Oestrogen Synthesis in Vitro by Ovaries From Rats in Different Phases of the Oestrous Cycle

Oakey, R. E.; Stitch, S. R.

doi:10.1677/joe.0.0390189

Cited by 7 publications

(4 citation statements)

References 13 publications

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“…Estrogen synthesis in the Graafian folli- Endo • 1975 Vol 96 • No 3 cle has been demonstrated in several species, such as cow (19), pig (20), rabbit (21,22,23), sheep (24), and human (25,26). Although it is generally theorized that the theca are the estrogen-producing cells of the Graafian follicle (1,4,14) there has been experimental evidence that the granulosa cells contribute to estrogen production.…”

Section: Discussionmentioning

confidence: 99%

Progesterone, Androstenedione, Testosterone, Estrone, and Estradiol Synthesis in Hamster Ovarian Follicle Cells

1975

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Isolated granulosa cells and theca from proestrous hamsters alone and in recombination, were cultured in order to study steroidogenic capacity of this tissue. Cells from medium size antral follicles (100-300 mum diam.) and large preovulatory follicles (500 plus mum diam.) were used. Steroids were measured by radioimmunoassay. Cultures of cells derived from both sizes of follicles made significant amounts of progesterone for up to 6 days in tissue culture. The preparations from the medium sized antral follicles synthesized little or no estrogen. Of the cells harvested from the preovulatory follicles, the granulosa and theca made moderate amounts of estradiol-17beta while the recombined system made similar to 5 times the estradiol-17beta made by theca or granulosa alone. The results indicate that in the in vitro system used: 1) The hamster follicle cells are similar to other species in that they spontaneously luteinize in culture and secrete large amounts of progesterone, 2) Androgen accumulation is greatest in media from cultured theca of preovulatory follicle, 3) A synergism between theca and granulosa of the large preovulatory follicle exists to effect maximal estrogen synthesis, and 4) Estrogen synthesis is short-lived in vitro in contrast to continued progesterone production.

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Section: Discussionmentioning

confidence: 99%

Progesterone, Androstenedione, Testosterone, Estrone, and Estradiol Synthesis in Hamster Ovarian Follicle Cells

1975

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“…Experiments on the direct stimulatory effect of LH on ovarian aromatizing enzymes have not been done by others. However, numerous indirect experiments indicate that this site of action exists (Rabinowitz & Dowben, 1955;Cedard, Varangot & Yanotti, 1964;Gospodarowicz, 1964;Oakey & Stitch, 1967;Kalvert & Bloch, 1968;Villee, Channing, Sulivich & Eckstein, 1969). The placental studies of Cedard, Alsat, Ego & Varangot (1968) clearly demonstrated that LH in vitro exerts a stimulatory action on androgen aromatization.…”

Section: Discussionmentioning

confidence: 99%

Studies on Tissue Culture of Equine Ovarian Cell Types: Effect of Gonadotrophins and Stage of Cycle on Steroidogenesis

Channing¹

1969

Journal of Endocrinology

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Granulosa cells were harvested from follicles of mares at various stages of the oestrous cycle and maintained in a tissue culture medium containing 15% horse serum, 30% medium '199' and 55% Hanks's solution. Between days 4 and 10 of culture the granulosa cells harvested from small follicles (1-2 cm. diam.) of mares in the midluteal phase of the cycle secreted an average of 0\m=.\36 pg. progesterone/cell/day. Cells harvested from large follicles of mares in the late and/or early oestrous stage of the cycle secreted an average of 29\m=.\5 pg. progesterone cell/day; the cells harvested from the large vascular follicles found at oestrus secreted an average of 173 pg./cell/ day. The small, poorly vascularized follicles found adjacent to the large vascular follicles of mares in oestrus yielded cells which secreted less progesterone than those from the larger follicles.Addition of 5 to 10 i.u. human chorionic gonadotrophin (HCG)/ml. at each medium change (every 2\p=n-\3 days) or for the first 4 days of culture brought about a marked stimulation of progesterone secretion in cultures of ' mi d\x=req-\ luteal phase' cells which was maximal after 4 to 7 days.Pregnenolone was converted primarily to progesterone, 20\g=a\-hydroxypregn-4-en-3-one and 17-hydroxyprogesterone; the metabolism was not significantly altered by the addition of a mixture of 10 i.u. HCG plus 10 i.u. pregnant mare serum gonadotrophin (PMSG). Cells harvested from mares in oestrus converted pregnenolone to progesterone in a higher yield compared with cells harvested from mares in the midluteal phase of the cycle. Addition of 10 i.u. HCG/ml. or PMSG plus HCG (10 i.u. each/ml.) stimulated aromatization of testosterone by 'midluteal phase' cultures but not by 'oestrous phase' cell cultures.These results demonstrate that the in vivo environment as well as the in vitro conditions influence the steroidogenic activity of equine granulosa cell cultures.

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“…However, the rate of synthesis of radioactive oestrone and oestradiol-17/? from labelled 4-androstene-3,17-dione was found to be independent of the oestrous state of the donor animals (Oakey & Stitch, 1967). It may be con¬ cluded from comparison of our results with the concentration of oestrogens in ovarian vein and peripheral plasma (Yoshinaga et al 1969;Brown-Grant et al 1970 In the experiments aimed to detect an effect of added gonadotrophin on [14C]-oestrogen synthesis, the particular experimental design used was selected to minimize problems associated with the variability in samples of ovarian tissue.…”

Section: Methodsmentioning

confidence: 70%

“…Previous studies from this labora¬ tory have identified [14C]oestrone and [14C]oestradiol-17/? as metabolites of [14C]-testosterone incubated with rat ovaries in vitro, following similar purification pro¬ cedures (Stitch, Oakey & Eccles, 1963;Oakey & Stitch, 1967).…”

Section: Methodsmentioning

confidence: 99%

Oestrogen Synthesis in Rat Ovaries in Vitro: Effects of Endogenous and Exogenous Gonadotrophins

Robinson¹,

Oakey²

1972

Journal of Endocrinology

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The rate of synthesis of [14C]oestrone and [14C]oestradiol-17\g=b\ from [14C]testosterone in vitro by ovaries from rats at different stages of the oestrous cycle was measured. The rate of [14C]oestrogen synthesis was highest in ovaries taken from rats in pro-oestrus and lowest in ovaries taken from rats early in the dioestrous phase of the cycle. Rates of synthesis in ovaries obtained from rats in the late dioestrous stage were intermediate between the rates of the other groups. The rates of [14C]oestrogen synthesis at these periods of the cycle paralleled the concentrations of oestrogens in ovarian vein plasma reported by other authors.Gonadotrophin preparations with either luteinizing hormone activity or both follicle-stimulating hormone and luteinizing hormone activities had no effect on [14C]oestrogen synthesis by rat ovaries in vitro at any of these stages of the oestrous cycle.

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Oestrogen Synthesis in Vitro by Ovaries From Rats in Different Phases of the Oestrous Cycle

Cited by 7 publications

References 13 publications

Progesterone, Androstenedione, Testosterone, Estrone, and Estradiol Synthesis in Hamster Ovarian Follicle Cells

Progesterone, Androstenedione, Testosterone, Estrone, and Estradiol Synthesis in Hamster Ovarian Follicle Cells

Studies on Tissue Culture of Equine Ovarian Cell Types: Effect of Gonadotrophins and Stage of Cycle on Steroidogenesis

Oestrogen Synthesis in Rat Ovaries in Vitro: Effects of Endogenous and Exogenous Gonadotrophins

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