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Biomedical subjects

J D Leander

Publications and source records attributed to J D Leander.

At least 127 records · Page 7Linked to original sources
PubMed1980

Comparison of morphine, meperidine, anileridine, and alphaprodine on schedule-controlled responding and analgesia.

The effects of morphine, meperidine, alphaprodine, and anileridine were studied alone and in the presence of 1 mg/kg of naloxone in rats on level pressing under a fixed-ratio 20-response schedule of food presentation and on tail-withdrawal latency from warm water (55 degrees C) as a measure of analgesia. All four narcotics decreased rates of lever pressing and increased tail-withdrawal latencies. Naloxone antagonized the effects of all four narcotics on tail-withdrawal, but did not antagonize the rate-decreasing effect of meperidine on lever pressing. Naloxone shifted the morphine dose-effect for lever-pressing by a factor of 4-8; the alphaprodine dose-effect curve by a factor of 4-8; and the anileridine dose-effect curve by a factor of 2. These results strengthen the interpretation that meperidine's effect on schedule-controlled responding is not mediated by a narcotic action whereas the analgesic effect is. The results also suggest that anileridine has significant non-narcotic actions like meperidine.

Alphaprodine↗
PubMed1980

Effects of drugs on behavior in pigeons tolerant to delta 9-tetrahydrocannabinol.

Schedule-controlled behavior was used to study how drug effects on behavior are modified by the development of tolerance to delta 9-tetrahydrocannabinol (delta 9-THC). Dose-effect curves were determined for pentobarbital, d-amphetamine and morphine on responding maintained by a multiple fixed-ratio fixed-interval schedule of food presentation in pigeons. The dose-effect curves were redetermined in combination with single injections of 1.0 mg/kg dose of delta 9-THC (which itself did not affect rates of responding) in birds made tolerant to delta 9-THC by multiple injections, and in combination with the 1.0 mg/kg delta 9-THC in birds tolerant to delta 9-THC. Acute doses of 1.0 mg/kg delta 9-THC potentiated the rate-decreasing effects of all three drugs. Pigeons tolerant to delta 9-THC were cross-tolerant to pentobarbital but not to d-amphetamine and morphine. Tolerance to delta 9-THC attenuated the potentiation of the effects of all three drugs by delta 9-THC. Determination of plasma pentobarbital levels in pigeons tolerant to delta 9-THC suggested that a drug dispositional mechanism played a role in the cross-tolerance from delta 9-THC to pentobarbital.

Amphetamine↗
PubMed1979

Attenuating the rate-decreasing effects of phenylpiperidine analgesics by pentobarbital.

The ability of pentobarbital, diazepam, and chlorpromazine to attenuate the rate-decreasing effects of a high dose (10 or 30 mg/kg) of meperidine was tested in pigeons responding under a multiple fixed-ratio, fixed-interval schedule of food presentation. Pentobarbital (10 mg/kg) attenuated the meperidine-induced rate decreases, whereas diazepam (0.3--3 mg/kg) or chlorpromazine (3--30 mg/kg) did not reliably attenuate the response rate decreases. The combination of 10 mg/kg of pentobarbital and meperidine resulted in a marked disruption of the pattern of responding in the fixed-interval component of the multiple schedule. Pentobarbital (1, 3, 10, and 17.5 mg/kg) was also tested in combination with rate-decreasing doses of normeperidine (17.5 mg/kg), anileridine (10 mg/kg), alphaprodine (10 mg/kg), and fentanyl (0.3 mg/kg). Pentobarbital reliably attenuated the rate-decreasing effects of normeperidine, anileridine, and alphaprodine, but not the rate decreases induced by fentanyl.

Analgesics↗
PubMed1979

Effects of propoxyphene, ethoheptazine, and azabicyclane on schedule-controlled responding: attenuation by pentobarbital but not naloxone.

The effects of propoxyphene, ethoheptazine, and azabicyclane, alone and in combination with 1 mg/kg naloxone, were studied in pigeons responding under a multiple fixed ratio, fixed interval schedule of food presentation. Low doses of pentobarbital (3, 5.6, and 10 mg/kg) attenuated the rate-decreasing effects produced by 20 mg/kg propoxyphene, ethoheptazine, and azabicyclane. Naloxone antagonized the rate-decreasing effects produced by 10 mg/kg azabicyclane but did not antagonize the rate-decreasing effects of propoxyphene or ethoheptazine.

Analgesics, Opioid↗
PubMed1978

Combined effects of ethanol and diazepam on performance and acquisition of serial position sequences by pigeons.

The effects of diazepam and ethanol, alone and in combination, were studied in pigeons responding under acquisition and performance chain schedules. Both diazepam and ethanol increased the number of pecks on the incorrect key (errors). Under the acquisition schedule both diazepam and ethanol increased errors at doses lower than those under the performance schedule. Under both schedules effects of combinations of ethanol and diazepam were usually greater than the sum of the effects of the individual drugs.

Animals↗
PubMed1978

Mazindol effects on schedule-controlled responding of the pigeon.

The effects of mazindol, a non-phenethylamine anorexic, were determined in pigeons key pecking under a multiple fixed-ratio 30 response, fixed-interval 5 min schedule of food presentation. The low average rates of responding under the fixed-interval schedule were greatly increased (from 0.7 response/sec to 2 responses/sec) at doses from 0.1 to 10 mg/kg. The higher rates of responding under the fixed-ratio schedule were only decreased by increasing doses of mazindol. Throughout the fixed interval, mazindol tended to produce a constant rate of responding completely disrupting the normal, positively accelerated pattern of responding. These rate-increasing effects of mazindol were much greater than those of phenethylamines tested under similar conditions. The large increases in rates of responding under the fixed-interval component were discussed in terms of the known biochemical effects of mazindol.

Animals↗
PubMed1978

Electric shock titration: effects of meperidine, anileridine and alphaprodine.

The effects of meperidine, anileridine and a alphaprodine were studied in the squirrel monkey whose behavior was maintained under a 2.0-sec schedule of shock increment. Low doses of all three drugs had no effect, whereas higher doses decreased responding at the zero shock intensity. Slightly higher doses of meperidine and anileridine increased responding at the zero shock intensity and produced convulsions.

Alphaprodine↗
PubMed1978

An analysis of normeperidine's contribution to the rate-decreasing effects of meperidine.

The effects of normeperidine (1-17.5 mg/kg) alone and in the presence of naloxone (1 and 10 mg/kg) were studied in pigeons responding under a multiple fixed-ratio 30 response, fixed-interval 5-min schedule of food presentation. Naloxone only potentiated the rate-decreasing effects of normeperidine. The effects of meperidine also were studied after pretreatment with SKF-525A (25 and 50 mg/kg), an inhibitor of drug metabolism. SKF-525A had no effects on responding when administered alone, but it potentiated the rate-decreasing effects of meperidine. It was concluded that meperidine's rate-decreasing effects cannot be due to normeperidine, the metabolite, but rather that both of these drugs have non-narcotic actions which produce decreases in schedule-controlled responding.

Animals↗
PubMed1978

Role of peripheral mechanisms in the behavioral effects of 5-hydroxytryptophan.

The effects of 5-hydroxytryptophan (5-HTP) were studied in rats trained to press a lever under a fixed-ratio (Fr-32) schedule of water presentation. d-, l-and d,l-5-HTP all decreased responding in a dose-related manner. The levo isomer (12.5-25 mg/kg) was twice as potent as the racemic form (25-50 mg/kg) in this respect. Moderate doses of d-5-HTP (less than 100 mg/kg) did not affect responding, whereas 200 mg/kg produced almost complete suppression. The response decrement produced by 25 mg/kg l-5-HTP was completely antagonized by pretreatment with either 50 mg/kg or 400 mg/kg of the decarboxylase inhibitor, benserazide (Ro4-4602). The specific peripheral decarboxylase inhibitor, carbidopa (MK-486) (50 mg/kg) and the peripheral serotonergic antagonist, xylamidine tosylate (1 mg/kg) also antagonized the effects of 25 mg/kg l-5-HTP. These results suggest that at least some of the behavioral effects of 5-HTP are due to increases in levels or turnover of 5-HTP in peripheral serotonergic neuronal systems.

5-Hydroxytryptophan↗
PubMed1978

Food, water and ethanol consumption by rats under a fixed-interval schedule of food presentation.

Rats could lever press 24 hours a day for 97 mg food pellets under a fixed-interval (FI) 90 second schedule. During the first 4 days, an ethanol solution was the only available fluid, after which both water and ethanol solutions were available. At ethanol concentrations (w/v) of 5%, 7.5% and l0%, total caloric intake and total fluid intake remained constant, while ethanol consumption was inversely proportional to the concentration of the solution. When the FI 90s schedule was changed to FI 45 s, or to FI 180 s, there were only small changes in total caloric intake, total fluid intake and in percentages of total fluid consumption and total caloric intake as ethanol. The data suggest that the intake of ethanol under this fixed-interval schedule depends more on the ethanol concentration than on the calories obtained from ethanol drinking.

Alcohol Drinking↗
PubMed1978

Comparing the effects of anileridine, alphaprodine and fentanyl on schedule-controlled responding by pigeons.

The effects of anileridine, alphaprodine and fentanyl were studied on responding by pigeons under a multiple fixed-ratio, fixed-interval schedule of food presentation. Generally, all three drugs produced dose-related decreases in responding under both components of the multiple schedule, but rate increases were observed after low doses of anileridine and alphaprodine in some birds. Naloxone (1 mg/kg) antagonized the rate-increasing and rate-decreasing effects of doses of anileridine and alphaprodine of 10 mg/kg or less, whereas the effects of higher doses were not antagonized by naloxone. Likewise, chronic methadone or morphine (120 mg/kg/day p.o.) dosing produced only a slight cross-tolerance to the rate-decreasing effects of anileridine and alphaprodine. In contrast, naloxone (0.01, 0.1 and 1 mg/kg) and chronic methadone or morphine administration shifted the dose-effect curve for fentanyl to the right, indicating narcotic antagonism and methadone and morphine-induced cross-tolerance. These data indicate that the rate-decreasing effects of anileridine and alphaprodine are related only slightly to narcotic effects, whereas the rate-decreasing effects of fentanyl are primarily narcotic effects.

Alphaprodine↗
PubMed1978

Chronic chlordiazepoxide and pentobarbital interactions on punished and unpunished behavior.

Dose-effect curves were determined in rats for the effects of drugs on punished and unpunished responding maintained by fixed-interval schedules of food presentation before, during and after the drinking of large daily doses of chlordiazepoxide and pentobarbital. An average intake of 50 mg/kg/day of chlordiazepoxide produced tolerance to the rate-decreasing effects of chlordiazepoxide on unpunished responding and cross-tolerance to the rate-decreasing effects of pentobarbital. During chlordiazepoxide drinking, rate-increasing effects of both chlordiazepoxide and pentobarbital on punished responding became apparent. There was no evidence for cross-tolerance between chlordiazepoxide and chlorpromazine. An average intake of 100 mg/kg/day of pentobarbital produced similar evidence of tolerance to the rate-decreasing effects of pentobarbital on unpunished responding and cross-tolerance to the rate-decreasing effects of chlordiazepoxide. Removal of chlordiazepoxide from the drinking water temporarily increased unpunished responding; however, 6 weeks after withdrawal of chlordiazepoxide or pentobarbital from the drinking water, the dose-effect curves for injections of these drugs appeared to be returning to their original positions.

Animals↗