Heterogeneity of Benzodiazepine Receptors: Experimental Differences Between [3H]Flunitrazepam and [3H]Ethyl-β-carboline-3-carboxylate Binding Sites in Rat Brain Membranes

Abstract: This study was designed to analyze possible differences in the binding of [³H]flunitrazepam ([³H]FNZP) and [³H]ethyl - β - carboline - 3 - carboxylate ([³H]β-CCE), to rat brain membranes, in various experimental conditions. In cerebral cortex, hippocampus, cerebellum, and orain stem the number of binding sites for [³H]β-CCE was higher than for [³H]FNZP; both were displaced by clonazepam. Until the 7th day of postnatal brain development the numbers of [³H]FNZP and [³H]β-CCE sites were equivalent; but later on, the β-carboline sites increased to a higher level. Noradrenergic denervation by 6-hydroxydopamine was followed in the hippocampal formation. Already after 2 days, there was a decrease in [³H]FNZP sites, which reached 70% of control after 14 days. Similar results were obtained with DSP-4 denervation. This change was only in B_max and not in K_D, In contrast, the [³H]β-CCE sites did not change with denervation. Neonatal injection of l - 2,4,5 - trihydroxyphenylalamine or DSP-4 produced in the adult a decrease in [³H]FNZP sites in the cerebral cortex, in parallel with the noradrenergic denervation. On the other hand, there was an increase in the cerebellum and brain stem, in correspondence with the hyperinnervation by sprouting. In these rats, the number of sites for [³H]β-CCE did not change in the different brain regions. With 0.1% Triton X-100, applied to synaptosomal membranes, [³H]FNZP binding was reduced by 35%, while that of [³H]β-CCE was not significantly changed. These results suggest that there is heterogeneity of binding sites for benzodiazepine receptors in rat brain. A tentative interpretation of the experiments involving noradrenergic denervation and hyperinnervation, as well as those with Triton X-100, is that [³H]FNZP binds to pre- and postsynaptic receptors, while [³H]β-CCE binds mainly to postsynaptic benzodiazepine receptors.     

The taxonomy of the family Paramphistomidae Fischoeder, 1901 with special reference to the morphology of species occurring in ruminants. III. Revision of the genus Calicophoron Näsmark, 1937

Summary The genus Calicophoron N?smark, 1937 is redefined. Only the following species originally assigned by N?smark to the genus are considered valid: C. calicophorum (Fischoeder, 1901) N?smark, 1937 (type species); C. papillosum (Stiles & Goldberger, 1910) N?smark, 1937; and C. raja N?smark, 1937. The following species previously assigned to the genus Paramphistomum Fischoeder, 1901 are considered valid but moved to the genus Calicophoron N?smark, 1937 in new combinations: C. bothriophoron (Braun, 1892); C. microbothrium (Fischoeder, 1901); C. papilligerum (Stiles & Goldberger, 1910); C. clavula (N?smark, 1937); C. microbothrioides (Price & McIntosh, 1944); C. sukari (Dinnik, 1954); C. phillerouxi (Dinnik, 1961); C. daubneyi (Dinnik, 1962) and C. sukumum (Dinnik, 1964). The genus Bothriophoron (Stiles & Goldberger, 1910) Grétillat 1958 is synoymized with Calicophoron N?smark, 1937. Paramphistomum crassum Stiles & Goldberger, 1910, P. cauliorchis Stiles & Goldberger, 1910, P. ijimai Fukui, 1922, P. (Cauliorchis) skrjabini Popova, 1937, P. erschovi Davydova, 1959, Calicophoron orientalis Mukherjee, 1966, C. wuchengense Wang, 1979 and Cotylophoron skrjabini Mitskevich, 1958 in part are considered synonyms of Calicophoron calicophorum (Fischoeder, 1901) N?smark, 1937. C. zhejiangense Wang, 1979 is regarded a synonym of C. papillosum (Stiles & Goldberger, 1910) N?smark, 1937. P. vangrembergeni Van Strydonck, 1970 and P. togolense Albaret, Bayssade-Dufour, Guilhon, Kulo & Picot, 1978 are considered synonyms of Calicophoron phillerouxi (Dinnik, 1961) n. comb. and Ceylonocotyle petrovi Davydova, 1961 is synonymized with Calicophoron microbothrioides (Price & McIntosh, 1944) n. comb. The species considered valid under the genus are redescribed and illustrated and scanning electron photomicrographs of the tegumental surfaces of some species are provided. A key to the species is given. Part of a thesis approved by the University of London for the award of the Ph.D. degree.     

POLYMORPHISM IN THE DESMID XANTHIDIUM REGULARE AND ITS TAXONOMIC IMPLICATIONS

This paper refers to a case of polymorphism in the desmid genus Xanthidium Ehr. It is based on material from Lake Dais Irmaios, the main body of water in the Zoological and Botanical Garden in Recife, Pernambuco, northeastern Brazil, collected at 4 different times of the year during 1967 and 1968. A detailed examination of almost 1300 specimens showed an enormous variety in form of Xanthidium regulare Nordst., X. fragile Borge, and X. pseudoregulare Borge, thus allowing the authors to draw the following conclusions: (1) the name X. regulare Nordst. should be retained until further and more detailed studies on form variation within the species are available; (2) the names X. regulare Nordst. var. asteptum Nordst. in Borge, X. regulare Nordst. var. sexangulare Grönbl., X. regulare Nordst. var. sexangulare Grönbl. f. robustior Grönbl., X. fragile Borge, X. fragile Borge forma, and X. fragile Borge var. depauperatum Borge should be considered synonymous, all referring to a single variety of X. regulare Nordst., var. asteptum Nordst. in Borge emend. C. Bic. & L. M. Carv.; (3) X. pseudoregulare Borge must be treated as a variety of X. regulare Nordst. and must be called X. regulare Nordst. var. pseudoregulare (Barge) C. Bic. & L. M. Carv. Finally, a key is given to the 3 varieties of X. regulare Nordst. proposed in the present paper.     

A further study on the dietary-regulated biosynthesis of high-sulphur wool proteins

When the diet of sheep is supplemented by the infusion of sulphur-containing amino acids or casein into the abomasum, the newly synthesized wool shows characteristic changes in its amino acid composition, with significant increases in cystine, proline and serine and decreases in aspartic acid and phenylalanine. This modification seems to be due entirely to an alteration in the overall composition of the high-sulphur proteins and to an increase in their proportion in the fibre. These variations are not the result of a change in the composition of individual proteins, but are due to alterations in their relative proportions and to the initiation of the synthesis of `new' proteins, many of which are extremely rich in cystine. It is suggested that the heterogeneity of the high-sulphur proteins may be due, in part, to similar changes in composition caused by natural variations in the nutrition of sheep.     

Ultrastructure of the peptidergic and monoaminergic neurons in the hypothalamic neurosecretory system of Anuran Batracians

Summary In the toad Bufo arenarum Hensel the following regions of the hypothalamic — neurohypophyseal system were studied under the electronmicroscope: preoptic and paraventricular nuclei, median eminence and infundibular process of the neurohypophysis.Neuronal perikarya of the preoptic nucleus are loaded with typical neurosecretory granules of peptidergic nature having a mean diameter of 1660 Å. While most neurons of the winter toad are in a storage stage a few show signs of a more active synthetic activity. A distinctive feature of preoptic neurons is the presence of large lipid droplets. The paraventricular nucleus contains small neurons containing granulated vesicles with a mean diameter of 800-1000 Å. In the region extending between these two nuclei and the median eminence axons containing either neurosecretory elementary granules or granulated vesicles are observed.The inner zone of the median eminence is occupied by axons of the preoptic neurohypophyseal tract; two types of axons, according to the size and density of the neurosecretory granules, may be recognized. The outer zone of the median eminence contains mainly axons and nerve terminals containing granulated vesicles of probable monoaminergic nature and only a few with granules of peptidergic type.The neurohypophysis contains two kinds of axons: one with more dense granules of 1800 Å and the other with granules of lesser electron density and 2100 Å. At the ending proper small clear vesicles of synaptic type are found.A progressive increase in volume of the peptidergic granules along the axon is demonstrated. This is of the order of 218% from the preoptic perikarya down to the infundibular process. The physiological significance of the two neurosecretory systems — i.e. the monoaminergic and the peptidergic — and the probable nature of the two types of peptidergic axons is discussed.Supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas and by the Air Force Office of Scientific Research (AF-AFOSR 963-67).The authors want to express their gratitude to Mrs. Defilippi-Novoa and Mr. Alberto Sáenz for their skillful assistance.     

Lack of sensitivity to ouabain in natural killer activity

Natural killer (NK) activity against K562 target cells is not an ouabain-sensitive process. Inhibition of 40% of cytotoxicity was achieved only with an ouabain concentration much higher than that required to inhibit cell activation in other systems such as leukocyte chemotaxis and B lymphocyte plaque formation. Pretreatment of effector cells with biological agents such as phorbol-ester 12-O-tetradecanoylphorbol-13-acetate or interferon increased the cytotoxicity. This activation was not counteracted by ouabain. The effect of ouabain on NK activity was compared with a well-known ouabain-sensitive process, for example, phytohemagglutinin-induced peripheral blood lymphocyte proliferation. Ouabain completely blocked [3H]thymidine incorporation, independent of the stage of the culture when the drug was added, with exception of the last 6 h. This inhibition could be partially reversed by addition of KCl. Ouabain was equally effective when whole blood cultures were used. These results suggest that NK activity is ouabain resistant, unlike other systems of cell activation that lead or do not lead to proliferation.     

Hormonal changes associated with fruit set and development in mandarins differing in their parthenocarpic ability

Satsuma [Citrus unshiu (Mak) Marc.] and Clementine [Citrus reticulata (Hort.) Ex. Tanaka, cv. Oroval] are two related species of seedless mandarins which differ in their tendency to set parthenocarpic fruits. Satsuma fruits naturally set parthenocarpically whereas Clementine mandarins show very low ability to set fruit in the absence of cross-pollination. The endogenous levels of gibberellins (GAs) and free and conjugated indole-acetic acid (IAA) and abscisic acid (ABA) throughout early stages of fruit development were investigated in seedless cultivars of both species. Analyses performed by full-scan combined gas chromatography-mass spectrometry (GC-MS) of extracts from ovaries at anthesis demonstrated the presence of GA₁₉, GA₂₀, GA₂₉, GA₁, GA₈, GA₃ and iso-GA₃ in Satsuma mandarin, whereas only GA₂₉, GA₃ and trace levels of GA₈ were detected in Clementine. At this developmental stage GA-like substances, as estimated by bioassay, reached their highest levels in Satsuma, while Clementine mandarins contained relatively lower levels. In both species the highest levels of free IAA were found at petal-fall stage at which time free ABA levels also peaked. Developing fruits of Clementine had higher amounts of both free IAA and ABA. In Satsuma, levels of conjugated IAA remained low throughout reproductive development whereas in Clementine they increased as the free form declined. In contrast, conjugated ABA was at low levels in Clementine but reached higher concentrations in Satsuma. These results suggest that in these mandarins the potential for setting parthenocarpic fruits is mainly influenced by the hormonal status of the fruit during the later stages of cell division and early stages of cell enlargement. Thus, the condition of low ability to set parthenocarpic fruits appears to be associated with lower levels of active GAs, lower capability to catabolize ABA to conjugated ABA and higher ability to conjugate IAA during this period.     

Band-specific localization of the microsatellite at D13S71 by microdissection and enzymatic amplification.

Microsatellite DNA consists of tandemly repeated simple DNA sequence motifs, the number of these repeats being polymorphic. These recently described polymorphisms are ubiquitously distributed throughout the human genome and are highly informative, making them ideal markers for linkage analysis. Physical localization of these microsatellites is an important prerequisite for aligning physical and genetic maps. We have physically mapped the microsatellite at D13S71, which has previously been assigned to chromosome 13. Band-specific mapping of D13S71 to the distal part of band 13q32, near 13q33, was achieved by microdissection of GTG-banded chromosomes and subsequent enzymatic amplification with a heminested PCR approach. Analysis of a panel of somatic cell hybrids confirmed this localization. The technique presented may also be useful in a variety of complex mapping situations and whenever the precise localization of very small (as small as 70 bp) DNA probes is necessary.