Differential effects of lipids on the osmotic fragility of lysosomes

Summary The effect of a wide range of concentrations of oleic acid, oleyl alcohol and oleic acid methyl ester on lysosomal stability has been studied under both hypotonic and isoosmotic medium conditions. Both oleic acid and oleyl alcohol exhibited a biphasic interaction pattern with lysosomes; stabilizing at low concentrations and labilizing at high concentrations. Lysosome labilization by the ester required an initial lag period.Acknowledgment. We should like to thank Mr.David Ginzburg for the assistance he gave us during the 3 months he spent at our department as a summer student.     

The osmotic fragility of thrombocytes of laboratory animals

Zusammenfassung Die osmotische Resistenz von Thrombozyten fünf verschiedener Tierarten wurde untersucht und mit der osmotischen Resistenz menschlicher Thrombozyten verglichen. Ein Zusammenhang zwischen der osmotischen Resistenz der Thrombozyten und Erythrozyten der gleichen Tierart konnte gezeigt werden.     

The influence of bee venom on the osmotic fragility of human red blood cells

Résumé Le venin des abeilles augmente la réfraction osmotique des globules rouges du sang humain. Il divise la population cellulaire en 2 groupes de réfraction osmotique. Ces 2 groupes semblent représenter les globules rouges «jeunes» et «vieux». La courbe obtenue peut servir de test spécifique révélant l'action du venin des abeilles sur le sang.     

Effect of acetylcholine on the osmotic fragility of papain-treated and untreated human red blood cells

Résumé L'hémolyse des globules rouges, incubés avec de fortes concentrations d'acétylcholine en conditions isotoniques est due à l'acide acétique libéré dans le milieu. Cette hémolyse est complètement inhibée par l'inactivation de l'acétylcholinestérase érythrocytaire avec la papaïne.

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This work was supported by research grant No. 151-1-31 of the Research Committee of Bar-Ilan University.     

Studies on lysosomes in rat heart cell cultures. II. The effect of exogenous lysosomes

Zusammenfassung Isolierte Lysosomen wie auch intakte Monozyten hatten keinen zytopathischen Einfluss auf Herzmuskelzellen von Ratten, gezüchtet im Medium mit pH 7,2. Ein erniedrigtes Medium wie auch Nachbehandlungen der Kulturen mit Vitamin A nach Chlorpromazin 10^–4 konnten keinen synergistisch zerstörenden Einfluss auf die Herzkulturen hervorrufen.

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Supported by Grant No. HE-05739 from the National Institutes of Health, U.S. Public Health Service.     

The effects of hydrocortisone and glycyrrhizine on the enzyme releases of arylsulfatase and hyaluronidase from lysosomes of liver

Summary Hydrocortisone and glycyrrhizine act as both stabilizers and labilizers of the lysosomes of liver. The effect of both agents on the lysosomes is changeable according to the duration of their administration.     

The effects of hydrocortisone and glycyrrhizine on the enzyme releases of arylsulfatase and hyaluronidase from lysosomes of liver

Hydrocortisone and glycyrrhizine act as both stabilizers and labilizers of the lysosomes of liver. The effect of both agents on the lysosomes is changeable according to the duration of their administration.     

Differential effects of ethanol on prostaglandin responses of arterial and venous smooth muscles.

The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF2alpha on at least 2 different types of vascular smooth muscle. At the very least, the present findings question that the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.     

ACTH: Differential effects on avoidance and discrimination

Zusammenfassung Andauernde ACTH-Behandlung beeinflusst sowohl Vermeidungs- als auch Fehlerkomponenten im Zweiwahl-Y-Labyrinthtest. Die Einwirkungen waren von der Intensität des Elektroschocks wie auch von der Reaktionsfähigkeit der Tiere abhängig.

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This work was supported by Medical Research Council Grant No. MA 1746. Some of the work was done while the first author held a pre-doctoral terminal year grant from the USPHS and while the second author held a Research Career Award from the Canadian Association for Retarded Children. We are indebted toSusanna Kertesz for help in running the subjects in these studies. Requests for reprints should be sent to Dr.J. A. Corson, Allan Memorial Institute, 1033 Pine Avenue West, Montreal 112 (P.Q., Canada).     

Prostaglandin-like substances in Propionibacterium acnes. III. Differential contractile effects on smooth muscle layers of the human utero-tubal junction.

The biological activity of a lipid fraction extracted from P. acnes was tested on isolated smooth muscle strips from the human utero-tubal junction. The bioassay experiments support the concept that prostaglandin-like substances (PLS) occur in P. acnes. However, in the bioassay system used, the effect of PLS was different from that of PGF2 alpha and PGI2 but similar, although not identical, to that of arachidonic acid and PGE2.     

Differential effects of the serotonin receptors on cultured rat cerebral cortical neurons

Effects of serotonin (5-HT) on cerebral cortical neurons were examined by patch clamp techniques. 5-HT produced a variety of responses such as outward (19/73 patches/neurons), slow inward (15/73 patches/neurons), fast inward (8/73 patches/neurons), and mixed currents (initially fast inward deflection followed by an outward response: 2/73 patches/neurons), with a latency of 12 sec, 15 sec, 0 sec, and 0 sec respectively, at a holding potential of −60 mV in whole-cell patches. The fast inward currents were again evoked by a selective 5-HT3 receptor agonist, 1-(m-chlorophenyl)-biguanide hydrochloride (CPBG). In the cell-attached patch clamp configuration, 5-HT inside the patch pipette elicited single channel currents with slope conductances of 42 pS and 132 pS (4/42 patches/neurons). CPBG inside the patch pipette evoked inward single channel currents with a lower slope conductance of 41 pS (3/23 patches/neurons). In contrast, application of 5-HT or a 5-HT₂ receptor agonist, α-methyl-5-hydroxytryptamine-maleate, outside the patch pipette induced outward single channel currents with a major slope conductance of 140 pS (8/30 patches/neurons) or 135 pS (6/20 patches/neurons), respectively. These results indicate that the outward and fast inward currents may be mediated respectively by the 5-HT₂ receptor, which is coupled to a G-protein, and by the 5-HT₃ receptor, which contains the non-selective cation channel, and that the mixed type may be caused by both the 5-HT₂ and 5-HT₃ receptors. Received 27 September 1996; received after revision 4 November 1996; accepted 7 November 1996     

The demonstration of lysosomes in the bovine adrenal medulla

Zusammenfassung Die Gomori-Reaktion für saure Phosphatase wurde an Nebennierenmarkschnitten von Rindern durchgeführt. Ihre elektronenmikroskopische Untersuchung ergab die Lokalisierung der Enzymaktivität in den Lysosomen. Chromaffine Granula und Mitochondrien zeigten keine Aktivität.     

Differential effects of ethanol on prostaglandin responses of arterial and venous smooth muscle

Summary The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF₂ on at least 2 different types of vascular smooth muscle. At the very least, the present findings question the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.Supported by NIH grant No. HL-18015 and NIMH grant No. MH-26236. The authors are indebted to Dr.John E. Pike and Dr.John Babcock of the Upjohn Company for generously providing us with the PGF₂ used in this study.     

Differential effects of monastrol in two human cell lines

The kinesin-related protein HsEg5 plays essential roles in mitotic spindle dynamics. Although inhibition of HsEg5 has been suggested as an aid in cancer treatment, the effects of such inhibition on human cells have not been characterized. Here we studied the effects of monastrol, an allosteric HsEg5 inhibitor, on AGS and HT29 cell lines and compared them to those of taxol. While both cell lines were similarly sensitive to taxol, AGS cells were more sensitive to monastrol. The differences in sensitivity were determined by the degree of inhibitory effect on cell proliferation, reversibility of monastrol-induced G2/M arrest, intracellular phenotypes and induction of apoptosis. In both cell lines, monastrol-induced apoptosis was accompanied by mitochondrial membrane depolarization and poly-ADP-ribose polymerase 1 cleavage. In AGS, but not HT29 cells, monastrol-induced apoptosis involved a prominent cleavage of procaspases 8 and 3. While in AGS cells, monastrol induced the formation of symmetric microtubule asters only, in HT29 cells, asymmetric asters were also formed, which may be related to specific HsEg5 functions in HT29 cells.Received 18 February 2004; received after revision 30 May 2004; accepted 16 June 2004     

The effect of ultraviolet light (UVL) on the lysosomes of hairless mouse epidermis

Summary An increased release of acid phosphatase from the lysosomes of UVL irradiated hairless mouse epidermis is demonstrated. The results indicate that lysosomal membrane stability is decreased when the hairless mouse is exposed to either acute or chronic UVL.Acknowledgments. The authors would like to thank Miss Gail Brown for technical assistance. This research was supported in part by the Morrison Trust, San Antonio, Texas, and USPHS, grant CA-13464-04, from the NCI.