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Biomedical subjects

C L Broekkamp

Publications and source records attributed to C L Broekkamp.

79 records · Page 5Linked to original sources
PubMed1975

The effect of microinjections of morphine and haloperidol into the neostriatum and the nucleus accumbens on self-stimulation behaviour.

The effect of stereotaxic injections of morphine and haloperidol via permanently implanted cannulas into the neostriatum, the nucleus accumbens or the ventricular system was studied on self-stimulation behaviour of rats with electrodes implanted into the ventral tegmentum. The self-stimulation rate was depressed by injections of haloperidol into the neostriatum or into the nucleus accumbens. Unilateral injections of haloperidol into the neostriatum depressed the self-stimulation rate either with applications ipsilateral to the electrode or contralateral to the electrode. Bilateral applications of haloperidol into the neostriatum (2 X 2.5 mug) were more effective as unilateral applications (5 mug) and were more effective as applications into the ventricular system (5 mug). Morphine had a strong depressant action on self-stimulation when applied into the ventricular system and was ineffective when applied into the neostriatum. It is concluded that these results do not favour the hypothesis that morphine interferes with dopaminergic transmission with the neostriatum.

Animals↗
PubMedDate not supplied

Acceleration of recovery from sciatic nerve damage by the ACTH (4-9) analog Org 2766: different routes of administration.

Functional recovery following a sciatic nerve crush in rats was investigated by measuring the reflex withdrawal of the hindpaw to a hot air stream. The ACTH(4-9) analog Org 2766 accelerated recovery when administered subcutaneously (two-daily injections: 10 micrograms/animal; minipumps: 20-40 micrograms/animal per 24 hr: biodegradable microspheres: 40 micrograms/animal per 24 hr), but oral administration (1.5-20 mg/animal daily, in the drinking water; 1.5-15 mg/animal daily, by gavage) was not effective.

Administration, Oral↗
PubMedDate not supplied

Locus coeruleus and substantia nigra: involvement in morphine-induced behavior.

Cats pretreated with morphine (5 mg/kg, IP) received naloxone into the area of the locus coeruleus (LC) or the area of the substantia nigra (SN). The LC-treated animals stopped the morphine-induced stereotyped behavior and showed normal but hyperactive behavior. The SN-treated animals, however, ceased their movements of the head and the forelegs, adopted a rigid posture with extended forelegs and became hypoactive. It is concluded that both the LC area, which contains noradrenergic cell bodies, and the SN area, which contains dopaminergic cell bodies, are sites of action of morphine on behavior.

Animals↗
PubMedDate not supplied

Pharmacological evaluation of in vivo tests for alpha 2-adrenoceptor blockade in the central nervous system and the effects of the enantiomers of mianserin and its aza-analog ORG 3770.

A series of compounds with actions on the central nervous system was tested for antagonism of clonidine-induced sleep in chicks and clonidine-induced mydriasis in rats for the purpose of evaluating these methods as tests for demonstrating an in vivo alpha 2-adrenoceptor blocking effect of a novel compound. Clonidine-induced mydriasis was found to be the most selective method. The order of potency for compounds fully antagonizing clonidine-induced mydriasis was MSD 26 greater than physostigmine = idazoxan greater than aptazapine greater than piperoxan greater than yohimbine greater than mianserin greater than tolazoline. Partial antagonism was found for quipazine and sulpiride. Misleading results can arise from the involvement of cholinergic mechanisms in the control of the pupil diameter. The order of potency for compounds antagonizing clonidine-induced sleep in chicks was apomorphine greater than yohimbine greater than idazoxan greater than aptazapine = MSD 26 greater than quipazine greater than methysergide greater than piperoxan = mianserin = bepridil = metergoline = cyproheptadine = desipramine greater than tolazoline greater than dexchlorpheniramine, although antagonism was not complete for all of these compounds. Misleading results can arise from effects on arousal of the chicks but cholinergic mechanisms do not play a disturbing role so that the method with chicks can be a useful supplement to the mydriasis method. The enantiomers of mianserin and of a compound related to mianserin, Org 3770, were tested in the 2 methods and the alpha 2-blocking effect of these compounds was found to be residing in the S(+)-enantiomers.

Adrenergic alpha-Antagonists↗