The microscopically demonstrable lipids of cyclic corpora lutea in the rat

Everett, John W.

doi:10.1002/aja.1000770302

Cited by 49 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The storage of hormone precursor also correlates well with the falling levels of progestins in the ovarian vein during pro-oestrus and oestrus (Hashimoto et al, 1968), the increased activity of hydrolytic enzymes (Lobel, Rosenbaum & Deane, 1961), the fragmentation and degen¬ eration of the Golgi apparatus (McDonald et al, 1969), and the appearance of 20a-hydroxysteroid dehydrogenase (Balogh, 1964;Pupkin, Bratt, Weisz & Lloyd, 1966;Turolla, Magrini & Gaetani, 1966). Everett (1945) suggested that old CL may be reactivated during pro-oestrus. He found that luteal cell lipid increased in late dioestrus but then decreased markedly, though transi¬ ently, during pro-oestrus.…”

Section: Discussionmentioning

confidence: 86%

See 1 more Smart Citation

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Guraya¹

1975

Reproduction

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 86%

“…The present histochemical study was undertaken to examine the lipid changes in rat CL during the oestrous cycle, pseudopregnancy, pregnancy and lactation to extend those of Everett (1945Everett ( , 1947.…”

Section: Introductionmentioning

confidence: 99%

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Guraya¹

1975

Reproduction

View full text Add to dashboard Cite

show abstract

“…During the normal occurrence of this pro¬ cess, corpora lutea develop patches of 'fatty necrosis' (Everett 1945) which can be easily recognized on serial sections. Numbers of follicles and corpora lutea were counted through the screening of all sections from both ovaries per rat.…”

Section: Ovarian Histologymentioning

confidence: 99%

Effects of dexamethasone on ovarian activity in rats

Greef

Schoot²

1987

Acta Endocrinologica

View full text Add to dashboard Cite

Rats with 5-day ovarian cycles were treated with dexamethasone (0.025 to 0.4 mg per rat per day) to examine its effects on ovarian activity. All doses of dexamethasone markedly suppressed endogenous secretion of ACTH as evidenced by decrease in weight of the adrenal glands after 7-23 days of treatment. Treatment with 0.4 mg of dexamethasone from the day of ovulation appeared to induce pseudopregnancy in more than 90% of the rats studied: pseudopregnancies lasted for 14-22 days. Induction of pseudopregnancy occurred less, in a dose-dependent fashion, when the lower doses of dexamethasone were administered.However, prolonged treatment with these lower doses resulted also in pseudopregnancy albeit after 1 or more cycles of 5 to 7 days. The effects of large doses of glucocorticoids on ovarian activity in rats, and possibly in humans as well, may be mediated predominantly through a stimulatory action of such drugs on prolactin secretion. Treatment with 0.4 mg per day of dexamethasone from the day before pro-oestrus did not interfere with ovulation and pseudopregnancy ensued this ovulation in all rats studied. Occasionally, unexpectedly large numbers of eggs per ovulating animal were found during treatment with dexamethasone. The data indicate failure of large doses of dexamethasone to interfere with ovulation and, possibly, induction of an increase in numbers of maturing follicles: this latter action deserves further analysis.

show abstract

“…Ascorbic acid appears to follow the same course as ovarian lipids (23,24), which are minimal at proestrus, and reach a maximum on the day of diestrus of 4-day cycles or diestrus day 2 of 5-day cycles. Both lipids and ascorbic acid are correlated, in turn, with ability to form functional corpora lutea when pituitary transplants are made to the kidney capsule (25): such corpora lutea will be produced at estrus, metestrus and early in diestrus, but not late in diestrus or in proestrus when luteolysis is occurring (23)(24)(25). In view of this correlation, and the demonstration in the cow that ascorbic acid concentration is much higher in corpora lutea than in the rest of the ovary (26), it is tempting to conclude that the source of cyclic variation in ascorbic acid is the set of corpora lutea from the previous ovulation.…”

Section: Resultsmentioning

confidence: 95%

OVARIAN ASCORBIC ACID AS AN ENDOGENOUS AND EXOGENOUS ASSAY FOR CYCLIC PROESTROUS LH RELEASE¹

Mills

Schwartz

1961

Endocrinology

View full text Add to dashboard Cite

Cyclic proestrous LH release was investigated by endogenous and exogenous assay in rats exposed to light from 5:00 A.M. to 7:00 P.M. daily. Pituitaries were removed from proestrous rats at 10:00-11:00 A.M. and 4:00-5:00 P.M., injected into immature, primed recipient rats and tested for ovarian ascorbic acid depleting ability (exogenous assay). "Morning" pituitaries were significantly more potent than "afternoon" pituitaries, confirming the finding of drug and hypophysectomy studies that LH is released from the pituitary between 2:00 and 3:00 P.M. Ovaries removed from the proestrous donor rats showed no consistent ascorbic acid depletion on the afternoon of proestrus (endogenous assay). There was, however, a cyclic variation in ovarian ascorbic acid, the highest values occurring in metestrus, the lowest in proestrus. I N RECENT years Everett and his co-workers (1,2) have accumulated indirect evidence suggesting that when cyclic female rats are exposed to light daily between 5:00 A.M. and 7:00 P.M., LH is released from the pituitary starting at 2:00 P.M. and completed in 90% of animals by 3:30 P.M. on the day of proestrus. Ovulation then occurs around midnight. This timing of LH release was demonstrated by injecting a variety of centrally-acting blocking drugs (1) or hypophysectomizing (2) at the critical time in the afternoon and looking for presence or absence of ovulation the following morning.The use of endogenous ovulation as a criterion of LH release necessitates the presence of prepared follicles, limiting the variety of experiments which might be utilized to elucidate the factors triggering LH release. In order to avoid the need for a prepared ovary, changes in LH content must be measured directly, either in the anterior pituitary or in the body fluids. Acute decreases in pituitary gonadotrophin content have been demonstrated following coitus-induced ovulation in the rabbit (3, 4), following the onset of heat in the ewe (5) and sow (6), and following post-partum ovulation in the mouse (7). This encouraged us to look for acute decreases

show abstract

The microscopically demonstrable lipids of cyclic corpora lutea in the rat

Cited by 49 publications

References 25 publications

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Effects of dexamethasone on ovarian activity in rats

OVARIAN ASCORBIC ACID AS AN ENDOGENOUS AND EXOGENOUS ASSAY FOR CYCLIC PROESTROUS LH RELEASE¹

Contact Info

Product

Resources

About

The microscopically demonstrable lipids of cyclic corpora lutea in the rat

Cited by 49 publications

References 25 publications

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Histochemical Observations on the Lipid Changes in the Rat Corpus Luteum During Various Reproductive States

Effects of dexamethasone on ovarian activity in rats

OVARIAN ASCORBIC ACID AS AN ENDOGENOUS AND EXOGENOUS ASSAY FOR CYCLIC PROESTROUS LH RELEASE1

Contact Info

Product

Resources

About

OVARIAN ASCORBIC ACID AS AN ENDOGENOUS AND EXOGENOUS ASSAY FOR CYCLIC PROESTROUS LH RELEASE¹