liter, but the response was attenuated in pinealectomized animals, concentrations increasing to only 3.4 +/- 1.2 pmol/liter. Similarly, following infusion of hypertonic saline, the increase in plasma vasopressin per unit increase in plasma sodium was lower in pinealectomized animals than the pineal intact controls. The response to hypovolaemia was also attenuated, plasma hormone concentrations following reduction in blood volume of approximately 10% increasing to only 3.6 +/- 0.6 pmol/liter as compared to 7.3 +/- 2.2 pmol/liter in the control groups. There were no significant differences in pituitary vasopressin content in any of the groups studied. Thus, the pineal may influence the vasopressin response to physiological stimuli.
J Pineal Res 1996 May
PMID:Release of vasopressin in response to altered plasma volume and sodium concentrations following pinealectomy in the rat. 883 55


1 2 Next >>