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K Hosoi

Publications and source records attributed to K Hosoi.

At least 127 records · Page 7Linked to original sources
PubMed1978

Effect of autonomic agents on the amount of androgen-dependent granules in convoluted tubular cells of the mouse submandibular gland.

The convoluted tubular cells of the male mouse submandibular gland contain many serous-like granules in their apical cytoplasm. The autonomic regulation of the secretory process of the contents of these granules was studied by the following two methods: (1) immunochemical method using an antiserum specific to the granular components; and (2) histometric observations using light and electron microscopes. The results obtained by these two methods were well in agreement. When male mice were administered either phenylephrine or norepinephrine, the amount of granules in the glands significantly decreased. These two adrenergic stimulators were very effective, whereas synephrine was less effective. When mice were injected with a beta-adrenergic agent(isoproterenol) or a parasympathomimetic agent (pilocarpine), the amount of granules in the glands did not change. The alpha-adrenergic blockers phenoxybenzamine and phentolamine almost completely neutralized the effect of alpha-adrenergic agents on the glands, whereas another alpha-blocker (ergotamine) was less effective. These facts suggest that the secretion of the granular components is mediated by way of alpha-adrenergic receptor sites in the glands.

Adrenergic alpha-Agonists↗
PubMed1978

Regulation of the secretory process of granular components from the convoluted tubular cells of the mouse submandibular gland.

Autonomic regulation of the secretion of granule components in the convoluted tubular cells of male mouse submandibular glands was investigated with the use of an agar gel diffusion test using an antisera for male specific components. Whereas the injection of neither a parasympathomimetic agent (pilocarpine) nor a beta-adrenergic agent (isoproterenol) decreased the amount of the components in the glands, the injection of alpha-adrenergic agents (norepinephrine or phenylephrine) significantly decreased the amount of male specific components. Phenoxybenzamine, an alpha-blocker, completely inhibited these actions of norepinephrine and phenylephrine. These facts suggest that the alpha-adrenergic receptor participates in the secretion of male specific components present in the granules in the convoluted tubular cells of mouse submandibular glands.

Animals↗
PubMed1977

Binding protein for 5 alpha-dihydrotestosterone in mouse submandibular gland.

The changes in the levels of the binding protein for 5 alpha-dihydrotestosterone in cytoplasmic extract of the submandibular glands during development were compared in male and female mice using a DEAE-cellulose filter assay. The binding protein was first detectable 5 days after birth in both sexes, at a time coincident with androgen-independent cytodifferentiation of the convoluted tubular cells in the submadibular gland. The level of the binding protein in female mice was maintained at 5 pmol/mg protein after birth, whereas in males it began to decrease from 3 weeks after birth with inccrease in serum testosterone, becoming much less than a quarter of the level in females or immature mice by 4 weeks after birth. However, after castration, the level of detectable binding protein in mature male mice increased within 7 days to the same level as that in females or immature mice. This suggests that the low binding capacity for exogenous hormone in mature male mice is due to occupancy of the binding sites by endogenous hormone.

Age Factors↗
PubMed1977

Effect of testosterone on the amount of serous-like granules in convoluted tubular cells of mouse submandibular glands.

The effect of testosterone on the amount of granules present in convoluted tubular cells of the submadibular glands of mice was studied by the following two methods; 1) an immunochemical method using antiserum specific to the granular components, and 2) a histographic method. The results obtained by these two methods were in agreement. The amounts of the granules in normal female and castrated male mice were one-tenth to one-twentieth of that in normal male mice. When male mice were castrated, the amount of granules decreased, reaching a minimum 20 days after the aperation the injection of the male hormone, testosterone, into castrated male mice caused an increase in the amount of granules; this increase reached a maximum 15 days after the injection. The increase of granules caused by testosterone injection was almost completely prevented by inhibitors of protein synthesis, actinomycin D and puromycin. This suggests that protein synthesis was indispensable to the increase in the amount of granules. In male mice, the injection of female hormones scarcely affected the amount of granules. Kinetic analysis of the decrease and increase of granules on castration and testosterone injection suggested that the male hormone stimulated granule synthesis, but it hardly influenced the loss of granules.

Animals↗
PubMed1975

Effects of pH indicators on various activities of chromatophroes of Rhodospirillum rubrum.

1. The effects of pH indicators on activities for ATP hydrolysis in the dark and ATP-Pi exchange in the dark were examined with chromatophores from Rhodospirillum rubrum. Of thirty-one pH indicators tested, eleven (metanil yellow, 2, 4-dinitrophenol, ethyl orange, bromocresol green, resazurin, neutral red, bromthymol blue, alpha-naphtholphthalein, o-cresolphthalein, phenolphthalein, and alizarin yellow G) almost completely inhibited the activities for ATP formation and ATP-Pi exchange at concentrations of 1 mM, and were studied in detail. 2. Of the eleven pH indicators, those other than alpha-naptholphthalein, o-cresolphthalein and phenolphthalein, when assayed at appropriate concentrations, inhibited ATP-Pi exchange, but not ATP hydrolysis. In ATP-Pi exchange, these eight pH indicators at the concentrations described above were competitive against Pi, and non-competitive against ATP. The remaining three kinds of pH indicators were non-competitive against either Pi or ATP, when assayed at concentrations of the dyes that inhibited both activities. 3. The amounts of pH indicators bound with chromatophores were measured. No correlation was found between the amounts of the bound dyes and the extents of their inhibition of either ATP formation or ATP-Pi exchange. 4. Ethyl orange (pKa=4.1) and 2, 4-dinitrophenol (pKa=3.9) stimulated ATP hydrolysis to the greatest extent. The latter dye was hardly bound with chromatophores. 5. The stimulatory effects of pH indicators on ATP hydrolysis were hardly affected by extraction of quinones from chromatophores. 6. Most of the pH indicators stimulated both succinate-cytochrome c2 and NADH-cytochrome c2 reductions in the dark. 7. The mechanism of uncoupling of the electron transfer system and the phosphorylation system by pH indicators and the mechanism of the coupling are discussed.

Adenosine Triphosphate↗
PubMed1975

[Experimental studies on absorption, distribution and excretion of fosfomycin. I. Absorption distribution and excretion of fosfomycin calcium salt (author's transl)].

In order to develop some oral drug preparations containing calcium salt of fosfomycin ((minus)-cis-1,2-epoxypropylphosphonic acid) which is a new antibiotic, the absorption, distribution and excretion were studied when it was administered orally to fasted test animals such as rats, rabbits and dogs. The results are as follows: 1) In the case of rats, the more dose size was increased, the more ratio of excretion in urine as index of gastrointestinal absorption was reduced and ratio of excretion in stools was adversely increased, which suggested a decrease in absorption efficiency. But, as absolute amount of excretion in urine became larger with dose size, it was considered that increase in dose size would serve for elevation of serum levels. 2) When the calcium salt was given to rats and rabbits in form of solution and suspension, the former was more eminent than the latter regarding to absorption efficiency, as generally known. The solution, however, needed relatively large quantity of water to solubilize the calcium salt, and it was not considered that the absorption efficiency depends on only dissolution step or dissolution rate. 3) Difference of the particle size varying from 1.50 mu(bulk particle size) and 0.64 mu(mechanical limit size) measured by Kozeny-Carman method did not affect on the absorption in rats and dogs. So it was considered that the bulk could be use directly without micronizing in manufacturing process for the oral preparations. 4) There were some differences of absorption among the animal species. Good absorption was shown in turn in rats, dogs and rabbits. These differences might depend not only on physiological factors but also anatomical differences such as length of gastrointestinal tract. 5) In rabbits high concentration was observed successively in kidney, lung, heart and so on. In any organ its level decreased similarly to the serum level, not sustaining its initial high concentration. The calcium salt did not possess any affinity to certain organs. 6) In conclusion, though some differences of gastrointestinal absorption were observed among the animal species, fosfomycin calcium salt was well absorbed without problem of micronizing the bulk particles. Moreover, it was perceived that fosfomycin calcium salt, once distributed, would not remain in particular organs, being excreted out of body.

Administration, Oral↗
PubMed1975

Experimental studies on absorption, distribution and excretion of a new antibiotic, fosfomycin. II. Absorption of oral preparations of fosfomycin calcium salt in dogs (author's transl).

To establish the best usage and dosage of fosfomycin granule and capsules which had been prepared based on our fundamental experiences as described in the first report, absorption of calcium salt contained in both preparations was evaluated using dogs as test animals. (1) Granule containing the calcium salt equivalent to 200 mg of fosfomycin free acid per g showed almost the same absorption as the bulk (fosfomycin calcium), having no disadvantage due to processing. (2) Capsules containing the calcium salt equivalent to 250 mg and 500 mg of the free acid per capsule showed slightly more retarded absorption than the bulk, probably due to some inevitable factors such as disintegration rate of capsules and dispersion rate of the calcium salt. But, once dispersed, the calcium salt in capsules was well absorbed as well as the bulk material. (3) Gastrointestinal absorption of granule and the capsule contents was almost the same. (4) Simultaneous administration of capsules and water improved the absorption efficiency. Though administration after feeding caused somewhat retarded absorption of the drug, the serum levels were rather well sustained with a slight drop but sufficiency of absorption, suggesting better clinical advantages than in the fasted animals. (5) Fosfomycin calcium salt in both preparations was well absorbed in the test animals through gastrointestinal tract as well as the bulk calcium salt, without any possible disadvantage caused by processing. In addition, the absorption efficiency was improved by giving with water or meal to the animals.

Administration, Oral↗