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)

Nanosecond time-resolved tyrosinate fluorescence lifetimes were compared for oxytocin (OXT) and vasopressin (AVP) in propylene glycol. Long-lifetime tyrosinate fluorescence (LTF), characteristic of stable intramolecular hydrogen bond formation of the Tyr hydroxyl group, was present for OXT but not AVP in propylene glycol. The Tyr OH proton was also found to be labile for OXT but not AVP in DMSO by 1H-NMR. The spectroscopic data illustrate that the Tyr hydroxyl in OXT participates in an intramolecular hydrogen bond in certain receptor-simulating environments; the absence of potent LTF for [Ala5] OXT suggests that the Tyr hydroxyl of OXT forms an H-bond with the Asn5 carboxamide side-chain. The lability of the Tyr OH proton of OXT, but not AVP, is in accord with the biological activities of the peptides (OXT 100%, AVP 1%) in the rat uterus assay, suggesting that propylene glycol and DMSO mimic the environment at uterine receptors. 1H-NMR studies in DMSO demonstrate that for AVP there is a perpendicular-plate ring pairing interaction between the Tyr and Phe side-chains in which the hexagonal axis of the Tyr ring interacts with the face of the Phe ring. The present findings are discussed in terms of the proposed "cooperative model" for neurohypophysial hormone action.
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PMID:Tyrosinate fluorescence lifetimes for oxytocin and vasopressin in receptor-simulating environments: relationship to biological activity and 1H-NMR data. 217 14

Multiparous Holstein cows (n=58) were used to study the effects of peripartum dietary supplementation on metabolic status, liver function and reproduction variables. Diets for cows were as follows: (a) no supplementation (CTL), (b) prilled fatty acids as 1.9% of DM (PrFA), (c) calcium salts of long chain n-6 fatty acids as 2.24% of DM (CaLFA) or (d) daily topdressing with 769 g of 65% propylene glycol (PGLY). Supplements were fed during the last 21 days before expected calving except for PGLY that continued until 21 days after parturition. Ovarian activity was monitored by transrectal ultrasonography and days to first ovulation were recorded. Liver biopsies were obtained on day 8 and 21 postpartum and analyzed for triglyceride content and mRNA expression of pyruvate carboxylase, cytosolic phosphoenolpyruvate carboxykinase, carnitine palmytoyltransferase 1A, and peroxisome proliferator-activated receptor-alpha. At 71 days following parturition, stage of ovarian cycles was synchronized and at day15 of the cycle oxytocin was injected i.v., blood samples were obtained at frequent intervals, and analyzed for 13,14 dihydro, 15-keto PGF(2alpha) (PGFM). Milk production and milk components were not different among treatment groups. Cows in PGLY gained body condition score (BCS) prepartum and net energy balance prepartum tended to be greater, but was not different postpartum from other groups. PGLY supplementation increased plasma insulin concentration prepartum, but not during the postpartum period. No significant differences were observed in plasma concentrations of glucose, NEFA, and insulin-like growth factor or hepatic triglyceride content, but all supplements tended to decrease beta hydroxybutyrate postpartum compared to CTL cows. Abundance of mRNA of gluconeogenic and lipid oxidation genes was not different among treatment groups. Days to first ovulation and uterine PGF(2alpha) production in response to an oxytocin treatment were not significantly different among treatment groups. Peripartum supplementation did not result in the substantial improvement of metabolic profile in early lactation nor significantly affect days to first ovulation and PGFM response to an oxytocin treatment.
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PMID:Effect of peripartum dietary energy supplementation of dairy cows on metabolites, liver function and reproductive variables. 1853 91

The goal of this work was to investigate a new nasal carrier for enhanced drug delivery to brain, we call Phospholipid Magnesome. The system contains soft phospholipid vesicles, composed of phospholipid, water, propylene glycol, magnesium salt, and the mucoadhesive polymer, alginate. The carrier was characterized by various methods: electron microscopy, calorimetry, and dynamic light scattering. The ability of the carrier's vesicles to entrap various molecules was studied by CLSM and ultracentrifugation combined with HPLC quantification. Mucoadhesivity of the carrier was tested in vitro using porcine nasal mucosa. The delivery of rohdamine 6G, insulin, and epidermal growth factor was estimated by two methods, multiphoton microscopy and near infrared (NIR) imaging. Pharmacodynamic effects of nasal treatment with oxytocin and insulin incorporated in Phospholipid Magnesome were evaluated in animal models. Results show that the system is composed of soft multilamellar nanosized vesicles with the ability to entrap both lipophilic and hydrophilic molecules. The mucoadhesivity test results indicate a prolonged contact time of the drug with the nasal membrane as compared to control. Multiphoton microscopy and NIR imaging of brain show effective delivery of the tested molecules to brain following nasal administration in Phospholipid Magnesome relative to controls. Moreover, the results of the pharmacodynamic study measuring the antinociceptive effect of oxytocin administrated nasally to an animal model indicate the efficiency of the Phospholipid Magnesome as compared to three control systems. Further, nasal administration of insulin resulted in a strong and prolonged hypoglycemic effect for the drug incorporated in the new carrier but not for control systems. Based on the results of the histopathological test, the carrier is safe for local administration on the nasal membrane. In conclusion, the results of this study suggest that Phospholipid Magnesome nasal carrier is able to improve drug effects, probably by a combined mechanism, absorption enhancement, and prolongation of mucosal contact.
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PMID:Phospholipid Magnesome-a nasal vesicular carrier for delivery of drugs to brain. 2952 65