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Biomedical subjects

E Widy-Tyszkiewicz

Publications and source records attributed to E Widy-Tyszkiewicz.

At least 19 recordsLinked to original sources
PubMed1994

3H-naloxone binding in brain regions of normotensive Wistar, spontaneously hypertensive and renal hypertensive rats.

In order to study the role of opioid receptors in two models of experimental hypertension the binding of 3H-naloxone to membranes prepared from discrete brain regions and spinal cord was determined. Renal hypertensive rats (RHR) were found to have a greater density of 3H-naloxone binding sites in the hippocampus and hypothalamus when compared to spontaneously hypertensive rats (SHR) and normotensive Wistar rats (NR). The apparent dissociation constant (Kd) for 3H-naloxone binding did not differ between groups.

Analysis of Variance↗
PubMed1993

Spatial navigation learning in spontaneously hypertensive, renal hypertensive and normotensive Wistar rats.

The relation between blood pressure and cognitive performance was assessed in the spatial navigation task. Spatial learning by rats with spontaneous hypertension (SHR) and Goldblatt renal hypertension (RHR) was compared with that of normotensive Wistar rats (NR). The task required the rats to escape from water by finding a submerged and hidden platform. It was found that SHR rats showed improved learning capacity in the maze task in acquisition compared to the RHR and NR groups already on Day 1 and Day 2. The performances of all tested groups reached almost similar asymptotic level on Day 4 and in the probe trial on Day 5. After a reversal training the SHR rats did not show preference to swim in the new platform position quadrant. The present results confirm earlier reports on different behavioural characteristics associated with hypertension.

Animals↗
PubMed1993

Enhanced disruptive spatial learning effect after sufentanil in renal hypertensive rats versus normotensive rats.

The effects of the peripherally administered sufentanil citrate (S), a potent opioid agonist with high affinity for mu receptors on the spatial navigation task, were tested in normotensive Wistar (NR) and renal hypertensive rats (RHR). Rats were injected subcutaneously once daily in doses of 0.25 or 1 microgram/kg S before the water maze training. In NR rats, weak effects of 0.25 micrograms/kg S and impairments after 1 microgram/kg S were seen, whereas in RHR 0.25 and 1 microgram/kg S showed clearcut impairments. These data from the Morris water maze task support previous reports that RHR have an increased sensitivity for opioid agonists.

Animals↗
PubMed1991

Normotensive Wistar rats differ from spontaneously hypertensive and renal hypertensive rats in their cardiovascular responses to opioid agonists.

1. The effects of three opioid receptor agonists on the blood pressure and heart rate of anaesthetized normotensive, spontaneously hypertensive and renal hypertensive rats were measured. 2. Mu agonist morphiceptin i.c.v. induced a pressor response and increase in heart rate in hypertensive rats, but hypotension in normotensive rats. After intravenous (i.v.) injection, morphiceptin produced a hypotensive response in all three groups of rats. 3. In contrast, the delta agonist DTLET i.c.v. decreased blood pressure and heart rate in hypertensive rats, but increased both pressure and beat rate in normotensive rats. After i.v. injections DTLET produced a hypertensive response and increase in heart rate in all groups of rats. 4. Kappa agonist U-50, 488H given i.c.v. induced effects similar to morphiceptin: an increase in blood pressure and heart rate in hypertensive and a decrease in normotensive rats. After i.v. injections U-50, 488H produced decreases in blood pressure and heart rate in all treated groups of rats. 5. Pretreatment with naloxone antagonized the activity of morphiceptin but prevented only the stimulating effect of DTLET in normotensive rats. Cardiovascular actions of U-50, 488H were not blocked by naloxone. 6. The results suggest that opioid agonists exert similar changes in cardiovascular function at central and peripheral sites in both models of experimental hypertension and these effects are different in normotensive rats.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1980

n-Pentylamine: effect on motor activity of mice.

Motor and autonomic effects of n-pentylamine in mice have been evaluated in relation to aminergic mechanisms by combining administration of the amine with drugs having well known effects on such mechanisms. Some evidence has been found to indicate the importance of dopaminergic pathways in the actions of pentylamine; these actions are modifiable by central blockade of muscarinic receptors with atropine. Serotonin-regulated pathways do not seem important for the effects of pentylamine that have been studied.

Amines↗
PubMed1978

Antagonism by morphine and pethidine of the contractile effects of PGE2 on isolated uterus of the rat.

Morphine antagonizes the twitches evoked by administration of PGE2 on spontaneous contractile activity in the isolated uterus of the rat. This action is dose-dependent. Concentrations as low as 2.6 nM completely abolished contractile activity of PGE2 added to the bath at a concentration of 0.5 ng ml-1. In contrast to morphine, pethidine partially antagonized the stimulatory action of PGE2 at much higher concentrations.

Animals↗
PubMed1976

[Not Available].

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History, Medieval↗
PubMed1976

[Not Available].

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Demography↗
PubMedDate not supplied

Analgesic activity of morphiceptin, beta-casomorphin-4, and deltakephalin in normotensive Wistar-Glaxo and spontaneously hypertensive rats.

The effects of intraventricular injection of beta-casomorphin-4, morphiceptin and deltakephalin (DTLET) on hot water tail flick and tail compression responses were investigated in Wistar Albino Glaxo (WAG) and spontaneously hypertensive rats (SHR). The effects of the mu agonist morphiceptin (20 nmol/rat), as assessed by the tail compression test, were significantly greater in SHR rats but did not differ between both strains when measured by tail flick latency. Opioid agonist deltakephalin (2 nmol/rat) in both tests elicited stronger analgesic effects in SHR as compared to WAG and these effects were blocked by naloxone in both tests used. beta-Casomorphin-4 exhibits moderate activity for mu receptors. In the tail flick test peptide (60 nmol/rat) produced an increase in latencies in SHR rats that was significantly greater than was observed in WAG rats. Naloxone pretreatment abolished the analgesic activity of beta-casomorphin-4 solely in the tail compression test in SHR. Analysis of the slopes of the dose-response curves seems to suggest that differences between the activity of these opioid peptides in SHR and WAG rats are based on a difference in the density and affinity of the subpopulation of the opioid receptors in these strains of rats.

Analgesia↗
PubMedDate not supplied

Effects of lesions of monoaminergic system in the brain on the hypotensive effects of clonidine in rats.

Bilateral lesions of the locus coeruleus markedly reduced hypotensive effects of clonidine in rats. Lesions shifted laterally did not evoke any significant change of the hypotensive effects of clonidine or bradycardia induced by it. Lesions of the ventral and dorsal noradrenergic tract at the midbrain level and lesions of the midbrain raphe area failed to change hypotensive response to clonidine.

Animals↗
PubMedDate not supplied

Cardiovascular responses to morphiceptin in spontaneously hypertensive and normotensive rats.

In the urethane anesthetized spontaneously hypertensive rats (SHR) intraventricular injections of morphiceptin produced dose-related increase in heart rate and blood pressure. In contrary, intraventricular administration of morphiceptin in Wistar rats induced a fall in blood pressure and heart rate. Yohimbine antagonized pressor responses to morphiceptin in SHR. Naloxone counteracted both the stimulatory effects of morphiceptin in SHR as well as hypotensive responses in Wistar rats. Bilateral vagotomy blocked depressant action of morphiceptin in normotensive but failed to alter the pressor effects in SHR rats. After systemic injections of morphiceptin a fall in heart rate and blood pressure was obtained in both strains.

Analgesics↗