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81.
Neurohormonal and metabolic effects of medetomidine compared with xylazine in healthy cats
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The purpose of this study was to investigate and compare the effects of medetomidine and xylazine on some neurohormonal and metabolic variables in healthy cats. Five cats were used repeatedly in each of 11 groups, which were injected intramuscularly with physiological saline solution (control), 20, 40, 80, 160, and 320 microg/kg of medetomidine, and 0.5, 1, 2, 4, and 8 mg/kg of xylazine. Blood samples were taken over 24 h from the jugular vein for determination of plasma glucose, insulin, cortisol, epinephrine, norepinephrine, glucagon, and nonesterified fatty acid concentrations. Both medetomidine and xylazine induced remarkable hyperglycemia that was dose-dependent except for the response to medetomidine from 0 to 3 h. Both agents suppressed epinephrine and norepinephrine release but not in a dose-dependent manner at the tested dosages. Both agents inhibited insulin release and lipolysis, with similar potency, and tended to suppress cortisol release. The glucagon levels did not change significantly in any of the groups. These results suggest that the effects of medetomidine and xylazine on glucose metabolism and catecholamine release may not be due only to the actions mediated by alpha2-adrenoceptors. 相似文献
82.
Yoshiaki Nakagawa Guy Smagghe Soichi Kugimiya Kazunari Hattori Tamio Ueno Luc Tirry Toshio Fujita 《Pest management science》1999,55(9):909-918
Insecticidal activity against the Colorado potato beetle, Leptinotarsa decemlineata, was measured for a series of substituted N-tert-butyl-dibenzoylhydrazines, in which one of the benzoyl moieties closer to the tert-butyl group was fixed as being 2-chloro-substitued and the other variously substituted singly or doubly. The effects of substituents on the activity were quantitatively analysed using the classical quantitative structure–activity relationship (QSAR) procedure. The activity against the Colorado potato beetle increases with the molecular hydrophobicity. In addition, various types of steric effect are at work, depending upon the positions. Hydrogen-bonding acceptor substituents at the para position enhance the activity. There seem to be threshold (or optimum) values, albeit position-dependent, in the molecular hydrophobicity, above which the activity starts to decrease. This biphasic contribution of the molecular hydrophobicity to activity against coleopterous larvae is the most conspicuous difference in substituent effects from those found for similar compounds against lepidopterous pest insects, and may be the basis of the variations in the activity spectrum for certain compounds in this series. The introduction of bulkier substituents into the meta- and para-positions of the benzene ring, apart from the tert-butyl group, is unfavorable to activity. LD50 values against Colorado potato beetle larvae of methoxyfenozide (RH-2485) and tebufenozide (RH-5992) were in the order of 10−7 mol per insect, whereas those of RH-5849, and halofenozide (RH-0345) were very low, 10−9–10−10 mol per insect being selective to the coleopterous larvae. © 1999 Society of Chemical Industry 相似文献
83.
Takashi Takagi Toshio Sekiguchi Yuichi Sasayama Atsuhiko Hattori Takushi X. Watanabe Yoichiro Kitani Yoshiaki Tabuchi Hajime Matsubara Ajai K. Srivastav Tran Ngoc Hai Thumronk Amornsakun Nobuo Suzuki 《International Aquatic Research》2019,11(3):267-276
To elucidate the physiological role of calcitonin (CT) in stingrays (cartilaginous fish), an enzyme-linked immunosorbent assay (ELISA) system using a specific antibody against stingray CT has been developed. Synthetic stingray CT was subcutaneously injected into mice four times—once every 2 weeks—together with an adjuvant. We purified the IgG antibody fraction using the protein A affinity chromatography from collected antiserum. Evaluating the antibody titer, we found the antibody’s optimum dilution ratio to be 600 times. Competitive ELISA has been developed using the antibody diluted 600 times. Our antibody did not cross-react with teleost CTs and muscle extraction, but cross-reacted with stingray plasma and the extract of the ultimobranchial gland, the secretary organ of stingray CT. Using this ELISA, we measured the plasma CT level in stingrays and examined its correlation with several mineral concentrations. Plasma CT did not show significant correlation to calcium, magnesium, inorganic phosphorus, sodium, chlorine, or urea, although there was a correlation among the factors involved in osmoregulation, such as sodium, chlorine, and urea. On the other hand, plasma CT was significantly correlated to body weight and length. Furthermore, there was a significant correlation between plasma CT and gonad weight. Since plasma CT was correlated with the weight of liver, which is involved in the synthesis of egg yolk protein, we examined the influence of 17β-estradiol (E2) on CT secretion. After E2 injection, the plasma CT level increased significantly. This is the first study to demonstrate that E2 induced plasma CT secretion in cartilaginous fish. 相似文献
84.
Narezushi extract was separated into peptide and nonpeptide fractions by ion-exchange column chromatography. The narezushi extract and fractions were administered to rats in a diet enriched with lipid and cholesterol for 30 days. In the narezushi extract and nonpeptide fraction groups, increases in triglyceride, total cholesterol, and low-density lipoprotein-cholesterol
levels in the plasma and accumulation of total lipids and triglyceride in the liver were suppressed, while both lipid and
cholesterol fecal excretion were increased. In the peptide fraction group, these effects were also observed, except for the
suppressing effect on liver lipid accumulation. Narezushi extract administration tended to increase fecal bile acids and promoted the activity of cholesterol 7α-hydroxylase, the rate-limiting
enzyme in the synthesis of bile acid from cholesterol in the liver. However, the activity of 3-hydroxy-3-methylglutaryl coenzyme
A (HMG-CoA) reductase, the rate-limiting enzyme in the cholesterol synthesis system in the liver, decreased due to regulation
by the feedback of lipid transportation from diet to the liver. These results suggest that both the increase in cholesterol
and bile acid fecal excretion and the promotion of cholesterol 7α-hydroxylase activities are related to the hypocholesterolemic
effects of narezushi extract. Amino acids and organic acids, which are abundantly contained in the nonpeptide fraction, seemed to have more intensive
hypocholesterolemic effects than peptides existing in the peptide fraction. 相似文献
85.
Dhirendra Prasad Thakur Katsuji Morioka Naoya Itoh Mizuho Wada Yoshiaki Itoh 《Fisheries Science》2009,75(6):1489-1498
The study was conducted to evaluate the meat texture, muscle proximate composition, lipid class composition, and collagen
content of cultured amberjack and to compare these parameters with those of the yellowtail. Our results showed that the meat
texture of cultured amberjack was tougher and had a lower degree of seasonality than that of cultured yellowtail. Muscle lipid
and collagen content also varied in the two fish species over the study period. Meat breaking strength was not correlated
with any of the muscle constituents, indicating that variations in the meat texture of cultured amberjack was not directly
influenced by the changes in the muscle biochemical constituents. 相似文献
86.
Keita Kodama Masaaki Oyama Jeong-Hoon Lee Yoshiaki Akaba Yoshihiro Tajima Takamichi Shimizu Hiroaki Shiraishi Toshihiro Horiguchi 《Fisheries Science》2009,75(4):875-886
To explore which lifestages affect the stock size of young-of-the-year mantis shrimp Oratosquilla oratoria in Tokyo Bay, Japan, we investigated interannual variations in the quantitative relationships among egg production, larval
density, and juvenile density. We collected adult females, larvae, and juveniles during monthly field surveys from 2004 to
2007. The interannual trend for the juvenile density index differed from those for egg production and larval density; although
indices of both egg production and larval density were high in 2004 and 2007, the juvenile density index was high only in
2007, suggesting high mortality during the pelagic larval stage or the early phase of the postsettlement juvenile stage in
2004. We found that larval settlement started at the end of August and peaked in October, although larvae from the early spawning
season (May–June) should have settled in August or earlier. Juveniles were found throughout the bay except in areas where
bottom hypoxia occurred, suggesting that hypoxia restricts the spatial distribution of juveniles. Our results suggest that
mortality during the early life history fluctuates among years, probably because of changes in environmental conditions in
the bay, resulting in interannual variation in the stock size of young-of-the-year juvenile O. oratoria. 相似文献
87.
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90.
Takashi Okayama Tooru Ooizumi Yoshiaki Akahane Sei-Ichi Kitakami Yo-Ichi Abe Jun Shirai 《Fisheries Science》2007,73(4):931-939
Changes in physical properties of two-step heated gels on addition of gluconate were investigated in terms of relationships
between breaking strength and gel stiffness. Regression lines between the breaking strength and the gel stiffness were extended
to the x-axis (gel stiffness), and the intercept was defined as SBSO. The SBSO of the two-step heated gels increased with gluconate contents in salt-ground surimis, suggesting that the harder but less elastic gels formed on addition of gluconate were dose-dependent. Conversely, the denaturation
rate constants of myosin in salt-ground surimis during preheating estimated by means of Ca-ATPase inactivation, loss of salt solubility, and decrease of denaturant solubility
were considerably reduced by gluconate. Thus, the progress of myosin denaturation was strongly suppressed. Increments of SBSO (δSBSO) of the two-step heated gels on addition of gluconate were inversely correlated with the denaturation rate constants of myosin
in salt-ground surimis for every index. Thus, the changes in physical parameters of two-step heated gel caused by gluconate may be associated with
the sluggish progress of myosin denaturation in salt-ground surimi during preheating. 相似文献