Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Groups of 9 or 10 cows were assigned to one of three treatments 1) machine-milking three times daily, 2) machine-milking six times daily, and 3) suckling three times daily in addition to machine-milking three times daily. Treatments were conducted during the first 6 wk postpartum. During wk 5, digestibility of the diet was estimated by the indigestible neutral detergent fiber method. During wk 6, milk yield and dry matter intake (DMI) were recorded daily, and plasma concentrations of glucose, nonesterified fatty acids, urea, protein, growth hormone, insulin, insulin-like growth factor I, oxytocin, and prolactin were determined. Milk yields were 38.5, 46.8, and 52.7 kg/d, and DMI were 18.1, 21.2, and 17.2, for cows on treatments 1, 2, and 3, respectively. Plasma glucose concentrations decreased, and plasma nonesterified fatty acid concentrations increased, for cows on treatments 2 and 3 compared with cows on treatment 1. Digestibility of dry matter was 57.5, 60.5, and 60.6%; of organic matter was 62.6, 64.6, and 66.8%; and of crude protein was 59.3, 62.7, and 64.6% for cows on treatments 1, 2, and 3, respectively. Concentrations of all assayed hormones, except insulin, increased moderately for cows on treatment 2 compared with cows on treatment 1 and increased dramatically for cows on treatment 3. Insulin concentrations followed the opposite trend. The DMI were positively related to milk yields and negatively related to oxytocin concentrations. Digestibility was negatively related to plasma glucose concentrations in a nonlinear pattern. The possible involvement of hormones in improvement of digestibility is discussed.
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PMID:The effect of enhanced milk yield of dairy cows by frequent milking or suckling on intake and digestibility of the diet. 962 Dec 46

The effects of ethanol were studied on single evoked spikes recorded at 20 degrees C with the perforated-patch method in acutely dissociated rat supraoptic neurons. In seven out of eight neurons, ethanol (50 mM) significantly reduced the spike duration by selectively decreasing the decay time (82+/-2% of the control), leaving the amplitude and rise time unaffected. Resting potential and threshold did not change. Similarly, CdCl2 at a concentration of 100 microM, which blocks all voltage-activated calcium current in the supraoptic neurons, reduced the decay time of single evoked spikes (76+/-3% of the control, n=10) without modifying the other above-mentioned parameters. In addition, exposure to 100 microM CdCl2 prevented any subsequent effect of 50 mM ethanol (n = 5). Exposure to apamin (10 nM) and iberiotoxin (10 nM) did not have any effect on single evoked spikes. Because these concentrations are effective in blocking, respectively, small (SK) and large (BK) conductance calcium-dependent potassium channels in these neurons, this result shows that these currents are not involved in either the shaping of single evoked spikes or the actions of ethanol on spike shape. The sustained component of whole-cell recorded calcium current measured at -10 mV (hp -60 mV) was inhibited by ethanol in a dose-dependent manner, with a significant effect detectable at 25 mM. Exposure to 50 mM ethanol significantly reduced the sustained current to 70+/-5% of the control (n=12), without any apparent shift of the current-voltage relationship. Control exposure of the neurons to either 50 mM urea or 50 mM sucrose did not affect the voltage-gated calcium currents. We conclude that ethanol reduces the duration of single evoked spikes by a specific inhibition of voltage-activated calcium currents. The results suggest that, in addition to its direct effects on release of vasopressin and oxytocin from neurohypophysial terminals, ethanol could also affect hormonal release via changes in firing patterns arising in the cell bodies.
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PMID:Ethanol reduces the duration of single evoked spikes by a selective inhibition of voltage-gated calcium currents in acutely dissociated supraoptic neurons of the rat. 968 42

The localization and pharmacological characteristics of vasopressin (VP) binding sites of the V(1a) subtype in developing and adult rat kidney were investigated by radioautography on kidney sections incubated in the presence of a radioiodinated selective V(1a) antagonist. Their localization after in vivo systemic infusion of the radioligand was also investigated. V(1a) binding sites first appear at embryonic day 16 on vascular elements. In the adult, they were localized in the cortex (vascular and tubular structures, juxtaglomerular apparatus), the outer medulla outer stripe (vasa recta) and inner stripe (thin descending limbs of short looped nephrons) and the inner medulla (collecting ducts). Data obtained in vitro were confirmed by in vivo binding at postnatal day 30 (PN30). Whatever their localizations, the V(1a) binding sites exhibited full V(1a) pharmacological profile in postnatal stages rats and in adult rats: a high affinity (nM range) for VP and for the V(1a) agonist, a lower affinity (microM range) for oxytocin and no affinity for the oxytocin agonist. The presence of V(1a) binding sites in these different structures raises the question of the putative roles of VP in modulating renal functions. A striking finding is the presence of V(1a) binding sites in the outer medullary thin descending limbs of short looped nephrons suggesting their colocalization with urea transporters.
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PMID:Historadioautographic localization, pharmacology and ontogeny of V(1a) vasopressin binding sites in the rat kidney. 1046 Oct 39

Most bony vertebrate species display a great evolutionary stability of their two neurohypophysial hormones, so that two molecular lineages, isotocin-mesotocin-oxytocin and vasotocin-vasopressin, have been traced from bony fishes to mammals. Chondrichthyes, in contrast, show a striking diversity of their oxytocin-like hormones, yet show a substantial decrease in vasotocin stored in neurohypophysis when compared to nonmammalian bony vertebrates. In the rays, glumitocin ([Ser(4),Gln(8)]-oxytocin) has been identified. In the spiny dogfish, aspargtocin ([Asn4]-oxytocin) and valitocin ([Val(8)]-oxytocin) have been characterized whereas in the spotted dogfish, asvatocin ([Asn(4),Val(8)]-oxytocin) and phasvatocin ([Phe(3),Asn(4),Val(8)]-oxytocin) have been found. Finally, in the holocephalian Pacific ratfish, oxytocin, the typical peptide of placental mammals, has been discovered. The duplication of the oxytocin-like hormone gene found in dogfishes has been observed only in some Australian and American marsupials. Cartilaginous fishes have developed an original urea-based osmoregulation involving a glutamine-dependent urea synthesis and blood urea retention through renal urea transporters. Furthermore, marine species use a rectal salt gland for sodium chloride excretion. Although vasopressin, in mammals, and vasotocin, in nonmammalian tetrapods, are clearly implied in water and salt homeostasis, the hormones involved in the blood osmotic pressure regulation of elasmobranchs are still largely unknown. It is suggested that the great diversity of oxytocin-like hormones in elasmobranchs expresses a release from an evolutionary receptor-binding constraint, so that amino-acid substitutions reflect neutral evolution. In contrast, the preservation of vasotocin suggests a selective pressure, which may be related to the regulation of renal urea transporter-recruitment mechanisms, as it has been shown for vasopressin in mammals. J. Exp. Zool. 284:475-484, 1999.
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PMID:Unique evolution of neurohypophysial hormones in cartilaginous fishes: possible implications for urea-based osmoregulation. 1046 84

1. Synthesis of oxytocin (OT) and arginine-vasopressin (AVP) is increased in induced models of Type I diabetes, such as the streptozotocin model. However, these parameters have not yet been evaluated in spontaneous models, such as the nonobese diabetic mouse (NOD). Therefore, we studied in the magnocellular cells of the paraventricular nucleus (PVN) of nondiabetic and diabetic 16-week-old female NOD mice and control C57B1/6 mice, the immunocytochemistry of OT and AVP peptides and their mRNA expression, using nonisotopic in situ hybridization (ISH). 2. In nondiabetic and diabetic NOD female mice, the number of OT- and AVP-immunoreactive cells were similar to those of the controls, whereas immunoreaction intensity was significantly higher for both peptides in diabetic NOD as compared with nondiabetic NOD and control C57B1/6 mice. 3. ISH analysis showed that the number of OT mRNA-containing cells was in the same range in the three groups, whereas higher number of AVP mRNA expressing cells was found in diabetic NOD mice. However, the intensity of hybridization signal was also higher for both OT and AVP mRNA in the diabetic group as compared with nondiabetic NOD and control mice. 4. Blood chemistry demonstrated that haematrocrit, total plasma proteins, urea, sodium, and potassium were within normal limits in diabetic mice. Thus, NOD mice were neither hypernatremic nor dehydrated. 5. We suggest that upregulation of OT and AVP reflects a high-stress condition in the NOD mice. Diabetes may affect neuropeptide-producing cells of the PVN, with the increased AVP and OT playing a deleterious role on the outcome of the disease.
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PMID:Diabetes increases the expression of hypothalamic neuropeptides in a spontaneous model of type I diabetes, the nonobese diabetic (NOD) mouse. 1144 Jan 95

The primary objective was to determine whether the dietary polyunsaturated fatty acids, eicosapentaenoic (EPA, C20:5, n-3) and docosahexaenoic (DHA, C22:6, n-3), present in fish meal (FM) can attenuate uterine secretion of PGF2alpha in response to a challenge with estradiol and oxytocin in lactating dairy cows. Cycling multiparous cows (n = 32) were fed diets containing 0 (OFM), 2.6 (2.6FM), 5.2 (5.2FM), or 7.8% menhaden FM (7.8FM). The diet consisting of 7.8FM also contained fish oil (0.28% of dietary dry matter) to increase intake of EPA and DHA. Average dry matter intake was 24.9 kg/d and unaffected by diet. Combined intakes of EPA and DHA averaged 0, 12.8, 24.1, and 54.0 g/d from the OFM, 2.6FM, 5.2FM, and 7.8FM diets, respectively. At 30 to 34 d after initiation of dietary treatments, cows received an i.m. injection of 100 microg of GnRH followed by i.m. administration of 25 and 15 mg of PGF2alpha after 7 and 8 d, respectively. Synchronous ovulation was induced by an injection of 3000 IU of human chorionic gonadotropin (hCG) given 24 h later on d 9. Subsequent luteal phase increases in plasma progesterone concentrations did not differ (0.88 ng/ml per day). At 15 d after hCG injection, cows were injected with estradiol-17beta (3 mg, i.v.) at 0900 h and oxytocin (100 IU, i.v.) at 1300 h. Plasma PGF2alpha metabolite concentrations after oxytocin injection were reduced in cows fed diets containing FM compared with those fed OFM. Milk production (39.1 kg/d) and concentrations of fat, protein, or urea nitrogen in milk were not affected by diet. Feeding fish meal and fish oil containing eicosapentaenoic acid and docosahexaenoic acid reduced the proportion of n-6 fatty acids and increased that of n-3 fatty acids in milk in a dose-responsive manner.
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PMID:Uterine, ovarian, and production responses of lactating dairy cows to increasing dietary concentrations of menhaden fish meal. 1201 20

Sharks and rays utilize a unique strategy for adaptation to the hyperosmotic marine environment by maintaining their plasma slightly hyperosmotic to surrounding seawater (SW) through the accumulation of urea. Since neurohypophysial hormones (NHs) are plausible candidates for osmoregulatory effectors, the synthesis and release of NHs were investigated after transfer of fish to different environmental salinities. Molecular cloning revealed three NHs from the hypothalamus of a dogfish, Triakis scyllium: vasotocin (VT), asvatocin, and a novel oxytocin-family peptide, phasitocin ([Phe3, Asn4, Ile8]vasotocin). The VT precursor consists of a signal peptide, VT, a neurophysin and a copeptin moiety. In contrast, the asvatocin and phasitocin precursors are shorter due to the lack of a copeptin moiety as is the case in oxytocin and mesotocin precursors in tetrapods and lungfish, but different from teleost isotocin precursors that have the copeptin moiety. In the hypothalamus, VT mRNA levels significantly increased after transfer to concentrated (130%) SW for 2 days, while no change was observed in mRNA levels of asvatocin and phasitocin following transfer to either 130% or diluted (60%) SW. The increase in VT mRNA was reflected in the plasma level of peptide; plasma VT concentration measured by highly sensitive and specific radioimmunoassay increased according to elevated environmental salinities. These results suggest that VT is an osmoregulatory effector in dogfish, especially when the dogfish is exposed to a hyperosmotic environment.
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PMID:Neurohypophysial hormones of dogfish, Triakis scyllium: structures and salinity-dependent secretion. 1530 58

Researchers have turned their attention to the effects of alcohol consumption on breastfeeding, with significant negative findings concerning both the mother and the newborn. This study is a meta-analysis of the principle research performed in the last decade that was concerned with lactation and alcohol. Results from experimental and human subject research has shown that effects of alcohol include: behavioural changes, reduced milk and luteinising hormone production, with increased fat content, reduced lactose content. Increased lipogenesis and increased activity of lipoprotein and hormone-sensitive lipase, structural alterations in the epithelial cells of the breast and abnormal casein production, reduced oxytocin and prolactin production with subsequent reduced milk ejection, and reduced weight and protein content of the breast. Reduction in food consumption, body weight, growth and development and hepatic glycogen, serum glucose, amino-acids, insulin, glycerol, fatty acids and urea, and an increase in serum acetoacetic acid is seen in newborn children that were breastfed by animals with a high intake of alcohol during pregnancy or the puerperal period. Alcohol consumption during lactation caused a reduction in liver weight and triglyceride, protein, DNA and lipid content, in the newborns. Serum changes included a reduction in protein, triglyceride, cholesterol, fatty acid and glycerol level with an increase in beta-hydroxybutirate levels. Changes also included alterations in the motor system and behaviour. Further studies are needed to determine, with confidence, the minimum level of alcohol consumption that can provoke pathological effects in both the mother and the child.
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PMID:[Lactation and alcohol: clinical and nutritional effects]. 1533 53

Hyponatremia can be classified as acute or chronic depending on its duration, and treatment options are tailored to this classification. However, it is sometimes difficult to differentiate acute from chronic hyponatremia in the Emergency Department (ED). The objective of this study was to identify characteristics to help diagnose and manage acute hyponatremia in the ED. Patients with acute hyponatremia in the ED were enrolled from a retrospective 2-year chart review. Eleven patients (0.8%) were identified with acute hyponatremia out of a total of 1321 hyponatremic patients. There were nine women and two men. The mean age was 48.9 years. The mean sodium (Na(+)) level was 115+/-4 mmol/L. Accompanying biochemical abnormalities included hypouricemia and hypouremia with increased fractional excretions of uric acid (UA) and urea. The estimated amount of water intake ranged from 2.5 to 10 liters (mean, 5.1+/-2.3 liters) during the day before ED presentation. All patients were treated with hypertonic saline and furosemide at a correction rate of 1.6+/-0.5 mmol/L/h. No patients had neurological sequelae after treatment. The causes of acute hyponatremia included induction of abortion with oxytocin (n=1), primary polydipsia on neuroleptic agents (n=2), polyethylene glycol (PEG) preparation for colonoscopy (n=1), diuretic therapy for hypertension (n=4), ecstasy use (n=1), and weight-reducing herbal teas (n=2). We conclude that in the right clinical setting, high free water intake and low serum urea and UA favor acute hyponatremia. A detailed drug history may be helpful in the differential diagnosis of acute hyponatremia.
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PMID:Biochemical and etiological characteristics of acute hyponatremia in the emergency department. 1624 91

Despite the common use of MDMA (ecstasy) in the UK, the mechanism underlying associated potentially fatal cerebral oedema is unclear. We used a new experimental approach working directly with clubbers to perform a study on 30 (17 male) experienced clubbers (mean 6.6 years of clubbing). Pre- and post-clubbing measurements were performed to compare plasma levels of pituitary hormones (vasopressin, oxytocin), plasma and urine osmolality, urinary pH, and plasma sodium and urea. Ecstasy consumption was confirmed by using urinary drug screening pre- and post-clubbing. MDMA was detected in the urine samples of 17 subjects, three of which tested positive during pre-clubbing tests. Mean plasma vasopressin concentration increased in the MDMA group (1.28 +/- 0.29 to 1.43 +/- 0.41 pmol/l), but fell in other participants (1.23 +/- 0.42 to 1.16 +/- 0.0.34 pmol/l). Similarly, mean plasma oxytocin concentrations increased after ingestion of MDMA (2.02 +/- 0.29 to 2.43 +/- 0.24 pmol/l), but fell in the group that did not use MDMA (2.17 +/- 0.36 pmol/l to 1.89 +/- 0.37 pmol/l). There was a significant group by time interaction for plasma osmolality and plasma sodium (p = 0.001 and p = 0.003, respectively) and between change in urinary osmolality (p < 0.001) and MDMA use, with the pattern of change being consistent with the induction of inappropriate vasopressin secretion (also known as SIADH) by MDMA. This report demonstrates SIADH in ecstasy-using "clubbers", which has important clinical implications.
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PMID:Vasopressin and oxytocin secretion in response to the consumption of ecstasy in a clubbing population. 2325 37


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