The subcellular distribution of lysergic acid diethylamide in the rat brain

Résumé Quinze min après une injection i.p. de LSD, près de 48% de la drogue présente dans le cerveau fut trouvée dans le surnageant, 20% dans la fraction nucléaire, 15% dans la fraction synaptosomale, 6% dans la fraction microsomale, 5% dans la fraction myélinique et près de 1,7% dans la fraction mitochondriale. Les fractions synaptosomale et mitochondriale sont presque saturées en LSD lors d'une injection de 10 mg/kg de LSD.

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Acknowledgment. I thank Dr.J. Knopp for his help with the spectrophotoflourometric analysis.     

Correlation between brain blood flow and catecholamine levels in rat brain areas under hypobaric hypoxia

Summary Hypobaric hypoxia induces an important increase in the cerebral blood flow in all areas and more particularly in the bulb and hypothalamus; the increase in the cerebral blood flow allows for an oxygen intake sufficient to maintain the norepinephrine level in these structures.     

Regional blood flow antagonism induced by central thermal stimulation in the conscious dog

Zusammenfassung Am wachen Hund wurde bei selektiver thermischer Reizung von Rückenmark und Hypothalamus ein regionaler Durchblutungsantagonismus für das kutane und intestinale Gefässgebiet als thermoregulatorische Antwort nachgewiesen.     

Serotonin and 5-hydroxyindoleacetic acid concentrations in individual hypothalamic nuclei and other brain areas of rat

Summary Serotonin and 5-hydroxyindoleacetic acid (5-HIAA) were measured in individual nuclei of rat hypothalamus and other brain areas using HPLC with electrochemical detection. 5-HIAA levels were first demonstrated in hypothalamic and some discrete brain areas. The 5-HIAA/5-HT ratio was highest in the n. caudatus putamen, high in the n. ventromedialis and lowest in the n. suprachiasmaticus.     

High affinity binding of 5-hydroxytryptamine to some membrane preparations from cattle brain. Relationship to lysergic acid diethylamide (LSD)]

5 hydroxytryptamine binds to crude brain membrane preparations with two different affinities (KD = 1 to 2 X 10(-9) M for the highest, 1 to 2 X 10(-8) M for the lowest). LSD also binds with two affinities (KD = 3 to 4 X 10(-9) M and KD = 2 to 3 X 10(-8) M). Subcellular distribution of these sites shows that binding involves the two binding affinities in microsomal membranes but solely the high affinity binding sites are present in purified synaptosomal membranes. High affinity sites for 5 HT and for LSD are different as no direct competitive inhibition is observed in that case. On microsomal membranes, direct relationship occurs between low affinity binding for 5 HT and high affinity binding for LSD.     

Changes in plasma enzyme concentrations in response to blood substitution with perfluorocarbon emulsion in the conscious rat

The effects of near total blood replacement with the proprietary perfluorocarbon (PFC)-based emulsion, Fluosol-DA 20%, on plasma concentrations of 2 enzymes, lactate dehydrogeanse (LDH) and alkaline phosphatase (ALP), have been examined in conscious, chronically catheterized rats. A pronounced fall in both plasma LDH (p less than 0.05) an ALP (p less than 0.01) occurred in response to exchange-transfusion. However, at 6 h following blood replacement, plasma concentrations of both enzymes had risen to values significantly greater than those measured immediately before perfusion. The observed changes in plasma LDH and ALP after blood replacement with Fluosol-DA indicated alterations in normal functioning of tissues from which these enzymes originate.     

Changes in the liver protein pattern due to lysergic acid diethylamide (LSD)

Riassunto Mediante elettroforesi in fase libera è stato studiato il protiogramma epatico durante l'intossicazione con dietilamide dell'acido lisergico (LSD) nel ratto albino.Si sono osservate profonde modificazioni del quadro le quali sonto completamente reversibili.     

Dopamine and cerebral cortical blood flow in the rat

Summary Dopamine topically applied to the cerebral cortex (1–20 g/ml) or administered i.v. (0.5–64 g/kg/min) has no effects on cerebral cortical blood flow in the rat.     

Pre- and postnatal lead exposure affects the serotonergic system in the immature rat brain

Summary The effect of pre- and postnatal lead exposure on the development of the serotonergic system in striatum and brain stem was investigated. Serotonin and its metabolite 5-HIAA where determined by HPLC-EC. A significant decrease of 5-HT was detected in the brain stem at postnatal day 28. At both days 6 and 28 postnatal, 5-HIAA was reduced in striatum and brain stem. The results provide support to the hypothesis that developing 5-HT neurons are sensitive to relatively low levels of lead exposure.     

Evidence of catecholamine mediation in the ‘Aberrant’ behaviour induced by lysergic acid diethylamide (LSD) in the rat

Zusammenfassung Der Einfluss verschiedener Pharmaka auf das durch LSD hervorgerufene bizarre Verhalten der Ratte wurde untersucht. Die Resultate zeigen, dass - und -Blocker sowie -Methyltyrosine eine starke Hemmung dieses Verhaltens erzeugen, im Gegensatz zu den Serotonin-Antagonisten Deseril, BOL-148 und Parachlorphenylalaninen, die nur schwache oder keine Hemmung hervorrufen. Es wird gefolgert, dass das bizarre Verhalten durch Wirkung von LSD an Katecholaminstrukturen hervorgerufen wird. Die Wirkung von 4 psychotropen Pharmaka am bizarren Verhalten wird im Rahmen dieser Hypothese diskutiert.     

Pre- and postnatal lead exposure affects the serotonergic system in the immature rat brain.

The effect of pre- and postnatal lead exposure on the development of the serotonergic system in striatum and brain stem was investigated. Serotonin and its metabolite 5-HIAA where determined by HPLC-EC. A significant decrease of 5-HT was detected in the brain stem at postnatal day 28. At both days 6 and 28 postnatal, 5-HIAA was reduced in striatum and brain stem. The results provide support to the hypothesis that developing 5-HT neurons are sensitive to relatively low levels of lead exposure.     

Genetic functional inactivation of neuronal nitric oxide synthase affects stress-related Fos expression in specific brain regions

To identify neuronal substrates involved in NO/stress interactions we used Fos expression as a marker and examined the pattern of neuronal activation in response to swim stress in nNOS knock-out (nNOS–/–) and wild-type (WT) mice. Forced swimming enhanced Fos expression in WT and nNOS–/– mice in several brain regions, including cortical, limbic and hypothalamic regions. Differences in the Fos response between the two groups were observed in a limited set (6 out of 42) of these brain areas only: nNOS–/– mice displayed increased stressor-induced Fos expression in the medial amygdala, periventricular hypothalamic nucleus, supraoptic nucleus, CA1 field of the hippocampus, dentate gyrus and infralimbic cortex. No differences were observed in regions including the septum, central amygdala, periaqueductal grey and locus coeruleus. During forced swimming, nNOS–/– mice displayed reduced immobility duration, while no differences in general locomotor activity were observed between the groups in the home cage and during the open field test. The findings indicate that deletion of nNOS alters stress-coping ability during forced swimming and leads to an altered pattern of neuronal activation in response to this stressor in specific parts of the limbic system, hypothalamus and the medial prefrontal cortex.Received 29 March 2004; accepted 21 April 2004     

Very small microspheres are useful for the determination of cardiac output but not organ blood flow in conscious rabbits

Summary Very small microspheres with a diameter of 8–10 m can be used for the measurement of cardiac output, by the reference flow method, in conscious rabbits. However, they were found not to be suitable for the determination of the distribution of cardiac output or blood flow to most organs. These small microspheres offer certain advantages for the measurement of cardiac output; the numbers required to achieve a specified accuracy of measurement are discussed.     

Diurnal fluctuation in the rate of synthesis of a specific protein fraction in the rat brain

Summary A protein fraction has been identified in microsomes prepared from the rat hypothalamus whose rate of synthesis fluctuates diurnally in ovariectomized animals.     

Reversal of human ophthalmic vein blood flow : selective cooling of the brain]

Direction of blood flow in angularis oculi veins was recorded in humans. In mild hypothermia, blood flow was weak and directed from brain to face. In hyperthermia, however, blood flowed rapidly in the opposite direction, angularis oculi vein collecting cool facial blood and supplying cavernous sinus. Therefore selective cooling of human brain is possible.