Search PubMed⌕ Search

Biomedical subjects

M Robin

Publications and source records attributed to M Robin.

At least 55 records · Page 3Linked to original sources

Differentiating opioids by their pupillary effects in the rat.

Pupillary effects of several opioids were examined as part of a broader in vivo study of multiple opioid receptors in the rat. Agonist activity, stereospecificity, and naloxone sensitivity were determined by methadone (Me), ethylketocyclazocine (EK), and N-allylnormetazocine (SKF 10,047), selected for their purportedly predominant actions at mu, kappa, and sigma receptors, respectively. After an acute, subcutaneous injection of each drug, pupil area and fluctuations in pupil size were measured by means of an infrared video pupillometer on line with a microcomputer data processing and storage system. Despite differences in the magnitude of the response, each opioid tested produced an increase in pupil size which was stereospecific, independent of behavioral responses to the drugs and, for 1-Me and 1-SKF 10,047, dose-related. Other differences among the opioids were found in their ability to induce fluctuations (1-Me and 1-EK) and a pendular nystagmus (1-SKF 10,047 only), and in their sensitivity to naloxone. Although 1.0 mg/kg naloxone completely reversed 1-Me-induced mydriasis, 10 mg/kg was needed to reverse 1-EK, and this dose only partially antagonized 1-SKF 10,047. These characteristic patterns of pupillary responses to opioids in terms of agonist activities and naloxone sensitivities indicate that the different opioid receptor types subserve different functions with respect to pupillary control.

Animals↗

The functional consequences of inhibition of monoamine oxidase type B: comparison of the pharmacological properties of L-deprenyl and MDL 72145.

The pharmacological properties of two selective inhibitors of monoamine oxidase (MAO) type B, L-deprenyl and MDL 72145 [(E)-2-(3,4-dimethoxyphenyl)-3-fluoroallylamine, HCl], have been investigated in rats and mice in relation to their effects on MAO. Selective inhibition of MAO B achieved following 18 h pretreatment with L-deprenyl and/or MDL 72145 did not per se lead to prominent pharmacological activity; no effects were seen in the mouse "Behavioural Despair" test, hypothermia induced by reserpine in mice was neither prevented nor reversed and there was no change in the cardiovascular responsiveness of the pithed rat to tyramine, noradrenaline or stimulation of the spinal sympathetic outflow. L-Deprenyl differed from MDL 72145 in that short term treatment with this drug caused positive effects in the "Behavioural Despair" test, reversal of reserpine hypothermia, indirect sympathomimetic stimulation of blood pressure and heart rate in the pithed rat and ipsilateral rotation in rats with unilateral nigro-striatal lesions. Qualitatively similar effects were seen with dexamphetamine. The marked difference between the pharmacological effects of MDL 72145 and L-deprenyl despite equivalent inhibition of MAO B suggests that many of the pharmacological actions of L-deprenyl result from its amphetamine-like sympathomimetic properties. MDL 72145 can, therefore, be considered a more reliable tool with which to explore the functional importance of MAO B inhibition in experimental animals and man.

Allylamine↗

Effect of chronic apomorphine on the development of denervation supersensitivity.

We hypothesised that it would be possible to prevent the development of post-synaptic dopamine receptor supersensitivity to 6-hydroxydopamine lesions of the nigro-striatal tract in rats if they were constantly infused with the dopamine agonist apomorphine. Using osmotic minipumps to infuse apomorphine for 15 days in unilaterally lesioned rats, it was possible to delay the development of supersensitivity of the lesioned side for 9 days but not to prevent its eventual appearance. At the same time, evidence for the development of subsensitivity of presynaptic dopamine receptors of the intact side following chronic infusion of apomorphine was inferred from the production of rotations directed towards the lesioned side.

3,4-Dihydroxyphenylacetic Acid↗

[Chemotherapy of embryonal carcinoma of the testis with lymph node invasion and/or pulmonary metastases. Results of a VBP type protocol].

Fourteen patients with histologically proven embryonal carcinoma of the testis with pulmonary metastasis (10 pts) or para-aortic nodal involvement (4 pts) were treated by a chemotherapy regimen including vinblastine, bleomycin and cisplatin. Extreme ages were 19 and 51 years with a median age of 32 years. Median duration of treatment was 6 months (6 cycles of chemotherapy) without maintenance treatment. After completion of chemotherapy, 6 patients in complete remission received para-aortic node irradiation (45 Grays in 25 fractions). One patient had a para-aortic node dissection, histologically negative. With a median follow-up of 47 months (maximum 92 months, minimum 12 months), eleven patients are in complete remission (78.6%). Three patients are dead from the disease, in spite of salvage chemotherapy. There were no toxic deaths. Disease-free actuarial survival is 74% at 4 years. Our results confirm the excellent therapeutic results of this chemotherapy regimen in embryonal carcinoma of the testis with pulmonary metastasis and/or para-aortic nodal involvement.

Adult↗

Spontaneous maze ambulation in two mouse strains.

A simple device is described, which permits us to quantify several parameters of spontaneous behaviour of small animals. Using this device with mice we obtained statistically satisfactory results, showing a strong genetic influence on the behavioural characteristics tested.

Animals↗

Median raphe canals of the penis.

Developmental abnormalities of the male genitalia can result in epithelial-lined canals or cysts which occur along the ventral median raphe from the glans penis to the anus. Although usually asymptomatic, secondary infection may produce swelling, tenderness and a purulent discharge. The canals are lined by stratified squamous epithelium which does not communicate with the urethra. Surgical excision is the treatment of choice.

Adult↗