Somatostatin inhibits in vitro release of luteinizing hormone releasing hormone from rat mediobasal hypothalamic slices

Summary Somatostatin, in concentrations ranging from 10^–10 M to 10^–7 M, induces a dose-dependent inhibition of LHRH release from mediobasal hypothalamic slices incubated in vitro. In contrast, VIP, secretin, glucagon, substance P, neurotensin and arginine-vasotocin do not affect spontaneous release of LHRH.     

On the structure of the natural dipeptide N-acetyl-aspartyl-glutamic acid (NAAGA)

Riassunto Si descrive la sintesi dei due dipeptidi isomeri acido N-acetil--l-aspartil-l-glutammico (I) e acido N-acetil--l-aspartil-l-glutammico (II). Il loro confronto con il NAAGA, dipeptide precedentemente isolato dal tessuto nervoso di alcuni mammiferi, ha dimostrato l'identità del nuovo metabolita con il-dipeptide (II).     

Comparison of rat,mouse, guinea-pig and human slow reacting substance of anaphylaxis (SRS-A)

Summary Slow reacting substance of anaphylaxis obtained from rat, mouse, guinea-pig and human tissues have exhibited similar biological activity and have reacted in the same way to chemical and enzymatic treatments. It is concluded that they appear to be the same substance or a similar class of compounds.Acknowledgments. The authors are grateful to Le Conseil de Recherche en Santé du Québec and to Fisons Ltd for financial support. This work was also partly supported by a grant to the late Dr R. P. Orange from the Medical Research Council of Canada (MT-4605).     

Size ofTrichinella spiralis (nematoda) muscle cysts in the rat,mouse and guinea-pig

Zusammenfassung Bei Ratte, Maus und Meerschweinchen ist die Grösse der Muskelzysten vonTrichinella spiralis 60 Tage nach standardisierter experimenteller Infektion bestimmt worden. Die Grösse der Muskelzysten variierte bei jeder der 3 untersuchten Tierarten erheblich. Bei der Ratte wurden durchschnittlich grössere Muskelzysten vonT. spiralis gefunden als bei der Maus, bei der die Muskelzysten wiederum durchschschnittlich grösser waren als beim Meerschweinchen. Die Zystengrösse vonT. spiralis scheint demnach vom Stoffwechsel der jeweils als Wirt dienenden Tierart abhängig zu sein.     

Evidence of urinary glomerular basement membrane (GBM) antigens excretion in 3 rodents (rat, mouse, and guinea-pig) (author's transl)]

Immunodiffusion technique, with rabbits antibodies against rat glomerular basement membrane (GBM), permits to evidence the presence of GBM antigens into normal urines of 3 rodents (rat, mouse, and guinea-pig). These results confirm the earlier works in human and rabbit urines and show the antigenic communauty existing between the 3 rodents GBM, since we can evidence antigens of 3 different mammals with the same antibody. The origin and the nature of this patterns and the signification of this presence into mammalian urines are discussed.     

Sulfhydryl oxidation induces calcium release from fragmented sarcoplasmic reticulum even in the presence of glutathione

Alcian blue and plumbagin induced transient Ca²⁺ release from fragmented sarcoplasmic reticulum. Dithiothreitol (DTT) and glutathione (GSH) partially blocked Ca²⁺ release induced by these oxidizing compounds. Pretreatment of alcian blue and plumbagin with DTT or GSH for more than 1 min was required to abolish the ability of the oxidizing compounds to release Ca²⁺. Mg²⁺ and ruthenium red completely blocked alcian blue-and plumbagin-induced Ca²⁺ release. These results suggest that oxidation of sulfhydryls on Ca²⁺ release channels induces Ca²⁺ release even in the presence of GSH in situ.     

Somatostatin reduces the release of colony-stimulating activity (CSA) from PHA-activated mouse spleen lymphocytes

Summary PHA-activated lymphocytes release colony-stimulating activity (CSA) for macrophage-granulocyte precursor cells (colony forming units, CFU_C) in the culture medium. Somatostatin, known to interfer with ribosomal protein synthesis, was demonstrated to reduce the release of CSA from PHA-treated mouse spleen lymphocytes.The technical assistance of Ulrike Wallner and Paulette Bais is thankfully acknowledged.     

Light evoked release of radioactivity from rabbit retinas preloaded with (3H)-GABA

Summary Light flashes evoke an increased release of radioactivity in vitro from rabbit retinas preloaded with (³H)-GABA in vivo. Constant light does not affect the release. No light evoked release can be demonstrated from the glia. Pentobarbitone and AOAA depress the evoked release. The results are consistent with GABA being a retinal neurotransmitter, most likely in a class of amacrines.This work was supported by grants from the Swedish Medical Research Council (project 04X2321), The Faculty of Medicine, University of Lund, Royal Physiographic Society.     

Somatostatin reduces the release of colony-stimulating activity (CSA) from PHA-activated mouse spleen lymphocytes.

PHA-activated lymphocytes release colony-stimulating activity (CSA) for macrophage-granulocyte precursor cells (colony forming units, CFUc) in the culture medium. Somatostatin, known to interfer with ribosomal protein synthesis, was demonstrated to reduce the release of CSA from PHA-treated mouse spleen lymphocytes.     

The effect of N-(2-hydroxyethyl)-palmitamide on delayed hypersensitivity in guinea-pig

Zusammenfassung Die Wirkung von N-(2-hydroxyethyl)palmitamid auf den Verlauf der Überempfindlichkeit des Spättypes in Meerschweinchen wurde verfolgt und festgestellt, dass die Verabreichung dieses Stoffes vor der Sensibilisierung eine Stimulation der Hypersensitivität bewirkt.     

Spikes of smooth muscle in calcium-free solution (isolated taenia coli of the guinea-pig)

Zusammenfassung An der glatten Darmmuskulatur (Taenia coli) des Meerschweinchens konnten nach völligem Entzug von Kalzium (und Magnesium) aus der Nährlösung über lange Zeit Spikes gemessen werden. Diese kalziumfreien Spikes werden, im Gegensatz zu den Spikes unter normalen Bedingungen, durch Tetrodotoxin 10^–5 blockiert, und sie werden wie die normalen Spikes mit 100fach niedrigerer Schwelle durch Manganionen blockiert. Es wird angenommen, daß Na-Ionen die für diese Spikes verantwortlichen Ladungsträger sind.

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This work was supported by a grant from the Deutsche Forschungsgemeinschaft (No. Go 130/7).     

Assessment of superoxide-mediated release of vascular-inhibitory factor(s) from endothelial cells by using a two-bath system

Summary Release of a vascular-inhibitory factor from endothelial cells (EC), different from endothelium-derived relaxant factor (EDRF), was identified through use of a two-bath system. This two-bath system precluded the effects of oxygen-free radicals that appear when electrical field stimulation (EFS) is directly imposed on detector muscle.     

Comparison of rat, mouse, guinea-pig and human slow reacting substance of anaphylaxis (SRS-A).

Slow reacting substance of anaphylaxis obtained from rat, mouse, guinea-pig and human tissues have exhibited similar biological activity and have reacted in the same way to chemical and enzymatic treatments. It is concluded that they appear to be the same substance or a similar class of compounds.     

Assessment of superoxide-mediated release of vascular-inhibitory factor(s) from endothelial cells by using a two-bath system

Release of a vascular-inhibitory factor from endothelial cells (EC), different from endothelium-derived relaxant factor (EDRF), was identified through use of a two-bath system. This two-bath system precluded the effects of oxygen-free radicals that appear when electrical field stimulation (EFS) is directly imposed on detector muscle.     

Intracerebroventricular injection of cerebrospinal fluid (CSF) from a patient with congenital indifference to pain induces analgesia in rats

Summary CSF from a patient with congential indifference to pain was found to produce analgesia in the rat following intracerebroventricular injections. The analgesic effect was attenuated by pretreatment with naloxone suggesting the involvement of hyperactive endogenous opiate mechanisms in this patient.