[Determination of acceptability of 2 cutaneous estradiol gels, in a dose of 1.5 mg daily]. / Appréciation de l'acceptabilité de deux gels d'estradiol cutané, à la dose d'1,5 mg par jour.

OBJECTIVE: The aim was to compare acceptability of a percutaneous 0. 1% estradiol gel (Gel A, Estreva(R) Gel, Laboratoire Théramex, Monaco) to that of an 0.06% estradiol gel (Gel B, Oestrodose(R), Laboratoires Besins-Iscovesco) in its new formulation and packaging. MATERIAL AND METHODS: This randomized, crossed, simple-blind study was carried out in 48 volunteer healthy postmenopausal women. The volunteers applied on one forearm 1.5 mg/day of cutaneous estradiol in the form of either gel, according to randomized allocation, for four days without free period between the two therapeutic periods. The application and drying times of the two gels were measured during the first application; gel subjective women assessment was collected at the beginning and at the end of the study. RESULTS: Mean application and drying times with Gel A are significantly reduced, compared to Gel B (p=0.0259 and p=0.0001, respectively) with drying time 61% shorter; these data are confirmed by subjective women evaluation. The two gels are not significantly different regarding several criteria as consistency, ease of application and sensation of lasting stickiness. However, a significant difference is found in favour of Gel A on the following items: practicality of application (p=0.007), ease of penetration (p<0.001), quantity of gel to apply (p<0.001) after the first application. After four days of administration, a same significant difference is observed concerning practicality of the gel (p=0.0078), duration of use (p<0. 001), packaging, women opinion on the gel (p=0.022) and the product, gel and packaging (p<0.001). At the end of the study, gel A utilization is considered by women more practical (p=0.001) with an easier application (p<0.001) and less restricting while applying (p=0.001), compared to Gel B; 72.9% of women prefer the Gel A and 12. 5% of women prefer the Gel B. CONCLUSION: A better acceptability of the 0.1% estradiol gel and of its packaging compared to that of the 0.06% estradiol gel in this new formulation and packaging is observed in this study.

[Comparative study of the acceptability of a new estradiol Tx 11323 (A) gel and a transdermal matrix system]. / Etude comparative de l'acceptabilité d'un nouveau gel d'estradiol TX 11323 (A) et d'un dispositif transdermique matriciel.

OBJECTIVE: to compare the acceptability of a new estradiol gel TX 11323 (A) and a transdermal matrix system. METHOD: this randomised open crossed study was conducted on 80 healthy menopausal female volunteers treated successively with 1.5 mg of estradiol per day in gel form (Estreva Gel, Theramex, Monaco) and by a transdermal matrix twice-weekly system delivering 50 micrograms/24 h of estradiol (Oesclim 50, Fournier, Dijon-France). The treatment was applied for 25 days with an interval of 6 days between the 2 administration cycles. Acceptability was evaluated and compared by a self-questionnaire given on D1 and D25 of each therapeutic cycle. RESULTS: the 2 treatments, after 25 days of use, were judged convenient, easy and fast to use by more than 90% of subjects. There was, nevertheless, a significant difference in favour of the gel in respect of the estimation of the "visual aspect" of the treatment, reported skin problems, problems with application technique, as well as discomfort during intimacy found in 11% of cases using the transdermal system. It is noted that 80% of the women consider the gel treatment more feminine (p < 0.001) and that 61.3% prefer this treatment compared to 32.5% preferring the transdermal system studied (p = 0.005). CONCLUSION: this study shows a better acceptability of the estradiol gel TX 11323 (A) compared to that of the transdermal matrix system studied.

Distribution of enkephalin immunoreactivity in sympathetic prevertebral ganglia and digestive tract of guinea-pigs and rats.

The aim of the present study was to determine the distribution of methionine-enkephalin (ME) and leucine-enkephalin (LE) immunoreactivity in the sympathetic prevertebral ganglia (coeliac plexus and inferior mesenteric ganglion) and in the myenteric plexus-muscular layer complex of the digestive tract in guinea-pigs and rats. This study was performed using the same immunological approaches including radioimmunoassays and HPLC characterization as those used previously on cats in order to be able to make inter-region and inter-species comparisons. In rat and guinea-pig prevertebral ganglia, the distributions of the enkephalin immunoreactivities were comparable and were characterized by a low ME/LE concentration ratio, of less than 1. In the digestive tract of rats, the enkephalin immunoreactivities were homogeneously distributed, whereas in guinea-pigs, they were found to be very low in the lower oesophageal sphincter and high in the duodenum. In both species, the ME/LE concentration ratio was around 2. The ME/LE concentration ratio determined in the present study in peripheral nervous structures was much lower than that determined previously in the rat brain. Radioimmunoassay and biochemical data might indicate that different mechanisms are responsible for the processing and/or degradation of enkephalins in the central and peripheral nervous systems. The present study provides further evidences that there are tissue- and species-dependent differences in the distribution of enkephalin immunoreactivities. These differences should be taken into consideration when dealing with the effects and the role of enkephalins in the nervous control of intestinal motility in mammals.

Ultrastructural study of delta-opioid receptors in the dorsal horn of the rat spinal cord using monoclonal anti-idiotypic antibodies.

The ultrastructural localization of delta-opioid receptors was studied using monoclonal anti-idiotypic antibody prepared with an anti-D-Ala2-D-Leu5-enkephalin. Immunocytochemical techniques were used on vibratome sections from rats perfused with paraformaldehyde. A high density of immunoreactivity was observed in the dorsal horn of the spinal cord, particularly the two superficial layers, the dorsolateral funiculus and the area surrounding the central canal. The labelling was absent when the antibody was preincubated with the immunogen. Competition between the anti-idiotypic antibody and different ligands, delta or mu, was controlled by preincubation of tissue sections with the ligand in the presence of peptidase inhibitors for 3-4 h before addition of the anti-idiotypic antibody. Enkephalin, dermenkephalin and naltrindole induced disappearance of the labelling at 10(-9) M while dermorphin or dermorphin Lys7 were ineffective at the same concentration. Lamina II of the dorsal horn was studied by electron microscopy. The immunolabelling was mainly localized on cell membranes at appositions between the two neurons. About one third were localized between an axon terminal and a dendrite, the same proportion of labellings were between two axon terminals. Labelling was occasionally observed at appositions between a glomerular terminal and a dendrite or a terminal or at axoglial appositions. Axosomatic localizations were rare. The presynaptic localization of the labelling is in favor of a presynaptic mechanism of action for delta-opioids in the spinal cord, providing that these receptors are functional. delta-Opioid peptides probably act non-synaptically since receptors were never localized on synaptic differentiations.

Characterization of methionine-enkephalin release in the rat striatum by in vivo dialysis: effects of gamma-hydroxybutyrate on cellular and extracellular methionine-enkephalin levels.

The opioïd system is implicated in mediating the effects produced upon administration of gamma-hydroxybutyrate. Gamma-hydroxybutyrate occurs endogenously in the mammalian brain, and is most probably involved in the regulation of some basic brain functions, particularly those concerning the dopaminergic nigrostriatal pathway, which is closely linked to the expression of enkephalins in the striatum. In the present study, in vivo microdialysis was used to examine the basic characteristics of methionine-enkephalin (met-enkephalin) release in the striatum of Wistar rats, using a high performance radioimmunoassay. Administration of gamma-hydroxybutyrate to the rats induced a dose-dependent decrease in the extracellular release of met-enkephalin. In parallel, a dose- and time-dependent gamma-hydroxybutyrate-induced accumulation of met-enkephalin in striatum was observed. These two phenomena (tissue accumulation and inhibition of release) were blocked by NCS-382, a gamma-hydroxybutyrate receptor antagonist. The striatal met-enkephalin accumulation does not seem to be exclusively due to the inhibition of its release. Thus, a gamma-hydroxybutyrate mediating effect on met-enkephalin synthesis is suggested, most probably occurring via functional modulation of striatal dopamine synthesis and release. To understand the role of this dopaminergic mechanism, unilateral lesions of the nigrostriatal dopaminergic pathway were carried out. In gamma-hydroxybutyrate-treated rats, striata exhibited a similar increase in met-enkephalin content. In untreated rats, only the lesioned striatum showed an identical increase in met-enkephalin levels. Thus, striatal met-enkephalin accumulation could be attributed to the suppression of the dopaminergic impulse flow, due to gamma-hydroxybutyrate or to the action of 6-hydroxydopamine. In the extracellular spaces (microdialysis experiments), gamma-hydroxybutyrate administration induced identical modifications of met-enkephalin release in lesioned or non-lesioned striata. These modifications could be reproduced by peripheral or striatal administration of sulpiride, a D2/D3 antagonist. From a functional point of view, the dopaminergic D2 receptor blockade or the gamma-hydroxybutyrate-induced inhibition of dopamine release could be considered to induce similar results, with identical consequences on striatal met-enkephalin accumulation and release. These results suggest that gamma-hydroxybutyrate-induced modifications in met-enkephalin release, presumably potentiated by 6-hydroxydopamine treatment, act via a functional modification of the nigrostriatal dopaminergic pathway.

Changes in enkephalin immunoreactivity of sympathetic ganglia and digestive tract of the cat after splanchnic nerve ligation.

The aim of the present study was to analyze changes in the enkephalin immunoreactivity of sympathetic prevertebral ganglia coeliac plexus and inferior mesenteric ganglion) and intestinal tract (myenteric plexus and external muscle layers) in cats 2 days after left thoracic splanchnic nerve ligation, using radioimmunoassay and immunohistochemical techniques. Specific polyclonal antibodies directed against methionine- and leucine-enkephalin were used. The nerve ligation led to a considerable increase in the enkephalin immunoreactivity in the cranial part of the ligated nerves. This finding confirms the presence, in the cat, of an enkephalin output originating from thoracic spinal structures which are probably enkephalin-containing preganglionic neurons. In prevertebral ganglia the nerve ligation induced a marked decrease in the enkephalin immunoreactivity, which was probably due to the interruption of thoracic enkephalin efferents projecting towards both the coeliac plexus and the inferior mesenteric ganglion. In the digestive tract, the nerve ligation depressed the methionine-enkephalin immunoreactivity only in the gastro-duodenal region, and had no effect on the ileo-colonic region. The results of the present study add to the growing evidence that the sympathetic nervous system is involved in regulating the enteric enkephalinergic innervation, which is probably involved in controlling the intestinal motility.

Monoclonal antiidiotypic antibodies against delta opioid receptors as an electron microscopy probe.

Four different rat monoclonal antibodies were produced against delta opioid receptor using an antiidiotypic approach in which antibodies directed against the opioid agonist DADLE were used as immunogen. In the first step, seven hybridomas were selected on the basis of their ability to inhibit the DADLE-anti-DADLE antibody interaction. After purification from ascitic fluids, these monoclonal antibodies were characterized. Four antiidiotypic antibodies, named 5, 11, 16, and 51, directed toward different epitopes, recognized the delta opioid receptor: (i) they bound directly to the NG108-15 cells, (ii) they inhibited the [3H]DADLE binding on the NG108-15 cells, (iii) they immunoprecipitated a 52,500 dalton protein present on the surface of the NG108-15 cells. The four monoclonal antiidiotypic anti-opioid receptor antibodies were used to immunocytologically detect the opioid receptors under light and electron microscopy in the rat spinal cord. The regional distribution of the immunoreactivity corresponded to layers known to be rich delta opioid receptor subtype. Moreover, at the ultrastructural level, the labeling was located mainly on plasma membranes, especially on non-synaptic zones. Our results show that monoclonal antiidiotypic antibodies constitute a valuable tool for visualizing cell surface receptors.