This study evaluated levo-alpha-acetylmethadol hydrochloride (LAAM), a long-acting morphine-like (mu) agonist approved in 1993 to treat opiate dependence. Sprague-Dawley rate (20/sex/group) were gavaged with doses of 3.0-33.5 mg kg-1 for 30 days followed by a 14-day drug-free recovery period. Treatment-related effects included dose-dependent CNS depression, decreased food consumption and body weight gain, reddish urine and abdominal staining. Tolerance developed by day 7. Mortality was dose-dependent; deaths occurred predominantly during the first week. Increased alanine aminotransferase (SGOT, AST) and lactate dehydrogenase (LDH), observed only in high-dose males, were associated with findings in liver. Decreases in spleen/brain weight and increases in brain/body weight ratios were seen in both sexes. Decreases in weights of heart, liver and kidney achieved statistical significance only for high-dose groups. Kidneys of mid- and high-dose groups displayed intertubular mineral/crystal deposition, focal corticomedullary mineralization and focal regenerative tubular epithelium. Centrilobular hypertrophy was observed in livers of high-dose males and mid- and high-dose females. Following the recovery period, decreased body weights and increased brain/body weight ratios occurred in mid-dose males and low-dose females. Weights of liver and kidney and organ/brain weight ratios were decreased in mid-dose males. Histopathological findings observed in kidneys and livers had abated. In summary, acute and repeated administration of LAAM produced a spectrum of activity consistent with its profile as a long-acting pure mu-agonist which stimulates microsomal enzymes in rodents. Renal and hepatic effects seen in initially drug-naive rats treated with morphine-type agonists are not observed in tolerant individuals stabilized on mu-agonists to treat opiate dependence.

Administration, Oral↗

PubMedDate not supplied

Toxicological evaluation of mu-agonists. Part II: Assessment of toxicity following 30 days of repeated oral dosing of male and female rats with levo-alpha-noracetylmethadol HCl (NorLAAM).

This study evaluated levo-alpha-noracetylmethadol (NorLAAM), the first N-demethylated metabolite of levo-alpha-acetylmethadol (LAAM), a long-acting morphine-like (mu) agonist, approved in 1993 to treat opiate dependence. After acute and 7-day pilot studies to define dose levels appropriate for use in longer term evaluations, Sprague-Dawley rats (20 of each sex per group) were gavaged with doses of 4.4-25.9 mg kg(-1) day(-1) for 30 days followed by a 14-day recovery period. Treatment-related effects included dose-dependent CNS depression paralleled by changes in food consumption, body weight gain and fecal output, as well as reddish urine and abdominal staining. Tolerance developed by day 7. The spectrum of activity observed differed from the parent compound primarily in its time course. Cage-biting and gnawing behavior were observed only with NorLAAM. Mortality was dose-dependent, with deaths occurring predominantly during the first week. At day 30, all male-treated groups exhibited statistically significant, dose-dependent decreases in body weight gain and increases in serum cholesterol that returned to the control range following recovery. Increases in brain/body weight and testes/body weight ratios and decreases in kidney/brain, liver/brain, spleen/brain and heart/brain ratios, as well as decreases in kidney, liver, spleen and heart absolute weights, achieved statistical significance only for males. At terminal sacrifice, histological findings in the kidneys included increased incidences of tubular mineral deposition in mid- and high-dose groups of both sexes and of corticomedullary mineral deposition in females. Hepatic centrilobular hypertrophy was evident in male and female mid- and high-dose groups. Histopathological changes abated following the recovery period. In summary, acute and repeated administration of NorLAAM produced a pharmacodynamic profile commensurate with its role as the primary N-demethylated metabolite of LAAM, which is more potent and less lipophilic than the parent compound; this was reflected in the toxicological outcomes observed. Like LAAM, NorLAAM's overall pattern of activity is consistent with its activity as a mu-agonist, which stimulates hepatic microsomal enzymes in rodents.

Administration, Oral↗

PubMedDate not supplied

Evidence for the existence of specific cannabinoid binding sites.

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Animals↗

PubMedDate not supplied

Effects of delta-9-THC and a water soluble ester of delta-9-THC on schedule-controlled behavior.

delta-9-Tetrahydrocannabinol (delta-9-THC) and one of its water soluble esters (SP-111) decreased the rates of responding by pigeons working under a variable interval 3-min schedule of food presentation, or a multiple fixed-ratio 30, fixed-interavl 5-min schedule of food presentation. delta-9-THC was 3-6 times more potent than SP-111 and had a faster onset of effects on behavior.

Animals↗

PubMedDate not supplied

Effect of propranolol on antinociceptive and withdrawal characteristics of morphine.

Propranolol at a dose (10 mg/kg) which did not alter tail-flick latency by itself, did not alter the ED50 of morphine when given 10 min prior to the narcotic. Propranolol at doses of 10 and 25 mg/kg given 10 min prior to naloxone challenge did not significantly alter the frequency of naloxone induced jumping 72 hr after morphine pellet implantation. The ED50 of naloxone in morphine pelleted mice was not altered by treatment with propranolol at 0, 24, and 48 hr after pellet implantation. Naloxone caused hyperactivity in mice when administered 72 hr after morphine pellet implantation. An injection of 25 mg/kg propranolol 10 min prior to naloxone did not block this hyperactivity. In addition, administration of 10 mg/kg of propranolol every 8 hr to rats during withdrawal from morphine failed to alleviate the withdrawal syndrome as evidenced by changes in either body weight or water intake. These data suggest that the beta-adrenergic blocking agent, propranolol, does not alter the antinociceptive activity or lessen the withdrawal syndrome of morphine in rodents.

Analgesics, Opioid↗

PubMedDate not supplied

Marihuana-like activity of new synthetic tetrahydrocannabinols.

11-Methy-delta8-, 9-nor-delta8, and 9-nor-delta9-tetrahydrocannabinol (THC), newly synthesized cannabinoids which are not 11-hydroxyated in vivo, were tested for cannabinoid activity. Delta8-, delta9-THC and each synthetic analog produced static ataxia in unanesthetized dogs, hypotension and bradycardia in anesthetized dogs, and decreased spontaneous activity in mice. All synthetic analogs tested produced a greater degree of tolerance to the behavioral effect in dogs than did delta8-THC. 11-Methyl-delta8-THC was more effective than delta8-THC in decreasing spontaneous activity in mice, but was less active in producing the behavioral and cardiovascular effects in dogs. 9-nor-delta9-THC was less active than delta9-TCH, but 9-nor-delta8-THC was as active as delta8-THC in all observations. These results suggest that the 11-hydroxy metabolites of delta8- and delta 9-THC are not solely responsible for the biological activity of tetrahydrocannabinol.

Analgesics↗

PubMedDate not supplied

Endocardial lesions following coronary artery by-pass surgery.

A series of post-operative deaths is presented in which coronary artery by-pass surgery had been performed at various ante-mortem intervals by the same surgical term in a single institution. When compared to an appropriate control population, these cases displayed a sequence of endocardial inflammation and progressive fibro-elastosis which suggested that injury had occurred during surgery. An assessment of the effects of this lesion and of possible etiologic factors is presented.

Adult↗

PubMedDate not supplied

Panhypopituitarism in a young drug abuser.

An intoxicated young man returned home from a drinking party and collapsed and died in his mother's presence. Three weeks earlier, he had been released from prison, having served a sentence for possession and sale of "street drugs". At the time of his release, he and his friends had gathered together for a celebration at which drugs were used. At the autopsy table, there was initial evidence of an intrasellar hemorrhage of recent onset with ablation of the adenohypophysis. At first the prosectors considered the case to be one of drug-induced pituitary "apoplexy". However, there was subsequent autopsy evidence of chronic panhypopituitarism. The intrasellar lesion proved to be a Rathke-cleft cyst of dysontogenetic origin, probably unrelated to drug abuse. This case is presented as an example of the increasing complexities encountered by the forensic pathologist in a world of increasing numbers of available toxic substances.

Adult↗

PubMedDate not supplied

Hyporesponsiveness to the immunosuppressant effects of delta-8-tetrahydrocannabinol.

Delta-9-tetrahydrocannabinol (delta 9-THC) and delta 8-THC have previously been shown to suppress humoral immunity in mice. The purpose of these investigations was to determine whether a hyporesponsiveness develops to the immunosuppressive effect of delta 8-THC. BALB/c mice were administered 60 mg/kg delta 8-THC i.p. 2 days after an i.p. immunizing dose of sheep erythrocytes (sRBC). Significant inhibition of direct hemolytic plaque-forming cells (PFC)/spleen was observed on days 3--6, with peak day of inhibition occurring on day 4. The effective inhibiting dose 50 (ED50) measured on peak day of response was 40 mg/kg for PFC/10(6) spleen cells and 38 mg/kg for PFC/spleen. When mice were pretreated daily for 5 days with different doses of delta 8-THC, similar ED50's were detected. Under this pretreatment regimen, 5 or 10 mg/kg produced no immunosuppression. Daily treatment with 5 or 10 mg/kg delta 8-THC for 5 days prior to sRBC and varying doses of delta 8-THC administered 2 days after sRBC resulted in significantly higher ED50's and increased values for the slopes of the dose response curves. These results suggest that a hyporesponsiveness develops to the immunosuppressive activity of delta 8-THC.

Animals↗