MOLECULAR CHARACTERIZATION OF CHOLINE ACETYLTRANSFERASE FROM BOVINE BRAIN CAUDATE NUCLEUS AND SOME IMMUNOLOGICAL PROPERTIES OF THE HIGHLY PURIFIED ENZYME

Choline acetyltransferase from bovine brain caudate nucleus has been purified to a specific activity of 25–30 μmol ACh formed per min and mg protein. Disc electrophoresis at pH 9.5 of the purified enzyme showed two protein bands localized close to each other. We were not able to show if ChAT was linked to one or both bands. In SDS disc electrophoresis the enzyme preparation showed one major and one minor protein band with molecular weights of 69,000 and 34,000, respectively. Heterogeneity of the enzyme preparation was also demonstrated by immunodiffusion and immunoelectrophoresis. After ammonium sulphate precipitation no aggregation of the enzyme could be detected by gelfiltration on Ultrogel AC-34 whilst a high molecular weight fraction was occasionally observed by gelfiltration on Sephadex G-200. The enzyme was, however, separated into two molecular forms (A and B) on CM-Sephadex chromatography. Both molecular forms had the same S²_20w but differed in heat stability and affinity for acetyl-CoA. Both forms were inactivated by an antibody preparation raised against either a purified preparation of ChAT, or A and B separately. The highly purified enzyme preparation was inactivated more than 98% by immunoprecipitation. The antibody crossreacted with ChATs from several mammalian species, but only slightly with ChAT from pigeon. The results of binding studies with affinity columns, suggest that the enzyme contains a hydrophobic lobe and a dinucleotide fold, and that a free purine rather than a free ribosyl ring of acetyl-CoA is important for the binding of the substrate to the active site. The hydrophobic lobe may be the same as the dinucleotide fold.     

Use of farmland by Ortolan Buntings (Emberiza hortulana) nesting on a burned forest area

Summary Most passerines have all-purpose territories in which both breeding and feeding take place. However, Ortolan Buntings (Emberiza hortulana) in Norway seem to depend on foraging areas outside nesting territories. We used radio transmitters to study patterns of farmland use by Ortolan Buntings nesting on a burned forest area. Territories on the forest burn were located closer to farmland than expected by chance. Males were absent from territories on average 27 % of the time and used foraging areas up to 2.7 km away from their territories. Males had to fly over an average of 1.4 territories of other males to reach those foraging areas. The distance between territory and closest area of farmland (range 40–460 m) did not affect the proportion of time absent from territories, or other measures of farmland use. However, there was a trend that duration of absences increased with territory-farmland distance among mated males, and duration of absences were shorter during the nestling period than before. Thus, it seems that minimizing travel costs may be a behavioural strategy. Even so, males with territories close to farmland were not more often paired than males further away from farmland. These findings indicate that the spatial distribution of one habitat (farmland) affects territory establishment and foraging behaviour of Ortolan Buntings nesting in another habitat (a forest burn).

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Nutzung von Ackerland durch Ortolane (Emberiza hortulana) einer benachbarten Brandfl?che

Zusammenfassung Bei den meisten Singv?geln ist das Revier sowohl Brut- als auch Nahrungsraum. Bei Ortolanen (Emberiza hortulana) in Norwegen, die auf Brandflachen brüten, scheint dies aber anders zu sein. Radiotelemetrische Untersuchen zeigten, dass sie von Nahrungsgründen au?erhalb der Brutterritorien abh?ngig sind. Die Nester auf den Brandflachen h?uften sich am Rand zum benachbarten Ackerland. M?nnchen waren durchschnittlich 27 % der Zeit vom Brutrevier abwesend und gingen his zu 2,7 km vom Brutplatz entfernt auf Nahrungssuche, wozu sie durchschnittlich 1,4 Reviere anderer M?nnchen überfliegen mussten. Der Abstand zwischen Brutrevier und n?chstem Nahrungsplatz (zwischen 40 und 460 m) hatte keinen Einfluss auf den Zeitanteil au?erhalb des Brutreviers. Die Dauer der Abwesenheit stieg jedoch bei verpaarten M?nnchen mit der Entfernung zwischen Brutrevier und Ackerland und sie war kürzer w?hrend der Nestlingsphase. Dies wird als Verhaltensstrategie zur Minimierung der Flugkosten interpretiert. M?nnchen mit Revieren n?her am Ackerland waren nicht h?ufiger verpaart als mehr entfernte Revierinhaber. Diese Untersuchungen zeigen, dass beim Ortolan die r?umliche Verteilung eines Habitats (hier Ackerland) einen Einfluss auf die Etablierung von Brutrevieren und das Nahrungssuchverhalten in einem anderen Lebensraum (hier Brandfl?chen) hat.

     

Correlations Between Acetylcholinesterase Activity in Guinea-Pig Iris and Pupillary Function: A Biochemical and Pupillographic Study

: Acetylcholinesterase (AChE) in guinea pig iris was inhibited by methylisocyclopentylfluorophosphate (soman) administered topically or parenterally, and enzyme activity was correlated to pupillary diameter by infrared pupillography. After a single topical soman instillation into the conjunctival sac there was an almost linear relationship between the reduction in AChE activity and pupillary diameter. Topical administration of soman at 24-h intervals in doses capable of almost complete inhibition of AChE in iris was accompanied by a reduced miotic effect of this drug. This was indicated by a reduced rate of the soman-induced pupillary constriction, a less pronounced reduction in pupillary diameter, and a more rapid return of the pupillary diameter to normal size. The change in pupillary diameter occurred after three daily administrations and remained constant during 31 days of treatment. These observations were seen irrespective of inhibition of blood AChE. The decrease in response to repeated administration could not be explained by a reduced inhibitory effect of soman on AChE, by a more rapid de novo synthesis of AChE, or by a change in the number of the muscarinic receptors as determined by quinuclidinyl benzilate binding. When soman or DFP was administered subcutaneously in high doses a severe AChE inhibition was obtained in iris without any concomitant miosis.     

Age-related variation in primary sexual characters in a passerine with male age-related fertilization success, the bluethroat Luscinia svecica

In passerine species with frequent extrapair mating, young (second calendar year) males often have a lower fertilization success than older (after second calendar year) males. This pattern might be explained by male- or female-driven mechanisms, such as female preference for older males or higher competitive ability of older males. In this study we measured the size of the testes, the seminal glomera and the cloacal protuberance as well as the size and motility of the sperm, in individual bluethroats Luscinia svecica . In this species, nearly all extrapair fertilizations (EPFs) are obtained by older males. We found that the mass of the testes and the seminal glomera were highly positively correlated and that older males had significantly larger testes (38%), seminal glomera (15%) and cloacal protuberance (23%) than young males. In contrast, there was no difference between age groups in average sperm size or sperm motility. Our results are consistent with the idea that higher fertilization success by older males in this species is due to their higher rate of sperm production, allowing larger ejaculates and/or more frequent copulations. Unequal sperm production capacities by young and older males have important implications for the interpretation of paternity patterns in extrapair mating systems.     

Anaerobic column chromatography in the presence of detergents and its application to a bacterial HCN-producing enzyme

An easy method to deoxygenize protein or detergent containing buffer solutions by stirring and sparge flushing with an inert gas is described. The deoxygenation of buffers and the establishment of anaerobic conditions in a column chromatography system was followed continuously with an oxygen electrode at the outlet. All polyethylene tubes were placed inside stainless steel tubes and the interspace flushed with nitrogen. A peristalic pump with silicone rubber tubing, mounted in a small plastic box, was likewise flushed with nitrogen. By this method a very unstable cyanide-producing enzyme preparation, solubilized with Triton X-100 from a Pseudomonas species, could be fractionated on a phenyl Sepharose CL-4B column without loss of activity.     

Compost heaps — refuges and stepping-stones for alien arthropod species in northern Europe

Abstract.  Compost heaps house a species-rich fauna of arthropods. This survey reviews changes in the composition of the beetle fauna in compost heaps in the Nordic countries during the 20th century. A total of 34 alien beetle species have established in compost heaps; 12 of these are also established in natural habitats. A combination of long-distance human transport and short-distance natural spread are proposed as dominant factors, explaining the dispersal of the species. An eastern route of immigration is proposed for Baeocrara japonica , Lithocharis nigriceps , Bohemiella paradoxa , Acrotona pseudotenera and Oxytelus migrator , while a southern route of immigration is proposed for Perigona nigriceps , Acrotona parens , Falagrioma concinna , Trichiusa immigrata , Cartodere nodifer , Ahasverus advena , Oryctes nasicornis and Atheta triangulum. There is no relationship between the types of compost preferred by the different species and the dominant way of dispersal. Among the trophic guilds that species belong to, the predators are more dependent on human transport than natural dispersal. The trophic guild to which a species belongs has no effect on whether or not the species is established away from compost heaps. The generalized compost fauna and species associated with bark compost naturalize away from compost heaps more successfully than expected. It is hypothesized that the successful establishment of alien species in compost habitats results from increased frequency of introductions and warm, thermal stability in large compost heaps during the Nordic winter. The establishment of new species in compost habitats probably has a minor impact on native inhabitants.     

Plasma renin activity and serum aldosterone during prolonged physical strain. The significance of sleep and energy deprivation

Plasma renin activity (PRA), serum aldosterone and the serum and urinary levels of sodium and potassium have been investigated in 24 young men participating in a 5-day military training course with heavy continuous physical exercise, energy and sleep deprivation. The subjects were divided into three groups. Group 1 did not get any extra sleep or food, group 2 were compensated for the energy deficiency, and group 3 slept 3 h each night. The basic diet given to all the subjects was about 5,000 kJ and 2 g NaCl X 24 h-1 X cadet-1. The high calorie diet contained approximately 25,000-35,000 kJ and 20 g of NaCl X 24 h-1 X cadet-1. The study showed that serum aldosterone and PRA were extremely activated during such prolonged physical strain combined with lack of food and salt, whereas sleep deprivation did not seem to have any large influence. Only small variations were found in the serum levels of sodium and potassium and the urinary level of potassium during the course, whereas a decrease was seen in urinary sodium concentration. The fairly good correlations between the decrease in urinary sodium levels and the increase in PRA (r = 0.7) and further between PRA and serum aldosterone (r = 0.8) during the course indicate that there is a causal connection between the decrease in urinary sodium excretion and the increase in PRA and serum aldosterone.(ABSTRACT TRUNCATED AT 250 WORDS)     

QUANTITATIVE HISTOCHEMISTRY OF GLUTAMATE DECARBOXYLASE IN THE RAT HIPPOCAMPAL REGION

Abstract— The distribution of glutamate decarboxylase (GAD) was studied in hippocampus regio superior and in area dentata. In both regions the enzyme showed a bimodal distribution profile with peak activities in the molecular and pyramidal layers of hippocampus, and in the molecular and granular layers of area dentata. The pyramidal and granular layers contain the terminals and perikarya of inhibitory intrinsic neurones, the basket cells. The molecular layers contain neurones of similar morphology but with unknown function. GAD showed a very low activity in fimbria, a major pathway of fibres efferent and afferent to the hippocampal region.
The data are consistent with GAD being concentrated within the inhibitory local neurones of the hippocampal region.