ACTH response induced by interleukin-1 is mediated by CRF secretion stimulated by hypothalamic PGE

Summary We investigated whether hypothalamic prostaglandin E₂ (PGE₂) and corticotropin releasing factor (CRF) are responsible for the development of the adrenocorticotropic hormone (ACTH) response induced by interleukin-1 (IL-1). The present results show that ACTH responses induced by intravenous injection of IL-1 were suppressed by systemic pretreatment with indomethacin and that intrahypothalamic injection of PGE₂ stimulates the secretion of ACTH. Furthermore, systemic pretreatment with anti-CRF antibody significantly suppressed the ACTH response induced by intrahypothalamic injection of PGE₂. These data suggest that the ACTH response induced by IL-1 is mediated by CRF secretion stimulated by hypothalamic PGE₂.     

ACTH response induced by interleukin-1 is mediated by CRF secretion stimulated by hypothalamic PGE

We investigated whether hypothalamic prostaglandin E2 (PGE2) and corticotropin releasing factor (CRF) are responsible for the development of the adrenocorticotropic hormone (ACTH) response induced by interleukin-1 alpha (IL-1 alpha). The present results show that ACTH responses induced by intravenous injection of IL-1 alpha were suppressed by systemic pretreatment with indomethacin and that intrahypothalamic injection of PGE2 stimulates the secretion of ACTH. Furthermore, systemic pretreatment with anti-CRF antibody significantly suppressed the ACTH response induced by intrahypothalamic injection of PGE2. These data suggest that the ACTH response induced by IL-1 is mediated by CRF secretion stimulated by hypothalamic PGE2.     

Modification by levo-propranolol of tremors induced by harmine in mice

It has been recently reported that the levo isomer of propranolol possesses anti-serotonin properties in animals. Since harmine-induced behavioural changes in mice are reported to be mediated through central serotonergic receptors, an attempt was made to test whether 1-propranolol would also modify harmine-induced responses by virtue of its anti-serotonergic or anti-adrenergic property. The results indicated that l- and dl-propranolol inhibited central serotonin receptor mediated responses to harmine in mice, a finding that is analogous to other recent observations.     

Modification by levo-propranolol of tremors induced by harmine in mice

Summary It has been recently reported that the levo isomer of propranolol possesses anti-serotonin properties in animals. Since harmine-induced behavioural changes in mice are reported to be mediated through central serotonergic receptors, an attempt was made to test whether 1-propranolol would also modify harmine-induced responses by virtue of its antiserotonergic or anti-adrenergic property. The results indicated that 1- and dl-propranolol inhibited central serotonin receptor mediated responses to harmine in mice, a finding that is analogous to other recent observations.     

Degradation by phytohemagglutinin of the antiviral state induced by interferon]

Phytohaemagglutinin (PHA M and P forms), when added to L 929 cells previously treated by murine interferon, degrades the antiviral state and restores virus sensitivity in the cells. This degradation depends on the amount of the lectin, the contact period with the cell and the presence of PHA membrane receptors. The importance of membrane configuration not only in the induction but also in the maintenance of the antiviral state is discussed.     

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.     

Enhanced depressor reflex by stimulation of superior cervical ganglion and by propranolol

Summary The systemic depressor reflex in cats evoked by inflation of an intrasinusal balloon is enhanced by stimulation of the superior cervical ganglion and by close infusion of 20g/ml/min of (d, 1) propranolol.This work was supported by grant No. 22600-1 NIH, Heart, Lung and Blood Institute, Bethesda, MD.     

Regulation of mycorrhizal infection by hormonal factors produced by hosts and fungi

Summary An overview of current research on hormonal factors produced by plants and fungi in mycorrhizal associations is presented. On the one hand, growth hormones in roots and their exudates influence the metabolism and growth of fungi. On the other, fungal hormones influence root morphology, metabolic changes and the growth of the entire plant.     

Oxidation of vanillin by cream xanthine oxidase and its inhibition by allopurinol

Zusammenfassung Es wird gezeigt, dass Vanillin durch Xanthinoxydase oxydiert und dass diese Reaktion durch Allopurinol gehemmt wird.     

Circling behavior induced by phencyclidine in mice and its inhibition by naloxone

Summary Phencyclidine (PCP), when given to mice, induces general hyperactivity and rapid circling, similar to that caused by morphine. These effects are partially antagonized by naloxone.Acknowledgment. We are grateful to Professor A. Kalir for the donation of PCP. Correspondence and reprint requests should be addressed to A. M. Korczyn.     

The in vivo membrane potential change by light and by reducing agents

Zusammenfassung Das Aktionsspektrum der lichtabhängigen Potentialänderung entspricht dem von Photosystem II. Mit Entkopplern kann die Beteiligung einer Phosphorylierungsstelle ausgeschlossen werden. Die Redox-Abhängigkeit weist auf die Beteiligung von Plastochinon. Die Depolarisierung des Membranpotentials kann sowohl durch Licht als auch durch reduziertes DCPIP+Ferricyanid im Dunkeln ausgelöst werden.     

Glycosaminoglycan synthesis by embryonic fibroblasts is age-dependent and modulated by environmental factors

Summary The glycosaminoglycans (GAG) secreted by primary fibroblasts cultures removed from chick embryo skin after 7 and 14 days of incubation have been investigated. Differences in GAG composition have been detected, depending on age and on the composition of the nutrient medium. This study was supported in part by an Italian Ministero Publica Istruzione grant.     

H reflex depression by soleus sinusoidal stretching and facilitation by voluntary contraction

Résumé Les courbes de recrutement du réflexe H permettent d'exprimer de faÇon commode les phénomènes inhibiteurs et facilitateurs spinaux. Lorsque l'on associe la mobilisation de la cheville à une contraction volontaire de mÊme intensité, l'effet observé est égal à celui obtenu par la contraction volontaire seule. Ces résultats suggèrent que la contraction volontaire pourrait contrÔler le mécanisme inhibiteur mis en activité par les afférences musculaires.