Biomedical subjects

Z Hoły

Publications and source records attributed to Z Hoły.

9 recordsLinked to original sources

PubMed1998

The participation of nitric oxide in the facilitator effect of arginine vasopressin on memory.

In this study we tested the hypothesis that nitric oxide (NO), which function as a novel type of inter-cellular messenger in the central nervous system (CNS) participated in the facilitator effect of arginine vasopressin (AVP) on learning and memory. Recent investigations have provided evidences that inhibition of NO synthesis attenuated the vasodilatation caused by AVP, and inhibited the improvement of learning and memory evoked by angiotensin II. AVP as well as pharmacologically produced increase in endogenous NO facilitates the consolidation of shock avoidance learning. We evaluated the behavioural effects of AVP at dose 1 microgram after the inhibition of NOS by NG-nitro-L-arginine methyl ester (L-NAME) at dose 10 micrograms, and after the injection of endogenous donor of NO -L-arginine- 10 micrograms in the retrieval of passive avoidance situation, and in consolidation of active avoidance responses. The locomotor activity of all investigated drugs was tested in the open field test. AVP facilitated the recall of passive avoidance responses and consolidation of active avoidance responses. Neither the increase of NO concentration after the injection of L-arginine nor the decrease of NO after the inhibition of NOS by L-NAME changed the behavioural effects of AVP. L-arginine increased the psychomotor behaviour and L-NAME decreased the activity of animals in the "open field" test. L-arginine itself improved the consolidation of active avoidance responses. Our results indicate that central action of AVP is probably independent of NO concentration in the brain.

Animals↗

PubMed1998

Effects of sulfated cholecystokinin octapeptide and cholecystokinin tetrapeptide in rat behavior after blockade of nitric oxide synthase by L-NAME.

This study was conducted to determine what, if any, role L-NAME (inhibitor of nitric oxide synthase) plays in the behavioral effects induced by sulfated cholecystokinin octapeptide CCK-8) and cholecystokinin tetrapeptide (CCK-4) in adult male rats. The motility, stereotypy, anxiety, extinction of conditioned avoidance responses and recall of passive avoidance behavior were estimated. CCK-8 (but not CCK-4) injected intracerebroventricularly (icv) at the dose 0.1 nmole decreased of locomotor activity in the "open field" test. Administration of CCK-8 intensified stereotypy evoked by apomorphine (1 mg/kg, i.p.). The CCK-4 was ineffective in this test. Both, CCK-8 and CCK-4 did not make any significant differences in passive avoidance behavior. Examine the influence of CCK-8 and CCK-4 on the extinction of conditioned avoidance responses (CAR) proved that both peptide tended to facilitate extinction of CAR's. CCK-8 and CCK-4 induced anxiogenic-like effect in the elevated 'plus' maze behavior. Application of L-NAME alone (50 nmole,-icv) decreased of motility and stereotypy behavior in control rats. It was ineffective in a passive avoidance behavior and extinction of CAR's. In elevated 'plus' maze behavior injection of L-NAME, similarly to cholecystokinin, induced anxiogenic-like effect. L-NAME induced of motility decreases in the "open field" test were blocked by injection of CCK-8 and CCK-4. Our results indicate that observed behavioral activity of CCK-8 and CCK-4 (except of influence on motility) is probably independent of NO concentration in the brain.

Analysis of Variance↗

PubMed1996

Nitric oxide in learning and memory.

The role of nitric oxide in the central nervous system is described. The main part of this article concerns the problem of learning and memory.

Adaptation, Physiological↗

PubMed1996

Behavioural activity of angiotensin II (3-7)4Phe--analogue of natural fragment 3-7 of angiotensin II.

A study was made of the influence of pentapeptide 3-7 angiotensin II [AII(3-7)], its analogue 3-7(4)Phe [AII(3-7)4Phe] and angiotensin II (AII) on the behaviour of adult male rats. The motility, stereotypy, spatial performance, learning of conditioned and passive avoidance responses allowing to avoid aversive stimulation were estimated. Examined peptides at the dose 1 nmol injected intracerebroventricularly 15 min before the experiment did not produce specific changes in psychomotor activity in the "open field" test and in retention of the spatial task in the Morris water maze. The rate of acquisition of conditioned avoidance responses was stimulated by AII(3-7)4Phe, AII(3-7) and AII administration. In the passive avoidance situation AII improved retention of the responses whereas analogue AII(3-7)4Phe and fragment 3-7 caused similar though less pronounced effect. All the peptides applied immediately before the experiment intensified stereotypy, a behaviour evoked by of apomorphine-1 mg/kg and amphetamine-7.5 mg/kg intraperitonealy injection. These results show similar psychotropic activity of analogue AII(3-7)4Phe, comparable with the activity of natural fragment 3-7 of angiotensin II.

Analysis of Variance↗

PubMed1995

Influence of sodium nitroprusside "NO-donor" on psychotropic activity of angiotensin II.

In this work we compared the influence of sodium nitroprusside [SNP] (a NO donor) on behavioural effects of angiotensin II [AII] in rats. The motility, stereotypy, learning of conditioned avoidance responses and recall of passive avoidance behaviour allowing to avoid aversive stimulation were estimated. The intracerebroventricularly injection--15 min before the experiment--of AII, SNP and AII combined with SNP did not produce changes in psychomotor activity in open field, not significantly accelerated acquisition of conditioned avoidance responses and significantly improved recall of the passive avoidance. AII, SNP and AII with SNP applied immediately before the experiment intensified stereotypy evoked by apomorphine in the dose of 1 mg/kg and amphetamine in the dose of 7.5 mg/kg given intraperitoneally. These results show that; 1) sodium nitroprusside as a donor NO participates in memory and learning processes, 2) overproduction of NO did not change behavioural effects of AII in these experiments.

Angiotensin II↗

PubMed1992

Angiotensin II--derived peptides devoid of phenylalanine in position 8 have full psychotropic activity of the parent hormone.

In this work we compared in rats the influence of heptapeptide 1-7-angiotensin II, hexapeptide 2-7-angiotensin II, pentapeptide 3-7-angiotensin II and angiotensin II on motility, stereotypy, learning of conditioned avoidance responses and recall of passive avoidance behaviour allowing to avoid aversive stimulation. The 4 peptides administered 15 min before the experiment, tended to increase the number of crossings, rearings and bar approaches in open field, significantly accelerated acquisition of conditioned avoidance responses and improved recall of the passive avoidance. All the peptides applied immediately before the experiment intensified stereotypy evoked by apomorphine in the dose 1 mg/kg and amphetamine in the dose 6.5 mg/kg given intraperitoneally. These results show full psychotropic activity of the examined fragments of angiotensin II, comparable with the activity of the parent octapeptide. Our previous hypothesis that the Val-Tyr-Ile-His-Pro fragment of angiotensin II is responsible for the psychotropic activity evoked by angiotensins in rats is thus confirmed.

Angiotensin I↗

PubMedDate not supplied

Examination of the influence of 3,5-DHPG on behavioral activity of angiotensin II.

The effects of the class I metabotropic glutamate receptor (mGluR) stimulation on the behavioral activity of angiotensin II (Ang II) was investigated in the present study. The experiments were performed on adult male Wistar rats. Stimulation of the group I of mGluR receptors was evoked by icv injection of (S)-3,5-dihydroxyphenylglycine (3,5-DHPG) at the dose of 0.01 and 1 nmol per rat. Fifteen minutes later, the animals were given icv solution containing 1 nmol of Ang II. Memory motivated affectively was evaluated in passive avoidance and active avoidance responses (CARs). Moreover, the speculative influence of the treatment on anxiety and motor activity was tested in elevated plus-maze and in open field, respectively. We observed that both compounds did not have statistically significant influence on motor activity of rats in open field test. However, 3,5-DHPG at the dose of 0.01 nmol given alone and combined with Ang II tended to increase locomotor activity. 3,5-DHPG, given alone, significantly facilitated consolidation process in a passive avoidance situation (only at the dose of 0.01 nmol) but had no influence on acquisition and recall of information. Examination of the influence of 3,5-DHPG on the acquisition and extinction of CAR proved that it did not alter acquisition and extinction of these responses. In the elevated plus-maze, 3,5-DHPG had anxiogenic-like profile. Ang II, as repeatedly shown before, greatly increased passive avoidance latency, rate of acquisition of CARs and decreased their extinction. On the other hand, Ang II induced anxiolytic-like effect in elevated plus-maze. The pre-treatment of rats with 3,5-DHPG tended to attenuate behavioral effects of the Ang II administration.

Angiotensin II↗

PubMedDate not supplied

Psychotropic effects of angiotensin II N-terminal fragments: Asp-Arg-Val-Tyr-Ile-His and Arg-Val-Tyr-Ile-His in rats.

In this study the effects of angiotensin II (AII) angiotensin II hexapeptide [AII(1-6)] and angiotensin II pentapeptide [AII(2-6)] on the motility, stereotypy, learning of conditioned avoidance responses (CARs) and recall of a passive behavior making it possible to avoid aversive stimulation in rats, were compared. All the peptides were injected into the lateral cerebral ventricle (icv) in a dose of 1 nmol. AII caused a statistically significant increase in the number of crossings, rearings, and bar approaches in an open field whereas [AII(1-6)] and [AII(2-6)] were inactive in this test. The stereotypic behavior induced by an intraperitoneal (ip) injection of apomorphine (1 mg/kg) and amphetamine (7.5 mg/kg) was statistically significantly enhanced only in the rats which received AII icv. The application of AII, but not that of [AII(1-6)] and [AII(2-6)] resulted in a quicker acquisition of the CARs. A better recall of passive avoidance was achieved only by AII, while the fragments [AII(1-6)] and [AII(2-6)] had no effect. These findings indicate that the 1-6 and 2-6 fragments of AII do not possess a psychotropic activity like that of the parent octapeptide.

Amino Acid Sequence↗

PubMedDate not supplied

Behavioral activity of angiotensin II after stimulation of L-arginine/nitric oxide pathway in rats.

This study was conducted to determine what, if any, role L-arginine [an endogenous donor of nitric oxide (NO)] plays in the behavioral changes induced by angiotensin II (AII) in rats. The motility, stereotypy, spatial learning performance, learning of conditioned avoidance response and retention of passive avoidance behavior allowing to avoid aversive stimulation were investigated. Saline (0.9% NaCl), AII, L-arginine and AII combined with L-arginine were injected 15 min before the experiment into lateral cerebral ventricles (icv). L-arginine significantly enhanced locomotor activity while the treatment with AIIplus L-arginine reduced number of bar approaches in the open field test. AII, L-arginine and AII combined with L-arginine (but not with D-arginine) significantly accelerated acquisition of conditioned avoidance responses and not significantly improved recall of the passive avoidance. Only L-arginine displayed a tendency to inhibit acquisition of spatial learning on the second day of investigation in the Morris water maze. AII, L-arginine and AII with L-arginine applied immediately before the experiment intensified stereotypy evoked by apomorphine at a dose of 1 mg/kg and amphetamine at a dose of 7.5 mg/kg given intraperitoneally. These results showed that: 1) L-arginine as a donor of NO might be involved in memory and learning processes, 2) overproduction of NO did not change behavioral effects of AII in these experiments.

Amphetamine↗