Ovarian Effluent Research Articles

Retrograde transfer of steroid hormones to the ovary in luteal and follicular phases of porcine oestrous cycle in vivo.

The efficiency of the retrograde transfer of steroid ovarian hormones from the ovarian effluent into blood supplying the ovary and the rate of its back transport to the ovary were determined for the first time in in vivo conditions. Sexually mature gilts (n = 25) were used in the physiological study. The concentration of oestradiol and progesterone in blood collected from the ovarian artery was higher in both the follicular phase (by 87.9 +/- 2.9% and 150.0 +/- 4.8%, respectively, P < 0.001) and the luteal phase (by 82.1 +/- 3.9% and 77.7 +/- 2.7%, respectively, P < 0.001) than in systemic blood reaching the initial part of the ovarian artery. The high efficiency of the retrograde transfer was not dependent on the concentration of hormones in the ovarian venous blood. However, the efficiency and rate of the retrograde transfer differed between phases of the oestrous cycle. We suggest that such effective retrograde transfer of ovarian hormones must affect the secretory function of the ovary.

Involvement of adrenoceptors in the ovarian vascular pedicle in the regulation of counter current transfer of steroid hormones to the arterial blood supplying the oviduct and uterus of pigs.

1. On Day 10 of the oestrous cycle in pigs, after laparotomy noradrenaline (NA), methoxamine (alpha 1-adrenomimetic, M), Prazosin (alpha 1-adrenolytic, Pr) in total doses of 4 mumol, and saline were infused (10 min) into the superficial layer of mesovarium on both sides of the ovarian pedicle vasculature, close to the ovary. 2. Blood flow in the ovarian artery, heart rate and progesterone (P4) and androstenedione (A4) secretion from the ovary and their concentrations in the ovarian venous effluent, as well as the concentrations of P4 and A4 in the blood supplying the oviduct and the uterus, were determined. 3. A significant increase of P4 and A4 secretion after NA and M infusion and increased concentrations of P4 and A4 in the ovarian venous effluent were found, but these changes did not influence the counter current transfer of hormones from the venous effluent into arterial blood supplying the oviduct and the uterus. 4. Infusion of Pr caused a significant decrease of P4 and A4 secretion and their concentrations in the ovarian venous effluent and significantly increased A4 concentration in the blood supplying the oviduct and uterus. 5. The results indicate that stimulation of alpha 1-adrenoceptors in the area of ovarian vasculature did not influence, whereas block of alpha 1-adrenoceptors affected, the local concentration of steroid hormones in the blood supplying the oviduct and the part of the uterus proximal to the ovary, despite the changes in the concentrations of steroid hormones in the ovarian effluent.

Angiotensin converting enzyme inhibition of the gonadotropin-stimulated rabbit: effect on estradiol production.

Our purpose was to determine whether angiotensin converting enzyme (ACE) inhibitors affect gonadotropin-stimulated estradiol (E2) production. This was a prospective, masked, randomized, placebo-controlled animal trial. Twenty female New Zealand White rabbits were hyperstimulated with gonadotropins. One-half of the rabbits received concomitant treatment with the ACE inhibitor, enalapril; one-half received concomitant treatment with a placebo. Baseline peripheral E2 (13 +/- 4 vs 11 +/- 2 pg/ml) and angiotensin II (Ang II) (22 +/- 5 vs 27 +/- 7 pg/ml) levels were similar in both groups. Significant inhibition of peripheral Ang II levels was achieved in the enalapril group (32 +/- 6 vs 93 +/- 15 pg/ml; P = 0.005). E2 was significantly higher in the rabbits receiving enalapril versus placebo (369 +/- 58 vs 183 +/- 35 pg/ml, P < 0.03), respectively. By day 10, peripheral E2 had returned to normal levels in both groups (13 +/- 1 vs 13 +/- 1 pg/ml). However, E2 levels in the ovarian effluent were 2.8 times higher in the enalapril rabbits. Peripheral Ang II levels increase after gonadotropin stimulation and ACE inhibitors are able to blunt this increase significantly. ACE inhibition has a significant stimulatory effect on ovarian E2 production. This implies that Ang II may normally inhibit ovarian E2 production in stimulated cycles.

Establishment of heterogeneity among blood vessels: hormone-influenced appearance of hepatic lipase in specific subsets of the ovarian microvasculature.

We used biochemical and structural approaches to analyze the influence of gonadotropic hormones on the association of hepatic lipase with specific subsets of ovarian blood vessels. Western blotting was used to detect this enzyme in effluent collected from heparin-perfused ovaries of nonhormone-treated immature rats and those primed with pregnant mare's serum gonadotropin (PMSG) alone or in combination with human chorionic gonadotropin (hCG). The effects of these hormones on hepatic lipase distribution among ovarian blood vessels was assessed before and after hCG and/or PMSG treatment by immunofluorescence and immunogold cytochemistry. For the latter, immunoreagents and fixative were delivered directly to chilled, unfixed ovaries by in situ vascular perfusion. Data from biochemical and structural analyses indicated that hepatic lipase was absent from nonhormone-treated ovaries. As shown by Western blotting of ovarian effluent, the enzyme appeared following treatment with PMSG and PMSG-hCG; it increased in amount in a time-dependent manner, with a transient decline in the early hours after hCG injection. Enzyme levels paralleled growth and vascularization of follicles and corpora lutea; the fall tended to coincide with early events in luteal angiogenesis. Immunogold microscopy showed that hepatic lipase was abundant in thin-walled blood vessels of theca interna of follicles, corpora lutea, and interstitial cells but sparse in those of the stroma. Moreover, during neovascularization of differentiating corpora lutea, vascular sprouts arising from hepatic lipase-laden thecal vessels appeared to lose, then regain, the enzyme as development progressed. Our findings thus suggest 1) that hormones influence the establishment of endothelial cell heterogeneity within the microvasculature of a single organ and 2) that development of novel endothelial cell properties in specific subsets of blood vessels underlies compartmentalization of function within a tissue.

Ultrasound-guided cannulation of the caudal vena cava in the bovine for selective sampling of ovarian effluent

The accuracy of real-time, B-mode ultrasonography was assessed in the visualization and placement of the cannula tip, cranial to the entrance of the ovarian veins as they enter the caudal vena cava of the bovine. A cannula containing a wire guide was introduced into the coccygeal vein via a 14-gauge needle, and was then directed cranially into the caudal vena cava. Once the caudal vena cava was successfully cannulated (7 of 14 cows), ultrasonography allowed for the visualization of the cannula in 7 out of 7 cows. The tip of the cannula was successfully placed cranial to the entrance of the ovarian effuent into the vena cava in 6 of these 7 animals using ultrasound guidance. This was confirmed using progesterone or prostaglandin F 2α radioimmunoassay (RIA). The primary limitation to this technique was the initial catherization of the coccygeal vein which was not achieved in 7 of 14 cows attempted in this study. Successful cannulation was limited to large framed Holstein cows that had at least one calf. Results from this study indicate that real-time, B-mode, ultrasonography is an effective tool for the visualization and accurate placement of the cannula tip within the caudal vena cava. This finding could have implications for research in ovarian hormonal physiology in the cyclic, postpartum or anestrous cow.

Deoxycorticosterone secretion by the human ovary

Progesterone (P), deoxycorticosterone (DOC), estradiol-17β (E 2) and cortisol (F) were determined simultaneously in the peripheral and the ovarian veins in 13 patients. Blood was collected either by direct sampling during laparotomy (12 patients) or by selective catheterization (1 patient). In all ovarian effluents P and E 2 levels were significantly higher than in the peripheral vein. This was also true for DOC except in one ovarian effluent. The gradient was higher on the side of the corpus luteum-bearing ovary. P and E 2 levels were correlated in ovarian as well as in peripheral veins. In ovarian effluents, DOC gradients were only significantly correlated with P levels ( r = 0.63; P < 0.01) suggesting a metabolic relationship between the two steroids.

Ovarian and adrenal vein steroids in seven patients with androgen-secreting ovarian neoplasms: selective catheterization findings

Standardized bilateral ovarian-adrenal vein catheterization was utilized to preoperatively assess glandular steroid release in seven consecutive cases of occult virilizing gonadal neoplasms. Peripheral testosterone (T) exceeded 1.5 ng/ml in all instances (range, 1.51 to 8.67 ng/ml). Endoscopy and radiography failed to locate the functional lesions. Catheterization showed a unilateral elevation of the ovarian-peripheral vein gradient for T greater than 2.7 ng/ml in six women. In the remaining patient, gradient analysis ruled out an adrenal tumor but did not facilitate lateralization of the gonadal lesion due to subselective ovarian effluent sampling. In addition to the consistent hypersecretion of T, variable excess gonadal output of dihydrotestosterone, androstenedione, dehydroepiandrosterone, and 17 alpha-hydroxyprogesterone was evident. Associated adrenal androgenic hyperfunction was documented in three subjects. Histologic evaluation of the implicated ovaries revealed three lipid cell, two Leydig cell, and two Sertoli-Leydig cell tumors, respectively, measuring between 0.6 and 2.2 cm in diameter. No correlation was found between any of the following parameters: peripheral or glandular vein steroid levels, androgen gradients, severity of symptoms, tumor morphology, and tumor size. In conclusion, appropriate application of selective catheterization may considerably reduce the frequency and extent of operative intervention.

Uptake of lipoproteins by in situ perfused rat ovaries: identification of binding sites for high density lipoproteins.

We have examined the uptake and distribution of 125I-labeled human high density lipoprotein, apolipoprotein E-free (hHDL3), 125I-rat high density lipoprotein (HDL), and human HDL (hHDL) reconstituted with [3H]cholesteryl linoleate after their in situ vascular perfusion to ovaries of gonadotropin-primed immature rats on days 6-9 post human chorionic gonadotropin (hCG)-injection. Some rats were treated with 4-aminopyrazolopyrimidine to reduce plasma lipoproteins and ovarian cholesteryl ester stores. Perfused ovaries were analyzed biochemically and autoradiographically, and progestin content of the ovarian effluent was quantified. Infusion of ovine luteinizing hormone and hHDL increased ovarian progestin secretion severalfold, indicating that the perfused ovary was functional. After perfusion with HDL reconstituted with [3H]cholesteryl linoleate, radioactive progestin appeared in the effluent; thus, sterol carried by exogenous HDL was converted to steroid. At 37 degrees C, uptake of 125I-hHDL3 was greatest after 15 min of perfusion with label. This was decreased by 80% when the perfusion was carried out at 4 degrees C and by 70-95% when excess unlabeled hHDL, but not human low density lipoprotein (hLDL), was included in the perfusate with 125I-hHDL. Aminopyrazolopyrimidine treatment enhanced 125I-hHDL uptake twofold. After perfusion for 15 min with 125I-hHDL3, radioactivity in the ovary was high for 3-30 min of HDL-free wash, then declined 75% by 30-60 min. With light and electron microscope autoradiography, 125I-hHDL3 was localized to corpora lutea, both along luteal cell surfaces and over their cytoplasm. The plasma membrane grains appeared to be associated with segments that lacked bristle coats. Perfusion with 125I-rat HDL produced a similar pattern of labeling. In ovaries perfused with 125I-BSA, silver grains were concentrated over macrophage-like cells but were sparse over luteal cells. We conclude that the in situ perfused rat ovary takes up 125I-hHDL3 by a temperature-dependent, lipoprotein-specific process, and that this lipoprotein is accumulated by luteal cells.

Estradiol-17-beta, progesterone and 20-alpha-hydroxypregn-4-en-3-one in rabbit ovarian venous plasma. I. Steroid secretion from paired ovaries with and without corpora lutea; effect of LH.

Estradiol-17β (E2) secretion in rabbits was measured in the ovarian venous blood by a radio-ligand binding procedure. Mean E2 secretion in 6 estrous rabbits studied was 17.7 ± 1.71 μg/ovary/hr. Levels of E2, progesterone and 20α-hydroxypregn-4-en-3-one (20α-OH) in the ovarian effluent of pseudopregnant and pregnant rabbits, each having one ovary with and one without corpora lutea (CL), indicated that estrogen secretion was independent of the CL or the volume of interstitial tissue. Estrogen secretion was not altered by acute administration of ACTH, but a single small injection of LH (0.5 μg/kg iv) induced an immediate increase in the output of E2, progesterone and 20α-OH. It is concluded that the follicle constitutes the sole source of ovarian E2 in the rabbit, and that physiological levels of LH stimulate estrogen release. (Endocrinology 89: 105, 1971)

Maintenance of corpora lutea and pregnancy in hypophysectomized rabbits.

Hypophysectomy during the second week of gestation resulted in severe follicular involution and degeneration of the corpora lutea (CL). Within 7 days, no progesterone could be detected in the ovarian effluent, and implant sites were the only remaining evidence of pregnancy. Degeneration of the interstitial tissue (1ST) was less evident; although little or no basal 20α-hydroxypregn-4-en-3-one (20α-OH) secretion was measurable, substantial amounts of this steroid (but no progesterone) were secreted following acute LH stimulation. None of the pituitary gonadotrophins (LH, FSH, or prolactin) supported luteal function when administered individually, but each one exerted a specific effect on ovarian structure and function: LH, in doses of 150 or 250 μg/X2 daily sc, depleted 1ST cholesterol and induced ovarian atrophy; FSH, 200-500 μ/X2 daily sc, stimulated follicular growth; and prolactin, 500μg/X2 daily sc, produced 1ST hypertrophy. When prolactin was combined with FSH (either with or without 5-20μg/ of LH), p...

Progestin Levels in the Ovaries and Ovarian Effluent Blood in Pregnant Rabbits.

54 adult rabbits were assigned to 1 of 3 groups pregnant pseudopregnant or superovulated and employed in determining progestin levels in ovaries and ovarian effluent blood. Progesterone and 20-alpha-hydroxy-pregn-4-ene-3-one (20 alpha-ol) were measured chemically at different stages of pregnancy or pseudopregnancy. During pregnancy the level of progesterone averaged .7 mcg/ml at Day 4 and 1.3 mcg/ml at Day 20 of pregnancy. The level of 20 alpha-ol in the ovarian blood varied from .2-1.5 mcg/ml with only slight correlation to the stage of pregnancy. Progestin levels correlated neither with number of corpora lutea nor to number of viable or degeneration implantations. At 9 days postcoitum the total amount of ovarian progesterone was higher in pregnant than in pseudopregnant does; this was not the case for 20 alpha-ol. The levels and total amount of 20 alpha-ol in the ovaries were 2-5 times those of progesterone. There was a correlation between the concentration of progesterone levels and 20 alpha-ol in the ovaries and that of the blood during pregnancy.