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Biomedical subjects

M Sano

Publications and source records attributed to M Sano.

At least 505 records · Page 28Linked to original sources
PubMed1988

The relaxation induced by indole and nonindole 5-HT agonists in the molluscan smooth muscle.

1. The abilities of two indole agonists and some nonindole agonists to induce relaxation of catch contraction and the influence of the agonists on cyclic AMP (cAMP) levels in the anterior byssus retractor muscle (ABRM) of Mytilus were investigated. 2. 5-MeOT (5-methoxytryptamine) and 5-MeODMT (5-methoxy-N,N-dimethyltryptamine) dose-dependently relaxed the contraction. 3. TFMPP (m-trifluoromethylphenyl piperazine), PAPP (p-amino-phenyl TFMPP) and mCPP (1-(3-chlorophenyl)piperazine dose-dependently relaxed the contraction, but 2MPP (1-(2-methylphenyl) piperazine and quipazine did not. 4. 5-MeOT (10(-6)M), 5-MeODMT (10(-6)M), TFMPP (10(-4)M), 2MPP (10(-4)M), quipazine (10(-4)M) and 8-OH-DPAT (3 x 10(-5) M) significantly reduced the cAMP levels, but PAPP (3 x 10(-4)M) and mCPP (10(-4)M) did not have any effect on cAMP levels. 5. These findings indicate that the pharmacological properties of 5-HT1-like receptors in the ABRM are similar to those of 5-HT1A receptors in mammalian tissues, and that the changes in cAMP levels induced by the agonists used are unlikely to be directly linked to the relaxation induced by them.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1988

[Calmodulin and neuron: immunohistochemical studies].

Calmodulin is present in higher concentrations in brain tissues. The content rapidly increased during the 2nd postnatal week in rat brain. Although the protein is ubiquitous in all eukaryotic cells, immunohistochemical studies have revealed that calmodulin is mainly localized in the neurons, exhibiting a similar distribution to that of gamma-type neuron-specific enolase. In the mouse retina, both calmodulin and gamma-enolase were found to be localized in optic nerves, ganglion cells, and inner and outer plexiform layers. The development study showed that gamma-enolase increased in the 2nd postnatal week and that the levels of calmodulin did not significantly change in that stage. In the mouse retina with an inherited retinal dysplasia (C3H), in which all the photoreceptor cells degenerate during the 2nd and 3rd postnatal weeks, calmodulin-specific staining decreased in the residual layers. Calmodulin is also enriched in mammalian testes. In the mouse testis, levels of calmodulin were high in the spermatocytes and in the spermatids, as compared to the level in spermatozoa. This suggests that the large amount of calmodulin in the testis may be associated with miotic divisions and/or spermatogenesis. Immunocytochemical staining of calmodulin in C6 glioma cells and PC12 pheochromocytoma cells showed a high level of calmodulin to be localized on the half spindles between poles and chromosomes in mitotic cells. The protein was also shown to be localized on fibrous structures in the interphase of those cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The effect of axotomy and denervation on calmodulin content in the superior cervical sympathetic ganglion of the rat.

Calmodulin (CaM) in the superior cervical sympathetic ganglion (SCG) of the rat and its changes after transection of the pre- or postganglionic nerves were studied biochemically and immunohistochemically. The concentration of CaM in the SCG was assayed using the extent of activation of CaM-dependent adenylate cyclase from bovine neural retina. In the SCG, CaM concentration was 4.5 micrograms/mg protein, a level similar to that in another peripheral ganglion, the nodose ganglion (4.9 micrograms/mg protein). Following denervation of the SCG, the total amount of ganglionic CaM did not change significantly within a week. On the other hand, CaM content per ganglion increased gradually 3 days after axotomy. Immunohistochemical examination revealed that CaM in unoperated SCG is present both in the neuronal fibers and in the cell soma of sympathetic neurons. But the intensity of the staining with CaM-antibody in the cytoplasmic soma varied among cells. The gross profile of the CaM immunostaining seemed to be unchanged one week after either denervation or axotomy, but the immunoelectron microscopic study showed heavy staining of the innercellular membranes of irregular shape in the axotomized SCG.

Adenylyl Cyclases↗
PubMed1987

Effects of oral physostigmine in Alzheimer's disease.

Previous studies of oral physostigmine in the treatment of Alzheimer's disease have: (1) assumed physostigmine is effective only in mildly affected patients; (2) relied on an initial "dose-finding" phase to determine the most effective dose and excluded nonresponders; and (3) primarily assessed memory. We examined the response of 22 patients to six different daily dosages of oral physostigmine, using selective reminding tests that were administered twice daily. Nine patients had a "best" dose/day (mode = 13 mg/day), which was used in a subsequent double-blind crossover study. The other 13 were given the highest tolerated dose. The selective reminding test and a full neuropsychological battery were given during the drug and placebo periods. As a group, the 22 patients improved significantly on the Wechsler Adult Intelligence Scale-Revised Digit Symbol subtest and a shape cancellation task (p less than 0.05). Nine patients showed improved performance on the selective reminding test during physostigmine treatment, and 9 showed no response; 4 patients performed better during placebo treatment. Dose finding did not help in predicting response in the crossover study; only 2 of the 9 who showed improvement had a best dose. Dementia severity did not predict crossover response. This suggests that: (1) physostigmine as administered had no pronounced effect on memory in Alzheimer's disease; (2) oral physostigmine produces no greater benefits on memory in mildly than in moderately demented patients; (3) response in a dose-finding phase does not predict response in double-blind crossover; and (4) Digit Symbol and cancellation tasks may be more sensitive than memory tests to the effects of oral physostigmine.

Administration, Oral↗
PubMed1987

Immunohistochemical study of calmodulin in developing mouse testis.

The purpose of this study was to determine the localization of calmodulin in the developing mouse testis by the indirect immunoperoxidase method. In addition, the amount of calmodulin in pachytene spermatocytes, spermatids, and residual bodies isolated from the mouse testis and epididymal spermatozoa was quantitated by the adenylate cyclase activation assay and by enzyme immunoassay. The relative levels of calmodulin in the developing mouse testis and in the isolated testicular germ cells were confirmed by western transfer staining. The level of immunoreactive calmodulin was very low in the testes from immature animals. In testes from the mature mouse, calmodulin was found to be localized in spermatocytes and spermatids, but was not found in spermatogonia, Sertoli cells, and interstitial cells. By contrast, immunochemical staining of tubulin was extremely intense in Sertoli cells. Biochemical determinations also showed that pachytene spermatocytes, round spermatids, spermatozoa, and residual bodies contained 14.9 micrograms, 15.8 micrograms, 2.3 micrograms and 5.2 micrograms of calmodulin per mg of protein, respectively. Both the immunochemical and the biochemical studies revealed that levels of calmodulin were high in the spermatocytes and in the round spermatids, as compared to the level in spermatozoa. This fact strongly suggests that the large amount of calmodulin in mammalian testes may be associated primarily with meiotic divisions and/or spermatogenesis.

Aging↗
PubMed1987

Neuritic growth from a new subline of PC12 pheochromocytoma cells: cyclic AMP mimics the action of nerve growth factor.

We have identified a new subline of PC12 pheochromocytoma cells (PC12D cells) in which neurites are extended within 24 hr in response to cAMP-enhancing reagents as well as in response to nerve growth factor (NGF), but not in response to epidermal growth factor or phorbol diester. Anti-NGF antiserum did not affect forskolin (FRK)-induced neuritic recruitment. FRK-induced neurites exhibited growth cones and contained secretion granules and many parallel arrays of microtubules as was the case with NGF-induced neurites. FRK, but not NGF, increased the levels of intracellular cAMP and activated adenylate cyclase in the membrane fraction. Both NGF and FRK enhanced the activities of tyrosine hydroxylase (TH), acetylcholinesterase (AchE), and ornithine decarboxylase (ODC), but not the levels of neuron-specific enolase. Enhanced levels of intracellular cAMP mimicked the effects of NGF on neuritic growth, TH, AchE, and ODC activities in PC12D cells, even though NGF does not act through elevation of levels of cAMP.

Adenylyl Cyclases↗
PubMed1987

The early expression of immunoreactivity for calmodulin in the nervous system of mouse embryos.

Calmodulin (CaM) is a major calcium-binding protein in the brain, where its immunoreactivity is mainly localized in the neurons. In this study, ontogenical changes in the distribution of CaM in the nervous system of mouse embryos were investigated immunohistochemically using a specific antibody against CaM and an indirect immunoenzyme method. Immunoreactive staining was first observed in the marginal layer of the cranial neural tube after 9.5 days of gestation; thereafter, the amount of stained structures increased rapidly. Particularly intense staining was observed in the long neuronal processes extending from or into the brain and spinal cord primordia. Intense immunostaining was also observed in the optic nerve layer of early retinae from 12.5 days of gestation. The appearance of CaM immunoreactivity is thus an early event during neuronal differentiation, apparently concomitant with the initiation of axon extension and the appearance of neurofilament proteins.

Animals↗
PubMed1987

Effects of milbemycin D on adult Angiostrongylus cantonensis in rats.

Effects of milbemycin D against adult Angiostrongylus cantonensis in rats were examined. The first-stage larval counts in rat faeces (larvae per gram of faeces per female worm recovered, LPG/female) were most conspicuously reduced in the group treated with nine consecutive weekly doses of 5.0 mg/kg. The effect was more marked in the group treated with five or ten successive daily doses of 5.0 mg/kg than the group treated with a single dose of 25.0 or 5.0 mg/kg. Host lung-body weight ratio and number of recovered worms were reduced significantly only in the group treated with five or ten successive daily doses of 5.0 mg/kg. These results suggest that the action of milbemycin D on the reproductive system of the worms might be differentiated from its killing action. The in vitro motility of females recovered from rats medicated with nine consecutive weekly doses of 5.0 mg/kg was inhibited, and almost all females and males were semitransparent and colourless. Results obtained from sectioned worms showed little content in their digestive tracts and uteri. In addition, there were few eggs and first-stage larvae in the lung tissues of treated rats. These suggest that milbemycin D affects the reproductive functions of the worms through an indirect mode of action including paralysis and inhibition in food intake and energy and/or synthetic metabolism.

Angiostrongylus↗
PubMed1987

Late development and fertility of adult worms derived from gamma-irradiated first-stage larvae of Angiostrongylus cantonensis.

Effects of gamma ray irradiation on the first-stage larvae of Angiostrongylus cantonensis were studied. Compared to the non-treated controls, infection of rats with third-stage larvae which developed from irradiated first-stage larvae resulted in reduced recovery rates of adults. There was also a change in the male-female adult worm ratio and a reduction in larval output per female in relation to increasing irradiation dosage. Morphological changes in the adults were noted.

Angiostrongylus↗