Induction of a microsomal butyrylesterase in rat liver by phenobarbital treatment

A carboxylesterase (carboxylic-ester hydrolase, EC 3.1.1.1) was induced in the liver of rats after repeated administration of phenobarbital. This enzyme migrated most rapidly towards the anode among Triton X-100-solubilized liver esterases by electrophoresis on the cellulose acetate membrane and it was tentatively designated as L-I. L-I increased in the microsomal fraction and was mainly concentrated in the fraction of smooth endoplasmic reticulum that proliferated after phenobarbital treatment. L-I- was separated from other liver esterases and purified about 800-fold. The purified L-I was homogeneous as judged by polyacrylamide gel electrophoresis and exhibited a molecular weight of about 55 000 as determined by gel filtration. L-I split the 1-naphthyl ester of butyric acid faster than esters of acetic, propionic or valeric acids; it therefore seemed to be a butyrylesterase.

Isolation of a sarcoma virus from a spontaneous chicken tumor

A spontaneous tumor was obtained from a hen of White-Leghorn stock raised in a local farm in Yamaguchi City, in December 1973. The tumor had characteristics of fibro- or myxofibro-sarcoma and could be maintained by transplantation in chickens of similar flocks. This tumor was proved to produce sarcoma virus at 33rd passage and the transforming virus was designated as Y73 sarcoma virus. Biological studies suggested that the virus recovered from the tumor belonged to avian leukosis-sarcoma complex having subgroup A specificity. The possibility of defectiveness of this virus will be discussed.

The monoamine-containing cell in the gustatory epithelium of some vertebrates

Fluorescence histochemistry has revealed that a specific formaldehyde-induced yellow fluorescence, suggesting the presence of serotonin-like monoamines, was regularly observed in a group of cells (monoamine-containing cells: MC cells) in the normal gustatory epithelia of the carp, catfish, frog and rabbit. The present report was also concerned with the ultrastructural features of the MC cell in the rabbit's foliate bud. The MC cells were found to have synaptic contacts with the intragemmal nerves. The synaptic morphology showed that the neural transmission may take place from the cell to the nerve. Two types of vesicles were encountered in the cytoplasm of MC cells. One was large cored vesicles (100--150 nm) suggesting storage of the serotonin-like monoamine. They were localized not only at the presynaptic area, but also in the infra- and supra-nuclear cytoplasm. The other was small vesicles (45-80 nm) containing variable amounts of dark material. They were similar in distribution to the large cored vesicles. The functional significance of the MC cells was discussed.

Lipoperoxide formation in the retina in ocular siderosis

Insertion of iron nail into the vitreous cavity provoke the formation of lipoperoxide in the retina. In acord with the increase in lipoperoxide in the retina, ERG began to decrease. In vitro experiment using isolated retina, lipoperoxide was found to be increased in the presence of ferric or ferrous ions, while it was inhibited by adding antioxidants or ethylenediamine tetraacetate. From these results, direct cause of retinal degeneration in siderosis could be ascribed to the formation of lipoperosice by iron-ions liberated from the piece of iron, resulting into the degeneration of the visual cell layers of the retina.

Formation of lipoperoxide in the retina of rabbit exposed to high concentration of oxygen

When rabbit was exposed to high concentrations of oxygen, lipoperoxide in the retina was increased at 12 h of the exposure, after which period amplitude of electro-retinogram decreased. The degeneration was observed in the visual cell layer of the retina of the exposed animal. The exposure increased lipoperoxide in isolated retina. These data show the intervention of lipoperoxide in retinal degeneration by exposure to high concentration of oxygen.

Effect of D-Glucarates on basic antibiotic-induced renal damage in rats

Dehydrated rats regularly develop acute renal failure following single injection of aminoglycoside antibiotics combined with dextran or of antibiotics only. Oral administration of 2,5-di-O-acetyl-D-glucaro-1,4-6,3-dilactone protected rats against renal failure induced by kanamycin-dextran. The protective effect was prevalent among D-glucarates, and also to other saccharic acid, hexauronic acids and hexaaldonic acids, although to a lesser degree, but not to a hexaaldose, sugar alcohols, substances inthe TCA cycle and other acidic compounds. D-Glucarates were effective against renal damage induced by peptide antibiotics as well as various aminoglycoside antibitocis. Dose-responses were observed in the protective effect of D-Glucarates. With a D-glucarate of a fixed size of dose, approximately the same degree of protection was obtained against renal damages induced by different basic antibiotics despite large disparities in administration doses of different antibiotics. D-Glucarates had the ability to prevent renal damage but not to cure it. Rats excreted acidic urine when they were spared from renal lesions by monosaccharides. The reduction effect of D-glucarates against nephrotoxicity of basic antibiotics was discussed.

Pharmaco-histochemical studies on a specific monoamine in the gustatory epithelia of the rabbit

The foliate, vallate and fungiform papillae of the rabbit's tongue were studied fluorescence-histochemically under normal and experimental conditions. In normal animals a yellow fluorescence suggesting the presence of a serotonin-like monoamine was demonstrated only in taste bud cells of the foliate papilla, though its intensity was very weak. The fluorescence disappeared completely following reserpine treatment, while it was significantly enhanced by the treatment with nialamide. The fluorescence of taste bud cells could be clearly distinguished from that of catecholamines by the treatment with alpha-MMT followed by nialamide. When 5-HTP, 5-HT and 5,6-DHT were administered separately, each of these drugs was selectively taken up in taste bud cells of the foliate and vallate papillae, but no fluorescent cells were observed in the fungiform papilla. From the present results, it seems reasonable to conclude that the fluorigenic amine of taste bud cells may be 5-HT (serotonin), or at least an indoleamine derivative. Also, it is suggested that the taste bud of the vallate papilla contains a cell type which can potentially synthesize a biogenic amine in situ, or is actually synthesizing it in a very small amount just like in the case of the taste bud of the foliate one.

Specific effect of 5,6-dihydroxytryptamine on the monoamine fluorophore of the frog's gustatory cells

A specific formaldehyde-induced yellow fluorescence, suggesting the presence of serotonin-like monoamine has been demonstrated in the gustatory cells of the frog. The fungiform papillae of frogs were examined fluorescence-histochemically after intraperitoneal injection of 5,6-dihydroxytryptamine. The results indicated that the fluorophore of gustatory cells was affected selectively by the drug injection: the yellow fluorescence was transiently enhanced 3 hours after the drug injection, thereafter being reduced rapidly. The effect of 5,6-dihydroxytryptamine was long-lasting with the reduction of the yellow fluorophore persisting at least for the experimental duration of 14 days. A single injection of 6-hydroxydopamine induced a complete depletion of noradrenaline fluorescence from adrenergic nerve terminals, while the fluorescence of gustatory cells was not affected by a high dose of the drug. The present results with pharmacologic treatments further support the view that the gustatory cell of the frog contains a serotonin-like monoamine.

Ultrastructural evidence for the uptake of 5,6-dihydroxytryptamine in the frog's gustatory cell

The fungiform papillae of the frog were examined electron-microscopically after a single injection of 5,6-dihydroxytryptamine (5,6-DHT). Thirty minutes after 5.6-DHT injection, numerous vesicles partially occupied with dark material were found in the cytoplasm of gustatory cell processes. Three days after the drug treatment, the majority of vesicles were completely filled with dark material so that their limiting membrane became obscure, while the terminal portions of gustatory cells showed no evidence for fine structural alteration indicative of drug retention. In addition, clear vacuoles, suggesting a degenerative change induced by the uptake of the neurotoxic agent, occurred in the cytoplasm of gustatory cell processes. It is suggested that the uptake of 5.6-DHT in gustatory cells may reflect the presence of an indoleamine, probably 5-hydroxytryptamine (serotonin).

The occurrence of the cell type containing a specific monoamine in the taste bud of the rabbit's foliate papila

The fluorescence histochemical examination on biogenic amines of the rabbit's foliate papilla revealed that a specific monoamine exhibiting an yellow fluorescence was present in a certain cell type of taste buds. The fluorescence had the emission maximum at 520 mmu and faded rapidly under the influence of the UV-irradiation. The green fluorescence of adrenergic nerve had the emission maximum at 480 mmu and was fairly stable upon the UV-irradiation. The yellow fluorescence disappeared completely following reserpine treatment, while it was markedly enhanced by nialamide treatment. From the observations, it is suggested that certain taste bud cells of the foliate papilla contain a biogenic monoamine, probably 5-hydroxytryptamine (serotonin).

A monoamine in the gustatory cell of the frog's taste organ: a fluorescence histochemical and electron microscopic study

Fluorescence histochemistry reveals that in the frog's taste organ a yellow fluorescence is regularly observed at the most basal region of the sensory epithelium. The fluorescence has a strong intensity, but it fades rapidly upon the UV-irradiation. The peak of the emission spectrum is at 520 mmug. Following reserpine treatment the yellow fluroescence is markedly reduced, but not depleted completely. From these characteristics the monoamine fluorescence is regarded as representing 5-HT (serotonin). The ultrastructural study on sensory epithelia shows that the terminal portions of gustatory cell processes are localized at the basal region. These portions are filled with dense cored vesicles (700-1000 angstrom in diameter) and frequently opposed with nerve fibers penetrating into the epithelium. The gustatory cell processes are also interposed between the terminal portions of nerve fibers. The cytoplasm of the gustatory cell process is characterized by many mitochondria, fine filaments and glycogen particles, but contains few cored vesicles. The distribution of terminal portions of gustary cell processes seems to correspond fairly well to that of the monoamine fluorescence observed discontinuously along the basal lamina. Accordingly it is concluded that the fluorigenic monoamine is localized in the cored vesicles of the gustatory cell.