Luteotropic effects of prostaglandin E2 on the human corpus luteum of the menstrual cycle and early pregnancy.

Human corpora lutea (CL) of the menstrual cycle and early pregnancy were excised at operation, cut into pieces, and incubated or superfused in the presence of hCG or prostaglandin (PG) E2. After incubation, the tissue levels of cAMP and the medium concentrations of progesterone (P) were determined, while the concentration of P was analyzed after superfusion. PGE2 stimulated cAMP formation in CL from all phases of the menstrual cycle as well as from early pregnancy and caused an increase in P formation in CL from the early and midluteal phases of the menstrual cycle as well as from early pregnancy. A difference was found in the latency, the lag phase until maximal response, and the duration of response between the effects of PGE2 and hCG on both cAMP and P formation. Thus, the effect of PGE2 started more rapidly and was of shorter duration than that of hCG. The stimulatory effect of PGE2 on CL from early pregnancy was of the same magnitude as that of CL from the menstrual cycle. On the other hand, hCG had less stimulatory effect on cAMP and P formation in CL from early pregnancy compared to CL from the menstrual cycle. We conclude that PGE2 stimulates P and cAMP formation in isolated human CL from all phases of the menstrual cycle as well as in early pregnancy, indicating a luteotropic effect of this PG.

Progesterone and adenosine 3',5'-monophosphate formation by isolated human corpora lutea of different ages: influences of human chorionic gonadotropin and prostaglandins.

From each of 24 women undergoing minilaparotomy at various stages of the luteal phase of the cycle, the corpus luteum (CL) was excised in toto, decapsulated, cut into pieces, and incubated for short time periods (5--120 min). Incubations were carried out in the absence and presence of hCG, prostaglandin F2 alpha (PGF2 alpha) and PGE2, both alone and in combination. Dating of the CL was done meticulously using several parameters. After incubation, the tissue levels of cAMP and the media concentrations of progesterone (P) were determined. The basal P production in vitro was highest in CL of the midluteal phase. hCG stimulated cAMP formation in CL of all ages, with the highest levels of cAMP being produced in CL of the midluteal phase. PGE2 was found to increase cAMP formation and potentiate the hCG effect in young CL, but not in CL of the midluteal phase. PGF2 alpha, alone or in combination with hCG, had no effect on cAMP or P formation in either young or old CL, while in CL of the midluteal phase, PGF2 alpha significantly counteracted the stimulatory effect of hCG on both cAMP and P formation. These in vitro data show that PGF2 alpha is capable of inducing functional luteolysis in humans.

Steroid and adenosine 3',5'-monophosphate formation in granulosa and thecal cells from human preovulatory follicles in response to human chorionic gonadotropin.

Granulosa and thecal cells from the preovulatory follicles of 14 women were mechanically isolated and separately incubated for short term periods (0.5-4 h) in the presence and absence of hCG. After incubation, tissue cAMP levels and medium progesterone content of (P), androstenedione (A), and 17 beta-estradiol (E2) were determined. All follicles appeared healthy and mature, as judged by their number of granulosa cells, histological examination of the oocytes, athe steroid levels in antral fluid, as well as the appearance of the oocyte-cumulus complexes. Under basal conditions, both granulosa and thecal cells had the capacity to synthesize all of the steroids measured. The predominant steroid formed by the granulosa cells was P, while the thecal cells formed A as the major steroid. Both cell types produced considerable amounts of E2. The addition of hCG in various concentrations gave rise to concentration-dependent increase in cAMP formation in both cell types. Furthermore, hCG caused a statistically significant increase in the formation of P and A by the thecal cells, while steroid formation by the granulosa cells was not significantly altered. With higher concentrations of hCG, however, there was a tendency toward a stimulation of P synthesis in the granulosa cells from most of the follicles tested. It is concluded that in preovulatory follicles of human origin, follicular steroidogenesis is not rigidly compartmentalized between the two cell types. Furthermore, both granulosa and thecal cells are sensitive to stimulation with hCG in this type of follicle.

Steroid production in vitro of a hilus cell tumor of the human ovary.

A 69-year-old heavily virilized woman with an androgen-producing tumor of the right ovary is described. After tumor removal, plasma testosterone levels fell from 5 to less than 0.6 ng/ml. Serum gonadotropins were low prior to surgery and rose to high levels postoperatively. Histologic examination of the right ovary revealed a hilus cell tumor. Incubation of small specimens of tumor tissue for 2 hours in oxygenated Krebs bicarbonate buffer containing glucose and bovine serum albumin yielded a release of predominantly testosterone and androstenedione into the medium. Human chorionic gonadotropin (hCG) added to the medium had no effect on steroid release. Incubation of tumor tissue in vitro may provide a useful functional adjuvant to the morphologic characterization of hormone-producing ovarian tumors. Such combined studies may increase our knowledge of the much-debated histogenesis of these tumors.

Antigonadotropic effect of oxytocin on the isolated human corpus luteum.

From each of 43 women who had gynecologic laparotomy at different and well-classified stages of the luteal phase of the cycle, the corpus luteum (CL) was excised, cut into pieces, and incubated for short time periods (30 to 240 minutes). Incubations were performed in the absence and presence of human chorionic gonadotropin (hCG) and different concentrations of oxytocin ([OT], 0.1 to 1000 mIU/ml). After incubation, the tissue levels of cyclic adenosine 3',5'-monophosphate (cAMP) and the media concentrations of progesterone (P) were determined. Although hCG stimulated both cAMP and P formation in CL of all ages, OT alone had no effect on the basal production of these parameters. However, under certain experimental conditions, OT counteracted the stimulatory effect of hCG on both cAMP and P formation. Because the maximal antigonadotropic effect was found for concentrations of OT in the magnitude of the physiologic intraluteal concentration, these in vitro data suggest a role for OT in the luteolytic process of humans.

Steroid production and responsiveness to gonadotropin and prostaglandins of human ovarian follicles at term pregnancy.

PIP: This article was undertaken to correlate the steroidogenic capacity of human follicles in later pregnancy to their histological appearance. Specimens for the study were obtained from the ovaries of 26 women undergoing elective cesarean section. Human chorionic gonadotropin did not influence follicular production of cyclic AMP (adenosine monophosophate) and steroids in vitro. However, prostaglandin E2 and F2 alpha did elicit a stimulating effect on the follicular cyclic AMP system, thus indicating a well-preserved adenylate cyclase system in spite of morphologic signs of early atresia.^ieng

Influence of human chorionic gonadotropin in vivo on steroid formation and gonadotropin responsiveness of isolated human preovulatory follicular cells.

Granulosa and thecal cells of preovulatory follicles taken from 12 women were isolated and incubated separately for 2 hours in the presence and absence of human chorionic gonadotropin (hCG). To six of these women, an ovulatory dose of hCG (9000 IU) had been given 24 to 30 hours before excision of the follicle. Following incubation, cellular cyclic adenosine 3':5' monophosphate (cAMP) levels and the medium content of progesterone (P), androstenedione (A), and 17 beta-estradiol (E2) were determined. All follicles appeared healthy and well developed, and the oocytes recovered were morphologically normal and mature. Exposure to hCG in vivo caused a shift in steroidogenesis from A toward P formation in isolated thecal cells and a marked increase in the P production by the granulosa cells of the preovulatory follicles. Furthermore, the thecal cells, but not the granulosa cells, developed refractoriness to further stimulation with hCG in vitro.

[Aids in the management of pathological pregnancies. Advances in current knowledge of corpus luteum function]. / Hjälp vid handläggning av patologiska graviditeter. Ny kunskap om gulkroppens funktion.

Technological advances during the past decade have yielded new knowledge of luteal function and its regulation. A number of new substances with luteotrophic and lutcolytic properties have been identified in the corpus luteum, and the picture which emerges of the mechanisms responsible for physiological luteolysis is becoming increasingly complex. As luteal function/regulation during the menstrual cycle in the absence of pregnancy differs both from that in normal pregnancy, and from that in pathological pregnancy, these advances in our knowledge should prove clinically useful, particularly with regard to the early diagnosis and management of pathological pregnancy.

Primary carcinoma of the Bartholin gland.

A report of a patient with a Bartholin gland cancer is presented. Although this desease is rare, it should be born in mind when treating common Bartholin gland enlargements. Bartholin gland carcinomas are misdiagnosed as common cysts or abscesses in half of the cases, leading to considerable delay in diagnosis. From a review of the literature concerning this disease some recommendations are made.

Human luteolysis--interaction between HCG and oestradiol-17beta in an in-vitro model.

Corpora lutea (CL) were excised from each of 24 women undergoing laparotomy at different and well-classified stages of the luteal phase of the menstrual cycle. Pieces were incubated for intervals between 30 min and 4 h, the incubations being carried out in the presence or absence of human chorionic gonadotrophin (HCG) and oestradiol-17beta (E2) along and in combination. Following incubation, the tissue levels of cAMP and the media concentrations of progesterone and, in certain cases, pregnenolone, were determined. HCG stimulated the production of cAMP and progesterone in CL of all ages. This effect on the formation of progesterone was significantly counteracted by E2 in CL of the early and mid-luteal phases. The addition of indomethacin to the incubation media did not alter this anti-gonadotrophic effect of E2 in-vitro. The formation of cAMP was not influenced by E2 in-vitro. These results suggest that the well-known luteolytic effect of E2 in-vivo is caused by inhibition of the gonadotrophin-stimulated synthesis of progesterone by corpora lutea, an effect mediated neither by prostaglandins nor cAMP.

Influence of prostaglandin E2 on proteoglycan synthesis in the human ovarian follicle wall.

The effect of prostaglandin (PG) E2 on the incorporation of 3H-glucosamine in the human follicular wall was investigated in vitro. Follicles were obtained from women undergoing sterilization via minilaparotomy. Tissue pieces of the follicular wall were incubated in the presence of PGE2 and 3H-glucosamine and the tissue-bound radioactivity was determined. PGE2 induced a significant increase of radiolabelling in the apex of the mature follicle wall but did not significantly affect the incorporation in other parts of the wall, nor in the wall of less developed follicles. The incorporation of glucosamine, a precursor of glucosaminoglycans, is regarded to reflect the synthesis of proteoglycans. The demonstrated increase in the incorporation of 3H-glucosamine in the apical wall of the mature follicle in response to PGE2 indicates that PG-mediated stimulation of proteoglycan synthesis is of importance for follicular rupture.

Granulosa and thecal cells from human ovarian follicles under growth: steroid formation in vitro and responsiveness to human chorionic gonadotropin.

In order to characterize the patterns of steroid production and gonadotropin responsiveness in growing human follicles, follicular thecal and granulosa cells were incubated for two hours in the presence or absence of human chorionic gonadotropin (hCG). After incubation, tissue cyclic AMP (cAMP) levels and medium content of progesterone (P), androstenedione (A) and estradiol-17 beta (E) were determined. A was the dominant steroid formed by the thecal cells, regardless if these were derived from small (diameter: 4-7.5 mm) or from large (diameter: 8-15 mm) follicles. Granulosa cells from small follicles formed minimal amounts of all steroids measured, while granulosa cells from large follicles produced considerable amounts of E in vitro. Thecal cells from both small and large follicles increased their production of cAMP in the presence of hCG. Steroid formation was significantly increased by hCG in thecal cells from large follicles only. Granulosa cells from large follicles responded to hCG in vitro with increased cAMP and steroid formation, while granulosa cells from small follicles appeared insensitive to hCG in vitro.

Interaction between catecholamines and prostaglandin F2 alpha in human luteolysis.

From each of 14 women undergoing laparotomy at different stages of the luteal phase of the cycle, the corpus luteum (CL) was excised, cut into pieces and incubated for 120 min. Incubations were performed in the absence and presence of hCG and prostaglandin F2 alpha (PGF2 alpha). In addition, noradrenaline (NA) was added to the incubation medium of newly formed CL, and the adrenergic blocker propranolol to incubated specimens of mid-luteal phase CL. After incubation the tissue levels of protein and cyclic AMP (cAMP) and the media concentrations of progesterone (P) were determined. In young CL, PGF2 alpha did not interfere with the stimulatory effect of hCG on neither cAMP nor P formation, while in CL of the mid-luteal phase PGF2 alpha significantly counteracted the stimulatory effect of hCG on these two parameters. In the presence of propranolol, however, this antigonadotrophic effect of PGF2 alpha in vitro was abolished. Furthermore, when NA was added to specimens of young CL, PGF2 alpha significantly counteracted the stimulatory effect of hCG on both cAMP and P formation. These in vitro data show that endogenous catecholamines may regulate the antigonadotrophic, 'luteolytic' effect of PGF2 alpha in human CL.

Influence of progesterone, androstenedione and oestradiol-17 beta on the incorporation of [3H]proline in the human follicular wall.

The incorporation of proline, a precursor for collagen specific hydroxyproline, is regarded to reflect the metabolism of collagen. In vitro experiments were carried out to investigate the influence of sex steroids on the incorporation of [3H]proline into the human follicular wall. Tissue pieces from the apical wall of follicles at different stages of development were incubated in the presence of the steroids and [3H]proline, and the tissue bound radioactivity was determined. Progesterone induced a decrease of radiolabelling in both unripe and pre-ovulatory follicles. Androstenedione caused a similar effect but only in pre-ovulatory follicles. The influence of oestradiol-17 beta on the incorporation of [3H]proline was less pronounced with a tendency towards a decrease of radiolabelling in both types of follicles. It is suggested that the observed biochemical changes induced by sex steroids are of importance for connective tissue remodelling preceding human follicular rupture.

Influence of clomiphene citrate in vivo on subsequent steroid formation and gonadotropic responsiveness in vitro of isolated human follicular cells.

Granulosa and thecal cells from human preovulatory follicles, extirpated from the ovaries of women undergoing sterilization by minilaparotomy, were incubated for 2 hours in the presence or in the absence of human gonadotropin (hCG). The follicles were obtained from 16 women, 8 of whom had previously been treated with clomiphene citrate (CC) to induce follicular maturation. The tissue contents of cyclic AMP (cAMP) and the content of progesterone (P), testosterone (T) and estradiol-17 beta (E2) in the incubation medium were measured. Granulosa and thecal cells from control and CC-induced follicles all responded to hCG in vitro with increased formation of cAMP. Both granulosa and thecal cells from CC-induced follicles produced larger amounts of P in vitro than cells from spontaneously matured follicles. There were no other differences in the patterns of steroid formation or reactivity to hCG between the cells from the two types of follicle. It is concluded that CC treatment in vivo induces the growth and maturation of preovulatory follicles with apparently normal biochemical characteristics, as far as the content of and capacity to form cyclic AMP, progesterone, testosterone and estradiol-17 beta are concerned.

Effects of danazol on steroidogenesis and gonadotropic responsiveness in isolated human preovulatory follicular cells.

In order to investigate the influence of danazol on steroidogenesis and gonadotropic responsiveness of human follicular cells, granulosa and thecal cells of preovulatory follicles were isolated and separately incubated for short term periods. Human chorionic gonadotropin (hCG) (100 IU/ml), FSH (0.5 IU/ml) and danazol (10 micrograms/ml) alone or in combination were added to the incubation medium. Following incubation the cellular cyclic adenosine 3'5' monophosphate (cAMP) levels and the medium content of progesterone (P), androstenedione (A) and 17 beta-estradiol (E2) were determined. All follicles included in the study were classified as nonatretic and well developed, i.e. less than 3 days before ovulation. Human chorionic gonadotropin caused an increase in cAMP formation in both cell-types and this effect was significantly counteracted by danazol in vitro. In granulosa cells danazol tended to counteract a stimulatory effect of FSH on cAMP formation. No significant influence of danazol was found on the basal steroid formation of both cell types during short term incubation. On the other hand, danazol significantly counteracted the FSH stimulated P formation of the granulosa cells and the hCG stimulated A and E2 formation of the thecal cells. It is concluded that danazol inhibits gonadotropin-stimulated steroidogenesis locally in the human follicular cells and that this effect of danazol is mediated via the cyclic AMP system.

Oxytocin in human follicular fluid and its possible role in the ovulatory process as studied in vitro.

Oxytocin immunoreactivity was determined in follicular fluid from human follicles at different stages of development. The concentration of oxytocin was highest in pre-ovulatory follicles. The measured oxytocin was found to co-elute with synthetic oxytocin in an h.p.l.c. system. The influence of oxytocin on the incorporation of [3H]proline into isolated human follicular wall was studied in vitro. Oxytocin induced a decrease of radiolabelling in both unripe and pre-ovulatory follicles, indicating an inhibitory effect on collagen synthesis. This effect of oxytocin was not affected by indomethacin. An oxytocin analogue, 1-deamino-2-D-Tyr(OEt)-4-Thr-8-Orn-vasotocin, did not inhibit the incorporation of [3H]proline. The pre-ovulatory augmentation of oxytocin concentration in follicular fluid might reflect a physiological role for oxytocin in the ovulatory process. This assumption is strengthened by the observation that oxytocin may influence follicular collagen metabolism in vitro and by this means participate in the regulation of follicular rupture in the human.