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Biomedical subjects

P Demenge

Publications and source records attributed to P Demenge.

47 records · Page 3Linked to original sources
PubMed1980

Stereospecific binding of 3H-haloperidol in rat dorsal spinal cord.

[3H]Haloperidol as dopaminergic ligand used on pooled microdiscs punched from the rat dorsal spinal cord allowed detection of a stereospecific binding. Characteristics of such a binding: dissociation constant, Hill's slope and IC50 of different specific drugs were nearly the same as those found in the striatum, which suggests the presence of individualized dopaminergic receptor sites in the rat dorsal horn. Their density (Bmax) is about three times lower than in the whole striatum.

Animals↗
PubMed1979

Derivatives of benzimidazole: vasodilator activity of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride. Preliminary study.

The effects of 2-(p-chloro-alpha-hydroxybenzyl)-benzimidazole hydrochloride (HBBPC) have been studied in the rabbit and rat. Most of these studies were performed comparatively with reference vasodilators and papaverine. HBBPC vasodilator activity is nearly the same as that of papaverine in the isolated rabbit ear. The characteristic of the vasoactive action of HBBPC seems to reside in its duration. The mechanism of action of HBBPC seems of peripheral type, that is to say it acts on the vascular smooth muscle.

Animals↗
PubMed1979

Vasodilator activity of 2-(p-chloro-alpha-hydroxybenzyl)benzimidazole (HBBPC) on femoral vascular bed of the rabbit.

The effects of 2-(p-chloro-alpha-hydroxybenzyl) benzimidazole HCl (HBBPC) have been studied on the femoral peripheral resistance (i.v. route) and only femoral blood flow (local i.a. injection), in comparison with other vasodilators, i.e., sodium nitroprusside, dihydralazine and piribedil. The vasomotor activity of HBBPC, namely, decreased peripheral resistance and increased femoral blood flow, seems interesting because it begins after pressure has returned to normal. This substance is likely to induce a vasoconstriction in other areas (increased femoral blood flow with decreased peripheral resistance without a fall of blood pressure).

Animals↗
PubMed1979

Impedance rheoplethysmography. The role of estimation of vasodilatory activity.

The activity of a number of vasodilatory drugs was studied, with the help of impedance rheoplethysmography, on the vascular bed of the hind limb of anaesthetized rabbits. The vasodilators under study induce changes in rheoplethysmogram to a more or less important degree. The results were compared with those obtained with electromagnetic flowmetry. This method seems to be useful in the study of vasodilators because it allows to measure their effects and the duration thereof in a non-aggressive way. This method using flowmetry, allows to study in an analytical way those substances' effects on artery, vein and also capillary.

Animals↗
PubMed1978

[Toxicologic study of a fluorescent tracer: rhodamine B].

The use of the rhodamine B as fluorescent tracer in hydrology ask the question of its possible toxic effects in the environment. This study aspire to specify and to complete the results of the former works by the successive examinations of the activity of the rhodamine B in regard to the "daphnies test", its DL50 on the rat and on the mouse, and its cutaneous tolerance. The obtained results confirm the former remarks and express that the solutions of the rhodamine B show any more immediate risks as soon as they appear no more coloured (higher dilutions 1.10(-7)). However it remains to evaluate its long-term carcenogenic activity.

Animals↗
PubMedDate not supplied

Hypertension in transgenic (mREN2)27 rats is not associated with the presence of B1 receptors.

B1 receptors are inducible receptors expressed only in stressful conditions. The aim of this study was to determine if, in (mREN2)27 transgenic rats, hypertension is associated with the presence of B1 receptors in the cardiovascular system and if a heat stress inducible effect is preserved during hypertension. Age-matched (16 weeks old) heterozygous hypertensive transgenic (mREN2)27 rats (HT rats) and the normotensive control animals (homozygous Sprague-Dawley rats, NT rats) were used. The study was conducted in two parts: in the first part the responsiveness of B1 receptors was studied in rats submitted to heat stress (42 degrees C rectal temperature, 20 min) or sham anaesthesia 24 h before, by recording changes in isometric tension in aortic rings in response to [des-Arg9]-bradykinin, a B1 receptor agonist. In the second part, we studied whether B1 receptor mRNA was present in aorta, heart and kidneys, using a semi-quantitative RT-PCR technique. [des-Arg9]-Bradykinin induced a concentration-dependent relaxation of aortic rings only from animals submitted to prior heat stress. This response was significantly higher in aortic rings from heat stressed HT rats than from heat stressed NT ones. B1 receptor mRNA was undetectable in organs from rats not submitted to heat stress but they were present 5 h after heat stress in aorta, heart and kidneys from both NT and HT rats. In conclusion, arterial hypertension observed in (mREN2)27 rats is not associated with the presence of B1 receptors. However, after heat stress, we observed an increase in responsiveness from HT rat aortas compared to NT ones.

Acetylcholine↗
PubMedDate not supplied

[The spinal dopaminergic system].

A new dopaminergic innervation has been described quite recently: the dopaminergic spinal cord system. In this review are presented the different steps which lead to the individualization of this dopaminergic system and the reported results actually available concerning its probable anatomical organization. Finally, most of the data which illustrate the possible functions of this system are discussed. Interestingly, its participation in the transmission of nociceptive signals and the control of cardiovascular patterns appear now well established. Such functional implications give new information on the possible targets of central dopaminergic agonists and antagonists, particularly at the cardiovascular level.

Animals↗