Search PubMed⌕ Search

Biomedical subjects

G Telegdy

Publications and source records attributed to G Telegdy.

At least 217 records · Page 12Linked to original sources
PubMed1982

Effects of H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH on passive and active avoidance behavior and on open-field activity of rats.

The action of H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH on the passive and active avoidance behavior and open-field activity of rats was studied after peripheral and intracerebroventricular administration. When applied before the test session, intracerebroventricular administration increased the avoidance latency of passive avoidance behavior. Subcutaneous, intraperitoneal and intracerebroventricular administration of the peptide delayed the extinction of active avoidance behavior. Both subcutaneous and intracerebroventricular administration increased the grooming activity of the rats. The data suggest that H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH is able to influence memory, acting mainly on the retrieval processes, and to modify open-field activity.

Animals↗
PubMed1982

Effects of beta-/Tyr9/melanotropin-/9-18/ on apomorphine-induced stereotyped cage-climbing and on striatal dopamine release in mice. Comparative studies with amphetamine.

beta-/Tyr9/melanotropin-/9-18/ significantly increased apomorphine-induced cage-climbing, while only a tendency towards an increase was observed after supersensitization with haloperidol. Amphetamine also enhanced apomorphine-induced climbing behavior. The peptide showed only a tendency to increase dopamine release from striatal slices, while amphetamine elevated this significantly. The results suggest that the striatal dopamine system is involved in the behavioral action of beta-/Tyr9/melanotropin-/9-18/.

Amphetamine↗
PubMed1982

Effects of lysine-vasopressin and 1-deamino-8-D-arginine-vasopressin on memory in healthy individuals and diabetes insipidus patients.

Central diabetes insipidus (DI) patients showed impairments in short- and long-term memory functions, but not in attention and concentration, as compared to healthy individuals. A single i.m. injection or sub-chronic intranasal administration of either lysine-vasopressin (LVP) or 1-deamino-8-D-arginine-vasopressin (DDAVP) normalized the disturbed memory functions in DI patients. These peptides also improved memory functions in healthy individuals.

Administration, Intranasal↗
PubMed1982

[A new synthesis of somatostatin].

The synthesis of somatostatin by linking together Boc-Ala-Gly-Cys(Bzl)-Lys(Z)-Asn-Phe-NHNH2 and H-Phe-Trp-Lys[Z(pCl)]-Thr-Phe-Thr-Ser-Cys(Bzl)-OBzl is described. The two partial sequences were obtained from segments which in general are also used in preparing somatostatin analogues. The synthesis of the partial sequences was optimized. The intracerebroventricular application of the somatostatin thus obtained to rats produced an increase of the dopamine and serotonin contents in the striatum. The results achieved were identical with those realized with standard somatostatin (Serono).

Animals↗
PubMed1982

[Synthesis of cyclo-[des(1,2-L-alanyl-glycine, 14-L-cysteine)-3-s-carboxymethyl-L-homocysteinamid, 8-D-tryptophan]-somatostatin].

The authors describe the synthesis of a shorter-chained somatostatin analogue in which the ring size of the native molecule is largely preserved by incorporation of S-carboxymethyl-L-homocysteinamid and ring closure via its side-chain function. This synthesis involves the linkage of Boc-Phe-D-Trp-Lys[Z(pCl)]-Thr-Phe-Thr-Ser-OH to H-Hcy(CH2-CO-Lys[Z(oCl)]-Asn-Phe-OMe)-NH2 and subsequent azide cyclization. In contrast to somatostatin, the somatostatin analogue thus obtained produces, when applied intracerebroventricularly to rats, a decrease in the dopamine content of the striatum.

Animals↗
PubMed1982

Comparative studies with linear and cyclic somatostatin on the self-stimulation of rats.

In the present study the dose-related effects of linear and cyclic somatostatin were compared on the self-stimulation rate of rats. Twenty micrograms of linear somatostatin administered intracerebroventricularly (icv.) markedly decreased the self-stimulation rate, while 5 micrograms and 10 micrograms was ineffective. Cyclic somatostatin in a dose of 1 microgram caused a transitory but not significant increase in the self-stimulation rate, which later returned to the control level. Five micrograms and 10 micrograms of the peptide decreased the self-stimulation rate. These results indicate that the cyclic somatostatin is more effective in inhibiting the self-stimulation rate than the linear one.

Animals↗
PubMed1982

Effects of cholecystokinin octapeptide sulphate ester and unsulphated cholecystokinin octapeptide on active avoidance behaviour in rats.

The effects of peripherally administered cholecystokinin octapeptide sulphate ester and its unsulphated form on the active avoidance behaviour of rats were studied. The acquisition of avoidance behaviour was impaired, while extinction was facilitated, following cholecystokinin octapeptide sulphate ester or unsulphated cholecystokinin octapeptide treatment. These peptides had no action on open-field activity. It is concluded that peripherally administered cholecystokinin octapeptide influences acquisition and extinction of active avoidance behaviour and this effect is unrelated to general motor activity of the animals.

Animals↗
PubMed1982

Effects of cholecystokinin-related peptides on retention of passive avoidance behaviour.

Effects of intraperitoneal administration of cholecystokinin (CCK)-related peptides were studied on retention of single-trial learning passive avoidance behaviour. The COOH-terminal octapeptide of CCK (CCK-1-8-SE), the unsulfated octapeptide (CCK-1-8-NS), as well as the COOH-terminal tetrapeptide of CCK (CCK-5-8), administered immediately after the learning trial, facilitated passive avoidance behaviour. The data indicate that these peptides may influence memory consolidation processes.

Animals↗
PubMed1982

Effects of intracerebroventricularly administered cholecystokinin antisera on active avoidance and conditioned feeding behaviour of rats.

The effects of intracerebroventricular administration of two different cholecystokinin antisera were tested on acquisition and extinction of active avoidance behaviour as well as on acquisition, maintenance and extinction of conditioned feeding behaviour of rats. Both antisera delayed the extinction of active avoidance and conditioned feeding response, while they were ineffective on acquisition and maintenance. These data suggest that the endogenous CCK of the brain might be a physiological modulator of extinction processes.

Animals↗
PubMed1981

Effects of cholecystokinin octapeptide on striatal dopamine metabolism and on apomorphine-induced stereotyped cage-climbing in mice.

The effects of sulfated (CCK-8-SE) and non-sulfated (CCK-8-NS) cholecystokinin octapeptide on striatal dopamine (DA) metabolism have been investigated on mice. CCK-8-NS facilitated the disappearance of striatal DA, measured after synthesis inhibition with 350 mg/kg of alpha-methyl-p-tyrosine. CCK-8-SE did not affect DA disappearance. In vitro uptake of [3H]DA by striatal slices was affected by neither CCK-8-SE, nor CCK-8-NS (10(-5) M). Potassium-induced in vitro release of [3H]DA from striatal slices was significantly increased by 10(-5) M CCK-8-NS: however, CCK-8-SE likewise increased DA release in this model system. Apomorphine-induced (1.0 mg/kg) stereotyped cage-climbing behavior was not affected by CCK-8-SE but was enhanced by CCK-8-NS. This effect could be antagonized by haloperidol, but not by naloxone. The data suggest that CCK-8-NS affects striatal DA release, disappearance and receptor sensitivity in the mouse. Dopaminergic mechanisms should therefore be regarded as a possible mode of action of CCK-8-NS on brain functions.

Animals↗
PubMed1981

Influence of cholecystokinin octapeptide sulfate ester on brain monoamine metabolism in rats.

The effects of intracerebroventricular administration of an 80 pmole dose of cholecystokinin octapeptide sulfate ester (CCK-8-SE) were tested on the dopamine (DA), norepinephrine (NE) and serotonin (5-HT) turnovers of the hypothalamus, mesencephalon, amygdala, septum, striatum and cerebral cortex in rats. CCK-8-SE in an 80 pmole dose decreased the DA turnovers of the hypothalamus, mesencephalon, amygdala and septum, while it increased that of the striatum. The NE turnovers were increased in the hypothalamus and amygdala, but decreased in the striatum. The 5-HT turnover decreased only in the hypothalamus.

Animals↗
PubMed1981

Effects of beta-(Tyr9)melanotropin-(9-18) decapeptide on passive and active avoidance behavior and on open-field activity of rats.

The effects of the administration of beta-(Tyr9)melanotropin-(9-18) into the lateral ventricle in a dose of 1.0 micrograms in 2 microliters were studied on passive avoidance behavior, extinction of active avoidance behavior, and open-field activity in rats. beta-(Tyr9) melanotropin-(9-18) given 30 min pretrial facilitated the acquisition of passive avoidance behavior; however, it was ineffective on retention when the material was given immediately posttrial or 30 min before retention testing. The extinction of active behavior was delayed. In open-field activity, the ambulation rate and rearing activity were increased 30 min following administration. The data suggest that beta-(Tyr9)melanotropin-(9-18) has distinct neurotropic properties, and is able to modify behavioral reactions.

Animals↗
PubMed1981

Effect of cholecystokinin octapeptide sulphate ester on brain monoamines in the rat.

The effect of different doses of intracerebro-ventricularly administered cholecystokinin octapeptide sulphate ester (CCK-8-SE) was studied on dopamine (DA), norepinephrine (NE) and serotonin (5-HT) contents in the hypothalamus, mesencephalon, amygdala, septum and striatum, 10, 20 and 60 min following administration. The DA and NE content increased and the 5-HT content decreased in the hypothalamus and mesencephalon. A biphasic action was observed in the amygdala of DA, NE and 5-HT depending upon the time and doses used. Similar action was seen on DA and NE in the septum. In the striatum, the DA and 5-HT content decreased while the NE level first increased and then decreased. The data indicate that the CCK-8-SE is able to modify the activity of DA, NE and 5-HT in different brain regions in a time and dose-dependent manner, with a local specific action.

Amygdala↗
PubMed1981

Effects of intraventricular administration of cholecystokinin octapeptide sulfate ester and unsulfated cholecystokinin octapeptide on active avoidance and conditioned feeding behaviour of rats.

The effects of cholecystokinin octapeptide sulfate ester (CCK-8-SE) and unsulfated cholecystokinin (CCK-8-NS) were studied following intraventricular administration on active avoidance and conditioned feeding behaviour of rats. In the CCK-8-NS and CCK-8-SE treated animals the acquisition of active avoidance and conditioned feeding behaviour were considerably impaired compared to the control; furthermore, these peptides caused a facilitated extinction of active avoidance and conditioned feeding behaviour. The data suggest that cholecystokinin octapeptide is capable of modifying the fear and hunger motivated behaviours of rats.

Animals↗