Facilitation of the dorsal root potentials by volleys spreading caudally and cranially in the spinal cord.

Conditioning volleys spreading along 3 segments of the cord produce larger facilitation of bilateral dorsal root potentials in sacral cord than volleys in neighbouring dorsal roots used to evoke the testing depolarization. Contralateral potentials are more facilitated by volleys descending from lumbar than ascending from caudal segments.     

Effect of glucocorticoids on the appearance of gamma-glutamyl transpeptidase activity in primary cultures of adult rat hepatocytes

Primary cultures of adult rat liver parenchymal cells showed a progressive rise of gamma-glutamyl transpeptidase (GGT) activity (E.C. 2.3.2.2) after the first 5 days of culture. The presence of dexamethasone and other synthetic glucocorticoids in the culture medium partially prevented this increase.     

Factors affecting high-frequency fungal protoplast fusion

Summary Factors influencing the fusion frequency of protoplasts have been examined with auxotrophic mutants ofAspergillus nidulans. The optimum conditions were a total of 5 to 15 million protoplasts per ml, and 25% polyethylene glycol (PEG) 4000 or 6000 as fusogenic agent in 10 to 100 mM CaCl₂ solution.     

An escape phenomenon from water and sodium retention induced by propranolol in rats

Summary Rats given a daily dose of propranolol 45 mg/kg b.wt retain water and sodium for 4 days, escaping during the 5th and 6th days in which their excretions are larger than basal values. Afterwards, in the period studied, they make a new retention and clearing is less accentuated. No relationship could be found between these retentions and plasma renin activity or renal renin content.Acknowledgments. The authors thank Mrs Inmaculada Millás for excellent technical assistance and Maria Isabel Navajos for secretarial help.     

Prolongation of skin homograft survival by local intralymphatic radioisotope injections

Zusammenfassung Injektion von¹³¹I-Lipiodol oder¹¹¹Ag-Kolloid beim Kaninchen in ein Ohrlymphgefäss verzögert die Abstossung eines Hautlappen-Hormotransplantes am Ohre wesentlich. Bei der Untersuchung der Verteilung intralymphatisch verabreichter Radioisotopen in den einzelnen Geweben wurde festgestellt, dass etwa 50% des¹¹¹Ag-Kolloids, aber unter 10% des¹³¹I-Lipiodols von den regionären Lymphknoten aufgenommen wird und dass Lipiodol hauptsächlich im Lungengewebe, Ag-Kolloid in der Leber gespeichert wird.     

Recurrent inhibition of the monosynaptic reflex in the upper caudal cord of the cat.

In spinal cats both ipsi- and contralateral antidromic volleys in the 3rd sacral ventral roots produce recurrent inhibition of the monosynaptic reflex evoked by stimulation of the 1st caudal dorsal root and recorded from the corresponding ventral root.     

Regulation of lymphokine production in peripheral blood mononuclear cell cultures

Summary An increase in the production of macrophage migration inhibitory factor, chemotactic factor for neutrophils, and skin reactive factor, was observed in lymphocyte cultures if the cells were allowed to age in culture for 24 h. The increased lymphokine production was reduced by adding concanavalin A-stimulated and mitomycin C-treated suppressor cells. It is suggested that the lymphokine production could be regulated by suppressive mononuclear cells.This work was supported by the Scientific Research Council, Ministry of Health, Hungary (Code No. 421 0304011/S).     

Glutathione andγ -glutamyl cycle enzymes in rat mammary gland

Summary The main enzymes of theγ-glutamyl cycle during the lactogenic cycle in rat mammary gland were studied. A significant increase was found in all of them with the onset of lactogenesis. The effect of methionine sulfoximine on reduced glutathione concentration was studied in tissue slices of lactating mammary gland. The findings suggest that this compound affects glutathione synthesis by inhibitingγ-glutamylcysteine synthetase. This work was supported by grant B1138-8223 from the Servicio de Desarrollo Cientifico, Universidad de Chile.     

A novel xanthone as secondary metabolite fromCentaurium cachanlahuen

Summary From the plantCentaurium cachanlahuen, swertiaperenine1, swercherine2, decusatine4, oleanolic acid5 and the xanthone 1,8-dihydroxy-2,3,4,6-tetramethoxy-9H-xanthone3 were isolated and characterized.