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S Inoué

Publications and source records attributed to S Inoué.

At least 91 records · Page 5Linked to original sources
PubMed1987

Interacting sleep-modulatory effects of simultaneously administered delta-sleep-inducing peptide, muramyl dipeptide and uridine in unrestrained rats.

A 10-h nocturnal intracerebroventricular infusion of 2 or 3 sleep substances such as 2.5 nmol delta-sleep-inducing peptide (DSIP), 2.0 nmol muramyl dipeptide (MDP) and 10 pmol uridine resulted in a significant, combination-dependent change in sleep-waking dynamics, which was quite different from the time-course sleep promotion induced by the single administration of each substance. The DSIP-MDP combination was characterized by a profound increase in SWS only at the middle infusion period. PS was little affected. The DSIP-uridine combination exerted a slight increase in SWS at the late infusion period with little change in PS parameters. The MDP-uridine combination caused a marked increase in both SWS and PS only at the early to middle infusion period. The DSIP-MDP-uridine combination induced an extremely large increase in SWS at the early to middle phase of the infusion period. PS significantly increased only at the early phase. These results may suggest that the sleep substances acted in tandem, either synergistically or antagonistically, on the sleep regulatory mechanism.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Flagellar gyration and midpiece rotation during extension of the acrosomal process of Thyone sperm: how and why this occurs.

The midpiece of Thyone sperm contains a large mitochondrion and a centriolar pair. Associated with one of the pair, i.e., the basal body of the flagellum, are satellite structures which apparently anchor the flagellar axoneme to the mitochondrion and to the plasma membrane covering the midpiece. Immediately before and as the acrosomal process elongates, the flagellum and the midpiece begin to rotate at 1-2 rotations per second even though the head of the sperm, by being firmly attached on its lateral surfaces to the coverslip, does not rotate at all. This rotation is not observed in the absence of flagellar beating whose frequency is much greater than that of its gyration. To understand how the midpiece rotates relative to the sperm head, it is first necessary to realize that in Thyone the flagellar axoneme projects at an acute angle to the principal axis of the sperm and is bent towards one side of this axis. Thus movement of the flagellum induces the sperm to tumble or yaw in solution. If the head is stuck, the midpiece will rotate because all that connects the sperm head to the midpiece is the plasma membrane, a liquid-like layer. A finger-like projection extends from the proximal centriole into an indentation in the basal end of the nucleus. In contrast to the asymmetry of the flagellum, this indentation is situated exactly on the principal axis of the sperm and, along with the finger-like projection, acts as a biological bearing to maintain the orderly rotation of the midpiece. The biological purpose of flagellar gyration during fertilization is discussed.

Acrosome↗
PubMed1986

The microfibrils of connective tissue: I. Ultrastructure.

The ultrastructure of connective tissue microfibrils was examined in two sites: the ciliary zonule of the eye and the foot pad, in 20-day-old mice perfused with glutaraldehyde. The microfibrils were classified into two categories, referred to as typical and atypical. Typical microfibrils predominate in both sites; they are unbranched, straight or gently curving, tubular structures of indefinite length with an overall diameter of 12.8 +/- 1.7 nm in the zonule and 13.8 +/- 2.8 nm in the foot pad. They are composed of two parts: tubule proper and surface band. The tubule is 7- to 10-nm wide and characterized in cross section by an approximately pentagonal wall and an electron-lucent lumen containing a 1- to 2-nm bead referred to as a spherule. When longitudinal sections of microfibrils are examined at high magnification, the wall of the tubule does not appear as a continuous line but as a series of successive dots. The interpretation of these findings is that the tubule is composed of successive annular segments with an approximately pentagonal outline. The surface band is a 3-nm-wide, ribbon-like structure wrapped around the tubule. The band has dense borders called tracks. Along the tracks, densely stained, 4.6-nm-long "spikes" are attached at 4.0-nm intervals. The wrapping of the bands is somewhat irregular. They may be in a transverse position across single or several microfibrils, in which case each band might constitute a distinct belt; more frequently, the bands are oblique and appear to form a continuous helix. It is proposed that surface bands play a role in holding together the juxtaposed segments making up a tubule. A model has been constructed to represent the association of tubule and band into a typical microfibril. Atypical microfibrils, which are more common in foot pad than in ciliary zonule, appear wavy, lack a definite tubule, and are characterized by distorted, irregular surface bands. They are attributed to proteolysis of typical microfibrils.

Animals↗
PubMed1986

The microfibrils of connective tissue: II. Immunohistochemical detection of the amyloid P component.

Immunohistochemical methods were used for the detection of the amyloid P component in the microfibrils of two regions: the zonule of the eye and the connective tissue of the foot pad in 20- to 50-gm mice. Following fixation by immersion in 4% formaldehyde, the eyes and foot pads were embedded in paraffin, and sections were immunostained for light microscopy by using antiamyloid P component antiserum followed by peroxidase-antiperoxidase procedure. For electron microscopy, formaldehyde-fixed tissues were immunostained for the amyloid P component with protein A-gold by using either thin Lowicryl sections or frozen sections which were then embedded in Epon for thin sectioning. In the zonule of the eye, the light microscope showed that zonular fibers were strongly immunostained for the amyloid P component; there was also weak staining of the nonpigmented ciliary epithelium at the distal end of the fibers and of the zonular lamella at their proximal end. The electron microscope revealed clear-cut immunolabeling of the microfibrils making up zonular fibers as well as of individual microfibrils. In the foot pad, the light microscope detected a weak diffuse staining of connective tissue, whereas the electron microscope showed immunolabeling restricted to microfibrils. It was concluded that the amyloid P component was present in, or associated with, microfibrils. Purified amyloid P component was prepared and examined in the electron microscope after either negative staining or routine processing. After negative staining, it appeared as flat pentagonal units, frequently associated into columns. After routine processing, the units looked like cross sections of microfibrillar tubules. The dimensions of the units matched those of the hypothetical segments of the tubules. It was concluded that this tubule consisted of a column of amyloid P units. The cohesion of the units within the column was likely to be reinforced by the bands present at the surface of microfibrils.

Amyloid↗
PubMed1986

Sleep and sleep substances.

Time-consuming studies in search of an endogenously occurring sleep substance started early in this century. The historical background of this field of sleep science is briefly reviewed. The search for "sleep-promoting substance (SPS)" started in 1972. A bioassay technique was developed based on the monitoring of the circadian sleep-waking rhythm in freely moving male rats. The partially purified SPS from the brainstem of 24-h sleep-deprived rats caused a reduction in locomotor activity and an increase in both slow wave sleep and paradoxical sleep, when nocturnally administered by either the intraperitoneal or intracerebroventricular route. SPS is composed of at least 4 different effective fractions, including uridine. The sleep-inducing and sleep-maintaining potencies of several putative sleep substances were compared. Circadian variations in their effectiveness were apparent. The role of sleep substances in sleep regulation is discussed.

Animals↗
PubMed1985

Sleep-promoting effects of intraperitoneally administered uridine in unrestrained rats.

An intraperitoneal injection of 0.1 nmol uridine in rats resulted in a transient excess slow-wave sleep if administered shortly before onset of the dark period. The sleep latency was remarkably shortened. A small dose (0.01 nmol) and larger doses (1, 10, 100 nmol) caused no effect. Uridine at a dose of 0.1 nmol was entirely ineffective if injected shortly before onset of the light period, while it resulted in transient excess paradoxical sleep if injected at an early phase of the light period. It is concluded that uridine, if timely administered through a systemic route, may pass the blood-brain barrier to modulate sleep in rats.

Animals↗
PubMed1985

Acrosomal reaction of the Thyone sperm. III. The relationship between actin assembly and water influx during the extension of the acrosomal process.

In an attempt to investigate the role of water influx in the extension of the acrosomal process of Thyone sperm, we induced the acrosomal reaction in sea water whose osmolarity varied from 50 to 150% of that of sea water. (a) Video sequences of the elongation of the acrosomal processes were made; plots of the length of the acrosomal process as a function of (time)1/2 produced a straight line except at the beginning of elongation and at the end in both hypotonic and hypertonic sea water (up to 1.33 times the osmolarity of sea water), although the rate of elongation was fastest in hypotonic sea water and was progressively slower as the tonicity was raised. (b) Close examination of the video sequences revealed that regardless of the tonicity of the sea water, the morphology of the acrosomal processes were similar. (c) From thin sections of fixed sperm, the amount of actin polymerization that takes place is roughly coupled to the length of the acrosomal process formed so that sperm with short processes only polymerize a portion of the actin that must be present in those sperm. From these facts we conclude that the influx of water and the release of actin monomers from their storage form in the profilactin (so that these monomers can polymerize) are coupled. The exact role of water influx, why it occurs, and whether it could contribute to the extension of the acrosomal process by a hydrostatic pressure mechanism is discussed.

Acrosome↗
PubMed1985

Compartmentalization of algal bioluminescence: autofluorescence of bioluminescent particles in the dinoflagellate Gonyaulax as studied with image-intensified video microscopy and flow cytometry.

Compartmentalization of specialized functions to discrete locales is a fundamental theme of eucaryotic organization in cells. We report here that bioluminescence of the dinoflagellate alga Gonyaulax originates in vivo from discrete subcellular loci that are intrinsically fluorescent. We demonstrate this localization by comparing the loci of fluorescence and bioluminescence as visualized by image-intensified video microscopy. These fluorescent particles appeared to be the same as the previously described in vitro "scintillons." We attribute the endogenous fluorescence to that of the bioluminescence substrate, luciferin, because (a) the fluorescence excitation and emission characteristics are comparable, (b) the autofluorescence is lost after exhaustive stimulation of bioluminescence, and (c) the fluorescence of discharged particles in vitro can be restored by adding luciferin. The fluorescence in vivo exhibits a standard property of circadian (daily) rhythmicity: under constant environmental conditions, the intensity of the particle fluorescence fluctuates cyclically (it is maximal during the night phase and is low during the day). Thus, luciferin is localized within the cell at discrete loci from which the bioluminescence emanates; the cellular quantity of luciferin is rhythmically modulated by the circadian clock.

Dinoflagellida↗
PubMed1984

Little sleep-promoting effect of three sleep substances diurnally infused in unrestrained rats.

Delta-sleep-inducing peptide (2.5 nmol), prostaglandin D2 (0.36 nmol) and uridine (10 pmol) were intraventricularly infused for 10 h at daytime in otherwise saline-infused freely moving male rats. In contrast to a nocturnal infusion which may result in marked sleep-promoting effects, such a diurnal infusion brought about almost no change in sleep parameters. It is postulated that the requirement of sleep in rats might be fully achieved at the environmental light period to cancel the effect of the exogenously administered sleep substances. It is proposed that an endogenous sleep substance should be characterized by a property not to cause excessive sleep at the time when sleep is physiologically saturated.

Animals↗
PubMed1984

Uridine as an active component of sleep-promoting substance: its effects on nocturnal sleep in rats.

A 10-h intraventricular infusion of 10 pmol of uridine from 19.00 to 05.00 h resulted in significant increases in sleep in otherwise saline-infused male rats (n = 8) during the environmental dark period (20.00-08.00 h). Increments of slow wave sleep (SWS) and paradoxical sleep (PS) were 21.0% and 68.1%, respectively, of the baseline value. This was due to increases in the frequencies of both SWS and PS episodes but not to their durations. Similar increases occurred the first recovery night under saline infusion, but sleep amounts returned to the baseline levels the second night. Brain temperature was not affected by uridine administration. A small dose of uridine (1 pmol/10 h) exerted no effect (n = 6) while larger doses (100 and 1000 pmol/10 h, each n = 5) resulted in slight but insignificant increases in SWS and PS. The 1000-pmol uridine administration seemed to be non-physiological since it brought about irregularities in locomotor activity and sleep-waking rhythms. Thus, authentic uridine exhibited the same sleep-enhancing effects as a naturally occurring active component of sleep-promoting substance, which was recently identified with uridine.

Animals↗