The relative distribution of soluble and insoluble cholinesterases in rat excitable tissues

Summary Three ratios were studied here: bound to free AChE (R₁), bound to free BChE (R₂), and the ratios between these two (R₃). The first one proved relevant in that it contributed to the division of the cholinergic tissues into 3 classes: high values (nicotinic tissues: skeletal muscle), low values(muscarinic tissues: small intestine, uterus, heart), and middle values (mixed, nicotinic and muscarinic cholinergic innervation:brain). The third ratio (R₃) showed different values in the muscarinic tissues studied; no significant differences could, however, be found between the ratios of brain and skeletal muscle. Further exploration of this ratio should indicate whether it is of some importance for the characterization of excitable tissues.     

An assay for dopamine-β-hydroxylase activity in tissues and serum

Zusammenfassung Eine isotopische Methode zur Bestimmung der DH-Aktivität wird beschrieben. Die Methode wurde verwendet zur Bestimmung der DH-Aktivität im menschlichen Serum und in verschiedenen Organen der Ratte. Das sympatische Nervensystem des Menschens kann mit dieser Methode weiter erforscht werden.

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This work was supported by USPHS Grant No. 5 R01 MH-02717-12.     

Construction of a PO2 microelectrode for use in small blood vessels

Summary The construction of a Clark-type PO₂ electrode is described. The electrode has a tip diameter of less than 0.4 mm and a 95% response time of about 2 sec.     

Amylase activity in laboratory animal serum and tissues

Riassunto Si è studiato il tasso amilasico nel siero di vari animali, nonchè nelle ghiandole salivari e nel fegato di ratto. L'amilasi sierica non varia significativamente nel ratto privo delle ghiandole salivari o di 2/3 del fegato.     

Distribution of polyamine oxidase activity in rat tissues and subcellular fractions

The activity of polyamine oxidase (PAO) in rat tissues, and its subcellular distribution, were assayed using a simple polarographic method. The highest PAO activity was measured in the liver and the lowest in the skeletal muscle. In liver, kidney and uterus the highest specific PAO activity was found in the light mitochondrial fraction. PAO was not found in the microsomal fraction except in the kidney.     

Monoamine oxidase activity in tissues of spontaneously hypertensive rats

Summary Monoamine oxidase (MAO) activity was assayed both in central and peripheral blood vessels of spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar Kyoto rats (WKR). The activity of MAO in the brain and peripheral vasculature was essentially the same in both SHR and WKR. It can therefore be concluded that central and peripheral vascular MAO activity is not altered in the genetically hypertensive animals.     

The measurement of transketolase activity in heart preparations

Zusammenfassung Methodenvergleich zur Transketolase-Analyse in Rattenherzen. Die neue Methode benützt als Substrat Hydroxypyruvat und Erythrose-4-Phosphat und bestimmt das Verhältnis der Transketolaseaktivität an der Bildung von Fructose-6-Phosphat. Der Wechsel der Myocard-Transketolaseaktivität während Hypertrophie wird beschrieben.

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M.G.C. acknowledges the support of an Imperial Chemical Industries of Australia and New Zealand Postgraduate Fellowship. J.F.W. and J.B.H. acknowledge the financial support of the National Heart Foundation of Australia and J.F.W. acknowledges the financial support of the Australian Research Grants Committee. G.K. is a Postgraduate Medical Scholar of the National Heart Foundation of Australia.     

Lysozyme activity in female genital tissues of normal and genetically lysozyme-deficient rabbits

The internal genitalia of female normal rabbits and mutant lysozyme-deficient rabbits, which lack genetically the leukocytic isozyme of lysozyme, were assayed for lysozyme activity. The ovaries, uteri, and vaginas of the lysozyme-deficient rabbits had less than 20% of the lysozyme activity of normals. The oviducts, and in particular the caudal portions of the oviducts, had lysozyme activities up to 71% of the levels in normals. These observations suggest that the lysozymes of oviduct and leukocytes of rabbits are under the control of different genes.     

Gonadotrophin-releasing activity of histones H2A and H2B

We report that histones H2A and H2B possess gonadotrophin-releasing activity in vitro and assess the signal transduction pathways involved in these effects. Perifused and incubated rat anterior pituitary (AP) cells were used, and luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by RIA. Perifusion of cells with histone H2A (30 μM) or histone H2B (30 μM), markedly stimulated LH release but failed to elicit any FSH response. Cells incubated with 6 or 30 μM histone H2A showed a dose- and time-dependent stimulatory effect on both LH and FSH release which was blocked by 1 μM peptide MB35, an 86–120 amino acid fragment of histone H2A. Incubation of pituitary cells with gonadotrophin-releasing hormone (GnRH) and histones H2A or H2B showed a stimulatory effect on LH and FSH release which was similar to the sum of the separate effects. Trifluoperazine, as well as ethylene glycol bis(b-aminoethyl ether) N,N,N′,N′-tetraacetic acid (EGTA), alone or in the presence of the calcium ionophore A23187, significantly reduced the response of AP cells to histones. Various cyclic adenosine monophosphate (cAMP) enhancers had no effect on histone-stimulated release of gonadotrophins in incubated AP cells. Our results confirm previous evidence that histones may act as hypophysiotrophic signals. Calcium- and diacylglycerol-associated pathways, but not cAMP, appear to participate in these effects. Received 11 August 1997; received after revision 20 January 1998; accepted 26 January 1998     

Lysozyme activity in female genital tissues of normal and genetically lysozyme-deficient rabbits

Summary The internal genitalia of female normal rabbits and mutant lysozyme-deficient rabbits, which lack genetically the leukocytic isozyme of lysozyme, were assayed for lysozyme activity. The ovaries, uteri, and vaginas of the lysozyme-deficient rabbits had less than 20% of the lysozyme activity of normals. The oviducts, and in particular the caudal portions of the oviducts, had lysozyme activities up to 71% of the levels in normal. These observations suggest that the lysozymes of oviduct and leukocytes of rabbits are under the control of different genes.Supported in part by grants RR00515, RR05465, K04-RR00003, and T32-GM07160 from the National Institutes of Health. We acknowledge the excellent technical assistance of LeeAndra Froseth.     

Distribution of polyamine oxidase activity in rat tissues and subcellular fractions.

The activity of polyamine oxidase (PAO) in rat tissues, and its subcellular distribution, were assayed using a simple polarographic method. The highest PAO activity was measured in the liver and the lowest in the skeletal muscle. In liver, kidney and uterus the highest specific PAO activity was found in the light mitochondrial fraction. PAO was not found in the microsomal fraction except in the kidney.     

Glutaminase I activity in guinea pig and rabbit liver and kidney tissues

Zusammenfassung Aktive Glutaminase I wurde in Meerschweinchen- und Kaninchenleber, in Nierengewebsextrakten und in Mitochondrienpräparaten der erwähnten Organe bei pH 7,2 nachgewiesen.dl-Glutaminsäure bewirkte eine ausgesprochene Hemmung des Enzyms nach Zusatz von Phosphat. In hypertonischer Sukrosenährlösung lässt sich eine Aktivierung durch Phosphatzusatz gewöhnlich nicht nachweisen, selbst nicht beim pH-Optimum 7,2, es sei denn bei sehr hohen Phosphatkonzentrationen.     

Effect of X-irradiation on phosphorylase activity in tissues of pregnant mice

Résumé Les niveaux de phosphorylase du foie et du placenta maternels oscillent, mais chez les souris, ceux du foie foetal augmentent constamment pendant la grossesse. L'effet des rayons X sur la phosphorylase du foie foetal est relativement plus élevé.     

Technical note about simultaneous recording of oxygen partial pressure and neuronal activity in cat cortex

Summary A method is described for simultaneous measurements of pO₂ and action potentials with microelectrodes using prefabricated gold wires. The construction and measuring with such gold electrodes is easier than with traditionally used platinum electrodes. Single electrode recording is done with a specially adapted electronic circuit, allowing the separation of both signals (pO₂ and action potentials. A measurement in cat brain illustrates this procedure.