Ovarian Support of Pregnancy in Ageing Inbred Mice

Gosden, Roger G.

doi:10.1530/jrf.0.0420423

Cited by 26 publications

(11 citation statements)

References 18 publications

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“…In the present study, observations made on Day 1 of pregnancy reveal that ovulation rates were similar in the young and 10-mo rats, whereas the ovulation rate was significantly decreased in the 13-mo females. While an eventual decline in ovulation rate occurs in aging mice, rats, and hamsters (Jones and Krobn, 1961;Thorneycroft and Soderwall, 1969;Harman and Talbert, 1970;Connors et al, 1972;Gosden, 1975;Man et aL, 1987), the present study substantiates previous observations that implantations and litter sizes have already been reduced prior to a decline in ovulation rate (Blaha, 1964;Thorneycroft and Soderwall, 1969;Harman and Talbert, 1970;Parkening and Soderwall, 1973;Man ci al., 1987). The two middle-aged groups examined in this study represent female rats that either experienced no significant reduction in ovulation rate (10-mo group) or those that did (13-mo group).…”

Section: Embryonicmentioning

confidence: 99%

An Abnormal Pattern of Embryonic Development during Early Pregnancy in Aging Rats1

Day¹,

Polt²,

Morales³

et al. 1989

Biology of Reproduction

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There is recent evidence that a decline in fertility and litter size precedes the cessation of regular estrous cyclicity in middle-aged female rats. This decline in litter size is related to a decrease in the number of normal blastocysts that are present on Day 5 of gestation, immediately prior to implantation. Thus, the pattern of embryonic development during the first 5 days of pregnancy may be altered in middle-aged rats, resulting in fewer implanting embryos and smaller litter sizes. The present study examined the ovulation rates, fertilization rates, and the patterns of embryonic development in regularly cyclic, young and middle-aged females during the first 5 days of pregnancy. Examination of the numbers of ovulated ova revealed that the ovulation rate was significantly reduced in 12- to 14-mo-old females (13 mo; 9.0 +/- 1.0/rat), but not in 9- to 11-mo-old females (10 mo; 12.2 +/- 0.8/rat), as compared to that in young animals (12.8 +/- 1.0/rat). However, there was no decrease in fertilization rate in either the 10-mo or 13-mo group. While the total numbers of embryos present on Days 2-5 were similar among all 3 groups, embryos from 10-mo females displayed a delayed pattern of development and an increased incidence of morphological abnormalities. These changes in embryo development were even more pronounced in the 13-mo group. By Day 5 of pregnancy there was a significant reduction in normal blastocysts in 10-mo (7.3 +/- 1.2/rat) and 13-mo (6.0 +/- 1.6/rat) rats, as compared to young females (10.6 +/- 0.9/rat).(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Embryonicmentioning

confidence: 99%

An Abnormal Pattern of Embryonic Development during Early Pregnancy in Aging Rats1

Day¹,

Polt²,

Morales³

et al. 1989

Biology of Reproduction

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“…All organs of the reproductive system have been implicated as the prime organs for initiating a decline in the litter size of laboratory rodents (for recent reviews see Peluso, 1976;Steger, 1976;Finch, 1977Finch, , 1978Talbert, 1977Talbert, , 1978Soriero, 1978;Meites, Huang & Simpkins, 1978). The hypothalamic-hypophysial complex is thought by many researchers to be the primary cause of reproductive senescence (Aschheim, 1964/5;Labhsetwar, 1970;Howland & Preiss, 1975;McPherson, Costoff & Mahesh, 1977;Huang, Steger, Bruni & Meites, 1978;Riegle & Miller, 1978), although others consider an ageing ovary which is no longer capable of responding to or secreting hormones largely to blame (Thorneycroft & Soderwall, 1969;Blaha, 1970; Gosden, 1975;Leathern & Murono, 1975;Chan & Leathern, 1977). The advent of techniques for the radioimmunoassay of hormones has led to studies on aged laboratory rats to determine which part of the reproductive system is influenced first or to the greatest degree by the ageing process (Howland & Preiss, 1975;McPherson et al, 1977;Huang et al, 1978;Riegle & Miller, 1978).…”

Section: Introductionmentioning

confidence: 99%

Plasma and pituitary concentrations of LH, FSH and prolactin in aged female C57BL/6 mice

Parkening¹,

Collins²,

Smith³

1980

Reproduction

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Plasma and pituitary concentrations of LH, FSH and prolactin were determined by radioimmunoassay in 2-month-old (young) and 16-20-month-old (old) C56BL/6 mice. There were no statistical differences in hormonal levels between aged females in oestrus (those exhibiting a copulatory plug) and those in constant dioestrus. In the old females plasma levels of LH (P < 0.002) and FSH (P < 0.001) were significantly elevated, while levels of prolactin (P < 0.001) were significantly depressed when compared with those from young animals. Pituitary homogenates from old females also contained more gonadotrophins (P < 0.001) and less prolactin (P < 0.001) than those of the young females. A radioreceptor assay utilizing a plasma membrane of luteinized rat or mouse ovaries indicated that LH from 2-month-old animals bound better to ovarian receptors (P < 0.05) than did LH from old mice, although radioimmunoassay of the same samples gave higher (P < 0.01) plasma LH levels for the old mice. Since the radioreceptor assay is considered to be a more sensitive test for biologically active LH, the results from these two types of assays suggest that there may be an alteration in the mouse LH molecule with age.

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“…Since a sufficient number of follicles persist in the ovary and ovulation is proceeding at relatively con stant rale throughout this period [13], the failure of a blas tocyst to implant or of the embryo to develop may be due to defects in the oocyte itself or a failure of the uterus to provide suitable conditions for implantation and em bryonic development. Reciprocal transfer of embryos have been made between young (10-week-old) and old 34 Tsu tsu m i/Ta keta n i/Oka Epidermal Growth Factor and Fertility (40-week-old) female mice and indicate lliat the major cause of infertility is due to aging in the uterus [3.…”

Section: Discussionmentioning

confidence: 99%

Evidence for the Involvement of Epidermal Growth Factor in Fertility Decline in Aging Female Mice

Tsutsumi

Taketani²,

Oka³

1993

Horm Res

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A decline in fertility, defined as the number of implantation sites, was observed in mice as they aged; the decline started at 30 weeks of age and reached a nadir by 60 weeks when no implantation was detected. Epidermal growth factor (EGF) levels in the submandibular gland and plasma increased as the female mice aged, and sialoadenectomy (surgical removal of the submandibular glands) attenuated the rise in the plasma EGF level without affecting the overall health or survival of the animals. Uterine weight at 10-20 weeks of age was about 70 mg, and it significantly increased with age. This weight has increased more than 2-fold by 60 weeks. These changes closely followed the increase in the concentrations of EGF in the submandibular gland and the plasma. After sialoadenectomy, uterine weight decreased immediately and remained at about 50-60 mg throughout the experimental period. Interestingly, sialoadenectomized mice became pregnant at an older age than the controls. These findings suggest that elevated levels of EGF may have a physiological role in fertility decline in aging mice perhaps via uterine hypertrophy.

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Ovarian Support of Pregnancy in Ageing Inbred Mice

Abstract: Summary. The

Cited by 26 publications

References 18 publications

An Abnormal Pattern of Embryonic Development during Early Pregnancy in Aging Rats1

An Abnormal Pattern of Embryonic Development during Early Pregnancy in Aging Rats1

Plasma and pituitary concentrations of LH, FSH and prolactin in aged female C57BL/6 mice

Evidence for the Involvement of Epidermal Growth Factor in Fertility Decline in Aging Female Mice

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