Cyclical changes in vaginal cytology and genital organs in Cynomolgus monkeys

Attia, Moncef Ben; Loget, Olivier

doi:10.1016/s0378-4274(98)80853-9

Cited by 3 publications

(2 citation statements)

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“…The endometrium of both human and nonhuman primates responds to changes in levels of steroid sex hormones by modifying its structure. Although the normal anatomic changes that occur during reproductive life are well known in women 14 and macaque monkeys, 1,5,13 the effects of various combinations of exogenous hormones can be unpredictable. Unusual combinations of proliferative, secretory, and atrophic changes involving the epithelium, stroma, and vessels of the endometrium can occur, depending on the particular hormones administered, as well as the dosage and duration of therapy.…”

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confidence: 99%

Endometrial Hyperplasia, Polyps, and Adenomyosis Associated with Unopposed Estrogen in Rhesus Monkeys (Macaca mulatta)

2002

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Abstract. The purpose of this study was to evaluate the effects of estrogen and progesterone on the vaginal mucosa and their role in vaginal transmission of simian immunodeficiency virus. Incidentally, endometrial hyperplasia was observed in estrogen-treated monkeys at necropsy. Six adult female rhesus monkeys (Macaca mulatta) were ovariectomized and 120 days later received two subcutaneous implants, each containing 200 mg estradiol. The animals were sacrificed 17-27 months later and the uterus examined at necropsy. All the monkeys had simple endometrial hyperplasia, some with polyps or adenomyosis, at the time of necropsy. The severity of the changes correlated with the time between implantation and necropsy. The lesions were similar to endometrial hyperplasia caused by unopposed estrogen in women, but occurred over a time period that is suitable for experimental manipulation. Rhesus monkeys could be used as a model to test the safety of various combinations of sex steroids for the prevention of postmenopausal symptoms in women.

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confidence: 99%

Endometrial Hyperplasia, Polyps, and Adenomyosis Associated with Unopposed Estrogen in Rhesus Monkeys (Macaca mulatta)

2002

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“…Old-World monkeys have well-documented similarities to women in terms of reproductive physiology. Endometrial and ovarian physiologies have long been regarded as nearly identical to that of women; only Old-World primates and great apes menstruate [Attia, 1998;Bellino & Wise, 2003;Hodgen et al, 1977], and there are many more subtle similarities in anatomy, development, peripheral steroid hormone metabolism, sex steroid receptor expression, and other features [Cline, 2007;Cline et al, 1996aCline et al, , 1998bCline et al, , 2002Cline et al, , 2007Cline et al, , 2008Kaiserman-Abramof & Padykula, 1989;Mahoney, 1970;Speert, 1948;Wood et al, 2006a]. These features are not shared by rodent models.…”

Section: Our Studies In Nonhuman Primates Why Nonhuman Primates?mentioning

confidence: 99%

Estrogen/isoflavone interactions in cynomolgus macaques (Macaca fascicularis)

Cline

Wood

2009

American J Primatol

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Soy isoflavones are phytoestrogenic components of dietary soy, which are widely consumed for their potential health benefits. Soy isoflavones appear to decrease breast and endometrial cancer risk in human observational studies, but paradoxically stimulate growth of breast cancer cells in culture and uterine enlargement in rodents. We have shown that these compounds are not estrogenic in cynomolgus monkeys even at relatively high doses, but that they reduce estrogen-induced proliferative responses of the breast and endometrium. This effect may be mediated through estrogen receptor interactions and/or modulation of endogenous estrogen metabolism. Interindividual variation in isoflavone absorption and metabolism contributes to the degree of estrogen antagonistic effect. Our recent studies have also shown that individual isoflavone metabolites such as glyceollins may have unique selective estrogen receptor modulator-like activity, acting as tissue-specific antagonists without agonist activity. Rodent studies and human epidemiologic data suggest that timing of exposure and dose relative to endogenous estrogen concentrations are important determinants of effect, and studies of dietary soy on breast development and pubertal maturation are under way. Because soy isoflavones are both abundant in standard monkey chow diets and widely available as dietary supplements for human beings, these findings have broad relevance to the health of human and nonhuman primates.

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Changes in the Reproductive Organs Depending on Phases of Reproductive Cycle and Aging in Female Cynomolgus Monkeys

et al. 2006

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Abstract:In order to prepare background data for toxicity studies, reproductive organs of a total of 106 purpose-bred female cynomolgus monkeys 2.0 to 9.0 years of age were surveyed for the sequence of events during reproductive cycles. Based on histological features, these animals were classified into groups according to the six phases of the reproductive cycle in addition to a group at the immature stage. Follicular phases were characterized by development of follicles and luteal phases by development of functional corpus luteum. Proliferation of endometrial glands started at the follicular phase and reached the maximum at the luteal phase. Features in the menstrual phase were almost the same as those in the follicular phases except for the shedding of superficial surface of endometrium. The percentage of animals in the phases of follicular development was 51%, and those in luteal development 46%, indicating roughly equal duration of both phases of the reproductive cycle. Absolute and relative weights of the ovaries and uterus were lowest in early follicular phase and gradually increased and reached the maximum in the early luteal phase, then decreased to the level of the early follicular phase. The difference in weight between the bigger and smaller ovaries, remarkable between 5.0 to 5.5 years of age, was at the maximum in the early luteal phase. The absolute weight of the ovaries and uterus increased rapidly and reached its peak between 5.0 to 5.5 years of age and remained unchanged thereafter, although the body weight gradually increased up to 9.0 years of age. (J Toxicol Pathol 2006; 19: 169-177)

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Cyclical changes in vaginal cytology and genital organs in Cynomolgus monkeys

Cited by 3 publications

References 0 publications

Endometrial Hyperplasia, Polyps, and Adenomyosis Associated with Unopposed Estrogen in Rhesus Monkeys (Macaca mulatta)

Endometrial Hyperplasia, Polyps, and Adenomyosis Associated with Unopposed Estrogen in Rhesus Monkeys (Macaca mulatta)

Estrogen/isoflavone interactions in cynomolgus macaques (Macaca fascicularis)

Changes in the Reproductive Organs Depending on Phases of Reproductive Cycle and Aging in Female Cynomolgus Monkeys

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