Male Japanese Monkeys Research Articles

Distribution of P2X3 purinoceptor-immunoreactive sensory nerve endings in the carotid body of Japanese macaque (Macaca fuscata).

In the carotid body of laboratory rodents, adenosine 5'-triphosphate (ATP)-mediated transmission is regarded as critical for transmission from chemoreceptor type I cells to P2X3 purinoceptor-expressing sensory nerve endings. The present study investigated the distribution of P2X3-immunoreactive sensory nerve endings in the carotid body of the adult male Japanese monkey (Macaca fuscata) using multilabeling immunofluorescence. Immunoreactivity for P2X3 was detected in nerve endings associated with chemoreceptor type I cells immunoreactive for synaptophysin. Spherical or flattened terminal parts of P2X3-immunoreactive nerve endings were in close apposition to the perinuclear cytoplasm of synaptophysin-immunoreactive type I cells. Immunoreactivity for ectonucleoside triphosphate diphosphohydrolase 2 (NTPDase2), which hydrolyzes extracellular ATP, was localized in the cell body and cytoplasmic processes of S100B-immunoreactive cells. NTPDase2-immunoreactive cells surrounded P2X3-immunoreactive terminal parts and synaptophysin-immunoreactive type I cells, but did not intrude into attachment surfaces between terminal parts and type I cells. These results suggest ATP-mediated transmission between type I cells and sensory nerve endings in the carotid body of the Japanese monkey, as well as those of rodents.

Oestrogen-induced activation of preoptic kisspeptin neurones may be involved in the luteinising hormone surge in male and female Japanese monkeys.

The oestrogen-induced luteinising hormone (LH) surge is evident in male primates, including humans, whereas male rodents never show the LH surge, even when treated with a preovulatory level of oestrogen. This suggests that the central mechanism governing reproductive hormones in primates is different from that in rodents. The present study aimed to investigate whether male Japanese monkeys conserve a brain mechanism mediating the oestrogen-induced LH surge via activation of kisspeptin neurones. Adult male and female Japanese monkeys were gonadectomised and then were treated with oestradiol-17β for 2 weeks followed by a bolus injection of oestradiol benzoate. Both male and female monkeys showed an oestrogen-induced LH surge. In gonadectomised monkeys sacrificed just before the anticipated time of the LH surge, oestrogen treatment significantly increased the number of KISS1-expressing cells in the preoptic area (POA) and enhanced the expression of c-fos in POA KISS1-positive cells of males and females. The oestrogen treatment failed to induce c-fos expression in the arcuate nucleus (ARC) kisspeptin neurones in both sexes just prior to LH surge onset. Thus, kisspeptin neurones in the POA but not in the ARC might be involved in the positive-feedback action of oestrogen that induces LH surge in male Japanese monkeys, as well as female monkeys. The present results indicate that oestrogen-induced activation of POA kisspeptin neurones may contribute to the LH surge generation in both sexes. The conservation of the LH surge generating system found in adult male primates, unlike rodents, could be a result of the capability of oestrogen to induce POA kisspeptin expression and activation.

Sex categorization of conspecific pictures in Japanese monkeys (Macaca fuscata)

We investigated whether monkeys discriminate the sex of individuals from their pictures. Whole-body pictures of adult and nonadult monkeys were used as stimuli. Two male Japanese monkeys were trained for a two-choice sex categorization task in which each of two choice pictures were assigned to male and female, respectively. Following the training, the monkeys were presented with novel monkey pictures, and whether they had acquired the categorization task was tested. The results suggested that while monkeys discriminate between the pictures of adult males and females, discrimination of nonadult pictures was difficult. Partial presentations of the pictures showed that conspicuous and sexually characteristic parts (i.e., underbellies including male scrotums or breasts including female nipples) played an important role in the sex categorization.

Cellular Localization of NGF and its Receptors trkA and p75LNGFR in Male Reproductive Organs of the Japanese Monkey, Macaca fuscata fuscata

The actions of neurotropins are not restricted to the nervous system. Immunohistochemical methods were used in the present study to clarify distribution of nerve growth factor (NGF) and its receptors TrkA and p75LNGFR in excurrent ducts of the adult male Japanese monkey (Macaca fuscata fuscata). NGF was found in the seminal vesicle, epididymis, and testis, and has been thought to affect male reproductive functions. Leydig cells, Sertoli cells, and spermatogonia at various stages were positively stained for NGF, as well as for TrkA and p75LNGFR. Signals for these proteins were also found in epithelial cells and stromal tissues of the caudal epididymidis, as well as in the seminal vesicle. In the prostate, smooth muscle cells and basal cells were positively stained for NGF, TrkA, and p75 LNGFR. The results were comparatively discussed.

Is Observability a Good Indicator of Male Japanese Monkeys Leaving Their Natal Group?

Is Observability a Good Indicator of Male Japanese Monkeys Leaving Their Natal Group?

Influence of two types of information trials on the formation of a discrimination‐reversal learning set in Japanese monkeys

Abstract: Three groups of male adult Japanese monkeys were trained in 30 discrimination‐reversal learning‐set (LS) problems using the Wisconsin General Test Apparatus. A control group (N = 3) was trained in the standard procedure: acquisition of up to 12 consecutive correct responses, reversal to the same criterion, and then shift to a new problem. To the other two groups, three information trials signaling the stimulus value in reversal were given after they reached the criterion in acquisition. Subjects in the positive‐stimulus information (PSI) group (N = 4) were exposed only to the reversal positive stimulus, and a response to it was rewarded. Subjects in the negative‐stimulus information (NSI) group (N = 4) were exposed only to the reversal negative stimulus, and any response to it was not rewarded. Information trials reduced reversal errors and NSI trials were more effective than PSI trials in error reduction (p < .05). Information trials also aided in acquisition: the NSI and PSI groups learned the acquisition phase of the problems with significantly fewer errors than control group (p < .01) in the last stage of training. The implications of these results are discussed in relation to strategy learning and attention learning in LS formation.

Microsomal aldehyde oxygenase (MALDO): purification and characterization of a cytochrome P450 isozyme responsible for oxidation of 9-anthraldehyde to 9-anthracenecarboxylic acid in monkey liver.

Oxidative activity of 9-anthraldehyde (9-AA) to 9-anthracenecarboxylic acid in monkey liver was mainly located in microsomes. The reaction required NADPH as an essential cofactor and was significantly inhibited by SKF 525-A, metyrapone, disulfiram, and CO, potent inhibitors of microsomal aldehyde oxygenase (MALDO). Two cytochrome P450 isozymes, named P450JM-A and P450JM-C, which mediate the oxidative biotransformation of 9-AA were purified from hepatic microsomes of untreated male and female Japanese monkeys, respectively. These isozymes each showed a single band of molecular mass 51,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2-terminal amino acid sequences of P450JM-A and P450JM-C are highly homologous with those of several P450s belonging to the CYP2A and CYP2B subfamilies, respectively. The anti-P450JM-C antibody significantly suppressed 9-AA MALDO activity in monkey liver, but anti-P450JM-A antibody did not. The antibody against CYP2C11, which is a major isozyme responsible for 9-AA MALDO in male rat liver, also inhibited the activity. These results indicate that P450JM-C and isozyme(s) immunologically related to CYP2C11 predominantly possess MALDO activity toward 9-AA.

Stereoselectivity in bunitrolol 4-hydroxylation in liver microsomes from marmosets and Japanese monkeys.

The stereoselectivity in 4-hydroxylation of bunitrolol (BTL), a beta-adrenoreceptor blocking agent, was examined in liver microsomes from monkeys (marmosets and Japanese monkeys) and compared with the results of human liver microsomes. The formation of (+)-4-OH-BTL from (+)-BTL from (+)-BTL was significantly higher than that of (-)-4-OH-BTL from (-)-BTL in the liver microsomal fractions from the two kinds of monkeys. The 4-OH-BTL-forming activity from racemic BTL was significantly lower than from enantiomeric BTL, indicating a possible metabolic interaction between BTL enantiomers. The in vitro profiles observed in the monkeys were very similar to those in humans, but the stereoselectivity in BTL metabolism [(+)-BTL > (-)-BTL] in the primates was found to be reverse to that in rats [S. Narimatsu et al., Anal. Biochem., 222, 256-261 (1994)]. The 4-OH-BTL-forming activity from BTL enantiomers was significantly suppressed by quinidine and quinine, while the former was more potent than the latter, and also by alpha-naphthoflavone. Furthermore, the activity was also suppressed by antisera against rat cytochromes P450-2D2 and -1A2 in concentration-dependent manners. However, kinetics showed that enantiomeric BTL 4-hydroxylation was monophasic in liver microsomes from marmosets of both genders and from male Japanese monkeys. These results suggest that cytochrome P450-2D and -1A enzymes with similar Km values are involved in BTL 4-hydroxylation in monkey liver microsomes.

THE POSSIBLE ROLE OF INTRAVENTRICULAR ARGININE VASOPRESSIN IN INTRACEREBEAL ANTINOCICEPTIVE MECHANISM IN MONKEY

The role of the neurohypophysial peptide hormone arginine vasopressin (AVP), which is thought to be involved in intracerebral antinociceptive mechanism of pituitary neuroadenolysis (NALP), was examined in non restrained adult male Japanese monkeys. The effect of intraventricular administration of AVP on somatosensory evoked potentials (SSEPs) elicited by stimulation of the median nerve and on the total urine output over a 2 hr period were measured.The results were compared with those obtained by using fentanyl and U-50, 488H. AVP, fentanyl and U-50, 488H only prolonged the late-component latencies of SSEPs, and did not alter short-component latencies. Opioid antagonists, such as naloxone and MR-2266BS, had no effect. AVP reduced the urine output.D (CH2) 5, Tyr (Me) -AVP (AAVP), a potent V1 vasopressin receptor selective antagonist abolished this AVP-evoked response, but opioid antagonists such as naloxone and MR-2266BS had no effect. The present results support our conclusions that the analgesic effect of AVP on the development of antinociception in monkey is the result of its direct or indirect physiological role in non-opioid pain inhibitory systems via V1 receptors.

Analysis of the expression and the first exon of aromatase mRNA in monkey brain

To elucidate the mechanism of the region-specific expression of the aromatase in the primate brain, we investigated the distribution and level of the total aromatase mRNA and the aromatase mRNA with the exon 1-f, which was reported to be the brain-specific exon 1 of the human aromatase gene, in male Japanese monkeys. Total RNAs extracted from the hypothalamus-preoptic area (HPOA), amygdala (AMY), cerebellum, hippocampus, brainstem, five regions of cerebral cortex and four peripheral tissues: liver, kidney, adipose tissue and testis were subjected to a semi-quantitative reverse transcription-polymerase chain reaction-Southern blotting (RT-PCR-SB) assay. The levels of the total aromatase mRNA was high in the HPOA, AMY and testis with a low level of message in the other regions. These results roughly paralleled the distribution of aromatase activity of the monkey brain previously reported. The level of the aromatase mRNA with the exon 1-f was high in the HPOA and AMY, and low in the other regions of the brain and the testis with an undetectable level of the messenger in the other peripheral tissues. Furthermore, the ratio of the aromatase mRNA with the exon 1-f to the total aromatase mRNA was different among various regions of the monkey brain, for example, the ratio in the AMY was distinctly higher than that in the HPOA. These results indicated that the level of the aromatase mRNA mainly regulated the level of aromatase protein and aromatase activity in a region-specific manner, and that the exon 1-f was used in most of the monkey brain regions. Moreover, the ratio of the aromatase mRNA with the exon 1-f to the total aromatase mRNA varied in the brain regions. It was implied that the aromatase mRNA using the other first exons was also expressed in the brain and was involved in the region-specific expression of the brain aromatase.

Remarkable increase of peroxisomes in the renal tubules cells of Japanese monkeys under fasting stress

As an extention of work on peroxisome proliferation in the kidney, fine structural alteration of epithelial cells of renal tubules of male and female Japanese monkeys under fasting stress was examined. A total of 6 monkeys (male 3, female 3) for control groups and 9 monkeys (male 4, female 5) for fasting groups were used for this experiment. Both the number and area of peroxisomes per unit cytoplasmic area (number/μm 2 and μm 2 /μm 2 ) in the epithelial cells of renal tubules significantly increased in fasting groups. It was more evident in the males than in females. The activity of catalase was localized on the matrix of peroxisomes. In fasting groups peroxisomes had two or more marginal plates. Proliferated peroxisomes were hexagonal or polygonal in shape. Microperoxisomes, which are not significant in the control groups, also increased under fasting stress.

Hypothalamo-pituitary-testicular function in male Japanese monkeys (Macaca fuscata) in non-mating season

We examined seasonal changes in serum testosterone and LH, and investigated mechanisms of reduction of testicular function in non-mating season in male Japanese monkeys. Blood samples were collected monthly throughout one year in 5 males, and hCG and LH-RH were administered to 5 and 3 animals, respectively, in non-mating and mating season. Serum testosterone and LH were measured by RIA. Serum testosterone showed the obvious seasonal changes, being low in March to August and high in October to February. Also we found the seasonal changes in LH being low in May to August and high in September to February. When hCG was administered to 5 monkeys in mating season (January), serum testosterone levels increased markedly 30 to 180 min after single administration and showed further increases after continuous administrations for four days. However, in non-mating season (August), serum testosterone showed a little increase for the same treatment as in mating season. These data showed that the reserve ability of testosterone secretion in testis in non-mating season decreased obviously in contrast to mating season. The increase of serum LH and testosterone levels in 3 males in non-mating season (July) after LH-RH single administration were less than those in mating season (December). In intermediate period (September) between non-mating season and mating season, LH showed higher level than that in mating season but the testosterone level was the same extent as in non-mating season.(ABSTRACT TRUNCATED AT 250 WORDS)

オスニホンザルにおける30分間隔による24時間内繰り返し強制保定採血が血中ホルモン値に及ぼす影響

We investigated effects of frequent blood collections under the compulsory restraints on serum testosterone, LH and glucocorticoids in adult male Japanese monkeys. Blood samples were withdrawn from three animals at 30-min intervals and two animals at 4-hr intervals during 24 hr. Serum testosterone and LH were measured by a radioimmunoassay, and glucocorticoids was determined by a competitive protein binding assay. Sampling at 4-hr intervals during 24 hr revealed diurnal changes in serum testosterone and glucocorticoids. Levels of testosterone were high throughout the night and low at the day time, conversely serum glucocorticoids were high levels in the morning and low in the evening. On the other hand, 30-min intervals sampling, serum testosterone levels decreased and glucocorticoids levels increased, respectively, immediately after the start of blood sampling. And then, low in testosterone and high in glucocorticoids levels were continually maintained. But serum LH levels had the pulsatile pattern and did not change markedly during 24 hr. After ACTH administration in five animals, serum glucocorticoids levels increased markedly and also testosterone levels increased slightly, but LH levels did not change. These data indicated that the every 30-min restraint stress caused the increment of glucocorticoids levels and the suppression of testosterone levels, but did not affect the serum LH levels. The increased glucocorticoids might inhibit the testicular steroidogenesis, without suppressing the LH secretion from the pituitary.

Seasonal Changes in Plasma Concentrations of Immunoreactive Inhibin and Testicular Activity in Male Japanese Monkeys

Seasonal changes in plasma immunoreactive (ir-) inhibin, testosterone, LH, and FSH concentrations were examined in five sexually mature male Japanese monkeys (Macaca fuscata fuscata) housed indoors individually, to explore the reproductive cyclicity in the male. Blood samples were collected monthly throughout one year, and testicular size, semen volume, and number of sperm in the semen were ascertained at the same time in the same animals. Semen samples were obtained by penile electrostimulation. The results showed a clear seasonal increase in all parameters: plasma ir-inhibin, testosterone, testicular size, semen volume, and total number of sperm in the liquid portion of the semen during the autumn and winter months in synchrony with the natural breeding season. In contrast, plasma LH and FSH remained unchanged throughout the year, although plasma FSH tended to increase during the breeding season concomitant with an increase in plasma ir-inhibin. A significant positive correlation between FSH and ir-inhibin was observed in two of five monkeys. The positive correlations between plasma ir-inhibin and testicular activities during both the developing and regressing phases of the testicular cycle indicate that plasma ir-inhibin is a useful indicator of testicular activity as well as an indicator of Sertoli cell function in the Japanese monkey.

正刺激情報は間接転移にプラスにならない

Three groups of male Japanese monkeys were given two block discrimination training in WGTA. Two groups of subjects were trained in modified successive reversals. Before each reversal, one group (group PSI, n=3) was presented with positive stimulus for the next reversal and the response to it was rewarded. Another group (Group NSI, n=4) was informed of negative stimulus by being exposed to unbaited new negative stimulus. The reversals were repeated for 30 and 20 times for the first and the second blocks of training, respectively. Still another group (Group OT, n=4) was given two blocks of overtraining trials. Before, in the middle of, and after the two blocks of training, the subjects of all three groups were faced with a series of oddity task probes.

The influence of the context on mounting and presenting behaviours in male Japanese monkeys

The influence of the context on mounting and presenting behaviours in male Japanese monkeys

Initiating Ethanol Drinking in a Simian Social Group in a Naturalistic Setting

We examined in nine group-living, male Japanese Snow monkeys the initiation of alcohol-drinking behavior in an enriched environment where both social and nonsocial stimuli could influence drinking. The monkeys usually could move freely between an indoor shelter and a large outdoor corral, which contained three drinkometers. During daily 2-hr sessions in pre- and post-training periods (with food and water available ad libitum), the drinkometers held (on different days) Koolaid-saccharin, water, water with 5% ethanol, Koolaid-saccharin with 5% ethanol, or Koolaid-sucrose with acetic acid (matched in calories and palatability to Koolaid-saccharin with 5% ethanol). Between pre- and post-training periods was a long training period, in which Koolaid-saccharin with various ethanol concentrations was presented with the daily food ration in 2-hr drinking sessions. On other selected training days, water with 5% ethanol was presented. During training sessions some monkeys drank high doses; others did not. During the period of peak drinking, the daily mean ethanol consumption ranged among animals from 0.54-1.99 ml/kg. Blood ethanol concentrations then sometimes exceeded 100 mg/dl. During the post-training period, with return to ad libitum food and water, consumption declined from these peaks, but remained significantly higher than pretraining consumption; the ethanol solution was established as a reinforcer. Monkeys differed significantly in the extent of this pre/post increase. In both pre- and post-training periods, consumption was significantly greater when all three drinkometers operated, compared with only one. On pretraining days when only one drinkometer operated, more dominant animals drank significantly more than less dominant animals; this difference disappeared by the post-training period, as less dominant animals learned to use the drinkometers at times when the dominant animals eschewed the machines. Pretraining consumption did not predict (among animals) post-training consumption. Before, during, and after training, these animals drank less of both alcohol and control solutions than did members of another species, which we had studied in smaller indoor pens. We discuss possible explanations and implications.

Diagnosis of cardiac allograft rejection by the detection of circulating plasma cardiac myosin light chains

Twenty adult male Japanese monkeys of the species Macaca fuscata were randomly paired and subjected to heterotopic cardiac transplantation performed by the Ono-Lyndsey method. Without immunosuppression, graft survival ranged between 8 and 27 days, with a mean survival of 14 days. Plasma cardiac myosin light chains were measured by radioimmunoassay, which showed transient increases in myosin levels just following transplantation. Three hearts showed high values at this period and stopped beating when the myosin levels decreased (type 1). The other 7 hearts showed low myosin values after transient increases and 5 of them were rejected with a preceding reincrease in the myosin levels (type 2). Pathological study revealed myocardial necrosis, perivascular cuffing of mononuclear cells and/or neutrophils and/or plasma cells in the type 1 hearts. Measurement of the plasma myosin light chain level was therefore revealed to be of great value in the monitoring of cardiac allograft rejection.

Rise in age of sexual maturation in male Japanese monkeys at Takasakiyama in relation to nutritional conditions

A few reports have suggested the possibility that feeding conditions might affect the sexual maturation of free-ranging Japanese monkeys in provisionized troops. In the present study, the sexual maturation of male monkeys at Takasakiyama in 1984, nine years after the start of restriction of artificial feeding, was examined externally and histologically and the results were compared with data obtained in 1971, when artificial foods were abundantly given. Spermatogenesis was not observed in any of the males under 4.5 years old in the present study, whereas it was noted in some premature 3.5-year-old males and in all males over 4.5 years old in the 1971 study. The age of sexual maturation thus rose by one or more years over the 13-year period from 1971 to 1984. The lag in sexual maturation of the males at Takasakiyama in 1984 could have been induced by the restriction of artificial feeding.

Characteristics of serial cross-sections of hairs of the Japanese monkey (Macaca fuscata fuscata)

The characteristics of serial cross-sections of hairs collected from an adult male Japanese monkey were investigated. Cross-sections were made of five to eight pieces per hair. The shapes of the cross-sections were elliptical or rounded on the whole. The fibre indices of the sections ranged from 83 to 100. In particular, those of proximal (basal) sections were close to 100. The hair diameter was 86.4 µ at maximum and 27.2 µ at minimum. A tendency was observed for the longer hairs to have thicker diameters. The changes in thickness along the fibre shaft were slightly different in relation to hair length. The thickest point was at around the middle of the fibre in the intermediate hair, somewhat towards the top of the central part in the long hair, and somewhat towards the base in the short hair. The hair of the Japanese monkey, however, was considered to be scanty in changes along the fibre shaft in comparison with many other animals. Medullae could scarcely be seen in the short hair and in the terminal and proximal sections of all hairs. Their shapes in cross-section were not uniform and rough at the margins. The fibre-medulla indices were generally less than 30 and smaller than those of many other mammals. Pigmentary granules were observed in all sections examined. The granules were black-grey in sections of the black-grey coloured part and yellow in the yellowish sections. They were dense in distal sections and scarce in sections close to the base. The cross-sectional appearance of the thickest part of the long hair was considered to be useful for hair identification, since it was good in pigmentation and medullation and relatively small fibre index.