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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Utilizing audiogenic seizure-prone P77PMC rats, the effects of cholecystokinin octapeptide (CCK-8) on genetic seizure susceptibility were studied in vivo, in cerebral cortical synaptosomes, and in cortical neuronal cell cultures. The results showed that CCK-8 could decrease seizure susceptibility, and that the K(+)-stimulated release of GABA in cerebral cortex synaptosomes from seizure-prone animals was depressed. The presence of exogenous CCK-8 (10(-7) M) together with elevated K+ (25 mM) causes a higher increased magnitude in GABA release from synaptosomes (enhanced by 100%) and cell cultures (17 days in vitro, increased by 177%) derived from seizure-prone rats than the controls (increased by 42%, in synaptosomes; and 107% in cell cultures). These preliminary results raise the possibility that the developmental abnormalities in modulation effect of CCK-8 on GABA release in central nervous system may play a role causing greater seizure susceptibility in genetic seizure-prone rats. The analysis of the brain tissue level and gene-expression of CCK-8 will be the important step of further investigation.
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PMID:Effects of cholecystokinin octapeptide on genetically determined seizure susceptibility. 159 69

Recent studies have demonstrated that the regulation of neuropeptide expression in forebrain neurons is responsive to external influences including changes in physiological activity. This has been demonstrated most clearly in studies of hippocampus where the synthesis and resting levels of several neuropeptides, localized within well-characterized components of hippocampal circuitry, have been shown to be selectively influenced by seizure activity. In studies described here, we examined the influence of recurrent limbic seizures on the expression of enkephalin, dynorphin, cholecystokinin, and neuropeptide Y (NPY) in rat and mouse hippocampus using immunohistochemical, in situ hybridization and blot hybridization techniques. The data demonstrate that seizures differentially influence the expression of each peptide as a part of a broader cascade of changes in genomic expression within individual hippocampal neurons. In particular, seizures increase preproenkephalin mRNA and enkephalin peptide but decrease dynorphin peptide in the dentate gyrus granule cell/mossy fiber system. Seizure-induced decreases in the concentration of preprodynorphin mRNA in the granule cells have been reported by others. Immunoreactivity for CCK, which is codistributed with the opioid peptides in the mossy fiber system of mouse, is also dramatically reduced in the granule cell axons by seizure. Recurrent seizures induce two temporally distinct changes in NPY expression in hippocampus. First, there is an increase in hybridization to preproNPY mRNA within scattered, probable local circuit neurons in all subfields. This is followed by the seemingly novel appearance of preproNPY mRNA within the dentate gyrus granule cells and pyramidal cells of field CA1. Clues about mechanisms of neuropeptide regulation have come from observations of other, more rapid, transcriptional events induced by seizure. Most notably, our results and those of others demonstrate that seizures increase the expression of messenger RNAs from immediate-early genes (c-fos, c-jun, and NGFI-A) which encode proteins that may mediate neuropeptide gene regulation. In addition, mRNA for nerve growth factor is dramatically increased in the dentate gyrus granule cells by seizure; increased production of this trophic factor might mediate the more delayed changes in genomic expression and growth responses observed to occur in hippocampus and other forebrain areas following seizure activity.
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PMID:Seizures, neuropeptide regulation, and mRNA expression in the hippocampus. 220 4

Electrolytic lesions of the dentate gyrus hilus have been demonstrated to induce behavioral seizure activity and to result in perturbations in the amount of enkephalin, cholecystokinin, and dynorphin immunoreactivity in the hippocampal mossy fiber system. In the present study, electroencephalographic (EEG) recordings, made from hippocampus contralateral to a hilus lesion in mouse, demonstrate the presence of recurrent hippocampal seizure activity which begins approximately one hour postlesion and continues for several hours thereafter. Behavioral seizures were found to correspond to periods of epileptiform hippocampal EEG. Immunocytochemical analyses of enkephalin-(ENK-I) and cholecystokinin-immunoreactivity (CCK-I) in contralateral hippocampus of animals sacrificed at various postlesion intervals revealed that both ENK-I and CCK-I were depleted from the mossy fibers at 6 and 12 hr postlesion, and that ENK-I rebounded to supranormal levels by 27 hr. In two animals sacrificed 60 days following lesions which induced extreme behavioral seizure activity, ENK-I was still elevated while CCK-I was completely absent from the mossy fiber system. These data suggest that heightened physiological activity, in the form of recurrent limbic seizures, induces long-lasting but quite different alterations in enkephalin and CCK concentration in the hippocampal mossy fiber system.
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PMID:Focal hippocampal lesions induce seizures and long-lasting changes in mossy fiber enkephalin and CCK immunoreactivity. 285 53

It has been shown in the behavioural experiments that combined pretreatment with haloperidol (0.25 mg/kg) and caerulein (40 micrograms/kg), and to a lesser extent pretreatment with caerulein alone caused long-term reversal of amphetamine (2 mg/kg) induced hyperexcitability in rats. Administration of proglumide (50 mg/kg), an antagonist of CCK-8 receptors, did not reverse long-term antiamphetamine effect of caerulein. In mice pretreatment with caerulein (50 and 100 micrograms/kg) alone or in combination with haloperidol (0.25 mg/kg) caused hypersensitivity to the behavioural effect of amphetamine (3 mg/kg). Intraventricular (I ng), but not systemic (100-500 micrograms/kg) administration of caerulein selectively antagonized seizures in mice induced by intraventricular administration of quinolinic acid (5 micrograms) and N-methyl-D-aspartate (0.2 microgram). Pretreatment with proglumide (50 mg/kg) reversed the anticonvulsive effect of caerulein in mice. In rats, caerulein failed to affect the seizures caused by intraventricular administration of quinolinic acid. The results of the present study demonstrate the existence of obvious interspecies differences in the behavioural effects of caerulein, the agonist of CCK-8 receptors, in mice and rats.
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PMID:[Species differences in the behavioral effects of cerulein--an agonist of the receptors of the octapeptide cholecystokinin--in white mice and rats]. 334 45

A tabular synopsis is presented for articles concerned with the effects of peptides on the central nervous system that appeared in the journal Peptides from 1980-1985. A table arranged alphabetically by peptide and one arranged by effects, both listing routes of injection, species, direction of change, and qualifying notes, provides easy cross-referencing of peptides and their effects. Over 80 peptides and over 135 effects are listed. The list of peptides includes, but is not limited to: ACTH, angiotensin, bombesin, bradykinin, calcitonin, casomorphin, CCK, ceruletide, CGRP, CRF, dermorphin, DSIP, dynorphin, endorphins, enkephalins, GRF, gastrin, LHRH, litorin, metkephamid, MIF-l, motilin, MSH, NPY, NT, oxytocin, ranatensin, sauvagine, substances P and K, somatostatin, TRH, VIP, vasopressin, and vasotocin. The list of effects includes, but is not limited to: aggression, alcohol, analgesia, attention, avoidance, behavior, cardiovascular regulation, catalepsy, conditioned behavior, convulsions, dopamine binding and metabolism, discrimination, drinking, EEG, exploration, feeding, fever, gastric secretion, GI motility, grooming, learning, locomotor behavior, mating, memory, neuronal activity, open field, operant behavior, rearing, respiration, satiety, scratching, seizure, sleep, stereotypy, temperature, thermoregulation and tolerance.
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PMID:Central nervous system effects of peptides, 1980-1985: a cross-listing of peptides and their central actions from the first six years of the journal Peptides. 353 8

The effects of several doses of cholecystokinin octapeptide sulphate ester (CCK-8-SE) and nonsulphated cholecystokinin octapeptide (CCK-8-NS), and two CCK-related peptide analogues Ac-Thr5-caerulein, and nonsulphated Ac-Thr5-caerulein were investigated on electroshock-(ES)-induced seizures after intraperitoneal administration in mice. As parameters, the duration of the tonic and clonic phase of the fit, and those of postictal coma and behavioural depression were measured. CCK-8-SE decreased the duration of the clonic phase; its highest dose, 3.2 mumol/kg, shortened the coma. CCK-8-NS antagonized only slightly the clonic phase of seizure. Ac-Thr5-caerulein did not influence ES-induced seizures in any dose, only increased the duration of behavioural depression. Similarly to CCK-8-NS, the nonsulphated form of Ac-Thr5-caerulein inhibited selectively the clonic phase of seizures. The reference drugs, diazepam and phenobarbital, antagonized dose-dependently and most effectively the tonic phase of ES-induced seizures, but in much higher doses than did the CCK-related peptides. Besides, diazepam increased and phenobarbital decreased the duration of postictal coma. The results showed that the tested CCK-related peptides inhibit prevalently the clonic phase of ES-induced seizures after peripheral administration.
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PMID:Inhibition of electroshock-induced seizures by cholecystokinin-related peptides in mice. 359 54

Pronounced changes in the content of cholecystokinin octapeptide (CCK-8) have been found after limbic seizures induced by i.p. injection of kainic acid. Three hours after injection of the toxin a significant decrease in CCK-8 was observed in the frontal cortex and amygdala/pyriform cortex reflecting an increased release during acute seizures. A persistent decrease in the content of the peptide in the amygdala/pyriform cortex suggests destruction of the respective neurons. In the substantia nigra and in the striatum and, more moderately, in the hippocampus and frontal cortex increases in CCK-8 were observed 10 days after injection of kainic acid suggesting an increased synthesis or decreased release of the peptide in these brain areas subsequently to the acute seizures.
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PMID:Increased brain levels of cholecystokinin octapeptide after kainic acid-induced seizures in the rat. 376 49

The dose-response curves for the anticonvulsive activity of sulfated and nonsulfated cholecystokinin octapeptide (CCK-8-SE and CCK-8-NS) against picrotoxin-induced (6 mg/kg SC) seizures were assessed either following or without pretreatment with a single high dose of CCK-8-SE or CCK-8-NS, to examine acute tolerance to the effect after IP injections in mice. As CCK-8-SE or CCK-8-NS pretreatment, a 1.6 mumole/kg dose was injected 2 hr prior to the second injection. No acute tolerance to the anticonvulsive activity was demonstrated, and CCK-8-NS pretreatment significantly potentiated its own anticonvulsive activity. Chronic (8-day) daily treatment with a 0.16 mumole/kg dose of CCK-8-SE or CCK-8-NS antagonized seizures by picrotoxin, presumably in a cumulative manner. To investigate the interactions of CCK octapeptides with other anticonvulsive agents, picrotoxin-induced seizures were antagonized with several doses of diazepam following or without acute, high-dose pretreatment with CCK-8-SE or CCK-8-NS. The two octapeptides only slightly modified the activity of diazepam: CCK-8-SE pretreatment displayed a tendency to antagonize it, while CCK-8-NS pretreatment to potentiate it. The results suggest that multiple treatment with CCK-8 induces sensitization of CCK receptors mediating anticonvulsive activity.
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PMID:Multiple treatment potentiates the anticonvulsive activity of cholecystokinin octapeptides. 383 11

The anticonvulsive activity of cholecystokinin octapeptide sulphate ester (CCK-8-SE), non-sulphated cholecystokinin octapeptide (CCK-8-NS) and three different N- and C-terminal fragments were investigated against seizures induced by picrotoxin and electroshock in rats after intracerebroventricular administration. Doses of 0.8 and 80 pmol of CCK-8-SE and CCK-8-NS significantly enhanced the latency of seizures induced by picrotoxin and shortened the duration of the clonic phase of the seizures induced by electroshock. Only CCK-8-SE shortened the recovery time and only 0.8 pmol of CCK-8-SE could shorten the duration of the tonic phase of convulsions induced by electroshock. Doses of the octapeptides of 8000 pmol were ineffective, with the exception of CCK-8-NS in the picrotoxin test. Of the fragments tested, the C-terminal tetrapeptide, CCK-5-8, enhanced the latency of seizures induced by picrotoxin in a dose of 0.8 pmol, and had a dose-dependent biphasic effect on the duration of the clonic phase of seizures induced by electroshock. Intracerebroventricular administration of diazepam enhanced only the latency of tremor and clonic seizures induced with picrotoxin in a dose of 40 nmol. Twelve nmole of diazepam shortened the clonic phase of convulsions induced by electroshock. The peptides tested were much more active than diazepam, and their effective doses were comparable to the amounts of cholecystokinin octapeptide found in brain structures.
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PMID:Inhibition of seizures induced by picrotoxin and electroshock by cholecystokinin octapeptides and their fragments in rats after intracerebroventricular administration. 609 Sep 68

Caerulein and the C-terminal octapeptide of cholecystokinin (CCK-8), after subcutaneous administration to mice, both delayed the onset and retarded the development of toxic effects of convulsants such as strychnine, pentetrazol, bicuculline, and picrotoxin. They also increased the seizure threshold doses of intravenously infused pentetrazol and picrotoxin. In this regard, both peptides were at least equipotent with diazepam.
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PMID:Anticonvulsant effects of careulein and cholecystokinin octapeptide, compared with those of diazepam. 624 26


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