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Biomedical subjects

J Vetulani

Publications and source records attributed to J Vetulani.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Different calcium requirements during incorporation of myo-inositol into membrane lipids for phosphatidylinositol hydrolysis stimulated by carbachol and noradrenaline.

Stimulation of phosphatidylinositol hydrolysis by noradrenaline requires the presence of calcium in the medium during the whole incubation and preincubation procedure, while carbachol-induced inositol phosphate formation is equally efficient in calcium-free and calcium-containing medium. This finding confirms the notion that phosphatidylinositols mobilized after stimulation of various receptors are present in different metabolic pools: the pool mobilized by alpha 1 adrenoceptors is apparently formed from myo-inositol incorporated into membrane phospholipids by a calcium-dependent process.

Analysis of Variance↗
PubMedDate not supplied

Stimulatory effect of chlordiazepoxide on locomotor activity in mice: importance of noradrenergic transmission.

Chlorodiazepoxide (CDP) produces stimulation of the locomotor activity of CD-1 and DBA/2 mice. This effect is strongly pronounced at the commencement of the testing session, and it is followed by a decline of the locomotor activity. The drugs impairing noradrenergic transmission: reserpine, clonidine and alpha-methyltyrosine, depressed or abolished the stimulatory effect of CDP; clonidine, in addition antagonized the subsequent decline of the locomotor activity in CDP-treated mice. Mice receiving reserpine subchronically (in the dose of 0.5 mg/kg daily for 3 days) displayed either motor depression or hypermotility. In approx. 50% of subchronically reserpinized mice CDP produced a strong hypermotility, lasting for at least 1 hr. It can be concluded that a noradrenergic mechanism is involved in the stimulatory effect of CDP on exploratory locomotor activity in mice, and that there exist two distinct subpopulations within the CD-1 strain, reacting differently to chronic reserpine treatment.

Animals↗
PubMedDate not supplied

Neurochemical correlates of differences in responses to psychotropic drugs. I. Apomorphine and morphine effects on locomotor activity of C57/BL and Balb/C mice.

C57/BL mice have higher basal locomotor activity than Balb/C mice and react to apomorphine (4 mg/kg) and morphine (20 mg/kg) with motor stimulation, while in Balb/C mice this dose of apomorphine depressed the basal locomotor activity and morphine did not affect it. No differences in the characteristics of opiate mu and delta receptors in the whole brain of mice of both strains were found, but the responsiveness of the central alpha-adrenoceptor system, as measured with the accumulation of inositol phosphate in brain slices after exposure to noradrenaline was different: the low concentrations of noradrenaline (5 microM) produced stronger effect in Balb/C mice, but the maximum responses tended to be stronger in C57/BL mice.

Animals↗
PubMedDate not supplied

Stability and variability of locomotor responses of laboratory rodents. I. Native exploratory and basal locomotor activity of Albino-Swiss mice.

The exploratory and basal locomotor activities were tested in four groups of Albino-Swiss mice twice, at a 4-5 day interval, to investigate the variability of responses and correlation between the exploratory and basal locomotor activity, and their stability in individual animals. We have found that there exists only a weak correlation between the exploratory and basal locomotor activities. The repetition of tests results in a slight but significant depression of the exploratory, but not of the basal locomotor activity. The correlation between individual performances in two subsequent tests is generally low, regarding both the exploratory and the basal locomotor activity. There are no differences in the density of cerebral alpha 1-adrenoceptors between mice exhibiting extremely different exploratory or basal locomotor activities. The results suggest that preselection of mice for the tests involving locomotor activity in attempt to reduce the variability of results is pointless.

Animals↗
PubMedDate not supplied

Stability and variability of locomotor responses of laboratory rodents. II. Native exploratory and basal locomotor activity of Wistar rats.

The exploratory and basal locomotor activities were tested in four groups of Wistar rats twice, at a 4 day interval, to investigate the variability of responses and their changes on repetition of the test. The locomotor activity of rats was much lower than that of mice, particularly when the basal locomotor activity is concerned, but the individual variability was much higher. The exploratory activity declined significantly on the repeated testing. However, there was a good correlation between the individual exploratory activity in two consecutive tests, which suggests that preselection in the rat may be useful.

Animals↗
PubMedDate not supplied

A comparison of locomotor responses to some psychotropic drugs and cerebral receptors in the Acomys cahirinus and the laboratory mouse.

Comparative studies of the laboratory mouse and Acomys cahirinus have shown differences in their motor activity patterns and motor responses to morphine, apomorphine and clonidine. The two species also differed in respect of the density of cerebral alpha 2-adrenergic receptors, but no significant differences between other types of receptors (alpha 1-adrenergic, beta-adrenergic, opiate mu and delta, and spiroperidol binding sites) were found. It is suggested that the high excitability of the Acomys may be related to a deficit in the inhibitory noradrenergic transmission in the central nervous system.

Animals↗
PubMedDate not supplied

The effect of morphine dependence and abstinence on opioid receptors in the cerebral cortex and spinal cord of the rat.

The characteristics of cerebral cortical and spinal cord opiate mu, delta and kappa receptors were investigated by measuring of the specific binding of [3H]naloxone, [3H]DADLE and [3H]bremazocine in drug-free rats and in rats rendered tolerant to morphine and in those in which morphine abstinence syndrome was precipitated with naloxone. The opiate receptors in the spinal cord were less dense than those in the cortex; the difference was most pronounced in the case of delta receptors. The characteristics of the investigated opioid receptors did not change in the state of tolerance or abstinence.

Animals↗
PubMedDate not supplied

Stability and variability of locomotor responses of laboratory rodents. III. Effect of environmental factors and lack of catecholamine receptor correlates.

The exploratory locomotor activity of rats differs between groups, and the results suggest the involvement of a seasonal factor. The body weight and the state of satiety do not appear to influence the locomotor activity. The individual activities of rats are correlated in subsequent tests only if the period between the tests is not long. The foehn wind changes the locomotor activity in the second test, depending on the animals' experience. No correlation between the native locomotor activity and cortical and striatal binding sites for [3H]prazosin and [3H]spiroperidol was found.

Animals↗
PubMedDate not supplied

The difference in stress-induced analgesia in C57BL/6 and DBA/2 mice: a search for biochemical correlates.

The level of opioid peptides: beta-endorphin and dynorphin, binding to the mu and kappa opioid receptors and the analgesic response of those endogenous opioid systems to stress were investigated in two strains of mice: C57BL/6 (C57) and DBA/2 (DBA). The nociceptive threshold of DBA mice was higher than that of C57 mice. KD values for spinal mu receptors were lower in C57, while KD for cerebral kappa receptors were higher in this strain. DBA mice have significantly higher concentrations of dynorphin in the hypothalamus and neurointermediate lobe of the pituitary. Stress-induced analgesia was much greater in C57 than in DBA mice. In the hypothalamus both stress procedures depressed the concentrations of beta-endorphin in C57, and dynorphin in DBA mice. The level of beta-endorphin increased in the neurointermediate lobe in C57 and in anterior lobe of the pituitary in DBA mice. In the spinal cord both stress procedures depressed the dynorphin level. The above data indicate that C57 and DBA mice differ in the endogenous opioid peptide content, stress-induced alteration and opioid receptor affinity, the effects which might correlate with their different responses to environmental factors and pharmacological agents.

Analgesia↗
PubMedDate not supplied

Lack of effect of chronic imipramine administration on beta-adrenoceptor density on rat lymphocytes.

Chronic administration of imipramine with drinking water to Wistar rats for two months did not affect the [3H]dihydroalprenolol binding to lymphocytic membranes, though the treatment depressed the radioligand binding to cerebral cortical membranes. The result suggests that the beta-adrenoceptor downregulation caused by the antidepressant in the central nervous system is not reflected in the lymphocytes.

Animals↗
PubMedDate not supplied

Head twitches produced by serotonergic drugs and opiates after lesion of the mesostriatal serotonergic system of the rat.

Electrolytical lesions of the dorsal raphe nucleus in the rat did not change frequency of head twitches produced by codeine and apocodeine. The action of serotonergic drugs was affected differently: the lesion depressed the frequency of head twitch episodes produced by 5-hydroxytryptophan (5-HTP), LSD and quipazine, but did not change the frequency of head twitches produced by 5-methoxytryptamine. On the other hand, the lesions protected against high mortality produced by combined treatment with tranylcypromine and 5-methoxytryptamine. There was a good correlation between the extent of lesion, measured by the depression of the level of prosencephalic serotonin, and the depression of head twitch frequency produced by 5-hydroxytryptophan and quipazine, while the correlation was not significant for the action of LSD. It is concluded that presynaptic serotonergic structures belonging to the mesostriatal serotonergic system are necessary for appearing of head twitches after treatment with 5-HTP, LSD and quipazine, and therefore these compounds have a presynaptic action in this test.

5-Hydroxytryptophan↗
PubMedDate not supplied

The difference in the tail-flick but not hot-plate response latency between C57BL/6 and DBA/2J mice.

The tail-flick latency, measured using radiant heat as a noxious stimulus, was significantly shorter in C57BL/6 than in DBA/2J mice, while no significant interstrain differences were observed in the hot-plate test. The experiments in which the animals' tail was painted indicated that the difference in the tail-flick latency between strains was caused by the difference in the color of animal's coat.

Animals↗