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PubMed2001

Functional consequences of repeated (+/-)3,4-methylenedioxymethamphetamine (MDMA) treatment in rhesus monkeys.

Six rhesus monkeys were trained to stable performance on neuropsychological tests of memory, reinforcer efficacy, reaction time and bimanual motor coordination. Three monkeys were then exposed to a high-dose, short course regimen of (+/-)3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") (4 days, 10 mg/kg i.m., b.i.d.). Following treatment, concentrations of 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) were reduced by approximately 50% in the treated animals, and this effect persisted for approximately three months post-MDMA. Behavioral performance was disrupted during acute MDMA treatment but returned to baseline within one week following treatment. MDMA also produced persistent alterations in late peak latencies of brainstem auditory evoked potentials (BSAEP), lasting three months post-MDMA. Both CSF 5-HIAA concentrations and evoked potential latencies were normalized four months after treatment. These findings indicate that serotonergic alterations associated with MDMA use may result in persisting changes in brain function.

Animals↗
PubMed2000

Music perception and octave generalization in rhesus monkeys.

Two rhesus monkeys were tested for octave generalization in 8 experiments by transposing 6- and 7-note musical passages by an octave and requiring same or different judgments. The monkeys showed no octave generalization to random-synthetic melodies, atonal melodies, or individual notes. They did show complete octave generalization to childhood songs (e.g., "Happy Birthday") and tonal melodies (from a tonality algorithm). Octave generalization was equally strong for 2-octave transpositions but not for 0.5- or 1.5-octave transpositions of childhood songs. These results combine to show that tonal melodies form musical gestalts for monkeys, as they do for humans, and retain their identity when transposed with whole octaves so that chroma (key) is preserved. This conclusion implicates similar transduction, storage, processing, and relational memory of musical passages in monkeys and humans and has implications for nature-nurture origins of music perception.

Analysis of Variance↗
PubMed2002

Glomerular hypertrophy is associated with hyperinsulinemia and precedes overt diabetes in aging rhesus monkeys.

BACKGROUND: Rhesus monkeys have a high prevalence of obesity and spontaneous type 2 diabetes mellitus after the age of 10 years. These monkeys go through a defined, sequential set of metabolic phases, including fasting hyperinsulinemia, impaired glucose tolerance, and fasting hyperglycemia. Using these monkeys, we addressed the hypothesis that renal structural features characteristic of diabetic nephropathy might precede the appearance of overt diabetes. METHODS: We carried out a quantitative analysis of renal tissue, using light microscopy and electron microscopy, from 6 metabolically normal young monkeys, 7 metabolically normal aged monkeys, 7 hyperinsulinemic monkeys, and 18 diabetic monkeys. RESULTS: Glomerular volume was increased significantly in hyperinsulinemic monkeys and diabetic monkeys compared with aged normal monkeys. In the normal monkey, glomerular basement membrane (GBM) width rises with age but reaches a plateau at about 20 years of age; the presence of diabetes was associated with markedly increased GBM width. Glomerular tuft volume and GBM width were correlated most closely with age and with glucose tolerance. CONCLUSION: Diabetic monkey kidneys are characterized by glomerular enlargement, glomerulosclerosis, and thickening of the GBM. Glomerular hypertrophy begins in the prediabetic hyperinsulinemic phase. This finding suggests that early intervention may be required in human patients to preserve normal glomerular structure.

Aging↗
PubMed1990

Metabolism of selenite and selenomethionine in the rhesus monkey.

Female rhesus monkeys were fed a commercial monkey diet and given selenium (Se) as either selenite or selenomethionine (SeMet) in the drinking water for 11 mo. Muscle and liver biopsies were taken initially and at the end of the experiment for determination of Se levels and glutathione peroxidase (GPX) activity. Blood was collected at monthly to bimonthly intervals, and the plasma and erythrocytes were subjected to gel filtration to determine the distribution of Se among proteins of various molecular weights. At the end of the experiment, there was significantly more Se in liver, muscle and hair from the monkeys given SeMet than in tissues from those given selenite, but there were no differences in liver or muscle GPX activity between the two treatment groups. The erythrocyte and plasma Se levels were significantly higher in the monkeys given SeMet than in those receiving selenite, but there were no differences in the GPX levels between these groups. About 68% of erythrocyte Se was associated with GPX in monkeys given selenite whereas only 34% was associated with GPX in those administered SeMet. The correlation coefficient for blood Se level and erythrocyte GPX activity was 0.92 in monkeys given selenite but only 0.37 in those given SeMet. Gel filtration of plasma revealed only one Se peak for plasma from the monkeys given selenite but at least two major Se peaks for plasma from monkeys receiving SeMet. The possible implications of these results for humans are discussed, including the reasons for poor correlations of GPX activity and blood Se levels.

Animals↗
PubMed1977

Biosynthesis of the blood-group-B-specific trisaccharide in a rhesus monkey.

A Rhesus monkey, serologically grouped as B, has been shown to excrete low-molecular-weight carbohydrate material in urine closely related to that found in human urine. Galactose feeding resulted in the excretion of a trisaccharide which was shown to be identical to the trisaccharide isolated from the urine of group B humans under the same conditions. Experiments in which [14C]galactose was administered both orally and via an intestinal vein demonstrated that the intestine is the site of biosynthesis.

ABO Blood-Group System↗
PubMed1995

Antihypertensive effects of captopril without adverse effects on glucose tolerance in hyperinsulinemic rhesus monkeys.

The rhesus monkey (Macaca mulatta), which has been found to develop spontaneous obesity, non-insulin dependent diabetes mellitus (NIDDM; Type 2), and hypertension, was used to evaluate the potential blood pressure-lowering effects of captopril as well as the specific effects, if any, on the prediabetic state. Intravenous and oral glucose tolerance testing was carried out with oral captopril dosing. Results showed that captopril significantly decreased both systolic and diastolic blood pressure in all monkeys and significantly decreased fasting plasma glucose levels. Based on these preliminary studies in monkeys, we conclude that captopril exerted antihypertensive effects without adverse effects on glucose metabolism.

Animals↗
PubMed1964

CALCIFICATION OF DECIDUOUS TEETH IN RHESUS MONKEYS.

The rhesus monkey probably has the same sequence of calcification of deciduous teeth as man: central incisor, first molar, lateral incisor, cuspid, and second molar. Initial calcification of the deciduous molar cusps is somewhat similar to that of man.

Animals↗
PubMed1969

Hyperphagia and polydipsia in socially isolated rhesus monkeys.

Three rhesus monkeys which had been isolated from social contact during their first year of life persistently overate and overdrank during adulthood. These monkeys ingested approximately twice as much fluid and food as the control animals reared normally.

Animals↗
PubMed1980

Primate memory: retention of serial list items by a rhesus monkey.

A rhesus monkey correctly recognized 86 and 81 percent of 10- and 20-item lists, respectively. It serial position curve was similar in form to a human's curve, revealing prominent primacy and recency effects. The key to these findings was in minimizing proactive interference through the use of a large pool of 211 color photographs.

Adult↗
PubMed1973

Immunocyte response to experimental mumps virus infection in Rhesus monkeys.

Nineteen rhesus monkeys were inoculated with mumps virus by retrograde ductal instillation into the parotid gland. Evidence of infection was obtained in all instances. Virus was isolated from buccal swabbings and parotid biopsies for 1 week after inoculation. A vigorous serum-neutralizing antibody response occurred within 3 weeks, and there was marked monocytic infiltration of the parotid stroma. The monocytic infiltrate comprised as much as 60% of the total gland volume 1 week after infection. The predominant inflammatory cells were non-immunoglobulin-containing mononuclear cells resembling lymphocytes. Plasma cells containing immunoglobulin G (IgG), IgA, IgM, and IgE increased in numbers in the gland after infection, the greatest increase occurring in IgG-containing cells. Neutralizing antibodies and interferon were found in extracts prepared from the infected glands. Neutralizing activity was highest in samples taken 3 weeks after infection but was detectable in samples taken as soon as 36 to 48 h after infection. Interferon activity was detected in significant amounts 36 to 48 h after infection. Challenge of previously infected animals resulted in an increase in the monocytic infiltrate as well as an increase in numbers of immunoglobulin-containing plasma cells. However, reinfection did not occur as evidenced by the inability to culture shed virus after challenge. This model should be useful for in vivo study of biochemical mediators which evoke inflammatory cell infiltration and which may be significant both in protection and in tissue damage.

Absorption↗
PubMed2000

Activation of lymphocyte signaling by the R1 protein of rhesus monkey rhadinovirus.

Rhesus monkey rhadinovirus (RRV) is a gamma-2 herpesvirus that exhibits a considerable degree of similarity to the human Kaposi's sarcoma-associated herpesvirus (KSHV). The R1 protein of RRV is distantly related to the K1 protein of KSHV, and R1, like K1, can contribute to cell growth transformation. In this study we analyzed the ability of the cytoplasmic tail of R1 to function as a signal transducer. The cytoplasmic domain of the R1 protein contains several tyrosine residues whose phosphorylation is induced in cells expressing Syk kinase. Expression of a CD8 chimera protein containing the extracellular and transmembrane domains of CD8 fused to the cytoplasmic domain of R1 mobilized intracellular calcium and induced cellular tyrosine phosphorylation in B cells upon stimulation with anti-CD8 antibody. None of the CD8-R1 cytoplasmic deletion mutants tested were able to mobilize intracellular calcium or to induce tyrosine phosphorylation to a significant extent upon addition of anti-CD8 antibody. Expression of wild-type R1 protein activated nuclear factor of activated T lymphocytes (NFAT) eightfold in B cells in the absence of antibody stimulation; expression of the CD8-R1C chimera strongly induced NFAT activity (60-fold) but only upon the addition of anti-CD8 antibody. We conclude that the cytoplasmic domain of R1 is capable of transducing signals that elicit B-lymphocyte activation events. The signal-inducing properties of R1 appear to be similar to those of K1 but differ in that the required sequences are distributed over a much longer stretch of the cytoplasmic domain (>150 amino acids). In addition, the induction of calcium mobilization was considerably longer in duration and stronger with R1 than with K1.

Amino Acid Sequence↗
PubMed1978

A comparison of the effects of 50 MeVd leads to be neutron and cobalt-60 irradiation of the kidneys of rhesus monkeys.

Twenty rhesus monkeys had one kidney irradiated (after undergoing unilateral nephrectomies) with one of four doses: 960 or 1080 rads of 50 MeVd leads to Be neutrons, or 2350 or 2700 rads of 60Co. Whereas animals treated with the lower dose of neutrons or 60Co are alive with relatively normal renal function, those treated with the higher dose of neutrons died of radiation nephritis. Animals treated with the higher dose of 60Co developed radiation nephritis but survived. The physiological and histopathological changes of radiation nephritis secondary to neutron irradiation are not qualitatively different from those reported for radiation nephritis secondary to photon irradiation.

Animals↗
PubMed1983

Gastric distension and short-term satiety in the rhesus monkey.

Fasted rhesus monkeys given access to a solution of glucose (0.5 kcal/ml) would, within 15 min, consume it to satiety. If, after such a 15-min bout of consumption, the contents of the stomach were removed via an indwelling cannula, the monkeys would again consume glucose in a following 15-min bout. With experiments paired such that gastric contents were either removed or left in place, the total glucose consumption over four successive bouts when the stomach was emptied between bouts was twice that when the contents were undisturbed. Despite this large difference in consumption, the amount of glucose passing through the pylorus to the intestine was not different in the two conditions. Similar results were demonstrated in a nine-bout series of the same design, in a two-bout series in which gastric contents remaining after the first bout were replaced with equivolumetric amounts of 0.15 M NaCl, and in a one-bout experiment in which consumption of glucose followed a 0.15-M NaCl preload equal in volume to the glucose intake in a single bout the preceding day. Since in the stomach-empty and the stomach-distended conditions of each experiment the postpyloric compartments (small intestine, portal, and systemic circulations) were exposed to identical and physiological amounts of glucose, the difference in consumption must be ascribed to the distension of the stomach.

Administration, Oral↗
PubMedDate not supplied

Hemodynamic response to profound hypoxia in intact rhesus monkeys.

Respiring rhesus monkeys with 2.5 or 4.5% oxygen greatly decreased their cardiac contractility, stroke volume and blood pressure but altered their total peripheral vascular resistance only slightly and inconsistently. All monkeys exposed to 15 minutes and 2 of 4 exposed to 30 minutes of hypoxia recovered and survived without brain injury. Though all animals recovered full cardiovascular function immediately after they were reoxygenated, 2 respired with 4.5% oxygen for 30 minutes began showing declines in blood pressure after a delay of 1 to 2 hours and both subsequently died in shock. Their reductions in blood pressure were associated with reductions in cardiac contractility and stroke volume. The hypotension the animals exhibited both during hypoxia and during development of shock afterwards resulted from pump failure rather than a reduced vascular resistance or an inadequate venous return.

Animals↗
PubMed1991

Effect of epidermal growth factor on the fetal development of the tracheobronchial secretory apparatus in rhesus monkey.

Fetal rhesus monkeys were treated with recombinant human epidermal growth factor (EGF) to determine if EGF can induce maturation of the tracheobronchial secretory apparatus. At 75% of gestation, EGF was administered simultaneously into both the amniotic fluid and fetal abdominal cavity at an average dose of 66 micrograms/kg body weight, by each route over a 7-d period. At the end of the treatment period, the fetuses were delivered and either euthanized immediately or after maintenance on ventilatory support for 6 h. The lungs were removed, and the trachea and one lobe of the right lung was fixed and embedded for light microscopy. The left lung was lavaged with saline, and the collected fluid was used to quantify released secretory product. Secretory product was also measured in amniotic fluid as well as in situ on histologic sections of tracheal epithelium. When the tracheas of EGF-treated monkeys were examined, the epithelium was found to be taller and to contain a greater proportion of secretory cells and a smaller proportion of intermediate cells than the control group. However, there was no significant change in the total number of cells per millimeter of basal lamina or in the proportion of the epithelial population made up of basal or ciliated cells. There was more secretory product stored in the epithelium and submucosal glands and increased quantities of respiratory secretions in both lung lavage and amniotic fluid of EGF-treated monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Plasmodium knowlesi malaria in the Rhesus monkey.

Twelve Rhesus monkeys were inoculated intravenously with about 500 000 malaria parasites, Plasmodium knowlesi. Acute hemolysis occurred 5 days later, and all animals died on the 6th or 7th day after inoculation. All organs were gray-green to gray-brown because of deposition of hemoglobin and malaria pigments. This deposition was particularly striking in the lung, brain, abdominal fat and serous surfaces. Microscopic changes indicative of acute hypoxia were found in the liver (centrilobular necrosis) and kidneys (acute tubular necrosis). Terminal intravascular coagulopathy was evidenced by widely distributed, recently formed, fibrin thrombi.

Animals↗
PubMedDate not supplied

Cardiovascular effects of enflurane and halothane on the rhesus monkey.

Ten rhesus monkeys were chronically instrumented to compare the cardiovascular effects of enflurane and halothane. In 17 experiments, each monkey was evaluated in the awake state and after equilibration at each of many anesthetic levels. End-expired gas concentrations were expressed in multiples of human minimum alveolar concentrations (MAC) for comparison. There was a predictable dose-related decrease in heart rate, mean arterial pressure, peak left ventricular dp/dt, and the latter divided by left ventricular developed pressure (see article) with both agents. Central venous pressure was increased by both. At equal MAC levels, no significant differences were detected between halothane and enflurane. Cardiac output and aortic flow acceleration were obtained on one of the animals for both agents. Results were consistent with those for the other measured parameters.

Animals↗