Changes in testosterone and behavior during adolescence in the male rhesus monkey.

Five adolescent male rhesus were followed for 3 years, from age 2 through age 4, with the collection of monthly testosterone levels, along with observation of behavior. Testosterone levels showed initial rises by age 3, but did not show the adult male seasonal pattern until 4. Play behavior fell significantly from age 2 to age 3, while sex behavior showed seasonal increases in both Year 2 and Year prior to the rise in plasma testosterone. The number of adult males in the social group may influence the timing of the rise in testosterone during adolescence. Injury may also serve to delay the increase in testosterone in males during their third year of development.     

Sham feeding in the rhesus monkey.

Adult male rhesus monkeys with chronic gastric fistulas were adapted to eating a liquid food during a 90 min test period after an overnight food deprivation. When the fistulas were opened for the first time, monkeys sham fed more than three times as much as they had eaten the previous day when the gastric fistulas were closed. The observed incidences of resting and non-ingestive activity were reduced during the sham feeding test. When monkeys sham fed for 5 successive test days, intake increased progressively with a concomitant decrease in the incidence of non-ingestive activity. The results demonstrate that under, these experimental conditions pregastric food stimuli (and their conditioned and/or unconditioned responses) are not sufficient to limit meal size at control levels, and they are not sufficient to elicit the behavioral sequence of normal satiety.     

恒河猴实验感染庚型肝炎病毒的实验研究

目的研究庚型肝炎病毒（ＨＧＶ）在恒河猴中的实验感染状态。方法用一名ＨＧＶＲＮＡ阳性、ＨＢＶ、ＨＣＶ均阴性的健康献血员血浆实验感染２只恒河猴，并取第一代猴感染后６周的血再感染１只第二代恒河猴，然后用以第二代猴感染６周后血继续感染２只第三代恒河猴。分别用逆转录聚合酶链反应（ＲＴ－ｎＰＣＲ）检测受感染猴血清中的ＨＧＶＲＮＡ，并每周抽血测定血清中丙氨酸转氨酶（ＡＬＴ）。结果感染１周后猴血清ＨＧＶＲＮＡ阳转，最长持续阳性２８周以上。不同感染个体血清ＡＬＴ水平有明显差异，其中１号猴有短期轻度升高，５号猴血清ＡＬＴ较长时间在１００Ｕ／Ｌ以上。肝活检发现，感染后１６周猴肝组织出现明显的病毒性肝炎样病理改变。进一步对该献血员血浆和感染后猴血清中的ＨＧＶ５’端部分非编码区基因ＰＣＲ产物进行测序，结果显示感染用献血员血浆和猴血清中ＨＧＶ序列与国外株ＨＧＵ４４４０２的同源性分别为９８３３％和９５８３％；与ＨＧＵ３６３８０株的同源性分别为９２５０％和８９１７％；感染猴血清中ＨＧＶ序列与献血员ＨＧＶ序列同源性为９５８３％。结论恒河猴对ＨＧＶ敏感，可以做为实验模型动物     

Gastric emptying and secretion in the rhesus monkey.

The volume and composition of the gastric contents as well as the rates of gastric emptying and secretion were determined simultaneously in conscious chair-adapted monkeys. These determinations were made during fasting and after a liquid meal, thereby allowing studies of the physiologic variables which regulate gastric emptying and gastric secretion. Administration of a water meal is followed by a complex pattern of changes in rates of secretion as well as the fractional rate of emptying. During administration of a 100-ml water meal (pH 7.4), intragastric volume increased while acid concentration decreased; both then returned to fasting values 50 min later. The fractional rate of emptying increased fivefold during administration of the water meal, returned to basal values after 30 min, and then increased again, indicating that gastric emptying cannot be characterized as a simple first-order process with a constant coefficient. The pattern of the change in the rate of water secretion was similar to that for fractional gastric emptying. In contrast, after the meal, gastric acid secretion increased steadily and did not become maximal until 20 min.     

The crossed cortico-caudate projection in the rhesus monkey.

In the normal young adult rhesus monkey, reduced silver staining of degenerating axons revealed that the lateral prefrontal cortex projects to the caudate nucleus of the contralateral hemisphere. This crossed prefronto-caudate projection provides a means whereby the prefrontal cortex can affect the neuronal activity of the extrapyramidal motor systems in both hemispheres. These findings also support the concept that apparent neuronal plasticity in this primate telencephalic system is a result of expanded projections of axons that normally issue a minor projection to the contralateral caudate nucleus.     

Cholecystokinin suppresses sham feeding in the rhesus monkey.

The satiety effect of slow intravenous infusions of impure cholecystokinin (CCK) was investigated in 5 rhesus monkeys during sham feeding. CCK suppressed sham feeding. The dose for 50% inhibition of sham feeding was about 10 U/kg-hr; 20 U/kg-hr abolished sham feeding. No dose produced retching, vomiting, diarrhea or other behavioral signs of toxicity. These results demonstrate the potency of CCK for inhibiting feeding in the monkey when gastric, intestinal and postabsorptive mechanisms are not activated by ingested food.     

Intercellular junctions in the rhesus monkey pars distalis.

Four rhesus monkey pituitary glands were examined by transmission electron microscopy. Three types of intercellular junctions, desmosomes, hemidesmosomes and zonula adherens-type junctions, were observed between adjacent granular cells, folliculo-stellate cells, and joining a folliculo-stellate cell with a granular cell. Demosomes were most commonly observed between granular cells while the zonula adherens-type junctions were generally found between the folliculo-stellate cells.     

Ascaris-induced respiratory responses in the conscious rhesus monkey.

Reproducible immediate-type respiratory responses were evoked in conscious monkeys, sensitive to inhaled Ascaris suum, for periods up to 18 months. These responses were characterized by decreases in tidal volume and increases in breathing rate that persisted for about 40 min. Maximum changes were seen 3--5 min after exposure to the aerosolized antigen and were often accompanied by coughing and increased movement of the animals within the plethysmograph used for monitoring their ventilatory changes. Significant inhibition of the Ascaris-induced respiratory changes were seen in animals treated with either isoproterenol or cromolyn sodium. However, the latter agent was not effective in reversing histamine-induced ventilatory changes. The conscious monkey appears to be a suitable animal for evaluating potential antiallergic drugs.     

Semi-automated detection of emesis in the rhesus monkey.

The use of a video recorder and the inclusion of a marker dye in material fed to rhesus monkeys has eliminated the need for the constant presence of an observer to detect an emetic response.     

Salt hunger in the rhesus monkey

Five rhesus monkeys (Macaca mulatta) were placed on a low-sodium diet and given injections of furosemide in order to promote sodium loss. The results indicated that these methods elicit a substantial and specific salt hunger. Issues surrounding salt hunger are discussed.     

Effect of potassium on ventilation in the rhesus monkey.

Increasing the concentration of arterial plasma K+ to 6-8 mM increased ventilation in two sedated analgesic-treated rhesus monkeys who had their end-tidal CO2 held constant during euoxia (arterial oxygen pressure, Pa,O2, ca 100 Torr) and hypoxia (Pa,O2, ca 40 Torr). During euoxia and hypoxia, hyperkalaemia increased ventilation up to 40 and 250%, respectively. This effect was reduced in euoxia and virtually abolished in hypoxia following an abrupt switch to 100% oxygen. Thus the ventilatory response of this primate to hyperkalaemia is at least as sensitive as that of the cat and if hypoxia is added the two stimuli generate a powerful drive to breathing.     

Airway mucosal permeability in the Ascaris suum-sensitive rhesus monkey.

The permeability of the airways to technetium 99m-labeled albumin was measured in Ascaris suum-sensitive rhesus monkeys. All 8 animals were skin-sensitive to Ascaris suum (AA) antigen, 4 being respiratory responders (R) and 4 nonresponders (NR) to aerosolized antigen. In the absence of antigen challenge there were no differences in the accumulation in the blood of radioactive material from the tracheobranchial tree between the R and NR animals. After a five-minute challenge with aerosolized AA, there was a threefold increase in the rate of accumulation of radioactive material in the blood over control for the R group with no effect noted in the NR group. Gel filtration data indicated that the radioactivity in the blood most likely represented low molecular weight albumin fragments, resulting from spontaneous degradation of Tc-albumin, that crossed the mucosa and partially bound to circulating albumin. It is concluded that hyperpermeability of the airway mucosa probably is not a factor that contributes to the selective responsiveness of the R group to aerosolized antigen, and that airway permeability is increased consequent to the allergic reaction mediating acute bronchoconstriction.     

Reversal learning in the neonatal rhesus monkey

Twenty-one day old and 31 day old monkeys were presented with a black-versus-white discrimination reversal problem after having completed 20 days of learning on the original problem. Age at the time of reversal was not a significant factor, but reversing to the white stimulus was significantly faster than reversing to the black stimulus. This preference persisted over repeated reversals. The infant monkey shows improvement in repeated reversal learning that is very similar to the behavior of the adult rat.     

Muscle spindles in the rhesus monkey platysma

The platysma of the rhesus monkey consists of two parts: a platysma myoides located similar to the human platysma, and a platysma cervicale passing the dorsal cervical region and being in contact with the cheek pouch. Our investigation showed that the muscle fiber morphology was comparable in both parts. Muscle spindles were only present in regions connected to the cheek pouch and contained only nuclear chain fibers. It is tempting to speculate that they sense the filling of the cheek pouch rather than mimic activities.     

Experimental autoimmune gastritis in the rhesus monkey

Three rhesus monkeys were injected with pooled monkey gastric mucosa suspension plus complete Freund adjuvant. All three animals developed organ-specific autoantibodies and delayed skin tests to gastric antigen. The circulating antibodies were demonstrated by tanned cell haemagglutination using a well-centrifuged, heated gastric extract, and by complement fixation tests employing a lightly centrifuged gastric suspension. In immunofluorescent tests, antibodies localized primarily in the parietal cell cytoplasm of the gastric mucosa. All three monkeys showed histological evidence of chronic multifocal gastritis consisting of monocytic infiltration of the mucosal layer with atrophy of the neighbouring glands. The thyroids and other organs of these monkeys were normal. Normal monkeys, or control monkeys injected with monkey thyroid, adrenal or testis extract did not show these gastric changes.