Female reproductive functions of the neuropeptide PACAP

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide originally isolated as a hypothalamic peptide. It has a widespread distribution in the body and has a diverse spectrum of actions. Among other processes, PACAP has been shown to be involved in reproduction. In this review we summarize findings related to the entire spectrum of female reproduction. PACAP is a regulatory factor in gonadal hormone production, influences follicular development and plays a role in fertilization and embryonic/placental development. Furthermore, PACAP is involved in hormonal changes during and after birth and affects maternal behavior. Although most data come from cell cultures and animal experiments, increasing number of evidence suggests that similar effects of PACAP can be found in humans. Among other instances, PACAP levels show changes in the serum during pregnancy and birth. PACAP is also present in the human follicular and amniotic fluids and in the milk. Levels of PACAP in follicular fluid correlate with the number of retrieved oocytes in hyperstimulated women. Human milk contains very high levels of PACAP compared to plasma levels, with colostrum showing the highest concentration, remaining steady thereafter for the first 7 months of lactation. All these data imply that PACAP has important functions in reproduction both under physiological and pathological conditions.

Investigation of pituitary adenylate cyclase activating polypeptide (PACAP) in human amniotic fluid samples

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide acting as a hormone, a neuromodulator, a neurotransmitter, a trophic factor and is involved in a variety of developmental and regenerative processes. PACAP is present in several human tissues and biological fluids. In many pathological conditions, changes in PACAP levels have been described to reflect disease progression, therefore PACAP has diagnostic value as a potential biomarker. Since PACAP has been shown to play an important role in reproductive physiology and development, it was of interest to examine whether this neuropeptide occurs in the human amniotic fluid. Amniotic fluid samples were collected between the 15-19^th weeks of gestation from volunteering pregnant women undergoing amniocentesis as a prenatal diagnostic tool due to maternal age. Pathological cases were excluded after prenatal karyotype analysis. PACAP-like immunoreactivity was measured by radioimmunoassay and could be detected in all samples. The present study provides evidence for the presence of PACAP in human amniotic fluid, but determination of the exact physiological or pathological significance awaits further investigation.

Comparative analysis of abdominal fluid cytokine levels in ovarian hyperstimulation syndrome (OHSS)

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a rare, yet severe, iatrogenic complication of ovulation induction therapy during assisted reproductive procedures. Our group previously detected atypical cells in the ascitic fluid of OHSS patients, although no malignancy developed during follow up. Here, the aim was to perform a comparative analysis of the cytokines present in the abdominal fluid of patients affected by OHSS versus patients with advanced ovarian cancer, a benign adnexal mass, or ovarian endometriosis.

METHODS

This prospective, non-randomized study was conducted at the Clinical Center of the University of Pecs Department of Obstetrics and Gynecology/Reproductive Center between October 2016 and March 2018. Abdominal fluid samples were obtained from 76 patients and subjected to Luminex analysis. The samples were collected from patients with OHSS (OHSS; n = 16), advanced ovarian cancer (OC; n = 22), a benign adnexal mass (BAM; n = 21), or ovarian endometriosis (EM; n = 17). Data were subjected to the non-parametric Kruskal-Wallis test and Spearman's rank correlation coefficient to identify statistical differences between the four study groups.

RESULTS

Leukocytosis and hemoconcentration were detected in the peripheral blood of OHSS patients. Abdominal fluid analysis further revealed significantly higher levels of interleukin (IL)-6, IL-8, IL-10, and transforming growth factor (TGF)-β in both the OHSS and OC groups compared to the BAM and EM groups. The highest concentration of vascular endothelial growth factor (VEGF) was detected in the OC group, while a significantly lower level was detected in the OHSS group. Moreover, VEGF levels in OC and OHSS groups were significantly elevated compared to the levels in the BAM and EM groups.

CONCLUSIONS

Vasoactive and hematogenic cytokines were present at higher levels in both the OHSS and OC abdominal fluid samples compared to the fluid samples obtained from the peritoneal cavity of the BAM patients. It is possible that these cytokines play an important role in the formation of ascites.

Endometrioid adenocarcinoma arising from adenomyosis: a case report

BACKGROUND

Endometriosis is most commonly found in the peritoneum of the lesser pelvis and in the genital tract (in the ovaries). Its malignant transformation is quite rare, which usually appears in patients who previously underwent surgical procedures aimed at treating endometriosis. Years of hormone substitution (unopposed estrogen therapy) is also considered to have a role. According to the present authors' current knowledge, these are mostly well-differentiated tumors with low malignancy, which are primarily treated surgically.

CASE

In the present case the authors present a 73-year-old female patient who underwent a laparotomy due to abdominal pain and a mass in the lesser pelvis. The authors performed hysterectomy along with bilateral adnexectomy and omental resection. The histological examination of the specimens verified an endometrial adenocarcinoma formed on the ground of adenomyosis and the endometrial adenocarcinoma of the left ovary.

CONCLUSION

The malignant transformation of endometriosis is rare, and the mechanisms how it develops on the grounds of adenomyosis is currently unclear.

Role of PACAP in Female Fertility and Reproduction at Gonadal Level - Recent Advances

Pituitary adenylate cyclase activating polypeptide (PACAP) is a pleiotropic neuropeptide, first isolated from hypothalamic extracts, but later shown in peripheral organs, such as endocrine glands, gastrointestinal system, cardiovascular system, and reproductive organs. PACAP plays a role in fertility and reproduction. Numerous studies report on the gonadal regulatory effects of PACAP at hypothalamo-hypophyseal levels. However, the local effects of PACAP at gonadal levels are also important. The present review summarizes the effects of PACAP in the ovary. PACAP and its receptors are present in the ovary, and PACAP plays a role in germ cell migration, meiotic division, follicular development, and atresia. The autocrine-paracrine hormonal effects seem to play a regulatory role in ovulation, luteinization, and follicular atrophy. Altogether, PACAP belongs to the ovarian regulatory peptides.

Investigation of pituitary adenylate cyclase activating polypeptide in human gynecological and other biological fluids by using MALDI TOF mass spectrometry

Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional and pleiotropic neuropeptide. PACAP has diverse effects in the endocrine system, among others, it plays important roles in oogenesis, implantation and development of the nervous system. However, it is not known whether PACAP is present in the fluids of the human reproductive organs. The aim of the present study was to determine, by means of mass spectrometry and radioimmunoassay, whether PACAP is present in human amniotic fluid, ovarian follicular fluid and cervico-vaginal fluid. Samples were obtained from healthy adult volunteers. Our MALDI TOF and MALDI TOF/TOF spectrometry results show that PACAP38 is present in all of the follicular fluid samples, and PACAP-like immunoreactivity was also measured by radioimmunoassay. However, we did not find the characteristic peak representing the unmodified 38 amino acid form of the peptide in normal cervico-vaginal smear and amniotic fluid samples. Furthermore, we analyzed other body fluids for comparison, such as human nasal fluid, saliva and aqueous humor. PACAP was not found in these latter samples. In summary, the present study provides evidence for the presence of PACAP in human follicular fluid, suggesting a role in oocyte function, but determination of the exact physiological significance awaits further investigation.

Time of sunrise and hours with daylight may have an effect on the seasonality and diurnal variation of heart attack

BACKGROUND

The time of onset of myocardial infarction shows seasonal and daily variation. We aimed to investigate whether the number of hours with daylight has an effect on the seasonal variation of heart attack, and whether the time of sunrise has an effect on the diurnal rhythm of myocardial infarction.

METHODS

We carried out a retrospective database study covering all patients admitted to any acute care hospital with the diagnosis of myocardial infarction in Hungary between January 2004 and December 2005 (n = 32 329). Data were collected from the National Health Insurance Fund Administration (OEP) according to the International Classification of Diseases (ICD I21, I22) and National Meteorology Service (OMSZ). In case of patients who occurred in the database several times the events have been considered as a separate case.

RESULTS

With consideration to seasonal variation, the peak period of heart attack was found in the spring, with the lowest number of events in the summer. The number of hours with daylight showed a weak negative correlation with the occurrence of myocardial infarction (r = -0.108, P < 0.05). With respect to diurnal variation, the peak period of daily events was between 6-12 in the morning (35.57%). We have found a positive correlation between the time of sunrise and sunset and the occurrence of myocardial infarction (P < 0.01).

CONCLUSION

Based on our findings, the number of hours with daylight and the time of sunrise may be connected with the chances of having heart attack; however other factors, such as high blood pressure, diabetes or smoking may also have an influence.

Effects of perinatal asphyxia on the neurobehavioral and retinal development of newborn rats

Perinatal asphyxia during delivery produces long-term deficits and represents a major problem in both neonatal and pediatric care. Several morphological, biochemical and behavioral changes have been described in rats exposed to perinatal asphyxia. The aim of the present study was to evaluate how perinatal asphyxia affects the complex early neurobehavioral development and retinal structure of newborn rats. Asphyxia was induced in ready-to-deliver mothers by removing the pups by cesarian section after 15 min of asphyxia. Somatic and neurobehavioral development was tested daily during the first 3 weeks, and motor coordination tests were performed on postnatal weeks 3-5. After completion of the testing procedure, retinas were removed for histological analysis. We found that in spite of the fast catch-up-growth of asphyctic pups, nearly all examined reflexes were delayed by 1-4 days: negative geotaxis, sensory reflexes, righting reflexes, development of fore- and hindlimb grasp and placing, gait and auditory startle reflexes. Time to perform negative geotaxis, surface righting and gait reflexes was significantly longer during the first few weeks in asphyctic pups. Among the motor coordination tests, a markedly weaker performance was observed in the grid walking and footfault test and in the walk initiation test. Retinal structure showed severe degeneration in the layer of the photoreceptor and bipolar cell bodies. In summary, our present study provided a detailed description of reflex and motor development following perinatal asphyxia, showing that asphyxia led to a marked delay in neurobehavioral development and a severe retinal degeneration.

Endometriosis: harmful survival of an ectopic tissue

Endometriosis results from implantation of endometrial tissue outside the uterine cavity. Endometriosis might remain asymptomatic and discovered accidentally. However, it may cause symptoms, which include chronic pelvic pain, bleeding, infertility, and increases susceptibility to development of adenocarcinoma. The most prevailing hypothesis is that endometriosis results from implantation of endometrial tissue that gains access to peritoneal cavity by retrograde flow during menstruation. The factors contributing to the establishment and persistence of the endometriotic lesions (plaques) most probably include abnormalities of the genital tract, genetic predisposition, hormonal imbalance, altered immune surveillance, inflammatory response and abnormal regulation of the endometrial cells. The mediators that contribute to survival and progression of endometriosis are likely involved in the development of the symptoms of this process. Genomic studies have started to delineate the wide array of mediators involved and the complex genetic background required in the development of endometriosis. This review summarizes our current knowledge regarding the pathogenesis of endometriosis, including progress made with transgenic animals, and a clinical perspective on the diagnosis and management of this common process.

Serotonin may alter the pattern of gonadotropin-induced progesterone release of human granulosa cells in superfusion system

Serotonin plays a hormonal function in several nonneuronal peripheral tissues, such as the ovaries. Our aim was to investigate whether there is a modulatory action of serotonin on gonadotropin-induced steroid secretion of human granulosa cells. In granulosa cell culture, serotonin was administered alone or in combination with luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Also, granulosa cells were transferred into a dynamic superfusion apparatus and challenged by FSH and LH alone or along with serotonin. Estradiol and progesterone concentrations of samples were measured by radioimmunoassay. As expected, administration of FSH, LH, and serotonin alone resulted in a significant estradiol and progesterone release in cell culture, as well as a significant increase in progesterone release in dynamic superfusion system. In cell culture, co-administration of serotonin with gonadotropins had no additive effect on gonadotropin-induced secretion of progesterone, while it further augmented that of estradiol. In superfusion system, when gonadotropins were added along with serotonin, the increase in progesterone release was markedly less, while peaks of hormone response were remarkably prolonged compared to challenges by LH and FSH alone. The observed effects of serotonin on gonadotropin-induced steroid release of granulosa cells may reveal further details about the regulation of granulosa cell function.

Lamprey gonadotropin hormone-releasing hormone-III has no selective follicle-stimulating hormone-releasing effect in rats

Lamprey gonadotropin releasing-hormone (LGnRH)-III, a hypothalamic neurohormone recently isolated from sea lamprey, was reported to have a selective stimulatory effect on follicle-stimulating hormone (FSH) release in rats and suggested to be the mammalian FSH-releasing factor. In this study, we determined the relative luteinizing hormone (LH)- and FSH-releasing potency of LGnRH-III compared to mammalian gonadotropin-releasing hormone (LHRH) in normal female rats, ovariectomized (OVX) and oestrogen/progesterone substituted rats and the superfused rat-pituitary cell system. The specificity of LGnRH-III for the mammalian LHRH receptor was investigated by blocking the receptor with an LHRH antagonist, MI-1544. In vitro, LGnRH-III dose-dependently stimulated both LH and FSH secretion from rat pituitary cells at 10(-7) to 10(-5) M concentrations, while LHRH stimulated gonadotropin secretion at a 1000-fold lower doses (10(-10) to 10(-8) M). The difference between its LH- and FSH-releasing potency was similar to that of LHRH. LGnRH-III bound to high affinity binding sites on rat pituitary cells with a Kd of 6.7 nM, B(max)=113 +/- 27 fmol/mg protein. In vivo, LGnRH-III also stimulated both LH and FSH secretion in a dose-dependent manner and, similar to LHRH, induced a greater rise in the serum LH than the FSH level. In normal cycling rats, it showed 180-650-fold weaker potency than LHRH in stimulating LH secretion and 70-80-fold weaker effect in stimulating FSH secretion. In OVX rats, LGnRH-III demonstrated a similarly weak effect on both gonadotropins. It was found to be 40-210-fold less potent than LHRH regarding LH release and 50-160-fold weaker regarding FSH release. LHRH-receptor antagonist MI-1544 prevented both the LH- and the FSH-releasing effect of LGnRH-III both in vitro and in vivo. These results do not support the hypothesis that LGnRH-III might be the mammalian FSH-releasing factor but demonstrate that it is a weak agonist for the pituitary LHRH receptor and stimulates both gonadotropins in a dose-dependent fashion.

Inhibition of the UCI-107 human ovarian carcinoma cell line by a targeted cytotoxic analog of somatostatin, AN-238

BACKGROUND

Cytotoxic analogs of somatostatin (SST), such as AN-238, which consists of 2-pyrrolinodoxorubicin (AN-201) linked to the SST carrier RC-121, can be targeted to tumors that express SST receptors. Because SST receptors are present in ovarian carcinoma cells, the authors evaluated the effect of AN-238 on the UCI-107 ovarian carcinoma cell line.

METHODS

An analysis of microsatellite alleles in cocultured SST receptor positive and receptor negative cells was used for the demonstration of in vitro targeting. The toxicity and antitumor effects of AN-238 in nude mice bearing UCI-107 human ovarian tumors were investigated with or without pharmacologic inhibition of serum carboxylesterases (CE). The expression of SST receptor subtypes was determined by reverse transcriptase-polymerase chain reaction analysis, and the binding affinity of AN-238 to SST receptors was determined by radioligand assays.

RESULTS

The proliferation of SST receptor positive UCI-107 cells in vitro was inhibited preferentially by AN-238. AN-238 showed high-affinity binding to UCI-107 tumor membranes at a 50% inhibition concentration of 3.39 nM +/- 0.74 nM. In vivo, the volume and weights of UCI-107 tumors treated with AN-238 were decreased by more than 60% (P < 0.05) compared with controls. Cytotoxic radical AN-201 or the unconjugated mixture of AN-201 with carrier RC-121 had no significant effects on tumors and were toxic. In mice with inhibited serum CE activity, AN-201 at 400 nmol/kg was lethal, whereas AN-238 at a total dose of 800 nmol/kg caused only 22% mortality and reduced tumor weight by 69% and volume by 70% (P < 0.05 vs. control).

CONCLUSIONS

Targeted chemotherapy with the SST conjugate AN-238 inhibits SST receptor positive experimental ovarian tumors. AN-238 may provide a new treatment modality for patients with advanced ovarian carcinoma.

Targeted cytotoxic analogue of somatostatin AN-238 inhibits growth of androgen-independent Dunning R-3327-AT-1 prostate cancer in rats at nontoxic doses

Receptors for somatostatin (SST) that are found on prostate cancers might be used for targeting of chemotherapeutic agents. Thus, doxorubicin derivative 2-pyrrolinodoxorubicin (AN-201) can be linked to SST analogue RC-121 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2) to form targeted cytotoxic SST analogue AN-238. In this study, we evaluated the effects of AN-238 on the growth of SST receptor (SSTR)-positive androgen-independent Dunning R-3327-AT-1 prostate cancers in Copenhagen rats. The dose range and tumor growth-inhibitory effects of AN-238 and AN-201 were investigated in preliminary experiments. Administration of cytotoxic radical AN-201 at single i.v. doses of 110, 125, and 150 nmol/kg resulted in 0, 77.7, and 100% mortality, respectively, within 6-10 days. Four weeks after the injection of 110 nmol/kg AN-201, mean tumor volume was reduced by 35.1 % (P < 0.05), as compared with controls. In contrast, a single i.v. injection of analogue AN-238 at a dose of 300 nmol/kg was nontoxic and remarkably potent in inhibiting the growth of Dunning AT-1 tumors, resulting in a 85.9% (P < 0.01) reduction in tumor volume after 4 weeks. Treatment with AN-238 extended the survival time of tumor-bearing rats from 52.0+/-3.75 to 91.8+/-3.70 days, corresponding to a 76.5% (P < 0.01) increase. In a comprehensive experiment, we compared the effects of radical AN-201 at 115 nmol/kg, analogue AN-238 at 115 and 300 nmol/kg, carrier SST analogue RC-121 at 300 nmol/kg, and a mixture of AN-201 and RC-121 at doses of 300 nmol/kg administered i.v. Administration of AN-201 at 115 nmol/kg led to 90.0% mortality in 12 days, but animals treated with 115 nmol/kg of AN-238 showed no signs of toxicity, their tumor volume was reduced by 40.0% (P < 0.05), and their tumor weight was reduced by 42.8% (P < 0.01) after 4 weeks, as compared with controls. The dose of 300 nmol/kg of AN-238 was also nontoxic and diminished tumor volume by 80.9% (P < 0.01) and tumor weight by 82.0% (P < 0.01). No reduction in tumor growth or toxic effects was observed with carrier RC-121, but after the injection of unconjugated mixture of AN-201 and RC-121 at doses of 300 nmol/kg, all rats died within 4 days. Specific high-affinity receptors for SST were found on Dunning R-3327-AT-1 tumor membranes by radioligand binding assay and were identified by reverse transcription-PCR as SSTR2. Our study indicates that cytotoxic SST analogue AN-238 can be targeted to SSTRs on tumors and produces a powerful inhibition of the growth of Dunning-AT-1 rat prostate cancer at doses that are nontoxic, whereas its cytotoxic component, 2-pyrrolinodoxorubicin, is toxic and ineffective.

Recovery of pituitary function after treatment with a targeted cytotoxic analog of luteinizing hormone-releasing hormone

Recently, we developed a targeted cytotoxic analog AN-207 of luteinizing hormone-releasing hormone (LH-RH), consisting of an intensely potent derivative of doxorubicin, 2-pyrrolinodoxorubicin (AN-201) conjugated to carrier agonist [D-Lys6]LH-RH. In this study, we investigated the effects of cytotoxic analog AN-207, designed for targeted chemotherapy and radical AN-201 on pituitary function in rats. A selective damage to the pituitary gonadotroph cells was found at 1 week after a single i.v. injection of 150 nmol/kg AN-207, as evidenced by a 63% decrease in the LH-RH-stimulated release of LH in vitro. The release of growth hormone (GH) and thyrotropin (TSH), stimulated by GH-releasing hormone (GH-RH) and TSH-releasing hormone (TRH), respectively, was reduced by only 11-12%. In contrast, even a smaller dose of 75 nmol/kg of AN-201 nonselectively damaged pituitary function, reducing the stimulated release of LH, GH, and TSH by 57%, 74%, and 67%, respectively. Two weeks after administration, the LH-RH-stimulated LH release in vivo entirely normalized in the AN-207-treated rats, and only a 13% decrease in the LH response was found in the group given AN-201. GH and TSH responses to receptor-mediated stimuli with GH-RH and TRH were normal at 2 weeks in both treated groups. Neither cytotoxic compound caused changes in the concentration of pituitary LH, GH, or TSH, as determined by RIA at 1 week and 7 weeks after treatment. This study demonstrates that the cytotoxic LH-RH analog AN-207 exerts highly selective effects on the gonadotroph cells containing LH-RH receptors and is less toxic for other cells. Conversely, its cytotoxic radical AN-201 nonselectively damages the pituitary cells. The damaging effect of both cytotoxic compounds on pituitary functions is reversible. In view of its high selectivity and reduced toxicity, AN-207 could be a potential therapeutic agent for the treatment of tumors that possess receptors for LH-RH such as prostatic, mammary, ovarian, and endometrial cancers.