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Biomedical subjects

K Mine

Publications and source records attributed to K Mine.

At least 55 records · Page 3Linked to original sources
PubMed1988

Simultaneous determination of noradrenaline and 3-methoxy-4-hydroxyphenylglycol in plasma with high-performance liquid chromatography using electrochemical detection.

We herein report the simultaneous determination of the levels of noradrenaline (NA), and 3-methoxy-4-hydroxyphenylglycol (MHPG), a major metabolite of NA. The sample was subjected to a Sep Pak C18 cartridge prior to the NA and MHPG assay by high-performance liquid chromatography with an electrochemical detector. The results correlated well with the established methods. The average percentage of recovery was 91.2 and 98.7% for NA and MHPG, respectively. The intraassay coefficients of variation were 3.7 and 4.6% for NA and MHPG. The interassay coefficients of variation were 3.5 and 7.5% for NA and MHPG, respectively.

Chromatography, High Pressure Liquid↗
PubMed1987

The involvement of neuropeptide Y in the antimuricide action of noradrenaline injected into the medial amygdala of olfactory bulbectomized rats.

The present study was designed to clarify the functional role of neuropeptide Y (NPY) in the regulation of muricide induced by olfactory bulbectomy (OB) in relation to that of noradrenaline (NA) in the medial amygdala (AME). NA injected into AME inhibited muricide dose-dependently in OB rats. NPY at doses of 5 and 10 micrograms/microliter injected alone into AME failed to suppress muricide. When NPY 10 micrograms was injected into AME in combination with the maximal non-effective dose of NA, which was determined in each rat, muricide was suppressed in 80% of OB rats. The present study has provided the first evidence suggesting that NPY may be involved in the regulation of OB-induced muricide.

Aggression↗
PubMed1986

Simultaneous determination of histamine and N tau-methylhistamine with high-performance liquid chromatography using electrochemical detection.

We have developed a liquid chromatographic method which uses electrochemical detection for the simultaneous quantitation of histamine and N tau-methylhistamine in rat brain. The amines are derivatized with the water-soluble Bolton-Hunter reagent (sulfo B-H). Perchloric acid extracts of rat brains are chromatographed on a strong cation-exchange resin. The eluate is evaporated and allowed to react with sulfo B-H at pH 9.8 at room temperature. The derivatization is complete after 30 s vortexing. The derivatives are purified using a cellulose-phosphate fibrous cation exchanger. They are quantified with an electrochemical detector at a potential of 0.56 V after preoxidizing the sample at 0.47 V. The derivatives of histamine, N tau-methylhistamine, and N alpha-methylhistamine are completely separated without interfering peaks. Since no N alpha-methylhistamine was detected in rat brain it was used as an internal standard. The detection limits are 0.1 pmol of histamine and 0.2 pmol of N tau-methylhistamine. The precision of this method is high, with within-run and between-run coefficients of variation of 2-7% and linearity of 0.999. Both histamine and N tau-methylhistamine peak heights increased significantly and selectively after treatment with pargyline. Because of the high sensitivity, accuracy, and precision, the histamine and N tau-methylhistamine contents of single nuclei of the rat hypothalamus can be routinely quantified.

Animals↗
PubMed1985

Electrochemical detection of biogenic amines following acylation by N-hydroxysuccinimide esters.

A general methodology for the selective derivatization of amines, to enable quantitation by high pressure liquid chromatography with electrochemical detection, is presented. N-Hydroxysuccinimide active esters present in large excess are suitably mild acylating agents to derivatize selectively trace quantities of amines for electrochemical detection. The 2 separate problems of extraction yield and detectability can be solved by this derivatization method. Due to its lipophilicity the resulting N-acylated amine, as demonstrated with serotonin, is extracted efficiently into organic solvents during sample preparation for chromatography. Moreover, the acyl group introduced can be designed to be electroactive, thus extending the procedure to amines not readily oxidized, e.g., histamine and phenylethylamine.

Acylation↗
PubMed1985

Effects of small amygdaloid lesions on pancreatic exocrine secretion.

To investigate the role of the amygdala in central regulation of pancreatic exocrine secretion, the effects of electrolytic lesions on pancreatic secretion were studied in rats. Small bilateral electrolytic lesions in amygdaloid body restricted to basolateral, medial and central nuclei were produced. Eight days after the lesions, bile-pancreatic juice was collected following anesthetization with urethane and chloralose. Basal secretion and secretion stimulated by exogenous pancreozymin and secretin were evaluated in terms of amylase output. In the group with basolateral nucleus lesions, both basal and stimulated secretion were significantly increased. After medial nucleus lesions, mean body weight was reduced to 59% of initial, and basal and stimulated secretion were significantly lower than in the control group and also significantly lower than in an unoperated group, whose mean body weight was reduced to the same level as that of the medially lesioned group by restricting daily food intake. After lesions of the central nucleus, basal secretion was significantly increased, while stimulated secretion was not affected. These results indicated that the amygdala is involved in regulating pancreatic exocrine secretion and that its various nuclei exert different effects.

Amygdala↗
PubMed1983

Autonomic drug effects and gastric secretion in a new experimental model of stress ulcers in rats.

A psychological procedure which does not involve the application of physical stimulation was used to produce gastric ulcers experimentally. Ulceration was induced in rats by exposing the animals to the aggressive attacks of rats treated with 6-hydroxy-dopamine (6-OHDA). Gastric secretion and the effects of autonomic drugs on ulcer formation were investigated. Atropine methylbromide did not significantly inhibit the occurrence of erosions. Phentolamine or hexamethonium bromide significantly inhibited the production of erosions, and combined administration of an anticholinergic agents and alpha-blocking agent led to a complete inhibition, with no notable behavioral change. In case of pylorus ligation, gastric secretion during exposure to attack of 6-OHDA-treated rats was significantly less than that in the controls. We suggest that the sympathetic nervous system plays an important role in the production of gastric erosions, as induced by the methods reported in this study.

Animals↗
PubMed1983

Attack stress and IgE antibody production in rats.

The effect of stress on production of immunoglobulin E (IgE) in rats was investigated, the IgE being titrated by passive cutaneous anaphylaxis (PCA) reactions. In rats, exposed to attack by other rats made aggressive by intraventricular injections of 6-OHDA for one hour per day for three consecutive days before the first immunization, there was no difference in the titer of IgE as compared to the control rats, but, in the rats exposed to stress procedure before the second immunization, the production of IgE was significantly suppressed.

Adrenal Glands↗
PubMed1972

Thiopeptin, a new feed-additive antibiotic: biological studies and field trials.

Thiopeptin is a new antibiotic, produced by Streptomyces tateyamensis and developed solely for animal use as a feed additive. The antibiotic content in animal tissue and feed was assayed in terms of the antimicrobial activity against Mycoplasma laidlawii A. This antibiotic was found to be relatively nontoxic in rats and mice. In chickens, this antibiotic is excreted into feces within 48 hr of administration and is not absorbed in tissue. It is well tolerated in both broilers and swine and is highly stable in animal feed. Thiopeptin-supplemented feed contributes to the improvement of weight gain, feed efficiency in chickens and swine, and the egg performance in layers. Thus, thiopeptin, when used as a feed additive, is quite suitable for supplementing animal nutrition.

Animal Feed↗