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Long‐chain polyunsaturated fatty acids (LC‐PUFAs) play crucial roles in growth, development and reproduction of Litopenaeus vannamei, one of the most important shrimp species cultivated in China in recent years. To investigate the effect of dietary n‐3 PUFA composition on growth and the expression of LvFAD6 and LvELOV5 genes and fatty acid composition of this species, ten diets, which contain different levels of α‐linolenic acid (C18:3 n‐3, ALA), eicosapentaenoic acid (C20:5 n‐3, EPA) and docosahexaenoic acid (C22:6 n‐3, DHA), respectively, were prepared for the culture of this species lasting 42 days. The results showed that the identified cDNA sequence of fatty acyl desaturases 6 from L. vannamei (LvFAD6) was 739 bp, encoding a protein of 210 amino acids. The LvFAD6 peptide sequence possessed two histidine‐rich motifs (QHHA and QIEHH), shared 96.6% identity with Apostichopus japonicus FAD6 and strongly clustered with FAD6 from A. japonicus and Octopus bimaculoides. The expression of LvFAD6 and LvELOV5 in muscle decreased with increase in dietary EPA, but increased with increase in dietary DHA. Dietary ALA has the potential to further increase the production of these health‐beneficial LC‐PUFAs in L. vannamei fed a diet with low levels of EPA and DHA, implying L. vannamei had the capacity to convert dietary ALA into EPA and DHA. These results suggest that the supplementation of ALA, EPA and DHA in diets for better growth of L. vannamei in ranges of 2.5% to 3.89%, 1.7% to 3.19% and 2.7% to 5.84% of total fatty acids respectively. [ABSTRACT FROM AUTHOR]

Aim: The feasibility of intranasal brain targeting drug delivery system via the olfactory pathway from nose to brain was explored., Methods: Using gellan gum, a cation-sensitive gel forming excipient, huperzine A (Hup A) nasal in situ gel was prepared by pH gradient precipitation method. The pharmacokinetics of Hup A in blood and cerebrospinal fluid (CSF) after intranasal, intravenous and intragastric adminstration to rats was studied using cisternal cannulation for serial CSF sampling and femoral artery cannulation for serial blood sampling. The distributions of Hup A into rat brain tissues following intranasal dosing were compared with those after intravenous and intragastric dosing by tissue homogeneization. The therapeutics effects of Hup A nasal in situ gel on cognitive function were tested in mice and rats with Morris water maze, step down test and step through test., Results: The AUC(0-->6 h) value in plasma obtained after nasal administration was 0.94 of that after intravenous administration, but the AUC(0-->6 h) of CSF after nasal administration was 1.3 and 2.3 times of that after intravenous and intragastric administration. The AUC(0-->6 h), of cerebrum, hippocampus, cerebellum, left olfactory bulb and right olfactory bulb after nasal administration were 1.5, 1.3, 1.0, 1.2 and 1.0 of that after intravenous administration, 2.7, 2.2, 1.9, 3.1 and 2.6 times of that after intragastric administration, respectively. Intranasal adminintration of 17.5-35 microg x kg(-1) showed equal effects after oral adminintration of 70 microg x kg(-1) commercial tablets, which was in good agreement with the results of pharmacokinetics., Conclusion: Intranasal administration of huperzine A nasal in situ gel significantly increased the distributions of Hup A into rat brain tissues, especially into cerebrum and hippocampus which should be the target areas of Hup A, and enhanced the brain targeting of Hup A.

Aim: To investigate the pre-synaptic metabolism of norepinephrine (NE), judged by variations in plasma concentration of 3,4-dihydroxyphenylglycol (DHPG) and 3,4-dihydroxymandelic acid (DOMA)., Methods: Pithed and electrically stimulated (2.5 Hz) rats were given intravenous infusion of exogenous NE (6 nmol . kg-1 . min-1). Plasma NE, DHPG, DOMA, and the activities of mono- amine oxidases (MAO) were measured with the radio-enzymatic assay., Results: Exogenous NE induces an about 100-fold increase in plasma NE concentration while blood pressure remained within normal limits. A 12-fold increase in plasma DHPG and 1.2-fold increase for DOMA were observed. When NE transportation across the pre-synaptic membrane was inhibited by desipramine (2 mg/kg, iv), a great reduction in plasma DHPG concentration (about 25 % of control) was observed while DOMA remained unchanged. When MAO-A activity was inhibited to 25 % of control by clorgyline (2 mg/kg, iv) and MAO-B to 30 % by deprenyl, the plasma DHPG and DOMA concentrations were reduced to 15 % and 70 % of controls, and to 26 % and 76 % of controls, respectively. When clorgyline and deprenyl were combined, plasma DHPG was vanished (less than 2 % of control) while plasma DOMA remained in the same range (72 % of control)., Conclusion: The metabolizing system of NE in pre-synapse, associating with the pre-synaptic reuptake plus oxidative deamination on the external membrane of mitochondria, is predominant for the reduction to DHPG.