The cynomolgus monkey (Macaca fascicularis) is the best animal model for the study of steroid glucuronidation

Intense research efforts performed during the past decade clearly established the major role of glucuronidation and uridine-diphospho-glucuronosyltransferase (UGT) enzymes for steroid metabolism in humans. However, a clear understanding of the physiological importance of this metabolic process requires in vivo studies. Numerous evidences ascertain that simians are the most appropriate animal models for such studies. Indeed human and monkey have a similar pattern of steroidogenesis, unlike common laboratory mammals such as rat or mouse. Furthermore, human and monkey are unique in having high levels of circulating androsterone glucuronide and androstane-3-diol glucuronide (3-Diol-G). In addition, characterization of eight monkey UGT proteins demonstrated the similarity of their conjugation activity toward steroid hormones. Like human ones, monkey enzymes are expressed in steroid target tissues, where they preferentially glucuronidate androgen and estrogen metabolites. In monkey tissues, immunohistochemical studies demonstrated that UGT2B proteins are expressed in a cell-type specific manner in ovary and kidney, where they control androgens and aldosterone inactivation. These results identify the cynomolgus monkey as an appropriate animal model for the determination of cellular localization of UGT enzymes in steroid target tissues and for the identification of endogenous or exogenous stimuli affecting steroid glucuronidation.     

Successful artificial insemination for indoor breeding in the Japanese monkey (Macaca fuscata) and the cynomolgus monkey (Macaca fascicularis)

Methods of artificial insemination (AI) for indoor breeding in the Japanese monkey and the Cynomolgus monkey were investigated. For the Japanese monkey AI was carried out in six females during the winter mating season and in six females during the summer non-mating season. During the mating season, semen was inseminated near ovulation time in natural menstrual cycles. In the mating season study, three females inseminated at the uterine cavity became pregnant. Three inseminated at the cervical canal failed to become pregnant. For the non-mating season study, ovulation was induced artificially by PMSG and hCG and AI was carried out near the induced ovulation time. In the non-mating season, no animals became pregnant. Of four Cynomolgus monkeys used, pregnancy occurred in two animals inseminated near ovulation time in natural menstrual cycles. AI occurred at the uterine cavity in one and cervical canal in the other. In both species ovulation was verified by laparoscopy. Semen was collected by penile electro-stimulation then diluted to 2.5 to 5.0×10⁷/ml with Whitten's medium. Diluted semen of 0.2l was inseminated at the uterine cavity or cervical canal. Our results indicate the usefulness of vaginal AI as a method of artificial indoor breeding.     

A case of acardiac anomaly in the cynomolgus monkey (Macaca fascicularis): a complication of monozygotic monochorial twinning

A case of acardius acephalus in a Macaca fascicularis is reported. This congenital anomaly occurs only in multiple-birth gestations (most commonly monozygotic twins). Artery-to-artery and vein-to-vein anastomoses appear to be a constant feature. This condition is very rare in man and probably even more so in monkeys. Classification and theories on etiology are discussed.     

Vitrification and transfer of cynomolgus monkey (Macaca fascicularis) embryos fertilized by intracytoplasmic sperm injection

Protocols for cryopreservation of monkey embryos are not well established. The objective of the current study was to determine the efficacy of the polypropylene strip method for cryopreserving cynomolgus monkey embryos. Cynomolgus monkey embryos, 63 and 56 at the 4- to 8-cell and 56 blastocyst stages, respectively, were produced by intracytoplasmic sperm injection and in vitro culture, and vitrified using a polypropylene strip. For these two stages, 95 and 86% survived after thawing and pregnancy rates were 29.2% (7 pregnant females/24 recipients, with three live births) and 0% (n = 16 recipients). These were apparently the first live births obtained from embryos fertilized by ICSI. In conclusion, 4- to 8-cell preimplantation cynomolgus monkey embryos were successfully cryopreserved using a polypropylene strip.     

Familial early onset macular degeneration in cynomolgus monkeys (Macaca fascicularis)

The mode of inheritance of macular degeneration was determined with 45 cynomolgus monkeys (18 females and 27 males) who were the offspring of one breeding male with typical macular degeneration. In the first generation, 27 offspring (10 females and 17 males) were born from mating between the macular degeneration-affected founder male and 5 normal female breeders. Among them, 18 monkeys (9 females and 9 males) were judged as having macular degeneration (affected). Next, the distribution of affected offspring was examined with 18 offspring who were born from 3 different mating pairs, normal vs normal, affected vs normal and affected vs affected, when they became 2 years old. All of the 9 monkeys (4 females and 5 males) obtained from the 2 pairs of normal vs normal were normal. On the other hand, 6 affected monkeys (3 females and 3 males) were detected in 8 offspring from the mating pair of affected vs normal, and the single offspring produced by the mating pair of affected vs affected was affected. These results showed that this degeneration must be early onset familial macular degeneration controlled by autosomal dominant gene(s).     

Occurrence of spontaneous diabetes mellitus in a cynomolgus monkey (Macaca fascicularis) and impaired glucose tolerance in its descendants

Spontaneous diabetes mellitus was diagnosed in a cynomolgus monkey. Clinical and pathological features, such as abnormal glucose tolerance, loss of insulin response, or degeneration of pancreatic beta-cells, resemble human noninsulin-dependent diabetes mellitus. Two descendants of the monkey have developed impaired glucose tolerance and insulin response. Genetic factors seem involved in the appearance of carbohydrate intolerance in this family group of monkeys.     

Establishment of a B-lymphoblastoid cell line infected with Epstein-Barr-related virus from a cynomolgus monkey (Macaca fascicularis)

A B-lymphoblastoid cell line (Ts-B) was established from lymph nodes of an apparently healthy cynomolgus monkey. The cells were demonstrated to contain Epstein-Barr virus-related antigens. Moreover, herpesvirus particles were found in the cells by electron microscopy. The cell-free culture medium transformed lymphocytes of cynomolgus rhesus monkeys, and of Japanese monkeys.     

Morphological characterization of ejaculated cynomolgus monkey (Macaca fascicularis) sperm

The aim of this study was to give reference values for the frequency of morphological sperm abnormalities present in the semen from nonexperimental cynomolgus monkeys as well as for the dimensions of sperm heads. Spermatozoa from the liquid portion of electroejaculates from 14 cynomolgus monkeys were air‐dried as smears, fixed, and stained with Harris's Haematoxylin and subjected to visual analysis of morphology and computer‐aided analysis of ten morphometric variables. The majority (83%) of sperm were morphologically normal. Tail defects were the most common (11%), and showed the highest variation between individuals, the values ranging between 4 and 23%. Head abnormalities consisted of large, tapering, and amorphous forms but were not frequent (0.4%), the values ranging between 0 and 1.3%. Midpiece imperfections were found in all the individuals; the mean percentage was 5%, and the range varied between 3 and 9%. Tail plus midpiece was the only multiple abnormality observed, with a mean value of 1.5% and a range between 0 and 8%. The majority of these double defects consisted of a coiled tail together with a coiled midpiece. Mean values for the morphometric parameters characterizing sperm heads were as follows: area 17.2 μm², perimeter 15.2 μm, length 5.8 μm, width 4.0 μm, L/W ratio 1.5, gray‐level 98, ellipticity 0.2, first shape factor 0.9, second shape factor 1.4, and third shape factor 1.1. Overall coefficients of variation for the majority of parameters were below 7%, showing the great homogeneity in the dimensions of cynomolgus sperm heads. Most useful parameters for sperm characterization, according to their low variability, were perimeter, length, width, L/W ratio, and shape factors. Differences in these parameters were, however, observed between monkeys. Am. J. Primatol. 47:105–115, 1999. © 1999 Wiley‐Liss, Inc.     

Isolation and culture of hepatocytes from the cynomolgus monkey (Macaca fascicularis)

Summary Isolation and culture techniques for hepatocytes from whole livers of the cynomolgus monkey,Macaca fascicularis, are described. Hepatocytes were isolated by two-step perfusion of livers, using collagenase with hyaluronidase; fructose and trypsin inhibitor were included to reduce cell loss. Yields from a single liver average 4×10⁹ cells with viabilities of 90.8±5.7%. Cells, plated on collagen substrates, were assessed for changes in morphology and various marker enzyme activities over a period of 7 d in culture. Cells exhibited a morphology similar to that observed for this species in vivo; little change in attached and spread cells was observed over the length of time monitored. Enzyme activities for catalase, succinate dehydrogenase, and tyrosine aminotransferase were observed to decrease significantly (though considerable activity remained), whereas acid phosphatase and 5′-nucleotide phosphodiesterase remained unchange. Activity of cytochrome P-450 reductase was observed to increase slightly for the first 2 d, then decrease to about 60% of initial levels. Activity of α-mannosidase was stable for 4 d but was observed to be increased at Day 7. Cells were observed to retain metabolic responsiveness demonstrated by glucose production by both gluconeogenesis and glycogenolysis in response to glucagon stimulation. The monkey hepatocytes obtained by methods described here thus retain hepatocellular morphology and activity through at least 1 wk in culture without medium or culture modification.     

A Flexible Restraint Chair for the Cynomolgus Monkey (Macaca fascicularis)1

We have found that commercial restraint chairs suitable for the rhesus monkey (Macaca mulatta) cause severe physical distress to many cynomolgus monkeys (Macaca fascicularis). A new restraint chair has therefore been designed specifically for the cynomolgus. The key features of the chair are an angled neck piece, a large opening to provide free movement for the tail, a soft waist restraint, and a level surface for both the heels and ischial pads. This new chair is not only suitable for the cynomolgus monkey but may also be more comfortable for the rhesus monkey than standard commercial chairs.     

食蟹猴取食位置偏好及改变的行为学研究

正偏好行为被认为是研究大脑半球功能偏侧性调控表达的一种预测指标(Elias et al.,1998)。偏好行为与大脑解剖结构和功能不对称之间关系的研究表明人类明显偏爱使用右手,是由大脑左半球控制(Zhao et al.,2010;崔媛媛,2012;付卫伟,2012),而手偏好正是大脑皮层结构和功能不对称最基本的行为表现,是大脑半球特化的一个行为标     

The cynomolgus monkey (Macaca fascicularis) is the best animal model for the study of steroid glucuronidation

Intense research efforts performed during the past decade clearly established the major role of glucuronidation and uridine-diphospho-glucuronosyltransferase (UGT) enzymes for steroid metabolism in humans. However, a clear understanding of the physiological importance of this metabolic process requires in vivo studies. Numerous evidences ascertain that simians are the most appropriate animal models for such studies. Indeed human and monkey have a similar pattern of steroidogenesis, unlike common laboratory mammals such as rat or mouse. Furthermore, human and monkey are unique in having high levels of circulating androsterone glucuronide and androstane-3α-diol glucuronide (3α-Diol-G). In addition, characterization of eight monkey UGT proteins demonstrated the similarity of their conjugation activity toward steroid hormones. Like human ones, monkey enzymes are expressed in steroid target tissues, where they preferentially glucuronidate androgen and estrogen metabolites. In monkey tissues, immunohistochemical studies demonstrated that UGT2B proteins are expressed in a cell-type specific manner in ovary and kidney, where they control androgens and aldosterone inactivation. These results identify the cynomolgus monkey as an appropriate animal model for the determination of cellular localization of UGT enzymes in steroid target tissues and for the identification of endogenous or exogenous stimuli affecting steroid glucuronidation.     

Characterization of an immortalized oviduct cell line from the cynomolgus monkey (Macaca fascicularis)

To establish reproductive biological techniques in mammals, it is important to understand the growth environment of the embryo. Oviduct epithelial cells are in close proximity to the embryo during pre-implantation development. We, therefore, established an immortalized oviduct epithelial cell line from the cynomolgus monkey, evaluated the usefulness of these cells as feeder cells for embryo culture, and investigated the gene expression of several growth factors and cytokines in the cells. The immortalized cells were positive for the anti-cytokeratin antibody, as determined by immunocytochemistry, indicating that they are epithelial. They also expressed oviductin, which is specific to oviduct epithelial cells, glyceraldehyde-3-phosphate dehydrogenase (control), leukemia inhibitory factor, vascular endothelial growth factor, epidermal growth factor, insulin-like growth factor 1, transforming growth factor beta-2, and interleukin 4. Mouse embryo development was improved when the immortalized cells were used as feeder cells. This cell line is also useful for studying the factors secreted by oviduct epithelial cells.     

Pregnancy-induced sclerosis in the myometrial vessels of cynomolgus monkeys (Macaca fascicularis)

Sclerotic changes were found histologically in the myometrial vessels of 27 out of 33 cynomolgus monkeys (Macaca fascicularis). The sclerosis was composed of fibrous proliferations and intimal thickening. These changes were not observed in nulliparous cases, but were found only in multiparous ones. The findings suggest that the sclerotic changes in the myometrial vessels of cynomolgus monkeys are a pregnancy-induced phenomenon.     

Alkaptonuria in a cynomolgus monkey (Macaca fascicularis)

An eight year old wild caught Cynomolgus monkey was diagnosed as having alkaptonuria, a condition characterized by the passage of a normal-colored urine which darkens upon standing. The underlying cause is the congenital lack of homogentisic acid oxidase with subsequent passage of homogentisic acid in the urine. No other clinical manifestations, such as deposition of pigment in the skin or mucous membranes or development of an ochronitic arthritis, were observed in this animal.     

Cryopreservation of cynomolgus monkey (Macaca fascicularis) hepatocytes for subsequent culture and protein synthesis studies

Summary A method is described for the preservation and subsequent recovery of hepatocytes obtained by collagenase perfusion of cynomolgus monkey (Macaca, fascicularis) livers. The fresh cells are suspended in fetal bovine serum containing 10% dimethylsulfoxide and, using a microprocessor-controlled, liquid nitrogen freezing chamber and a specific cooling protocol, processed in such a way that they can be stored in liquid nitrogen for several months and still restored to active culture. When the cryopreserved cells were established in culture they were found to actively synthesize and secrete both albumin and apolipoprotein A-I. That, taken together with morphologic evidence, was viewed as indication that the cells recovered in culture were in fact hepatocytes and not some other cell type from the monkey liver. The availability of this procedure for storing hepatocytes should contribute significantly to the efficient use of nonhuman primates as models with which to study hepatic metabolism.     

Spontaneous endometriosis in a cynomolgus monkey (Macaca fascicularis)

An adult female Macaca fascicularis developed anorexia and minimal fecal production. Abdominal palpation was unrewarding. Rectal palpation revealed a rectal stricture and a large soft tissue mass in the area of the uterus. Clinical pathology tests were within normal limits. Exploratory surgery and histopathology confirmed a diagnosis of endometriosis.     

Ameloblastic odontoma in a cynomolgus monkey (Macaca fascicularis)

An ameloblastic odontoma occurred in an adult cynomolgus monkey (Macaca fascicularis). The neoplasm involved the upper left maxilla as a disfiguring, fleshy growth. The tissue and cellular changes were consistent with an ameloblastic odontoma which is rare in man, nonhuman primates (NHP), and other vertebrate animals. The monkey was one of 50 adult, single-caged housed cynomolgus monkeys. No additional clinical signs of disease were present. Hematology and serum chemistries were within normal limits. There have been three reports in the literature of ameloblastic odontomas in NHP; however, this is the first reported case of an ameloblastic odontoma in a cynomolgus monkey.     

Early embryonal culture of the cynomolgus monkey (Macaca fascicularis)

Ovaries of ten female cynologus monkeys (Macaca fascicularis) were superstimulated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). During this treatment, follicular development was monitored by ultrasonography. After three to four injections of PMSG, ovaries began to show an increase in their size. After seven to ten injections of PMSG and a hCG injection, a total of 183 oocytes (18.3±14.1/ animal, mean±SD) were recovered from these females by laparotomy. Five nulliparous females produced 24.2±18.2 oocytes per animal, and the remaining five parous females produced 12.5±5.46 oocytes per animal. In total, 133 (72.6%) of the 183 oocytes were classified morphologically as matured, and 130 of them were inseminated with cynomolgus monkey sperm for 18 hours in vitro. The second polar body was observed in 92 (71%) of the inseminated oocytes, and 54 (59%) of the 92 oocytes showed cleavage division at least once. When these oocytes were fertilized and cultured in serum-free media, they stopped their development at 4-cell stage. In contrast to this condition, about a half of fertilized oocytes in serum-free media were able to develop to morula stage 4 days after insemination by transferring them into serum-containing media after 2-cell stage.