Acetylcholine, ATP, and Proteoglycan Are Common to Synaptic Vesicles Isolated from the Electric Organs of Electric Eel and Electric Catfish as Well as from Rat Diaphragm

Cholinergic synaptic vesicles were isolated from the electric organs of the electric eel (Electrophorus electricus) and the electric catfish (Malapterurus electricus) as well as from the diaphragm of the rat by density gradient centrifugation followed by column chromatography on Sephacryl-1000. This was verified by both biochemical and electron microscopic criteria. Differences in size between synaptic vesicles from the various tissue sources were reflected by their elution pattern from the Sephacryl column. Specific activities of acetylcholine (ACh; in nmol/mg of protein) of chromatography-purified vesicle fractions were 36 (electric eel), 2 (electric catfish), and 1 (rat diaphragm). Synaptic vesicles from all three sources contained ATP in addition to ACh (molar ratios of ACh/ATP, 9-12) as well as binding activity for an antibody raised against Torpedo cholinergic synaptic vesicle proteoglycan. Synaptic vesicles from rat diaphragm contained binding activity for the monoclonal antibody asv 48 raised against a rat brain 65-kilodalton synaptic vesicle protein. Antibody asv 48 binding was absent from electric eel and electric catfish synaptic vesicles. These antibody binding results, which were obtained by a dot blot assay on isolated vesicles, directly correspond to the immunocytochemical results demonstrating fluorescein isothiocyanate staining in the respective nerve terminals. Our results imply that ACh, ATP, and proteoglycan are common molecular constituents of motor nerve terminal-derived synaptic vesicles from Torpedo to rat. In addition to ACh, both ATP and proteoglycan may play a specific role in the process of cholinergic signal transmission.     

The possible involvement of polyamines in the development of tomato fruits in vitro

The apparent involvement of ornithine decarboxylase (ODC) and putrescine in the early stages of fruit growth in tomato (Lycopersicon esculentum Mill.) has been previously described. Further evidence presented here supports the direct involvement of ODC and putrescine in the cell division process in tomato fruits. In tomato fruits grown in vitro, in which basic growth processes are inhibited, the activity of ODC and arginine decarboxylase (ADC) and the level of free polyamines were reduced. While ODC and ADC activity was correlated with the period of cell division in the tomato fruit, the free polyamine content was correlated with the DNA content, cell size, and fruit fresh weight. The addition of exogenous putrescine, however, did not restore the basic growth processes in the fruits grown in vitro.     

Distribution of neurotensin-like immunoreactivity in rat and cat area postrema

The distribution of neurotensin-like immunoreactive (NT-LI) fibers and cell bodies in the area postrema (AP) of rat and cat, utilizing the peroxidase, antiperoxidase (PAP) technique, is described. In the rat, the greatest accumulation of NT-LI fibers were present along the borders of the AP, while there were very few NT-LI fibers in central regions. In the cat, scattered NT-LI fibers occupied the majority of the central AP, while moderate numbers of NT-LI fibers were present at the ventromedial border. In more rostral cat AP levels, the number of NT-LI fibers decreased. NT-LI somata were present in rat AP, but were lacking in cat AP. The localization of NT within the AP suggests that the cardiovascular and gastric effects attributed to NT may be mediated, in part, through the AP.     

Osmotic control of luminescence and growth in Photobacterium leiognathi from ponyfish light organs

Osmolarity was found to control the luminescence and growth of Photobacterium leiognathi strain LN-1a isolated from the light organ of the ponyfish Leiognathus nuchalis (family Leiognathidae). Low osmolarity (ca. 400 mOsm) stimulated luminescence per cell 80 to 100-fold to a level (ca. 2.0×10⁴ quanta·s^-1·cell^-1) equal to that of bacteria taken directly from the light organ and increased the level of luciferase per cell 8 to 10-fold compared to high osmolarity (ca. 800 mOsm). Conversely, high osmolarity stimulated oxygen uptake and growth rate 2 to 4-fold compared to low osmolarity. Of 21 additional tested strains of P. leiognathi from light organs of 9 other ponyfish species, all responded similarly. Low osmolarity may be a host control factor that functions to stimulate the luminescence and restrict the growth of ponyfish light organ bacteria in situ.     

中缝大核在臂旁内侧核区注射吗啡所致呼吸抑制效应中的作用

实验在33只浅麻醉、肌肉麻痹、人工呼吸及切断双侧颈迷走神经的家兔上进行。观察中缝大核区电解损毁或微量注射利多卡因对呼吸活动及臂旁内侧核区微量注射吗啡所致呼吸抑制效应的影响。结果是:电解损毀中缝大核区,使呼吸频率增加,膈神经放电的幅度和频率均无明显变化,而臂旁内侧核区微量注射吗啡抑制呼吸的程度减轻;中缝大核区微量注射利多卡因,则部分消除臂旁内侧核区微量注射吗啡的呼吸抑制效应。中缝大核旁网状结构电解损毁或微量注射利多卡因,不影响吗啡的呼吸抑制效应。上述结果提示,中缝大核区可能在脑桥臂旁内侧核区微量注射吗啡抑制呼吸的机制中起一定作用。     

Functional and ultrastructural effects of nontypeable haemophilus influenzae in a hamster trachea organ culture system

Summary A hamster trachea organ culture system was utilized to evaluate quantitatively the effects of a strain of nontypeableHaemophilus influenzae (NTHI) and culture supernatants of the same strain on ciliary activity. Tracheal explants were maintained in organ culture for 96 to 144 h and ciliary activity was observed daily with an inverted microscope. Explants continuously exposed to a strain of NTHI had a progressive decline in ciliary activity which was significantly lower than uninfected controls evaluated concomitantly by 48 h of exposure and thereafter. Histologic studies revealed a progressive degeneration of mucosal cells and exfoliation of ciliated cells. Scanning electron microscopy showed little adherence of NTHI to the mucosal surface. Sterile broth cultures of NTHI and supernatants of organ cultures infected with the same NTHI strain had no adverse effect on ciliary activity. Infected tracheal explants treated with ampicillin 24, 48, or 72 h after continuous bacterial challenge had no significant decline in ciliary activity compared to controls. The lack of adherence and the histologic changes observed when hamster trachea cultures were infected with NTHI suggested a toxin might mediate the damage observed. Broth and organ culture supernatants, however, produced no damage. Therefore, further studies are needed to determine the role, if any, of a toxin in the production of damage to hamster tracheal explants by NTHI. This work was supported by a Merit Review grant from the Veterans Administration and by Grant AI-19641 from the National Institute of Allergy and Infectious Diseases.     

Concanavalin A-binding glycoproteins in the subcommissural and the pineal organ of the sheep (Ovis aries)

Summary Glycoproteins rich in mannosyl or glucosyl residues were analyzed in the subcommissural organ (SCO) and the pineal organ of the sheep (Ovis aries). By use of concanavalin A labelled with fluorescein isothiocyanate, fluorescent material was found both in ependymal and hypendymal cells of the SCO. In the pineal organ, either isolated or grouped parenchymal cells showed a marked fluorescence. These cells may correspond to ependymal elements also called interstitial cells or supporting cells. In addition, scarce slender, fluorescent processes were observed in the pineal parenchyma. The techniques of electrophoresis and electrotransfer on nitrocellulose paper have been applied to analyze the glycopeptide content of the SCO and the pineal organ in comparison to cerebellar and cerebral fractions solubilized by use of Triton X 100. Approximately 30 different concanavalin A-reactive glycopeptides were revealed in each fraction. In the SCO extract four glycopeptides (30, 54, 72, 100 kd) might correspond to subunits of the glycoprotein(s) characteristically stored in the ependymal cells of the SCO. In addition, two glycopeptides (32/33, 115 kd) are specific to the pineal organ extract. The possible similarity of the concanavalin A-reactive material in both organs is discussed and a putative secretory activity of the pineal ependymal cells is postulated.     

Characteristic pattern of monoaminergic nerve fibers in the pineal organ of the monkey,Macaca fuscata

Summary Monoaminergic nerve fibers were studied in the pineal organ of the monkey, Macaca fuscata, by use of fluorescence and immunohistochemical procedures. Abundant formations of noradrenergic nerve fibers were observed in the pineal organ. They entered the parenchyma in the form of several coarse bundles via the capsule in the distal portion of the organ and spread throughout the organ after branching into smaller units. The density of the autonomic innervation decreased gradually toward the proximal portion of the organ. In the distal portion, numerous nerve fibers formed perivascular plexuses around the blood vessels and some fibers ran as bundles unrelated to the blood vessels in the stroma. Fine varicose fibers and bundles derived from these plexuses penetrated among the pinealocytes. However, only a few intraparenchymal fluorescent fibers were detected in the proximal third of the gland. With the use of serotonin antiserum serotonin-immunoreactive nerve fibers were clearly restricted to the ventroproximal part of the pineal organ. Although the somata of the pinealocytes showed intense immunoreactivity, their processes were not stained. In one exceptional case, clusters of pinealocytes displaying very intense immunoreactivity were found in an area extending from the distal margin of the ventral portion of the pineal stalk to the proximal portion of the pineal organ proper; these cells were bipolar or multipolar and endowed with well-stained processes.     

Reproductive structures and phylogenetic significance of extant primitive Angiosperms

A brief survey is presented on fossil reproductive structures of early Angiosperms from the Lower and mid-Cretaceous and at the same time on the reproductive structures of those extant Angiosperms which resemble most closely these fossils and which seem to be especially primitive also on other grounds: a first group (Degeneriaceae, Himantandraceae, Eupomatiaceae, Austrobaileyaceae) possessing relatively complicated and conspicuous flowers with elaborated inner staminodes, a second group (Chloranthaceae, Trimeniaceae, Amborellaceae) possessing small and relatively simple, inconspicuous flowers with peculiar features in the carpels, and a third group (Winteraceae) possessing flowers with unusual variability in organ number and size. The three groups exhibit a certain diversity in pollination biology, although cantharophily seems to prevail, however different the cantharophily character syndromes may be between the groups. In the extant primitiveMagnoliidae variability occurs on other morphological levels than in the higher advanced Angiosperms. This has to be taken into consideration in evaluations of the systematic relationships of the various groups of theMagnoliidae. Presumably often their relationships are closer than it may appear at first sight. This is also true for the three groups here discussed.     

Muscarinic Acetylcholine Receptors in Torpedo Electric Organ: Effect of Guanine Nucleotides

Abstract: The effect of guanine nucleotides on the binding properties of presynaptic muscarinic receptors has been studied in a membrane preparation from the electric organ of Torpedo marmorata by measuring the competitive displacement of the radiolabelled antagonist, [³H]quinuclidinyl benzilate, by nonradioactive muscarinic ligands. The binding of the antagonists, atropine, scopolamine and pirenzepine was to a single class of sites [slope factors (pseudo Hill coefficients) close to 1] and was unaffected by 0.1 m M GTP. The binding of the N -methylated antagonists, N -methylatropine and N -methyl-scopolamine was more complex (slope factors <1) but also insensitive ( N- methylatropine) to 0.1 m M GTP. Agonist binding was complex and could be resolved into two binding sites with relatively high and low affinities. The proportion of high-affinity sites varied with the nature of the agonist (15–80%). Agonist binding was depressed by 0.1 m M GTP, and the order of sensitivity was oxotremorine-M > carbamoylcholine > muscarine > acetylcholine > arecoline > oxotremorine. The binding of pilocarpine, a partial agonist, was unaffected by GTP. With carbamoylcholine as a test ligand the GTP effect on agonist binding was half-maximal at 12 μM. GDP and guanylylimidodiphosphate produced comparable inhibition of carbamoylcholine binding, but GMP and cyclic GMP were ineffective, as were various adenine nucleotides. Analysis of agonist binding in terms of a two-site model indicates that the predominant effect of guanine nucleotides is to reduce the number of sites of higher affinity.