Biomedical subjects

T Uwano

Publications and source records attributed to T Uwano.

23 records · Page 2Linked to original sources

PubMed1991

Succinylcholine-induced acceleration and suppression of electrically evoked acetylcholine release from mouse phrenic nerve-hemidiaphragm muscle preparation.

The effects of a depolarizing neuromuscular blocker on electrically evoked acetylcholine (ACh) release were studied using a mouse phrenic nerve-diaphragm muscle preparation preloaded with [3H]-choline, and the changes in muscle tension were recorded simultaneously. Succinylcholine at a low concentration (1 microM) enhanced evoked [3H]-ACh release, which tended to follow the increase in peak amplitude of tetanic tension; whereas at high concentrations (10 and 30 microM), it simultaneously reduced both release and tension. Decamethonium even at 10 and 30 microM had little effect on [3H]-ACh release despite producing a significantly greater reduction in tension compared with succinylcholine. (+)-Tubocurarine (5 microM) prevented the enhancing effect of [3H]-ACh release induced by 1 microM, but not the decreasing effect induced by 10 microM succinylcholine. These results suggest that succinylcholine induced acceleration at low concentrations due to a positive feedback mechanism through presynaptic nicotinic ACh receptors and the inhibition of ACh release at high concentration contributes in part to the neuromuscular blockade.

Acetylcholine↗

PubMedDate not supplied

Rat preference for food-related odors.

Preferences for food-related odors and the effects of fasting on those preferences were investigated during rat bar pressing for brief odor presentation. A rat was housed in an equilateral octagonal cage and had free access to food and water, except during fasting. Among 8 food-related odor substances (black pepper, cheese, coffee, milk, nut, peppermint, plum and orange), black pepper, milk and coffee were most preferred, and cheese was least preferred, but even the bar pressing rate for cheese was above the operant level. This data indicates that all 8 odors were preferred by rats, although there were different degrees of preference in individual animals. Fasting substantially increased the rate of bar pressing for odors and changed the odors preferences. This result was probably due to increased search for food and water. Since bar pressing was reinforced by nothing other than odor presentation, the results reveal inherent odor preferences of rats.

Animals↗

PubMedDate not supplied

Red ginseng ameliorated place navigation deficits in young rats with hippocampal lesions and aged rats.

Effects of hippocampal lesions and aging on spatial learning and memory and ameliorating effects of red ginseng on learning deficits were investigated in the following two experiments: performance of young rats with selective hippocampal lesions with red ginseng by mouth (p.o.; Experiment 1) and aged rats with red ginseng (p.o.; Experiment 2) in the spatial tasks was compared with that of sham-operated or intact young rats. Each rat in these two behavioral experiments was tested with the three types of spatial-learning tasks (distance movement task, DMT; random-reward place search task, RRPST; and place-learning task, PLT) in a circular open field using intracranial self-stimulation as reward. The results in the DMT and RRPST tasks indicated that motivational and motor activity of young rats with hippocampal lesions with and without ginseng were not significantly different from that of sham-operated young rats in Experiment 1. However, young rats with hippocampal lesions displayed significant deficits in the PLT task. Treatment with red ginseng significantly ameliorated place-navigation deficits in young rats with hippocampal lesions on the PLT task. Similarly, red ginseng improved performance of aged rats on the PLT task in Experiment 2. The results, along with previous studies showing significant effects of red ginseng on the central nervous system, suggest that red ginseng ameliorates learning and memory deficits through effects on the central nervous system, partly through effects on the hippocampal formation.

Aging↗

PubMedDate not supplied

Ameliorative effects of a cognitive enhancer, T-588, on place learning deficits induced by transient forebrain ischemia in rats.

In the present study, we investigated the effect of (1R)-1-benzo[b]thiophen-5-yl-2-[2-(diethylamino)ethoxy]ethan-1-ol hydrochloride (T-588), a newly synthesized cognitive enhancer, on place learning deficits in rats with damage selective to the hippocampal CA1 subfield induced by transient forebrain ischemia. Three weeks after the ischemic insult, T-588 was daily administered (0.3 or 3.0 mg/kg/day po). Place learning was tested in a task in which the rat was required to alternatively visit two places located diametrically opposite each other in an open field. The ischemic rats without the treatment of T-588 displayed severe learning impairment in this task; their performance level was significantly inferior to that of the sham-operated rats. The treatment of T-588 improved dose-dependently the task performance in ischemic rats, although no apparent protective effects on ischemic damage were found histologically. These results suggested that T-588 has ameliorative effects on learning deficits induced by brain ischemia, which could be produced through enhancement of residual cognitive functions.

Animals↗

PubMedDate not supplied

Detection of the circulating lung cancer marker LCAP with a new monoclonal antibody TRD-L1.

Lung Cancer Associated Protein (LCAP) is a high molecular weight glycoprotein defined by the monoclonal antibody (MAb) DF-L1 prepared against a primary adenocarcinoma of the lung. Previous studies have demonstrated that LCAP circulates at elevated levels in patients with lung cancer. However, a suitable assay for monitoring LCAP levels has not been available. The present work describes the development of a double-determinant LCAP assay using MAb TRD-L1 as the capture antibody and MAb DF-L1 as the tracer. In 60 normal subjects, the mean LCAP level was 4.8 U/ml with 2 (3.3%) subjects having values > 12 U/ml (mean + 2SDS). By contrast, 37 of 67 (55.2%) patients with lung cancer had LCAP levels > 12 U/ml. Moreover, only 14 of 203 (6.9%) patients with benign lung disease had elevated levels. LCAP levels were most commonly elevated (62.7%) in patients with adenocarcinoma of the lung and with advanced disease. These results indicate that LCAP as detected by MAb TRD-L1 is a potentially useful marker for the evaluation of patients with lung cancer.

Adenocarcinoma↗