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Effects of H1 blocking agents on age-related osteopenia in the mouse.

Tyan ML, Blahd WH.

Old female B6AF1 mice were given acidified tap water, distilled water, one of five H1 blockers or chlorpheniramine (an H1 blocker) and trifluoperazine (a phenothiazine with no H1 blocking activity) in their drinking water for 5 months, and the effects of these agents on bone mineral metabolism were assessed by determining ash weights of femur, ilium and sacrum at the end of the study. In one experiment 24 h whole-body retention (WBR) of Tc 99m methylene diphosphonate (Tc 99m MDP, an indicator of bone metabolism) was measured at the beginning of the study and 40 days later. It was found that: promethazine and dimenhydrinate were the most effective of the H1 blockers in preventing age-related loss of bone mass; distilled water, chlorpheniramine, and chlorpheniramine plus trifluoperazine had no effect on the loss of bone mass; mean bone mass in the groups given meclizine and pyrilamine were greater than but not significantly different from that in the control group given acidified tap water; and only promethazine induced a significant reduction in the WBR of Tc 99m (the other H1 blockers induced small but not significant reductions).

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2887716&dopt=Abstract dimenhydrinate meclizine Antivert



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Suncus murinus as a new experimental model for motion sickness.

Ueno S, Matsuki N, Saito H.

Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.

Characteristics of motion sickness and effects of possible prophylactic drugs were studied using Suncus murinus (house musk shrew) for its potential use as an experimental model in motion sickness. Mild reciprocal shaking (amplitude: 10-40 mm; frequency: 0.5-3.0 Hz) induced vomiting in most of Suncus murinus within 2 min. Adaptation was observed when the motion stimulus was repeated with an interval of 2 to 3 days. During the repetitive motion training, both the ratio of sensitive animals and the number of vomiting episodes decreased, and the time from the start of shaking to the first vomiting was extended. Subcutaneous injection of scopolamine (100 mg/kg), chlorpromazine (8 mg/kg), promethazine (50 mg/kg), diphenhydramine (20 mg/kg), chlorphenylamine (20 mg/kg) and methamphetamine (2 mg/kg) decreased the emetic effect of motion sickness, but pyrilamine (20 mg/kg), meclizine (20 mg/kg) and dimenhydrinate (32 mg/kg) were not effective or very weak. These results indicate that the Suncus murinus is sensitive to the motion stimulus and antiemetic drugs are effective as prophylaxis. The Suncus murinus is useful as a new experimental animal model for motion sickness.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2899827&dopt=Abstract dimenhydrinate meclizine Antivert



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Experimental design for the C3H/10T1/2 CL8 cell transformation assay.

Oshiro Y, Balwierz PS, Piper CE.

Research and Development Division, G. D. Searle & Co., Skokie, Illinois 60077.

The C3H/10T1/2 CL8(10T1/2) cell transformation assay has been used as an important in vitro tool for screening potential carcinogens. In this paper we describe an experimental design that increases the sensitivity and specificity of the assay. One half of the total dishes was allocated to the solvent control and the other half was equally subdivided into four treatment dose groups of low to high cytotoxic effects. The transformation frequency was calculated on the basis of the number of dishes with Type III foci. Each treatment group, as well as the pooled treatment groups, was compared to the solvent control using Fisher's exact test. The sensitivity of our design, as evaluated by power analyses, greatly exceeded that of a standard test design in which about 20 dishes are allocated to each of the control and treatment groups. Furthermore, our use of an expanded number of control and treatment dishes reduces the chance for both false positive and false negative responses. Our experimental design is illustrated with data from experiments in which the transforming potential of two drugs, dimenhydrinate and SC-32006, was examined.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3183291&dopt=Abstract dimenhydrinate meclizine Antivert



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Ion mobility spectrometry and ion mobility spectrometry/mass spectrometric characterization of dimenhydrinate.

Lawrence AH, Nanji AA.

Unsteady Aerodynamics Laboratory, National Aeronautical Establishment, Ottawa, Ontario, Canada.

Positive and negative ion mobility spectra of dimenhydrinate are presented, and the calculated reduced mobility (K0) values for the most significant peaks are reported. Mass identification of the ionic species associated with the peaks in the ion mobility spectra was achieved by interfacing the ion mobility spectrometer to a mass spectrometer. The application of ion mobility spectrometry to the detection of dimenhydrinate and other drug residues on the hands of patients admitted to hospital with drug overdose is also discussed.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3242691&dopt=Abstract dimenhydrinate meclizine Antivert



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Effect of drug therapy on compensation from vestibular injury.

Peppard SB.

The influence of selected drugs on compensation from unilateral labyrinthectomy was studied in the cat. The drugs investigated included: a. amphetamine, b. diazepam, c. dimenhydrinate, d. scopolamine, and e. trimethobenzamide. The most beneficial drugs for improving recovery were a stimulant (amphetamine) and a general anti-emetic (trimethobenzamide). It is postulated they had this effect by improving the overall activity level with general exercise being a known positive influence. Conversely the other drugs either had little effect on recovery or hindered it, by presumably suppressing the sensory imbalance in the vestibular system that is essential stimulus to ultimate recovery.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3488482&dopt=Abstract dimenhydrinate meclizine Antivert