Biomedical subjects

A Tamás

Publications and source records attributed to A Tamás.

14 recordsLinked to original sources

PubMed2006

Effect of PACAP in 6-OHDA-induced injury of the substantia nigra in intact young and ovariectomized female rats.

Pituitary adenylate cyclase activating polypeptide (PACAP) has neuroprotective effects in various neuronal cultures and in models of brain pathologies in vivo. Among others, it protects dopaminergic neurons in vitro, against 6-OHDA- and rotenone-induced injury. Recently, we have shown that PACAP reduces dopaminergic cell loss and ameliorates behavioral outcome following unilateral 6-OHDA-induced injury of the substantia nigra in male rats. However, after castration, PACAP led only to a slight amelioration of the behavioral symptoms. The aim of the present study was to investigate the degree of neuroprotection exerted by PACAP in female rats, using the same model. It was found that PACAP had no effect on the dopaminergic cell loss in intact female rats, only caused amelioration of certain acute behavioral signs. In contrast, PACAP effectively increased dopaminergic cell survival and decreased behavioral deficits in ovariectomized females. These results indicate that the neuroprotective effect of PACAP in a rat model of Parkinson's disease is gender-specific.

Adrenergic Agents↗

PubMed2006

Effects of systemic PACAP treatment in monosodium glutamate-induced behavioral changes and retinal degeneration.

The present article investigated effects of systemic pituitary adenylate cyclase-activating polypeptide (PACAP) treatment in monosodium glutamate (MSG)-induced retinal degeneration and neurobehavioral alterations in neonatal rats. It was found that the dose of PACAP that effectively enhances neurobehavioral development in normal rats was able to counteract the retarding effect of MSG on righting, forelimb placing, and grasp reflexes and caused a significant amelioration of the righting and gait reflex performance and motor coordination at 2 weeks of age. In the retina, significant amelioration of neuronal loss in the inner retinal layers was achieved, but it was much less than that observed by local administration.

Animals↗

PubMed2006

Comparative study of the effects of PACAP in young, aging, and castrated males in a rat model of Parkinson's disease.

We have previously shown that PACAP ameliorates the neurological symptoms and reduces the dopaminergic cell loss in young male rats, in a 6-hydroxydopamine (6-OHDA)-induced lesion of the substantia nigra, a model of Parkinson's disease. In the present study, we compared the effects of PACAP in young, aging, and castrated males. Our results show that PACAP significantly reduced the dopaminergic cell loss in young and aging males. In castrated males, 6-OHDA did not induce such a severe cell loss, and it was not altered by PACAP. However, PACAP effectively ameliorated behavioral symptoms in all groups, with a degree of recovery depending on age and endocrine status.

Aging↗

PubMed2006

Protective effects of PACAP in excitotoxic striatal lesion.

The present article investigated the effects of pituitary adenylate cyclase-activating polypeptide (PACAP) treatment in a quinolinic acid (QA)-induced unilateral lesion of the striatum, a model of Huntington;s disease (HD). PACAP was given locally, preceding the lesion. Behavioral analysis was performed after 1, 10, and 30 days, when motor activity and asymmetrical signs were evaluated. Three weeks after the treatment, a catalepsy test was performed by haloperidol administration, and finally histological assessment of the striatum was done. Our results show that PACAP treatment attenuated the behavioral deficits and reduced the number of lesioned neurons in the striatum.

Animals↗

PubMed2005

Pituitary adenylate cyclase activating polypeptide protects cardiomyocytes against oxidative stress-induced apoptosis.

Pituitary adenylate cyclase activating polypeptide (PACAP) has well-known neuroprotective effects, and one of the main factors leading to neuroprotection seems to be its anti-apoptotic effects. The peptide and its receptors are present also in the heart, but whether PACAP can be protective in cardiomyocytes, is not known. Therefore, the aim of the present study was to investigate the effects of PACAP on oxidative stress-induced apoptosis in cardiomyocytes. Our results show that PACAP increased cell viability by attenuating H2O2-induced apoptosis in a cardiac myocyte culture. PACAP also decreased caspase-3 activity and increased the expression of the anti-apoptotic markers Bcl-2 and phospho-Bad. These effects of PACAP were counteracted by the PACAP antagonist PACAP6-38. In summary, our results show that PACAP is able to attenuate oxidative stress-induced cardiomyocyte apoptosis.

Animals↗

PubMed2003

Examination of sensorimotor performance following middle cerebral artery occlusion in rats.

Middle cerebral artery occlusion (MCAO) in rats is the most commonly used stroke model. Besides the infarct size, assessment of sensorimotor performance has become increasingly important in neuroprotective drug research. However, contradictions exist about procedures for testing functional outcome following MCAO. The aim of the present study was to evaluate a relatively simple set of neurological tests based on the most commonly used scoring systems, and to describe the functional recovery and correlation with the infarct size in rats sacrificed 2 or 14 days after permanent or transient MCAO. The smaller infarct size of rats with transient occlusion was reflected in the neurological scores only during the first 6h. By day 14, no recovery occurred in postural signs, lateral resistance and spontaneous activity, other signs showed different degrees of recovery. Correlation with the infarct size was found only on certain days in gait disturbance, placing reactions, daily body weight and spontaneous activity. According to our observations, the most commonly used sensorimotor tests provide a useful initial screening of functional deficits, but these tests most probably measure deficits caused by infarction of the core area. It is suggested that these tests should be completed by more refined tests when testing a neuroprotective drug which reduces the infarct size in penumbral areas.

Animals↗

PubMed2002

Effects of pretreatment with PACAP on the infarct size and functional outcome in rat permanent focal cerebral ischemia.

PACAP exerts neuroprotective effects under various neurotoxic conditions in vitro. In vivo, it reduces brain damage after global and transient focal ischemia. The present study investigated whether PACAP has neuroprotective effects when applied before the onset of permanent ischemia. Rats were given bolus injections of PACAP38 intracerebroventricularly, and then underwent permanent middle cerebral artery occlusion. The results show that 2 microg of PACAP significantly reduced the infarct size measured 12 and 24h after the onset of ischemia. No further reduction was obtained by a 7-day pretreatment. PACAP also ameliorated certain sensorimotor deficits. Our present study provides further evidence for the neuroprotective effects of PACAP, and implies that it might be a promising preventive therapeutic agent in ameliorating ischemic brain damage.

Animals↗

PubMed1982