PubMed Health⌕ Search

Biomedical subjects

T Tadano

Publications and source records attributed to T Tadano.

At least 91 records · Page 5Linked to original sources
PubMed1982

Linkage studies on an esterase locus in the mosquito Aedes togoi.

An electrophoretic survey of esterases in 7 wild-type and 10 mutant strains of the mosquito Aedes (Finlaya) togoi was undertaken using thin-layer agar gels. Three esterases (Designated the Est-1, Est-2, and Est-3 loci in decreasing order of electrophoretic mobility) could be detected from fourth-instar larvae, pupae, and 2- to 5-day-old adults. Homogenates of the larvae gave the most intensely stained bands in the gels, especially for Est-3. The three esterases were designated carboxylesterases based on their responses to the two esterase inhibitors, eserine and paraoxon (diethyl-p-nitrophenyl phosphate). The Est-3 locus was found to have alleles including at least one null. The linkage results of six backcrosses suggest that Est-3 is located only 5-8 map units from the sex allele (m) and the gene arrangement is Est-3-m-s (straw colored larva) in linkage group I.

Aedes↗
PubMed1982

Intracranial injection of thyrotropin releasing hormone (TRH) suppresses starvation-induced feeding and drinking in rats.

The sites at which TRH produces suppression on feeding and drinking were examined anatomically in the rat brain. This was accomplished by microinjecting nmol concentration of TRH into 6 different brain sites. Intracerebroventricular injection of TRH (25, 50, 100 nmol/rat) suppressed starvation-induced feeding and drinking in a dose related manner. The microinjection in a small amount of TRH (8 nmol/hemisphere) into the medial and lateral hypothalamus produced relatively severe anorexia and adipsia as compared with the other areas including the nucleus accumbens, the substantia nigra, the globus pallidus and the amygdala. It was concluded that the medial hypothalamus is the most sensitive site of TRH-induced anorexia and adipsia and the action of TRH on the lateral hypothalamus is also a possible mechanism mediating the decrease in water intake.

Amygdala↗
PubMed1982

[Effects of methyl o-(4-hydroxy-3-methoxycinnamoyl) reserpate (CD-3400) on erection and ejaculation in dogs].

Effects of methyl o-(4-hydroxy-3-methoxycinnamoyl)reserpate (CD-3400), a new antihypertensive agent belonging to the class of rauwolfia alkaloids, on erection and ejaculation in dogs were investigated and compared with such effects of reserpine and rescinnamine in dogs. A single dose of CD-3400 (0.125 mg/kg) administered orally to normal dogs produced no effects on erection and ejaculation, although the same dose of reserpine and rescinnamine resulted in a marked suppression of only ejaculation at 24 and 48 hr after administration. CD-3400 (0.5 mg/kg) administered orally, as well as reserpine (0.125 mg/kg) and rescinnamine (0.125 mg/kg) suppressed ejaculation at 24 hr after administration; however, the suppressive effect of CD-3400 on ejaculation was weaker and shorter than that of reserpine or rescinnamine and recovered 96 hr after administration. The order of the suppressive effect of the agents was as follows: reserpine greater than rescinnamine greater than CD-3400. Repeated administration of reserpine (0.01 mg/kg/day p.o.) for 20 days, produced a marked suppressive effect on ejaculation, whereas the effect of CD-3400 (0.06 mg/kg/day p.o.) was also weaker than that of reserpine. 24 hr after oral administration in a single dose of CD-3400 (0.5 mg/kg), reserpine (0.125 mg/kg) or rescinnamine (0.125 mg/kg), the ratios of dopamine (DA) to serotonin (5-HT) in the anterior hypothalamus and hippocampus were decreased significantly as compared with the control. These results indicate that CD-3400 results in a weaker suppressive effect on ejaculation as compared to reserpine and rescinnamine, and CD-3400-induced suppression may be due to a decrease in the ratio of DA to 5-HT in the anterior hypothalamus and hippocampus.

Administration, Oral↗
PubMed1982

[Effect of d-pseudoephedrine on the central nervous system in mice].

Some pharmacological actions of intraperitoneally (i.p.) administered d-pseudoephedrine (d-pseudo) on the central nervous system of mice were compared with those of l-ephedrine (l-eph). Locomotor activity was increased by l-eph (50, 100 and 200 mg/kg,) but not by d-pseudo (50, 100 and 200 mg/kg). Wheel-revolving activity was reduced by a 200 mg/kg dose of both drugs. Rectal temperature was increased by l-eph at 50, 100 and 200 mg/kg. However, it was decreased by 50 and 100 mg/kg doses of d-pseudo, and the change in response to 200 mg/kg of d-pseudo was biphasic, decreasing first and increasing subsequently. Pentobarbital-induced sleeping time was shortened by l-eph (50 and 100 mg/kg), but was not influenced by any of the doses of d-pseudo. In the experiment on locomotor activity, L-3,4-dihydroxyphenylalanine (400 mg/kg, i.p.) potentiated the effects of d-pseudo and l-eph, but reserpine (1 mg/kg, day X 5 days, i.p.) and 6-hydroxydopamine (40 micrograms/mouse, intracerebroventricular injection) potentiated only the effect of l-eph. These results suggest that the effect of d-pseudo on the central nervous system of mouse is not only weaker than that of l-eph, but also the mechanisms of action of these two substances are different.

Animals↗
PubMed1981

Effect of cyclic dipeptides containing histidine on pentobarbital narcosis.

We examined the effect of cyclo (His-Pro) and its analogs on pentobarbital narcosis in mice. Cyclo (His-Pro), 500 nmol/mouse, administered via intracerebroventricular (i.c.v.) route significantly prolonged the sleeping time. Methylation of histidine in the structure of cyclo (His-Pro) did not increase the activity of cyclo (His-Pro). Some of other cyclo (His-Pro) analogs, of which proline was replaced with other amino acids, cyclo (His-Phe), cyclo (His-Tyr), cyclo (His-His) and cyclo (D-His-Leu) produced significant prolongation of the sleeping time as compared with cyclo (His-Pro). These results suggest that cyclo (His-Pro) has opposing effect to that of thyrotropin releasing hormone (TRH) and the prolongation of pentobarbital narcosis by cyclic dipeptides might be caused by their central action.

Animals↗
PubMed1980

A simple determination of serotonin, 5-hydroxyindoleacetic acid and 5-hydroxytryptophan decarboxylase activity in rat brain areas and parallel correlation among the levels.

We devised a simple method for the separation of serotonin (5HT) and 5-hydroxyindoleacetic acid (5HIAA) using small P-cellulose and DEAE-Sephadex columns, respectively. Both substances were estimated fluorometrically by the reaction with o-phthalaldehyde (OPA). In this method, some known interfering substances in addition to many primary amines and amino acids were separated from 5HT and 5HIAA. The recoveries of 5HT and 5HIAA were 80 and 71%, respectively. The fluorescence intensities of 30 pmol of 5HT and 15 pmol of 5HIAA were about twice over the reagent blank. The complete separation of 5-hydroxytryptophan (5HTP) from 5HT made it possible to determine 5HTP decarboxylase activity in rat brain areas without using an isotope-labeled substrate. The method allows for quantitation of the enzyme activity in mg amounts of the brain tissues. The activities in discrete areas were in good parallel with the 5HT contents, except for the striatum. The levels of 5HIAA were also much in parallel with those of 5HT.

Animals↗
PubMed1980

[The effect of thiamine deficiency on the actions of drugs affecting the central nervous system in rats (author's transl)].

Male Wistar rats, 35-days-old, maintained on a thiamine deficient diet for 30 days showed marked growth inhibition and a heart rate less than 70% of that of control rats. We examined the effect of thiamine deficiency on the action of drugs effecting the central nervous system at this period. In thiamine deficient rats treated with chloral hydrate 200 mg/kg, ketamine 100 mg/kg sodium pentobarbital 50 mg/kg, and hexobarbital 100 mg/kg, the sleeping time increased. Pretreatment with 15 mg/kg of the metabolic enzymes inhibitor, SKF-525A, 30 min prior to the hexobarbital administration resulted in prolongation of sleeping time in all groups. The thiamine deficient rats slept almost 3.5 times longer than did the control group. Pretreatment with 100 mg/kg of the metabolic enzyme inducer, sodium phenobarbital, 48 hours prior to hexobarbital treatment resulted in decreased sleeping time in all groups, as compared with only hexobarbital treatment. In the thiamine deficient rats the catalepsy and ptosis induced by the i.p. administration of tetrabenazine 50 mg/kg was reduced even when the control and pair-fed groups responded to this drug at the drug peak time. The spontaneous neuronal activity of lateral hypothalamus was most sensitive to the administration of 5-hydroxytryptophan in thiamine deficient rats.

5-Hydroxytryptophan↗
PubMed1979

Disturbed venation, a new sex-linked mutant, in the mosquito Aedes togoi.

Genetic linkage of a new sex-linked mutant, disturbed venation (dv), in Aedes (Finlaya) togoi has been studied by utilizing representative markers, s (straw-coloured larva), ru (ruby eye), and y (yellow larva), of the three linkage groups. The dv allele is recessive, disturbs drastically venation of the wing veins, cu1, m1+2, m3+4, r2, r3, and r4+5, and also affects shape of the wings along with loss of many fringe scales. The wings become shortened, especially in females, and somewhat narrowed in males. Much variation occurs in the expression of dv with its fairly good penetrance, although an increased mortality of the dv homozygotes may occur at pupal stage or during emergence. This allele was located at 5 to 6 recombination units from s and 28.56 units from sex locus (M) in the gene order of s-dv-M.

Aedes↗
PubMed1979

[Effects of d-pseudoephedrine on tracheo-bronchial muscle and the cardiovascular system (author's transl)].

The action of d-psuedoephedrine on bronchial smooth muscle, respiratory resistance and blood pressure was compared with that of 1-ephedrine. The following results were obtained. 1) Administration of dl-isoproterenol on isolated guinea pig tracheal muscle previously constricted with acetylcholine (ACh) or histamine (his) was the most effective and d-pseudoephedrine had the same effect as 1-ephedrine. The relaxing effect of dl-isoproterenol, 1-ephedrine or d-pseudoephedrine on ACh or His induced tracheal constriction was competitively antagonized by the pretreatment of propranolol. 2) The intravenous or sublingual administration of d-pseudoephedrine on the increased respiratory resistance induced by His produced the same effect as 1-ephedrine. 3) The increase in blood pressure with d-pseudoephedrine was weaker than that of 1-ephedrine. 4) When 1-ephedrine of d-pseudoephedrine was repeatedly injected into the same animal, signs of tachyphylaxis were observed. It was found that d-pseudoephedrine, the main alkaloid of Ephedrine Helba, exhibited the relaxing effect on bronchial smooth muscles as did 1-ephedrine. The respiratory resistance increased by His was inhibited by the sublingual administration of d-pseudoephedrine and 1-ephedrine.

Administration, Oral↗
PubMed1979

[Effects of diazepam on rage reaction elicited by the lateral hypothalamus (LH) and on single unit activities in the LH and the basal medial amygdaloid nucleus (Abm) in cats (author's transl)].

Effects of diazepam were examined on the whine reaction elicited by LH stimulation and on unit activities in the LH and Abm in cats. The spontaneous firing frequency of Abm neurons was 5 to 30 spikes/sec and in all 6 neurons isolated the firing frequency increased by non-nociceptive and/or clap-stimulation. Diazepam decreased the spontaneous firing frequency of all Abm neurons isolated and the increased firing frequency elicited by non-nociceptive and/or clap-stimulation was also depressed by diazepam. The spontaneous firing frequency of neurons in the LH was 4 to 5 spikes/sec and all 6 neurons isolated firing frequency increased by non-nociceptive stimulation. Only one of 6 neurons, however, was activated by clap-stimulation. Diazepam decreased the spontaneous firing frequency of all LH neurons. Out of 6 neurons responsive to non-nociceptive stimulation, 3 were also depressed by diazepam. The other neurons were not affected by diazepam. These results suggest that depressed action of diazepam on the whine reaction elicited by the LH stimulation may be related to the decrease of firing in the Abm and/or the LH by diazepam.

Amygdala↗
PubMed1979

[Effects of diethyldithiocarbamate on ejaculatory inhibition and change in monoamine levels of accessory glands (author's transl)].

Effects of diethyldithiocarbamate(DDC) on erection and ejaculation were investigated and monoamine levels in central nervous system, gonad and accessory glands were determined in dogs. Intraperitoneal administration of 50, 75 and 100 mg/kg of DDC suppressed ejaculation 1 hour after administration, although penial erection did occur. This suppression of ejaculation was recovered to some extent 3 hours after DDC and completely recovered 24 hours after DDC. One hour after the administration of 100 mg/kg of DDC, noradrenaline (NA) level in the caudate and serotonin (5-HT) level in the posterior hypothalamus decreased significantly, as compared with the control. However, there were no significant changes in the regions of anterior hypothalamus and hippocampus which are known to play an important role in sexual behavior. In the epididymis, NA and adrenaline levels decreased significantly, though 5-HT levels increased, as compared with those of the control. In the prostate and posterior urethra, NA levels decreased significantly, as compared with the control. The seminal emission induced by hypogastric nerve stimulation induced a gradual rise in the posterior urethral pressure. When the pressure reached the maximum level, rhythmic alterations of the pressure considered to be a phenomenon associated with ejaculation occurred. DDC (100 mg/kg) abolished both seminal emission and rhythmic alterations of the posterior urethral pressure. These findings indicate that the sperm transport may be inhibited by decrease of NA level in accessory glands.

Amines↗
PubMed1978

Genetics of a new mutant, curved wing, of the mosquito Aedes togoi.

A new recessive mutant curved wing (c) in the mosquito Aedes (Finlaya) togoi (Theobald), a vector of various species of filariae in the Far East, has been shown to be linked to yellow larva (y), with a recombination value of 13.26 +/- 1.41 to 20.53 +/- 1.41%. These linked alleles are inherited independently of either sex (M), straw-coloured larva (s), ruby eye (ru), or pigmented pupa (p). Evidence has now been produced that sex (M)-s, ru-p, and y-c mark the three linkage groups in this species (2n = 6), and these markers, respectively, have been placed provisionally in linkage groups 1, 2, and 3.

Aedes↗
PubMed1978

[Muricide induced by thiamine deficiency in the rats (author's transl)].

The emotional behavioral aspects and the interaction between the changes of the polyamine contents and muricide response in thiamine deficient rats were investigated. In the thiamine deficient group, there was evidence of muricide and such increased progressively with advanced thiamine deficient feeding. This muricide was characteristic in the following respects; 1) the killer-rats did not eat but only kill a mouse and it was quite difficult to remove a sacrificed animal from the cage. 2) they bit at random into any body region of the mouse. 3) the killer-rats did not bite inanimate objects such as nails nor chalk. 4) the muricide induced by thiamine deficiency could not be suppressed by a single injection of thiamine HCl. On the 30th day of the experimental feeding, both spermidine and spermine levels in the brain of the thiamine deficient group decreased significantly as compared to the control and the pair-fed groups. Both spermidine and spermine levels were reversed to the control levels with a intraperitoneal administration of thiamine. There were no significant differences in spermine and spermidine levels between the killer-rats and non-killer-rats in the thiamine deficient group.

Aggression↗
PubMed1977

The inheritance of a mutant yellow larva in the mosquito Aedes togoi.

In the mosquito Aedes (Finlaya) togoi (Theobald), which usually breeds in seawater in tidal pools and is a natural or experimental vector of various species of filariae, the mode of inheritance of a new mutant yellow larva (y) was investigated; the y allele is recessive and inherited independently of sex and its linked alleles, and independently of ruby eye (ru) and pigmented pupae (p), both of which are not sex-linked; therefore y is presumed to be on the third linkage group in this species. The allele y is completely penetrant with little variation in its expressivity, but its phenotype could not be reliably distinguished from that of sex-linked allele straw-coloured larva (s).

Aedes↗