Increased amphetamine potency following chronic naltrexone administration in rats

Chronic administration of the long acting opiate antagonist naltrexone potentiated the amphetamine and apomorphine- -induced stimulation of locomotor activity in rats. Similar treatment also resulted in increased locomotor activity in saline injected rats. The results suggest that chronic opiate receptor blockade may lead to the development of supersensitivity in dopamine systems that mediate motor control. The results provide further support for the notion that endogenous opioids modulate the function of dopamine systems in the brain.     

Malignant uterine mesotheliomas in squirrel monkeys following diethylstilbestrol administration

10 adult female squirrel monkeys were implanted subcutaneously with 4 60 mg pellets of diethylstilbestrol (DES); 4 animals were implanted with cholesterol pellets to serve as controls. Animals were killed at 5, 9, 11, and 14 months after insertion of pellets. All animals implanted with DES had evidence of extreme estrogenic stimulation, including marked edema of the labia, heavy vaginal cornification, and enlargement of the uterine corpus. There were several stages of uterine lesions, in general in proportion to the duration of treatment. The less advanced lesions were restricted to hyperplasia and hyperthrophy of the serosal cells. In more advanced lesions the myometrium was infiltrated; in the most advanced cases there was invasion of the endometrium. The 7 most advanced uterine tumors were classified as malignant mesotheliomas. Cholesterol-treated controls did not have any significant lesions. These observations indicate that DES is carcinogenic in the squirrel monkey, as it has been demonstrated to be in other lower mammalian species.     

Food intake in rhesus monkeys following central administration of orexins

Orexin A has been reported to stimulate food intake in rats while orexin B does not. The purpose of this study was to determine the role of orexin A or orexin B administration on food intake in adult, male rhesus monkeys. Food intake was measured at 2 and 8 h after the morning feeding following central injections of vehicle, orexin A (10, or 20 microg) or orexin B (10, 30, or 100 microg). When compared to vehicle injections, the 10 and 20 microg doses of orexin A decreased food intake at 2 h post-dose by 45% and 64%, respectively. Eight-hour food intake was decreased at only the 20 microg orexin A dose. Orexin B at all doses and time points did not alter food intake when compared to vehicle. These results indicate that orexin A exhibits anorectic activity while orexin B does not affect food intake in the rhesus monkey.     

Olfactory sensitivity for aliphatic aldehydes in squirrel monkeys and pigtail macaques

Using a conditioning paradigm, the olfactory sensitivity of three squirrel monkeys and three pigtail macaques for a homologous series of aliphatic aldehydes ( n-butanal to n-nonanal) was assessed. With only few exceptions, the animals of both species significantly discriminated concentrations below 1 ppm from the odorless solvent, and with n-butanal and n-hexanal individual pigtail macaques even demonstrated thresholds below 1 ppb. The results showed (1). both primate species to have a well-developed olfactory sensitivity for aliphatic aldehydes, (2). pigtail macaques to generally perform better than squirrel monkeys in detecting members of this class of odorants, and (3). no significant correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of the aliphatic aldehydes in both species tested. These findings lend further support to the growing body of evidence suggesting that between-species comparisons of the number of functional olfactory receptor genes or of neuroanatomical features are poor predictors of olfactory performance. Further, our findings suggest that olfaction may play an important and hitherto underestimated role in the regulation of behavior in the species tested.     

Role of some physical characteristics in species recognition by pigtail monkeys

Three adult pigtail monkeys pressed a lever to see pictures of pigtail and Japanese monkeys with a variety of physical features being removed. The features included head, tail, body, background, and color. The duration and the interval of exposure of these visual stimuli were dependent upon subjects' responding. Preferences for those pictures were evaluated by the ratio of lever-pressing duration to interval of lever-pressing. Two of the subjects showed a consistent preference to see pictures of pigtail monkeys over those of Japanese monkeys. Though this preference tended to maintain when these physical features were removed, it became relatively weak when head and head + tail were removed. These results suggest that pigtail macaques may discriminate species based not on a single characteristics but on some combination of features, and that head may be relatively important than the other features.     

Olfactory sensitivity for carboxylic acids in spider monkeys and pigtail macaques

Using a conditioning paradigm, the olfactory sensitivity of four spider monkeys and four pigtail macaques for a homologous series of carboxylic acids (n-propionic acid to n-heptanoic acid) was investigated. With only few exceptions, the animals of both species significantly discriminated concentrations <1 p.p.m. from the odorless solvent and in several cases individual monkeys even demonstrated thresholds <1 p.p.b. The results showed (i). both primate species to have a well-developed olfactory sensitivity for carboxylic acids, which for some substances matches or even is markedly better than that of species such as the rat or the dog and (ii). a significant correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of the carboxylic acids in both species tested. These findings lend further support to the growing body of evidence suggesting that between-species comparisons of the number of functional olfactory receptor genes or of neuroanatomical features are poor predictors of olfactory performance, and that general labels such as 'microsmat' or 'macrosmat'-which usually are based on allometric comparisons of olfactory brain structures-are inadequate to describe a species' olfactory capabilities.     

Pharmacokinetics of ketoprofen enantiomers in monkeys following single and multiple oral administration

Pharmacokinetic studies are reported after single oral administration of 3 mg/kg of stereochemically pure (S)-ketoprofen [(S)-KP] and (R)-ketoprofen [(R)-KP] to three male Cynomolgus monkeys and after repeated administration for 6 months of 3, 15 and 75 mg/kg/day of (S)-KP to both male and female monkeys. A high-performance liquid chromatographic (HPLC) analysis was performed without derivatization of the samples, using a chiral column. The pharmacokinetic parameters for (S)-KP after administration of (S)-KP and for (R)-KP after administration of (R)-KP were, respectively, elimination half-life 2.32 ± 0.36 and 1.64 ± 0.40 h; oral clearance 3.50 ± 0.66 and 7.50 ± 3.20 ml/min/kg; apparent volume of distribution 0.74 ± 0.24 and 1.16 ± 0.76 liter/kg; mean residence time 1.79 ± 0.77 and 1.41 ± 0.65 h; area under the concentration/time curve 14.16 ± 2.93 and 7.31 ± 2.98 μg·h/ml. Forty-nine percent unidirectional bioinversion of (R)-KP to (S)-KP was observed in this species and the pharmacokinetic parameters for the (S)-KP resulting from this inversion were also calculated. In the study of 6-month repeated administration of (S)-KP, linear pharmacokinetic behavior and no evidence of drug accumulation were observed at the three dose levels. © 1994 Wiley-Liss, Inc.     

Diurnal variation of common behaviors of pigtail monkeys (Macaca nemestrina)

Diurnal variation of eight common behaviors was studied in a social group of pigtail macaques (Macaca nemestrina). In agreement with previous work, all behaviors showed marked variation throughout the day, and differences between day and night levels were significant for most behaviors. Several significant inter-behavior correlations were found which suggested that common factors were major determinants of groups of behaviors. Significant correlations between separate diurnal cycles of sleep, grooming, and general activity demonstrated that these behaviors were among the most consistent with respect to diurnal cycles. The results point to the usefulness of diurnal studies in planning primate research designs, e.g., in controlling for variables associated with diurnal cycles.     

Social density and aggression in captive groups of pigtail monkeys (Macaca nemestrina)

A survey of aggressive behavior in 72 groups of pigtail monkeys (Macaca nemestrina) housed under identical spatial conditions revealed that frequency of contact aggression (grab, push, hit, bite) was directly related to social density. This result conforms with expectations of effects of crowding, but contrasts with previous work on responses to manipulation of spatial density. A similar paradoxical contrast between the effects of social density and spatial density has been documented in humans, and consequently development of a nonhuman primate model for study of crowding stress may be warranted. The choice of social density for captive nonhuman primate groups should be made with great care to avoid densities that result in destructive aggression.     

Sex differences in use of a species-typical facial gesture by pigtail monkeys (Macaca nemestrina)

A species-typical gesture, the “jaw thrust”, was sequentially analyzed in a group of adultM. nemestrina. The major finding was a sex difference in apparent function with male jaw thrust sequences most likely to result in sexual behavior and female sequences most likely to terminate in agonistic behavior. Sex differences in the initiation and reception of jaw thrusts were also observed; they were most commonly initiated by males and directed toward females. Marked stereotypy of the behavioral sequences including jaw thrusts was observed: only a small proportion of the species’ behavioral repertoire was exhibited in temporal association with the gesture. Despite the striking nature of the gesture and the frequency with which it was exhibited, a majority of the signals had no overt social effect.     

Immune response following administration of multicomponent vaccine VP-4 in elderly patients

The dynamics of immunological characteristics after the administration of polycomponent vaccine B[symbol: see text]-4 to elderly persons, constituting a risk group with respect to acute respiratory diseases and exacerbations of chronic inflammatory diseases of respiratory organs, was studied. The nasal-oral administration of the vaccine induced immunological shifts in the systems of local and systemic immunity. The content of the populations of lymphocytes with markers CD3, CD4, CD16, CD20 was found to have positive dynamics. Considerable shifts in the system of local immunity were registered: the content of sIgA and IgA in the saliva greatly increased; in addition, an increase in the titers of antibodies to Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli was observed in persons with initially low titers.