On the metabolism of prostaglandins by rat brain homogenate

Summary Using radio-immuno assays for prostaglandins and prostaglandin metabolites, three prostaglandin metabolizing enzymes were found in the 100,000×g supernatant of rat brain, 15-hydroxy-prostaglandin-dehydrogenase, ¹³ and prostaglandin E-9-keto-reductase. Specific activity of the latter enzyme was highest in striatum and midbrain and lowest in cortex, cerebellum and spinal cord.This work was supported by the Deutsche Forschungsgemeinschaft (SFB No. 70).     

Development of tolerance to the antinociceptive effect of morphine after intraventricular injection

Zusammenfassung Die Entwicklung von Toleranz bei der Hemmung nociceptiver Reaktionen (Leckreaktion und Flexorreflex am Kaninchen) nach fortgesetzter intraventrikulärer und systemischer Morphininjektion wurde vergleichend untersucht. Beide Reaktionen entwickeln bei beiden Applikationsweisen des Morphins eine ähnliche Toleranz, obwohl im Fall des Flexorreflexes die Schaltstellen des Reflexbogens im Rückenmark nur von geringen Morphinkonzentrationen erreicht werden.     

Inter omental-cerebral vascularization induced by omental graft to the rat brain

Summary The omentum of 13 rats were removed from the abdomen and placed directly on the brain. 5–14 days later the omentum and the underlying brain were joined by numerous vascular anastomoses in 9 rats. The purpose of this work was to study the use of omentum to establish extracranial vascularization of the brain.Supported by funds from Grant RR 514 from the Jefferson Medical College General Research Fund.     

Aggressive behaviour induced by marihuana compounds and amphetamine in rats previously made dependent on morphine

Résumé Les rats soumis à la morphine ont été traités pendant la phase d'abstinence avec des injections i.p. d'amphéta mine et (–) ⁹-trans-tätrahydrocannabinol.

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With a fellowship from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). We are very grateful to Prof.J. Ribeiro do Valle, Escola Paulista de Medicina, for the generous supply of THC.     

Radiation induced avoidance behavior transfer by brain extracts of mice

Zusammenfassung In «naiven» Mäusen werden Verhaltensveränderungen nach Injektion kleiner Mengen von Gehirnmaterial aus Saccharin bevorzugenden und röntgenbestrahlten Mäusen beobachtet. Es trat Vermeidung der Saccharinlösung ein, und zwar ähnlich wie sonst in «trainierten», Saccharin bevorzugenden Tieren nach der Bestrahlung.     

Formation of lipoperoxide in brain edema induced by cold injury

Zusammenfassung Biochemische Untersuchung zur Frage der Membranschädigung bei experimentellem Hirnödem: Lipoperoxid tritt 12 h nach der Traumatisierung in der höchsten Konzentration auf, was pathogenetisch bedeutungsvoll sein könnte.     

Inhibition by tetanus and botulinum A toxin of the release of [3H]noradrenaline and [3H]GABA from rat brain homogenate

Rat brain homogenate was preloaded with [3H]noradrenaline or [3H]GABA and stimulated with high K+. Tetanus toxin and botulinum A neurotoxin partially prevent the evoked [3H]noradrenaline release in the same range of toxin concentrations starting below 10(-10) M. In contrast, release of gamma-amino butyric acid (GABA) is much more sensitive to tetanus than to botulinum A toxin.     

Inhibition by tetanus and botulinum A toxin of the release of [3H]noradrenaline and [3H]GABA from rat brain homogenate

Summary Rat brain homogenate was preloaded with [³H]noradrenaline or [³H]GABA and stimulated with high K⁺. Tetanus toxin and botulinum A neurotoxin partially prevent the evoked [³H]noradrenaline release in the same range of toxin concentrations starting below 10^–10M. In contrast, release of -amino butyric acid (GABA) is much more sensitive to tetanus than to botulinum A toxin.     

Changes in electrical activity of the cockroachBlatta orientalis L. brain induced by anti-lobster brain antibody

Zusammenfassung Bei mit Langustenhirn immunisierten Kaninchen werden Anti-Hirn-Antikörper gebildet. Werden diese auf die Hirnoberfläche der SchabeBlatta orientalis L. gebracht, so kommt es zu erheblichen Veränderungen in der elektrischen Hirntätigkeit des Insekts.     

Feeding induced by blockade of histamine H1-receptor in rat brain

Summary Histamine antagonists were infused into the third ventricle of the cerebrum in rats. All the H₁-, but none of the H₂-antagonists tested, induced initial feeding during the early portion of the light phase when histamine level was highest. No periprandial drinking was observed. Ambulation increased during feeding. The effect on feeding was attenuated when brain histamine was normally low during the early portion of the dark phase, or was decreased by -fluoromethylhistidine. Hypothalamic neuronal histamine may suppress food intake through H₁-receptors, and diurnal fluctuations of food intake may mirror neuronal histamine levels.     

Feeding induced by blockade of histamine H1-receptor in rat brain

Histamine antagonists were infused into the third ventricle of the cerebrum in rats. All the H1-, but none of the H2-antagonists tested, induced initial feeding during the early portion of the light phase when histamine level was highest. No periprandial drinking was observed. Ambulation increased during feeding. The effect on feeding was attenuated when brain histamine was normally low during the early portion of the dark phase, or was decreased by alpha-fluoromethylhistidine. Hypothalamic neuronal histamine may suppress food intake through H1-receptors, and diurnal fluctuations of food intake may mirror neuronal histamine levels.     

The effects of acute and chronic morphine on regional distribution of cardiac output in brain

Both acute and chronic administration of morphine resulted in an increase in the percent cardiac output received by brain. However, various brain regions were affected differently by the drug treatments. The greatest increases in percent cardiac output received after chronic administration of morphine occurred in pons and cerebellum, while the greatest increases after acute administration occurred in cortex and midbrain. The changes found are in contrast with earlier studies which suggest that morphine has no effect on cerebral blood flow.     

Lack of pyrogenic tolerance transmission between brain and periphery in the rabbit

Successive injections of lipopolysaccharide (LPS) either intravenously (i.v.) or intracerebroventricularly (i.c.v.) induced pyrogenic tolerance to LPS in rabbits. Tolerance was shown by a decrease of the magnitude of the fever response to repeated doses of LPS, irrespective of the route of pyrogen administration. A significantly greater and more dramatic decrease of the fever index, however, was observed in rabbits made tolerant to pyrogen given i.v. than when the pyrogen was given i.c.v. Transmission of the pyrogenic tolerance between brain and peripheral tissues, however, has not been ascertained.     

Lack of pyrogenic tolerance transmission between brain and periphery in the rabbit

Summary Successive injections of lipopolysaccharide (LPS) either intravenously (i.v.) or intracerebroventricularly (i.c.v.) induced pyrogenic tolerance to LPS in rabbits. Tolerance was shown by a decrease of the magnitude of the fever response to repeated doses of LPS, irrespective of the route of pyrogen administration. A significantly greater and more dramatic decrease of the fever index, however, was observed in rabbits made tolerant to pyrogen given i.v. than when the pyrogen was given i.c.v. Transmission of the pyrogenic toleraance between brain and peripheral tissues, however, has not been ascertained.