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Biomedical subjects

J Uesugi

Publications and source records attributed to J Uesugi.

5 recordsLinked to original sources
PubMed1983

Development of physical dependence on and tolerance to morphine in rats treated with morphine-admixed food.

1. The development process of physical dependence on and tolerance to morphine has been explored in rats treated with morphine-admixed food (0.5 mg/g of food) during 1 to 7 days. 2. In the morphine-treated animals, body weight loss was observed after the abrupt morphine withdrawal. 3. Intensity and time course of the weight loss were correlated to the morphine treatment. 4. On the other hand, the morphine-treated rats showed abnormal behaviors, such as diarrhea, ptosis, teeth chattering, salivation, body shakes, vocalization, nose bleed, irritability, aggression, lacrimation and writhing upon naloxone injection. 5. Loss of body weight, measured 3 hours after naloxone injection, was also correlated to the duration of morphine treatment. 6. Tolerance to the analgesic effect of morphine developed within one day in rats treated with morphine-admixed food. 7. The drug-admixed food ingestion method has the advantage of rapidly inducing a high degree of physical dependence and tolerance without causing morbidity or lethality in animals. It also eliminates the need for excessive handling of animals.

Animals↗
PubMed1981

[Codeine seeking behavior in rats using a weight-pulling method].

The purpose of this work was to examine the development of preference for codeine and codeine-seeking behavior by using an apparatus in which rats were compelled to pull against a weight to gain access to codeine-admixed food but not in the case of normal food. Rats developed a strong preference for codeine-admixed food by the repetition of choice and forced trails. The preference for codeine-admixed food was maintained at levels between 60 to 80% for 14 days without any forced trial. After rats developed this preference, they were tested as to whether they might pull against the weight in the apparatus. We observed that the rats did pull at most 40-120 g/100 g body weight in order to reach the drug-admixed food. This is defined as maximum pulling weight. As the weight load was increased, the rats showed more frequent weight pulling behavior for the codeine-admixed food while the duration of eating decreased. The maximum weight pulled was more than 70 g/100 g body weight in 4 out of 6 rats. These results suggest that the degree of drug-seeking behavior in rats can be detected by the use of the weight-pulling method.

Animals↗
PubMed1981

[The quantitative evaluation of the preference for morphine by rats (author's transl)].

We examined the quantitative evaluation of preference for morphine by assessing the conflict behavior between positive motivation and negative motivation. The apparatus consisted of a single runway in which both the usual diet and morphine-admixed food were placed. For access to the latter, the rats were compelled to pull heavy weights which were connected to their necks. During the forced trials (only morphine-admixed food was given) and the choice trials (rats could select either food), the preference rates gradually increased and then became stable at levels of 60%. After these trials, experiments on conflict behavior were performed using several different weights. Assessment of relation between the intensity of the dependence on the drug and the degree of weight showed a good correlation. We conclude that the preference for a drug can be quantitatively measured by means of assessing conflict behavior.

Animals↗
PubMed1980

A psychic dependence study of cinepazide in rats.

I. V. self-administration of cinepazide by rats and the preference of the animals for this drug were studied; and the following were found: 1. I. V. self-administration of cinepazide to rats at dosages of 4, 15, 30, and 60 mg/kg/injection for 7 consecutive days resulted in no self-administration by the animals of the drug far beyond the operant level. 2. Rats undertook the self-administration of cocaine at 1 mg/kg/injection continuously, unlike that of saline or cinepazide. 3. Cross application of cinepazide at dosages of 4, 15, 30 and 60 mg/kg/injection to rats on i. v. self-administration of cocaine failed to substitute itself for the latter. These findings suggested that cinepazide was not a positive reinforcer. 4. Rats exhibited preference for morphine, codeine and pethidine but not for cinepazide. 5. The rats exhibiting preference for morphine also exhibited preference for codeine and pethidine in cross choice trials with these drugs but not for cinepazide in the cross choice trial with this drug. The findings in 4 and 5 suggested that rats showed no preference for cinepazide and that cinepazide failed to maintain the rats' preference for morphine.

Animals↗