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Synthesis of spiro[isobenzofuran-1(3H),4'-piperidines] as potential central nervous system agents. 4. Central nervous system depressants.

The synthesis of 1'-[3-(4-fluorobenzyoyl)propyl]-3-phenylspiro[isobenzofuran-1(3H),4'-piperidine] (2a) and eight halo and methoxy analogues is described. The compounds were generally more potent per os than chlorpromazine in the Sidman avoidance paradigm in rats and less potent than haloperido. 1'-[3-(4-Fluorobenzoyl)propyl]-3-(4-fluorophenyl)spiro[isobenzofuran-1(3H),4'-piperidine] (2e) approached the per os potency of haloperidol in this test and was shown to be active in inhibiting monkey avoidance also. Compound 2e was much less active than haloperidol in antagonizing apomorphine-induced emesis in dogs, apomorphine-induced stereotypy in rats, and amphetamine-induced circling in lesioned rats. This lack of nonselective, dopamine-receptor blocking effects makes 2e attrative as a potential neuroleptic.

Amphetamine

Modulation of electrical activity and cyclic nucleotide metabolism in molluscan nervous system by a peptide-containing nervous system extract.

A peptide-containing extract (PE) from Helix nervous system modifies the endogenous bursting pattern of electrical activity in Helix neurone F-1. This effect is similar to that induced in neuron F-1 by certain phosphodiesterase inhibitors and cAMP derivatives. The PE, and the vertebrate peptide hormones vasopressin and oxytocin, also cause an accumulation of cAMP in Helix ganglia in vitro. The factor in the PE which causes the cAMP accumulation is destroyed by Pronase, is lost on dialysis, and is stable to boiling. In all these respects it is identical to the factor which causes the change in neuronal electrical activity. The PE also stimulates adenylate cyclase activity in a crude membrane fraction prepared from Helix ganglion homogenates. This stimulation is abolished by prior dialysis of the PE, or pretreatment of the PE with pepsin, but is not affected by boiling of the PE. Pepsin-treated PE has no effect on electrical activity in neuron F-1. The adenylate cyclase-stimulating activity of the PE, like the factor which modifies neurone F-1 electrical activity, elutes in the void volume of a Sephadex G-10 column. The included volume of this column contains a factor which inhibits PE modification of neuronal electrical activity, and also inhibits both basal and PE-stimulated adenylate cyclase activity. The data are consistent with the possibility that cAMP mediates the effects of the PE on electrical activity in molluscan neurones.

Adenylyl Cyclases

[Dysautonomia and multi-systemic atrophy of the nervous system (Shy-Drager's syndrome)].

The clinical expressions of primary autonomic nervous system failure are more or less numerous, orthostatic hypotension being only one of them. Clinical analysis reveals 3 categories of manifestations: pure progressive dysautonomia, dysautonomia associated with Parkinson's disease, and dysautonomia associated with multiple system atrophy of the nervous system also known as Shy-Drager syndrome. Neuropathological studies show that lesions of the efferent autonomic nervous system (tractus intermediolateralis, sympathetic ganglia) are frequently associated with lesions of the central nervous system the role of which in dysautonomia is still imperfectly known. Lesions of the central nervous system may present as genuine Parkinson's disease with Lew bodies or as multiple systemic atrophy with its two best individualized aspects: striatonigral atrophy and olivopontocerebellar atrophy. These various neurological aspects have their counterpart in biochemical abnormalities, prognosis and response to treatment.

Aged

Immunocytochemical localization of rat peripheral nervous system myelin proteins: P2 protein is not a component of all peripheral nervous system myelin sheaths.

Specific antibodies have been developed against P1, P2, and P0 myelin proteins and were used to study the localization of these proteins in the rat peripheral nervous system. Both peripheral and central nervous system myelin sheaths contain P1 protein. P0 and P2 proteins are found exclusively in peripheral nervous system myelin sheaths. Antisera to P1 and P0 proteins stain all peripheral nervous system myelin sheaths uniformly. P2 protein is not a component of all peripheral nervous system myelin sheaths. In sheaths that do contain P2 protein, it is concentrated in the area of the Schmidt-Lanterman incisures.

Animals

The renin-angiotensin system and the central nervous system.

One of several factors affecting the secretion of renin by the kidneys is the sympathetic nervous system. The sympathetic input is excitatory and is mediated by beta-adrenergic receptors, which are probably located on the membranes of the juxtaglomerular cells. Stimulation of sympathetic areas in the medulla, midbrain and hypothalamus raises blood pressure and increases renin secretion, whereas stimulation of other parts of the hypothalamus decreases blood pressure and renin output. The centrally active alpha-adrenergic agonist clonidine decreases renin secretion, lowers blood pressure, inhibits ACTH and vasopressin secretion, and increases growth hormone secretion in dogs. The effects on ACTH and growth hormone are abolished by administration of phenoxybenzamine into the third ventricle, whereas the effect on blood pressure is abolished by administration of phenoxybenzamine in the fourth ventricle without any effect on the ACTH and growth hormone responses. Fourth ventricular phenoxybenzamine decreases but does not abolish the inhibitory effect of clonidine on renin secretion. Circulating angiotensin II acts on the brain via the area postrema to raise blood pressure and via the subfornical organ to increase water intake. Its effect on vasopressin secretion is debated. The brain contains a renin-like enzyme, converting enzyme, renin substrate, and angiotensin. There is debate about the nature and physiological significance of the angiotensin II-generating enzyme in the brain, and about the nature of the angiotensin I and angiotensin II that have been reported to be present in the central nervous system. However, injection of angiotensin II into the cerebral ventricles produces drinking, increased secretion of vasopressin and ACTH, and increased blood pressure. The same responses are produced by intraventricular renin. Angiotensin II also facilitates sympathetic discharge in the periphery, and the possibility that it exerts a similar action on the adrenergic neurons in the brain merits investigation.

Adrenocorticotropic Hormone

Electrostimulation of the nervous system for patients with demyelinating and degenerative diseases of the nervous system and vascular diseases of the extremities.

The results of electrostimulation of the spinal cord for symptoms other than that of pain are recorded in this publication. 50% of patients with multiple sclerosis, primary lateral sclerosis and hereditary spino-cerebellar disorders were observed to have enduring favourable changes in neurological function during the 15 to 27 months they have been followed. The patients who were the least severely disabled had the greatest amount of increased function and were benefitted the most by the stimulation. Those who had the fewest neurological pathways affected make the most rapid progress. For example, the patient with only an ataxic or spastic gait was observed to improve faster than the patient with an ataxic and a spastic gait. The long-term effect of electrostimulation of the spinal cord on patients with these diseases is unknown at the present time. The purpose of the stimulation is to increase neurological function so that the patient can live a better life style. It is not thought that the electrical current is responsible for a 'cure' of the basic disease process. Electrostimulation of the posterior spinal roots and spinal cord, while not new, has not been used extensively for the treatment of patients with arterial disease. The patients who have responded the most dramatically to electrostimulation are those with vasospastic disorders. A larger percentage of patients showed a greater response to implanted stimulation than to transcutaneous stimulation. Electrostimulation of the nervous system is not designed to replace standard therapeutic measures of treatment of patients with vascular disease but to supplement them.

Ataxia

The influence of captopril on the epinephrine response to insulin-induced hypoglycemia in humans. The interaction between the renin-angiotensin system and the sympathetic nervous system.

The aim of this study was to assess whether an interaction exists between the renin-angiotensin system and the sympathetic nervous system at the level of the adrenal medulla during insulin-induced hypoglycemia in normal humans. Seventeen healthy volunteers were studied in a randomized, single-dose, double-blind, cross-over fashion using 25 mg captopril v placebo followed by an intravenous injection of 0.15 IU/kg insulin. Blood samples were obtained before and at 15 min intervals after insulin injection. Both plasma glucose level and heart rate were identical during captopril and placebo at rest and after insulin. Plasma renin activity increased after insulin and captopril. The increase in plasma epinephrine was lower after insulin and captopril compared to after insulin and placebo. Likewise the increase in plasma norepinephrine was blunted on insulin and captopril. Thus, when the generation of angiotensin II was blocked by captopril the insulin-induced rise in epinephrine and norepinephrine was blunted. This indicates that an interaction exists between the renin-angiotensin system and the sympathoadrenal system.

Adult

Embryonic development and organogenesis in the snail Marisa cornuarietis (Mesogastropoda: Ampullariidae). V. Development of the nervous system.

The nervous system is ectodermal in origin. All nerve ganglia arise separately by proliferation and later delamination from the ectoderm, not by invagination. They become secondarily connected to one another by commissures and connectives developing as extensions from the peripheral layer of ganglionic nerve cells. Rudiments of the cerebral, pedal, pleural and intestinal (parietal) ganglia arise almost simultaneously at a relatively early stage (Stage V). The cerebral ganglia develop from the ectoderm of the head plates. Rudiments of the pedal and pleural ganglia are separate at their inception. They later fuse (Stage VI) to form a pleuro-pedal ganglionic mass on each side. The 2 intestinal ganglia are symmetrical at the beginning, but they soon lose their symmetry as a result of torsion. The right ganglion crosses to the left over the gut and persists as the supraintestinal ganglion. The left or subintestinal ganglion shifts to the right and forward, and fuses with the right pleural ganglion (Stage VIII), thus obscuring the chiastoneury. The paired buccal and single visceral (abdominal) ganglia start differentiating in Stage VII. The former develop from the ectodermal wall of the stomodaeum, while the visceral ganglion delaminates from the right wall of the visceral sac, then shifts to the left during torsion. The statocysts develop early (Stage V) from 2 ectodermal invaginations on either side of the rudimentary foot. They later separate from the overlying ectoderm and statoconi appear in their lumina. Contrary to earlier reports on related ampullariids, the osphradium proved to be ontogenetically older than the mantle and mantle cavity. It starts differentiating as a thickened ectodermal plate in the right wall of the visceral sac (Stage V). During torsion, it becomes engulfed in the mantle cavity and shifts to the left side, then is carried forward as the mantlegrow. The eyes develop late (Stage IX) as ectodermal invaginations which rapidly separate from the ectoderm to form closed vesicles. Their cells start differentiating before hatching to form the retina, in which pigment is deposited, and the inner cornea. The lens is secreted in the lumen of the eye and grows by addition of concentric layers of secretion.

Animals

Nephrotoxic nephritis in rabbits. The role of the sympathetic nervous system.

The sympathetic nervous system and catecholamines play a major role in fibrin deposition in organs in rabbits after endotoxin administration. Glomerular fibrin deposition is also a key factor in the pathogenesis of nephrotoxic nephritis in rabbits, but the role of the sympathetic nervous system in this type of fibrin deposition has not been defined. We investigated sympathetic nervous system involvement in nephrotoxic nephritis using a model of isolated chemical sympathectomy with 6-hydroxydopamine. Different quantities of pooled nephrotoxic serum were injected intravenously into control and sympathectomized rabbits to produce a known spectrum of pathology in normal rabbits. Animals were killed and their organs were analyzed to ascertain that sympathectomy had been accomplished. Biochemical, immunohistologic, and histopathologic evaluation of the animals, comparing controls and sympathectomized rabbits, revealed no differences in the degree of renal damage for a given quantity of nephrotoxic serum. We conclude that, in the rabbit model, the sympathetic nervous system plays no significant role in the pathogenesis of fibrin deposition and glomerular damage in nephrotoxic nephritis.

Animals

The effects of convective cooling and rewarming on systemic and central nervous system physiology in isoflurane-anesthetized dogs.

Recent studies have demonstrated that small (i.e., 2-5 degrees C) reductions in temperature may protect the brain and spinal cord from ischemic injury. The present study evaluated the physiologic response of anesthetized animals to convective-based cooling and warming. Six shaved, isoflurane-anesthetized (1.50% end-expired; 1 MAC), pancuronium-paralyzed dogs were subjected to temperature manipulation. The flow of cool (13-14 degrees C) or warm (39-41 degrees C) air was uniformly applied to the the dorsal and lateral surfaces of the dog using an inflatable blanket with perforations in the interior surface. Convective cooling reduced pulmonary artery temperature (Tpa) from 37.0 +/- 0.2 degrees C (Mean +/- S.D.) to 33.0 +/- 0.0 degrees C over a 93 +/- 18 min period. Thereafter, the active cooling was discontinued and passive cooling resulted in a further reduction in Tpa to 32.4 +/- 0.3 degrees C over the next 60 min. Institution of convective warming resulted in an increase in Tpa from 32.4 +/- 0.3 to 33.0 +/- 0.0 degrees C in 23 +/- 14 min and from 33.0 to 37.0 +/- 0.0 in an additional 137 +/- 26 min. During the periods of active cooling, passive cooling and active warming, there were strong correlations between Tpa and temperature within the brain, cisterna magna, parietal epidural space, lumbar subarachnoid space and other commonly used temperature measurement sites non-invasively monitored (e.g. tympanic membrane, esophagus, rectum) r greater than or equal to 0.97; P less than 0.0001). The combination of isoflurane anesthesia (a potent EEG-suppressor) plus mild hypothermia (less than 34 degrees C) resulted in an EEG attenuation in five dogs, two of which progressed to burst suppression. The magnitude of EEG changes correlated with the degree of temperature reduction. Upon rewarming to 37 degrees C, all dogs had normal EEG activity and normal brain concentrations of high energy phosphates, glucose and lactate. Blood pressure and cardiac output did not change during the study and no dog exhibited acid-based anomalies or blood lactate accumulation. Whole body oxygen consumption and heart rate decreased in a temperature-dependent fashion. Cardiac rhythm disturbances were rare. The authors conclude that convection-based corporeal cooling and rewarming are efficacious methods for non-invasively and uniformly altering CNS temperatures without adversely affecting cerebral or systemic physiology.

Anesthesia

The VD1/RPD2 neuronal system in the central nervous system of the pond snail Lymnaea stagnalis studied by in situ hybridization and immunocytochemistry.

VD1 and RPD2 are two giant neuropeptidergic neurons in the central nervous system (CNS) of the pond snail Lymnaea stagnalis. We wished to determine whether other central neurons in the CNS of L. stagnalis express the VD1/RPD2 gene. To this end, in situ hybridization with the cDNA probe of the VD1/RPD2 gene and immunocytochemistry with antisera specific to VD1 and RPD2 (the alpha 1-antiserum, Mab4H5 and ALMA 6) and to R15 (the alpha 1 and 16-mer antisera) were performed on alternate tissue sections. A VD1/RPD2 neuronal system comprising three classes of neurons (A1-A3) was found. All neurons of the system express the gene. Division into classes is based on immunocytochemical characteristics. Class A1 neurons (VD1 and RPD2) immunoreact with the alpha 1-antiserum, Mab4H5 and ALMA 6. Class A2 neurons (1-5 small and 1-5 medium sized neurons in the visceral and right parietal ganglion, and two clusters of small neurons and 5 medium-sized neurons in the cerebral ganglia) immunoreact with the alpha 1-antiserum and Mab4H5, but not with ALMA 6. Class A3 neurons (3-4 medium-sized neurons and a cluster of 4-5 small neurons located in the pedal ganglion) immunoreact with the alpha 1-antiserum only. All neurons of the system are immunonegative to the R15 antisera. The observations suggest that the neurons of the VD1/RPD2 system produce different sets of neuropeptides. A group of approximately 15 neurons (class B), scattered in the ganglia, immunostained with one or more of the antisera, but did not react with the cDNA probe in in situ hybridization.

Adrenocorticotropic Hormone