Pharmacological and Physicochemical Properties of Pre-Versus Postsynaptic 5-Hydroxytryptamine1A Receptor Binding Sites in the Rat Brain: A Quantitative Autoradiographic Study

Numerous data suggested that the pharmacological and biochemical properties of 5-hydroxytryptamine1A (5-HT1A) receptors exhibit some regional differences in the CNS, notably within the raphe nuclei compared with various forebrain areas (such as the hippocampus). This possibility has been further investigated in the dorsal raphe nucleus and two areas within the hippocampus, the dentate gyrus and the CA1 area, using the quantitative autoradiographic technique. The potencies of 5'-guanylylimidodiphosphate to inhibit the specific binding of 125I-Bolton-Hunter-8-methoxy-2-(N-propyl-N-propylamino)tetralin (125I-BH-8-MeO-N-PAT) to 5-HT1A sites and of N-ethylmaleimide to block these sites irreversibly were identical in the dorsal raphe nucleus and the hippocampal areas in rat brain sections. In contrast, slight but significant differences were noted in the pH dependence and pharmacological properties of 5-HT1A sites labeled by 125I-BH-8-MeO-N-PAT in these three regions. Similarly, heat denaturation experiments and tissue exposure to either phospholipase A2 or the alkylating agent 8-methoxy-2-(N-2'-chloropropyl,N-propyl)aminotetraline revealed regional differences in the properties of 5-HT1A sites. However, in most cases, the observed variations were of greater amplitude between the CA1 area and the dentate gyrus, where 5-HT1A sites are located postsynaptically, than between any one of these areas and the dorsal raphe nucleus where they act as (presynaptic) somatodendritic autoreceptors. These data further support that subtypes of 5-HT1A receptors probably exist in the rat brain, but this heterogeneity seems unrelated to the pre- or post-synaptic location of these receptors.     

Identification of Tumor Antigens in the HLA Peptidome of Patient-derived Xenograft Tumors in Mouse

1. Download : Download high-res image (147KB)
2. Download : Download full-size image

Highlights

• •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
• •Using patient derived xenograft (PDX) tumors can overcome this limitation.
• •The large PDX HLA peptidomes expand significantly those of the original biopsies.
• •The HLA peptidomes of the PDX tumors included many tumor antigens.

     

Proteomic Analysis of Specific Proteins in the Root of Salt-Tolerant Barley

Comparative two-dimensional electrophoresis showed six proteins, which were significantly produced in the root of salt-tolerant barley. These proteins were identified as stress/defense-related proteins that do not scavenge reactive oxygen species directly, suggesting that salt-tolerant barley develops not only an antioxidative system, but also physical and biochemical changes to cope with salt stress.     

Detection of linkage between marker loci and loci affecting quantitative traits in crosses between segregating populations

Summary By making use of pedigree information and information on marker-genotypes of the parent and F-1 individuals crossed to form an F-2 population, it is possible to carry out a linkage analysis between marker loci and loci affecting quantitative traits in a cross between segregating parent populations that are at fixation for alternative alleles at the QTL, but share the same alleles at the marker loci. For two-allele systems, depending on marker allele frequencies in the parent populations, 2–4 times as many F-2 offspring will have to be raised and scored for markers and quantitative traits in order to provide power equivalent to that obtained in a cross between fully inbred lines. Major savings in number of F-2 offspring raised can be achieved by scoring each parent pair for a large number of markers in each chromosomal region and scoring F-1 and F-2 offspring only for those markers for which the parents were homozygous for alternative alleles. For multiple allele systems, particularly when dealing with hypervariable loci, only 10%–20% additional F-2 offspring will have to be raised and scored to provide power equivalent to that obtained in a cross between inbred lines. When a resource population contains novel favorable alleles at quantitative trait loci that are not present (or rare) in a commercial population, analyses of this sort will enable the loci of interest to be identified, mapped and manipulated effectively in breeding programs.Contribution no. 2124-E, 1987 series from The Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel     

Bean lectins

Summary Seeds of forty bean cultivars having different lectin types based on two-dimensional isoelectric focusing-sodium dodecyl sulfate polyacrylamide gel electrophoresis (IEF-SDS/PAGE) were analyzed for quantities of lectin, phaseolin and total protein. Significant differences were found among groups of cultivars with different lectin types for the quantity of lectin and phaseolin. Cultivars with more complex lectin types based on IEF-SDS/PAGE tended to have higher quantities of lectin and lower quantities of phaseolin than cultivars with simple lectin types. An association between lectin type and the quantity of lectin and phaseolin was found also in the seeds of F₂ plants that segregated in a Mendelian fashion for two lectin types. Seeds from plants with the complex lectin type had more lectin and less phaseolin than seeds from plants with the simple lectin type. Therefore, the genes controlling qualitative lectin variation also may influence the quantitative variation of lectin and phaseolin. The results of this study are related to other studies on the quantitative variation for seed proteins and to the possible molecular basis for variation in the quantity of lectins in beans.     

Quantitativ-morphologische Untersuchungen an Herzmuskelzellen von normalen und hypoxischen Ratten

Zusammenfassung Normale und hypoxische Herzmuskelzellen aus der Wand des linken Ventrikels der Ratte wurden quantitativ-morphologisch anhand von elektronenmikroskopischen Längsschnitten nach Perfusionsfixierung untersucht. In normalen Zellen waren alle Myofibrillen relaxiert, die mittlere Sarcomerlänge betrug 2,2 m. Die Schnittfläche wurde zu 55% von Myofibrillen, zu 27% von Mitochondrien und zu 18% von Grundplasma und Reticulum eingenommen. Die zwischen den Myofibrillen liegenden Mitochondrien waren längsoval und im Mittel 2,3mal so lang wie breit. Es bestand kein Unterschied zwischen subendokardial und subepikardial gelegenen Zellen.10 min nach Erstickung der Tiere waren in den sonst unauffälligen Muskelzellen die Glycogengranula vermindert. Nach 20 min führte die Hypoxie zu einer Zunahme der relativen Schnittfläche der Mitochondrien um etwa 16% und zu einer beginnenden Kontraktur der Myofibrillen (Sarcomerlänge 2,0 m). 20 min Hypoxie in Hypothermie (25–30°C intrathorakal) veränderte die normale Zellstruktur dagegen kaum. Wenn die Herzen während der 20 min dauernden Hypoxie in Normothermie mit einer procainhaltigen sauerstoff- und glucosefreien Blutersatzlösung durchspült wurden, waren die Myofibrillen relaxiert, die Schwellung der Mitochondrien dagegen wurde nicht reduziert. 30 min nach Erstickung wurde die Kontraktur stärker (Sarcomerlänge 1,7 m). Nach 60 min bildeten sich Superkontraktionsknoten, einzelne Myofibrillen waren in Höhe der I-Bänder unterbrochen. Die Cristae der Mitochondrien wichen auseinander, die Schnittfläche der Mitochondrien hatte um 27% zugenommen.Während in Normotherapie eine Asphyxie des Tieres bereits nach 10 min die Herzmuskelzellen funktionell schwer schädigt, ist die Schädigung morphologisch erst nach 20 min eindeutig. Das bedeutet, daß für die elektronenmikroskopische Präparation eine Hypoxie von unter 10 min bedeutungslos ist. Hinsichtlich der morphologischen Manifestationszeit für die Unterbrechung der Sauerstoffversorgung stimmen unsere Befunde an Herzmuskelzellen gut mit vergleichbaren Angaben an Leberzellen überein.

---

Quantitative-morphological investigations of heart muscle cells of normal and asphyctic rats

Summary In heart muscle cells of the left ventricle of rats the distribution of cell organelles and their reaction to hypoxia were investigated by electron microscopy.In normal hearts fixed by perfusion with aldehydes, the mean sarcomere length was 2.2 m. 27% of the longitudinal sectional area was occupied by mitochondria, 55% by myofibrils and 18% by sarcoplasmic reticulum and ground plasm. The mitochondria situated in rows between the fibrils were oval and measured 2.3 times more in length than in width. There was no difference between cells from subendocardial and subepicardial regions.10 min hypoxia (complete occlusion of the trachea) did not affect the appearance of muscle cells but diminished the number of glycogen granules. After 20 minutes the area occupied by mitochondria was increased by 16%, the mitochondria between the myofibrils were more spherical and only 1.5 times longer than wide. The sarcomeres shortened to 2.0 m. With hypothermia (25–30°C) hypoxia of 20 minutes duration did not affect the cell structure. Perfusion of the heart by a saline solution, which contained procaine but neither oxygen nor glucose, for 20 minutes prevented shortening of the sarcomeres but not swelling of the mitochondria. 30 minutes after occlusion of the trachea the myofibrils shortened to a sarcomere length of 1.7 m. After 60 minutes irregularly and excessively contracted myofibrils appeared and some sarcomeres were interrupted at the level of the I-bands. In some of the swollen mitochondria the cristae were widely separated. The increase of the area occupied by mitochondria was 27%.Asphyxia affects heart muscle cells severely with respect to function within 10 min, but morphologically it takes 20 min before a definite effect can be noticed. As to the time after which lack of oxygen is manifested morphologically, our results are consistent with findings in liver cells.

     

Quantitative phenotypical expression of three mutant genes in barley and the basis for defining an ideotype for Mediterranean environments

Summary Three mutants induced in the two-rowed barley variety Beka and their three binary recombinants have been used in an attempt to define an ideotype suitable for Mediterranean agroclimatic conditions. Physiological methods (classical plant growth analysis) together with the study of genotype x environment interaction for grain yield were used to characterize the genotypes. That characterization brought out the huge phenotypical variation produced by only three mutant genes, suggesting that single Mendelian genes may alone explain the quantitative variation, including grain yield, without the necessity of using the polygenic concept. The genotype best adapted to the environments studied is later in heading and has shorter straw and denser spikes than Beka; it also has higher inverse of leaf area rate and grain: leaf area ratio, a lower rate of leaf senescence, and a shorter grain filling period than the original variety.