心房钠尿肽（ANP）对大鼠卵巢细胞生成雌激...

Isolated ovarian corpus luteal cells and granulosa cells of rat were employed to investigate the effect of alpha-ANP on the secretion of progesterone and estradiol. The contents of the steroid hormones are determined by RIA. The results showed that 0.1-10 ng/ml ANP promoted progesterone production in a dose dependent manner. alpha-ANP also enhanced progesterone production by granulosa cells, but not estradiol. It seems that the effect of alpha-ANP on ovarian steroidogenesis is a direct one.     

Twenty-four-hour secretory patterns of cortisol,progesterone and estradiol in heifers during the follicular and luteal phases of the ovarian cycle

Daily variations of plasma cortisol, progesterone and estradiol concentrations were measured by radioimmunoassay in six different normally cycling heifers during estrus (day 1 of the cycle) and diestrus (days 12–15 of the cycle). Each animal was fitted with an indwelling jugular catheter, and blood was withdrawn at 30-min intervals over a 24-h period. Statistical evaluation of the hormonal profiles using time series analysis revealed that all three steroids are secreted episodically with secretory episodes varying in number, magnitude and timing among different heifers. After dividing the 24-h into three 8-h time periods (I, 09.00–17.00 h; II. 17.00–01.00h; III, 01.00–09.00 h) a prominent circadian rhythm was found for cortisol during estrus and diestrus. Diurnal periodicity similar to that of cortisol was noticed for plasma progesterone during estrus but not diestrus when a functional corpus luteum was present. Estradiol secretion during the follicular and luteal phase of the estrous cycle was characterized by intermittent sustained elevations lasting about 9–15 h and marked by a graded rise and fall of hormone levels unrelated to photoperiod.From our results obtained in cycling heifers we conclude the following: (1) Plasma cortisol exhibits a distinct circadian rhythm during estrus and diestrus which is highly correlated with the light–dark cycle. (2) Plasma progesterone during estrus demonstrates a diurnal pattern which is absent in diestrous heifers bearing a corpus luteum. (3) Plasma estradiol lacks circadian rhythmicity but shows a distinct pattern different from that of progesterone, indicating that both steroids are secreted independently and not controlled by a circadian pacemaker.     

Effect of estradiol and progesterone on glucosamine 6-phosphate synthase in the uterus of rat

Injection of estradiol to ovariectomised rats caused significant increase in the activity of glucosamine 6-phosphate synthase of uterus. Progesterone did not cause any increase in the activity of the enzyme; however, it antagomised the effect of estradiol. It was observed that the enzyme is predominantly localised in the endometrium of uterus.     

The effects of estradiol and progesterone on rat ovarian 17-hydroxylase and 3 beta-hydroxysteroid dehydrogenase activities

Testosterone biosynthesis by Leydig cells can be modulated by estradiol. This modulation appears to occur at the 17-hydroxylase and 17,20-desmolase stage. In this study we have examined the effects of estradiol and progesterone on the activities of the 17-hydroxylase (17-OH) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) in rat ovarian tissue, to examine the hypothesis that estradiol may regulate these enzymes in the ovary as well as in the testis. Estradiol capsule implants produced a decrease in 17-OH activity (0.5 +/- 0.05 vs. 2.1 +/- 0.1 nmol/mg protein/min, mean +/- SEM, p less than 0.001), and an increase in 3 beta-HSD activity (15.5 +/- 0.9 vs 9.7 +/- 0.7 nmol/mg protein/min p less than 0.001). Progesterone injections produced a decrease in both 17-OH (0.9 +/- 0.1 vs. 2.3 +/- 0.2 p less than 0.005) and 3 beta-HSD (2.5 +/- .4 vs. 8.6 +/- 0.5; p less than 0.005) activities. We conclude that estradiol decreases 17-OH activity in the ovary as it does in the testis. This, coupled with an increase in 3 beta-HSD may explain the pre-ovulatory increase in progesterone seen in many species. Progesterone seems to decrease the steroidogenic activity of the ovarian tissue, perhaps offering an explanation for the gonadotropin resistance seen in corpus luteus bearing ovaries.     

Effect of estradiol and progesterone on long chain fatty acyl-coenzyme A levels in the rat uterus

Fatty acyl-CoAs are potential in vivo inactivators of glucose-6-phosphate dehydrogenase (G6PD). Ovariectomized mature rats (n = 74) were given 5 micrograms of estradiol intravenously, then killed 0, 24, 36, 48 and 72 h later. Control levels of myristoyl-, palmitoyl-, stearoyl-, arachidonoyl-, oleoyl- and linoleoyl-CoA were 0.6, 3.2, 4.7, 3.4, 2.4 and 3.0 micrograms/uterus and were increased 39, 110, 146, 100, 84 and 69% at 36-48 h, respectively. Levels of fatty acyl-CoAs in the rat uterus become elevated 36 h after estradiol treatment. At the same time G6PD changes from a stable enzyme to one that is irreversibly inactivated, possibly due to being rapidly degraded. Progesterone (2 mg subcutaneously every 12 h, n = 30), administered beginning at either 24 or 36 h after estradiol treatment, had no effect on estradiol-induced changes in myristoyl-, palmitoyl-, or stearoyl-CoA. Compared to the groups of rats treated with estradiol alone, animals treated with combinations of estradiol and progesterone exhibited higher levels of arachidonoyl-CoA after 48 h, and oleoyl-CoA and linoleoyl-CoA were greater after 72 h. Progesterone increased the estradiol-induced levels of unsaturated fatty acyl-CoAs suggesting that progesterone may induce uterine fatty acid desaturase activity and/or uptake of dietary fatty acids. Addition of fatty acyl-CoAs, at concentrations seen in vivo at 36-48 h after estradiol, to purified G6PD, causes irreversible G6PD inactivation.     

Rhythms in the ovulatory cycle. 2nd: LH, FSH, estradiol and progesterone

The circadian profiles of LH, FSH, estradiol and progesterone were compared in a homogeneous group of 15 young normally cycling women, at 4 well characterized times of the menstrual cycle: early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) stages. The circatrigintan profiles of the same hormones were also evaluated. Population-mean cosinor analysis failed to demonstrate a circadian periodicity of LH in any of the 4 stages of the menstrual cycle; a circadian rhythm for FSH was present only in the 2 luteal phases (EL, LL); the same type of rhythmicity was present for estradiol only in the late luteal stage; on the contrary, a highly significant circadian rhythm of progesterone was present in each of the 4 menstrual stages considered (EF, LF, EL and LL). Population-mean cosinor analysis showed a highly significant circatrigintan periodicity of LH and FSH with the acrophases respectively between -109 degrees and -181 degrees and between -74 degrees and -125 degrees. Circatrigintan rhythmicity was also present for estradiol (acrophases between -161 degrees and -245 degrees) and progesterone (acrophases between -246 degrees and -296 degrees).     

Effect of progesterone, estradiol & stilbestrol on serum ceruloplasmin in rabbits

To test whether progesterone also influences the serum ceruloplasmin activity (CSA) like estrogen (in the form of ethinyl estradiol and stilbestrol) and oral contraceptives containing both estrogenic and progestogen components, and if so to find out the relative influence of estrogen and progesterone, rabbits were treated with progesterone, estradiol dipropionate, a combination of these two and diethyl stilbestrol, and the SCA was estimated. Progesterone caused 194 and 262% increase in two and three weeks respectively. (p less than .001) Estradiol dipropionate failed to increase SCA, while diethyl stilbesterol caused an increase similar to that of progesterone.     

Effects of estradiol and progesterone on uterine prostaglandin levels in the pregnant rat

Prostaglandin D₂ was found to be a potent inhibitor of B-16 melanoma cell replication $\text{in vitro}$. The inhibition was dose-dependent between 3×10^?9M and 3×10^?6M (IC_50～ 0.3 μM after 6 days). On a molar basis, PGD₂ was a better inhibitor than PGA₂ or 16,16-dimethyl-PGE₂-methyl ester (di-M-PGE₂) and in higher concentrations (10^?6?10^?7M), comparable to retinoic acid. In higher concentrations, PGD₂ inhibited DNA, RNA and protein synthesis. The B-16 melanoma cell line which we used synthesized arachidonic acid metabolites which comigrated with PGA₂, PGD₂, PGE₂ and PGF_2α on a thin layer chromatography system.     

Acute effects of unilateral sectioning the superior ovarian nerve of rats with unilateral ovariectomy on ovarian hormones (progesterone,testosterone and estradiol) levels vary during the estrous cycle

The present study analyzed the participation of the left and right superior ovarian nerves (SON) in regulating progesterone, testosterone, and estradiol serum levels in unilaterally ovariectomized rats on each day of the estrous cycle. For this purpose, ovarian hormone concentrations in serum were measured in animals with either sham-surgery, unilateral ovariectomy (ULO), unilateral sectioning of the SON, or sectioning of the SON innervation of the in situ ovary in rats with ULO.     

Effects of estradiol, progesterone, and norethisterone on regional concentrations of galanin in the rat brain.

Concentrations of immunoreactive galanin were compared in eight gross brain regions of ovariectomized female rats treated with either estradiol, estradiol + progesterone, estradiol + norethisterone, or placebo. Higher concentrations with estradiol treatment compared with placebo were found in the pituitary (357%), frontal cortex (162%), occipital cortex (174%), hippocampus (170%), and median eminence (202%). A more profound difference with addition of progesterone or norethisterone was seen in the pituitary (529% and 467%, respectively). Sex steroids, particularly estradiol, modulate galanin concentrations not only in reproductive, but also in nonreproductive, brain regions.     

Effects of estradiol and progesterone on rat uterine ribonuclease inhibitor activity

The effects of estradiol (E2) and progesterone on rat uterine RNase inhibitor activity were investigated. RNase inhibitor activity was found to be most prominent in nuclear and cytosolic fractions of the uterus. Uterine RNase inhibitor activity in the 45,000 x g cytosolic fraction was stimulated by E2 over a 6-24 hr treatment period. Progesterone did not produce a significant change in the uterine cytosolic RNase inhibitor activity during the same period.     

Effect of cannabinoids on progesterone production by ovarian granulosa cells of pig and rat

Various cannabinoids inhibited both basal and FSH-stimulated progesterone synthesis by pig and rat granulosa cells $\text{in vitro}$ in a dose- (0.09 – 16 μM) and time- (4 – 24 h) dependent manner. The data present further evidence for a possible direct interference of cannabinoids with ovarian functions.     

Prostaglandin release from the guinea-pig uterus superfused in vitro. Effect of stage of estrous cycle, progesterone, estradiol, oxytocin and A23187

Prostaglandin (PG) E2 was the major PG released from the superfused guinea-pig uterus on Day 7, followed by in descending order 6-oxo-PGF1 alpha, thromboxane (TX) B2 and PGF2 alpha. However, the outputs of all four substances were low and were very similar. By Day 15, PGF2 alpha output from the superfused uterus had increased 21.9-fold, whereas the outputs of PGE2, 6-oxo-PGF1 alpha and TXB2 had increased only 1.8-, 2.9- and 1.2-fold, respectively. A mechanism is apparently "switched on" between Days 7 and 15 which causes a fairly specific increase in the release of PGF2 alpha from the uterus. Progesterone and/or estradiol had no effect on PG or TX release when superfused over the uterus on Day 7, nor did they have any effect on PG and TX release from the Day 15 uterus when administered separately. When administered together, however, they significantly inhibited PGF2 alpha, PGE2 and 6-oxo-PGF1 alpha, but not TXB2, release from the Day 15 uterus. Oxytocin had no effect on PG release from the Day 7 or Day 15 uterus, while A23187 stimulated PGF2 alpha, 6-oxo-PGF1 alpha and, to a lesser extent, PGE2 release from the uterus on both Days 7 and 15. Oxytocin is apparently not important for stimulating PGF2 alpha release from the guinea-pig uterus in relation to luteolysis, whereas increasing intracellular free Ca++ levels may be part of the mechanism for "switching on" uterine PG synthesis. Furthermore, changes in intracellular free Ca++ levels in the endometrium may be responsible for the pulsatile nature of PGF2 alpha release from the uterus.     

Prostaglandin release from the guinea-pig uterus superfused in vitro. Effect of stage of estrous cycle, progesterone, estradiol, oxytocin and A23187

Prostaglandin (PG) E₂ was the major PG released from the superfused guinea-pig uterus on Day 7, followed by in descending order 6-oxo-PGF_1α, thromboxane (TX) B₂ and PGF_2α. However, the outputs of all four substances were low and were very similar. By Day 15, PGF_2α output from the superfused uterus had increased 21.9-fold, whereas the outputs of PGE₂, 6-oxo-PGF_1α and TXB₂ had increased only 1.8-, 2.9- and 1.2-fold, respectively. A mechanism is apparently “switched on” between Days 7 and 15 which causes a fairly specific increase in the release of PGF_2α from the uterus.Progesterone and/or estradiol had no effect on PG or TX release when superfused over the uterus on Day 7, nor did they have any effect on PG and TX release from the Day 15 uterus when administered separately. When administered together, however, they significantly inhibited PGF_2α, PGE₂ and 6-oxo-PGF_1α, but not TXB₂, release from the Day 15 uterus. Oxytocin had no effect on PG release from the Day 7 or Day 15 uterus, while A23187 stimulated PGF_2α, 6-oxo-PGF_1α and, to a lesser extent, PGE₂ release from the uterus on both Days 7 and 15 Oxytocin is apparently not important for stimulating PGF_2α release from the guinea-pig uterus in relation to luteolysis, whereas increasing intracellular free Ca⁺⁺ levels may be part of the mechanism for “switching on” uterine PG synthesis. Furthermore, changes in intracellular free Ca⁺⁺ levels in the endometrium may be responsible for the pulsatile nature of PGF_2α release from the uterus.     

Plasma estradiol, testosterone, and progesterone levels during the ovulatory cycle of the skate (Raja erinacea)

Amounts of estradiol, testosterone, and progesterone in plasma were measured during the reproductive cycle of female Raja erinacea. Estradiol titers correlated directly with follicle size in females undergoing ovarian recrudescence, while highest concentrations were found in females with preovulatory follicles. These data indicate that as follicles grow, their steroidogenic capacity increases. In mature, nonspawning females, titers of estradiol and testosterone varied markedly. Progesterone was not detected in peripheral plasma of skates that did not produce eggs during the observation period. In females producing eggs, estradiol and testosterone predominated during the follicular phase of each spawning cycle. While estradiol and testosterone were elevated, progesterone was not detectable in the peripheral circulation. As ovulation and formation of capsules approached, plasma estradiol and testosterone declined to near baseline levels. Circulating progesterone rose sharply two days before encapsulation of ovulated eggs and remained elevated for only two days. On the day of encapsulation, concentrations of plasma progesterone had fallen to nearly baseline levels. Progesterone titers remained low throughout egg retention and oviposition. These measurements demonstrate that progesterone titers are elevated at specific times during the reproductive cycle of the skate and clearly suggest that progesterone is critically involved in events occurring at ovulation, encapsulation, and possibly oviposition.