Reduction of polyovular follicles and polynuclear ova by estradiol monobenzoate

Kent, Harry A.

doi:10.1002/ar.1091340308

Cited by 15 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the tenrec, litter size is related to the number of oocytes which are shed, and polyovulation therefore may increase the number of conceptuses. Polyovular follicles in other species are usually observed in immature individuals (Hartman, 1926;Kent, 1959Kent, , 1960Kent, , 1962Bodemer & Warnick, 1961a, b;Leach & Conaway, 1963;Collins & Kent, 1964;Shehata, 1974). Kent & Mandel (1968) suggest that polyovular follicles and polynuclear oocytes are abundant immediately following the period when circulating oestrogens are at their lowest level.…”

Section: Discussionmentioning

confidence: 99%

Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus)

Nicoll¹,

Racey²

1985

Reproduction

View full text Add to dashboard Cite

Reproduction in female tenrecs was studied on Praslin Island (4 degrees 20'S, 55 degrees 45'E) in the Seychelles from November 1977 to September 1980. Dissection and histological examination of reproductive tracts revealed that each ovary is encapsulated in a bursa. Polyovular follicles were abundant and contained up to 5 oocytes. The occurrence of more implanted fetuses than corpora lutea (CL) indicated successful polyovuly in 25% of pregnancies. No antrum was observed during follicular growth at oestrus, and follicles were relatively small at maturation, reaching a maximum diameter of 570 microns. Ovulation involves a gentle extrusion of the granulosa and ovum into the periovarian space. Spermatozoa were abundant in the female reproductive tract including the periovarian space at oestrus. Spermatozoa penetrated the loosely-packed theca of mature follicles and were present in CL, indicating that intrafollicular fertilization may occur. The relatively small CL formed by eversion, reaching a maximum size after implantation. Fusion of up to four CL occurred in the ovaries of 41% of pregnant females. Polyovulation in the tenrec was confirmed by the occurrence of 10.4 +/- 0.5 (mean +/- s.e.m.) CL and 9.7 +/- 0.5 (mean +/- s.e.m.) implantations. Resorption occurred in 74% of 19 dissectable pregnancies, occurring in both uterine horns in 26% of pregnancies. Coefficients of variation in weights of fetuses in each litter were 10.0-26.8%, with the largest value corresponding to 273% variation in fetus weights. Litter size in the Seychelles tenrecs was smaller than in the same species in Madagascar (17.1 +/- 1.9 implantations) where the tenrec is native.

show abstract

Section: Discussionmentioning

confidence: 99%

Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus)

Nicoll¹,

Racey²

1985

Reproduction

View full text Add to dashboard Cite

show abstract

“…Kent [1958] obtained a reduction of polyovular follicles and poly nuclear ova by pituitary extracts. Moreover, Kent (19591 was able to produce a reduction of polyovular follicles and polynuclear ova in golden ham sters by estradiol inonobenzoate injections.…”

Section: Discussionmentioning

confidence: 99%

“…This proves th a t the production of these unusual phenomena takes place under horm onal control. Kent [1959] assum ed th at the underlying factor is a deficient estrogen condition in the young anim al, and postulated | Kent, 19621 th a t the action of estradiol monobenzoate is by indirect effect through the pituitary gland.…”

Section: Discussionmentioning

confidence: 99%

Polyovular Graafian follicles in a newborn kitten with a study of polyovuly in the cat

Shehata¹

1974

Cells Tissues Organs

View full text Add to dashboard Cite

“…Bacsich (3) suggested, that their presence in early life may be linked to the withdrawal of maternal gonadotrophin hormones or estrogens at the time of birth. Polynuclear oocytes have often been described in the ovaries of immature animals of many species (10,13,16,17,18,19). Administration of estrogen reduced the number of polynuclear oocytes normally seen in the hamster ovary (17).…”

Section: Discussionmentioning

confidence: 99%

“…Polynuclear oocytes have often been described in the ovaries of immature animals of many species (10,13,16,17,18,19). Administration of estrogen reduced the number of polynuclear oocytes normally seen in the hamster ovary (17). It is suggested, that the persistence of binuclear oocytes in the cases of Down's syndrome might be the result of a low estrogen level.…”

Section: Discussionmentioning

confidence: 99%

Follicular Development in Ovaries of Children With Down's Syndrome

Højager¹,

Peters²,

Byskov³

et al. 1978

Acta Paediatrica

View full text Add to dashboard Cite

Ovaries of children with Down's syndrome were examined histologically in order to determine in what way the ovarian development differed from the normal. Twenty-six specimens obtained at autopsy at various ages between birth and 14 1/2 years were available and compared with ovaries from normal children of similar ages. All ovaries from normal children were characterized by active follicle growth. The ovaries of the children with Down's syndrome, however, showed absence or retardation of follicle growth. Furthermore the number as well as the size of the antral follicles differed from those in the normal ovary. The decrease of the number of small follicles occurs earlier in life in the ovaries of children with Down's syndrome than in the control. The possible relationship between an abnormal ovarian growth pattern and hormonal imbalance is discussed.

show abstract

Reduction of polyovular follicles and polynuclear ova by estradiol monobenzoate

Cited by 15 publications

References 7 publications

Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus)

Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus)

Polyovular Graafian follicles in a newborn kitten with a study of polyovuly in the cat

Follicular Development in Ovaries of Children With Down's Syndrome

Contact Info

Product

Resources

About