Effect of neighborhood and individual-level socioeconomic factors on breast cancer screening adherence in a multi-ethnic study

BACKGROUND

Although mammography can significantly reduce breast cancer mortality, many women do not receive their annual breast cancer screening. Differences in screening adherence exist by race/ethnicity, socioeconomic status (SES), and insurance status. However, more detailed investigations into the impact of neighborhood disadvantage and access to resources on screening adherence are lacking.

METHODS

We comprehensively examined the effect of individual social, economic, and demographic factors (n = 34 variables), as well as neighborhood level SES (nSES) indicators (n = 10 variables) on breast cancer screening adherence across a multi-ethnic population (n = 472). In this cross-sectional study, participants were surveyed from 2017 to 2018. The data was analyzed using univariate regression and LASSO for variable reduction. Significant predictors were carried forward into final multivariable mixed-effect logistic regression models where odds ratios (OR), 95% confidence intervals and p-values were reported.

RESULTS

Nineteen percent of participants were non-adherent to breast screening guidelines. Race/ethnicity was not associated with adherence; however, increasing age (OR = 0.97, 95%CI = 0.95-0.99, p = 0.01), renting a home (OR = 0.53, 95%CI = 0.30-0.94, p = 0.04), food insecurity (OR 0.46, 95%CI = 0.22-0.94, p = 0.01), and overcrowding (OR = 0.58, 95% CI = 0.32-0.94, p = 0.01) were significantly associated with lower breast cancer screening adherence.

CONCLUSION

Socioeconomic indicators at the individual and neighborhood levels impact low breast cancer screening adherence and may help to inform future screening interventions.

Community Outreach and Engagement at U.S. Cancer Centers: Notes from the Third Cancer Center Community Impact Forum

Community outreach and engagement (COE) is a fundamental activity of cancer centers as they aim to reduce cancer disparities in their geographic catchment areas. As part of COE, NCI-Designated Cancer Centers must monitor the burden of cancer in their catchment area, implement and evaluate evidence-based strategies, stimulate catchment area relevant research, support clinical trial enrollment, and participate in policy and advocacy initiatives, in addition to other responsibilities. The Cancer Center Community Impact Forum (CCCIF) is a national annual meeting of COE professionals who work at or with cancer centers across the country. CCCIF grew out of earlier discussions at American Society of Preventive Oncology (ASPO) annual meetings, where COE was often discussed, but not exclusively. The third annual CCCIF meeting-hosted by the Sidney Kimmel Cancer Center at Thomas Jefferson University-was held in June 2022 in Philadelphia, PA, where more than 200 participants listened to dynamic presentations across 12 COE-related panel sessions. CCCIF leadership and ASPO AD/PL Workshop Planners worked together on the agenda. The 12 sessions used a COE lens to focus on: Diversity, Equity, and Inclusion; Policy; State Cancer Coalitions; Evaluation and Metrics; Implementation Science; In-reach; Outreach; Training and Education; Funding, Personnel and Resources; Clinical Trials; Innovative Methods; and Lessons from the COVID-19 pandemic. This article is a summary of main points and key lessons from each session, as well as a summary of overarching themes that were evident across the sessions.

The effect of social determinants of health on utilization of surgical treatment for hepatocellular carcinoma patients

BACKGROUND

A paucity of data exists on how social determinants of health (SDOH) influence treatment for Hepatocellular carcinoma (HCC). We investigated associations between SDOH (healthcare access, education, social/community context, economic stability, and built/neighborhood environment) and receipt of surgery.

METHODS

The Pennsylvania Liver Cancer Registry was linked with neighborhood SDOH from the American Community Survey. Multilevel logistic regression models with patient and neighborhood SDOH variables were developed.

RESULTS

Of 9423 HCC patients, 2393 were stage I. Only 36.3% of stage I patients received surgery. Black patients had significantly lower odds of surgery vs Whites (OR = 0.73; p < 0.01), but not after adjustments for SDOH. All 5 SDOH domains were associated with odds of surgery overall; 2 domains were associated in Stage I patients, social context (e.g., racial concentration, p = 0.03) and insurance access (p < 0.01).

CONCLUSIONS

SDOH impact utilization of surgery for HCC. Findings can guide healthcare professionals to create programs for populations at risk for poor liver cancer outcomes.

Abstract A035: Let's talk research: Community ambassadors engaging African Americans

The role of research has been instrumental in extending cancer survivorship and improving overall cancer care. Despite these advances, African Americans continue to suffer disproportionately from cancer. Research shows that the majority of people with cancer are unaware that clinical trials are an option; given the opportunity, most stated that they would enroll. Fox Chase Cancer Center is committed to improving health care outcomes for the communities it serves by expanding education and outreach efforts focused on cancer prevention, screening, early detection, treatment, and survivorship. Using a community-based intervention, we designed a Community Ambassador Training (CAT) program to develop a cohort of lay community members to engage primarily African American communities in conversations regarding the importance of research participation. We also evaluated the efficacy of the CAT in increasing participants' knowledge regarding clinical trials and biospecimen research and their ability to accurately, disseminate this knowledge. Working through community partners and building on prior research efforts, Community Health Educators (CHE) funded by NCI's Center to Reduce Cancer Health Disparities trained three cohorts of African Americans to become community ambassadors. Thirty-five individuals participated and 19 completed the full training. The seven-week program included didactic teaching that addressed the role of research, the research process, past abuses, and existing laws and regulations. The program also included interactive exercises that empowered participants to feel comfortable sharing information with other community members. Results from the study show that following completion of the program, there was a notable increase in participants' knowledge and comfort with discussing cancer research with others. During our session, we will share our approach, methods, activities, lessons learned, challenges, and next steps.

Citation Format: Armenta Washington, Evelyn T. Gonzalez, Rosa Ortiz. Let's talk research: Community ambassadors engaging African Americans [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A035.

Abstract C056: Application of precision public health approaches to maximize limited resources for community-based liver cancer prevention educational sessions

Objectives: To address the growing liver cancer burden in the city of Philadelphia and support precision public health, we utilized existing data resources from our community health partners and the PA Department of Public Health to conduct a geospatial analysis that identified communities at the census tract level with both a higher than expected rate of liver cancer and a strong community partner presence to target for liver cancer prevention education. Methods: Pennsylvania(PA) Liver Cancer Registry data from 2007-2014 were linked to the address location of community partners associated with the Fox Chase Cancer Center at the census tract (CT) level using ArcGIS software. Space-time scan statistics (SatScan software) identified CTs with significantly elevated rates of incident liver cancer (p-value&lt;0.05), adjusting for age, gender, race/ethnicity, diagnosis year. Point locations of community partners were plotted against liver cancer cluster maps to identify existing community partners in those areas where liver cancer rates were higher than expected in Philadelphia. The Office of Community Outreach (OCO) worked with community partners in high risk areas to deliver bilingual (English-Spanish) liver cancer education sessions. Plain language materials were then developed by the OCO to support the program. Pre-post tests were administered utilizing automatic response system to assess the impact and utility of the educational sessions and the likelihood to change behavior. Results: Of the 386 census tracts in Philadelphia, 153 were found to have higher than expected rates of liver cancer. 15 of 65 existing community partners were located in a high risk census tract. OCO staff have embarked on an educational outreach initiative, working with the identified community partners, offering bilingual education. Preliminary results from pre-post surveys will be analyzed and presented. Conclusions: Coupling disease cluster and community partner data improves the identification of areas with a liver cancer burden and reduces intervention targets. These methods could be utilized in other cancer control settings to maximize limited resources and prioritize cancer prevention efforts.

Citation Format: Evelyn T Gonzalez, Min Nguyen, Shannon Lynch. Application of precision public health approaches to maximize limited resources for community-based liver cancer prevention educational sessions [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C056.

Abstract C06: Adapting a breast cancer education program to reach Arab Muslim women

Breast cancer (BC) is the most common cancer in women in the United States as well as in Arab countries. Yet, Arab women have lower mammography rates than women of other ethnicities. This is due to an array of barriers, including but not limited to lack of knowledge, cultural and linguistic barriers, and fear of discrimination. Moreover, Arab immigrants have been underserved by research and outreach efforts primarily because many Arabs are considered of the White (Caucasian) race. Given that there is a large Arab population in our catchment area (Philadelphia, PA) we customized a breast cancer education program specifically for Arab Muslim women. In the first phase of the project, 10 Arab Muslim women (ages 35 and older) living in Philadelphia were recruited to provide formative feedback regarding the appropriateness and clarity of the presentation. Participants were encouraged to communicate their thoughts, preferences, concerns, and questions surrounding breast health. Even though most participants indicated that they are insured, can find health information easily, and can understand what health professionals say, their discussion conveyed a strong need for breast health education in this community. After analyzing their input, we refined the presentation and evaluated its effectiveness in a second group of Arab Muslim women (n = 21). Knowledge, attitudes, and beliefs surrounding BC were captured at the beginning of the workshop and at the end using a pre/post-test. A paired t-test showed a significant increase in BC knowledge scores after the presentation (93.5%, SD = 8.46) than before the presentation (79.22%, SD = 17.37); t (20) = -4.088, p = 0.001. In addition, there was an improvement in attitudes and intent regarding self-awareness of breast health and mammography screening. To further augment the educational program, an Arab plain-language brochure was developed and reviewed with the participants. Results from Phase I and II will be reviewed during the session, including additional questions asked by participants during the formative evaluation process. The findings from this effort further indicate the need to expand education (and screening) services to this community.

Citation Format: Evelyn T. Gonzalez, Alia Salam. Adapting a breast cancer education program to reach Arab Muslim women [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr C06.

Abstract A22: Improving the community's understanding of research through lay ambassadors

Clinical trials are pathways to the discovery of effective new methods of prevention, treatment and rehabilitation for many diseases, including cancer. In addition, the collection of biospecimens is a critical element in emerging genetic and biologic studies. However, evidence has shown that despite the increasing advances in newly developed novel and targeted biologic therapies and the compelling scientific and social justice arguments for participation by all populations, ethnic and racial minorities continue to be under-represented. One key reason noted is the lack of awareness minority populations have regarding research options. Through our Community Ambassador Training program, we established a connection with African American audiences by educating trusted community stakeholders and representatives about the importance of research participation and how the research process works. Working through community partners and building on prior research efforts, Community Health Educators (CHE) funded by NCI's Center to Reduce Cancer Health Disparities recruited 21 African American lay educators (cancer and noncancer survivors) to participate in the study. Results from the training include changes in knowledge, attitudes, and intent to participate in research; dissemination reach; lessons learned; and next steps in our efforts to enhance and expand the program to address this gap in research participation.

Citation Format: Evelyn T. Gonzalez, Armenta Washington, Nestor F. Esnaola. Improving the community's understanding of research through lay ambassadors [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A22.

Elevated levels of endothelin-1 and prostaglandin E2 and their effect on nitric oxide generation in placental tissue from neonatal streptozotocin-induced diabetic rats

Endothelin-1 (ET-1), nitric oxide (NO) and prostaglandin E(2) (PGE(2)) are regulators of feto-placental hemodynamics. In this study we explore the inter-regulatory pathways that modulate the levels of these vasoactive agents in control and neonatal streptozotocin-induced (n-stz) diabetic rat placenta. ET-1 levels are increased in diabetic placenta when compared to controls (P<0.001), and are strongly reduced by an NO synthase inhibitor (P<0.001). PGE(2) production is increased in diabetic placenta when compared to controls (P<0.01), but these levels are not modulated by ET-1. NO levels, similar in control and in diabetic placenta, are not influenced by PGE(2), but they are negatively modulated by ET-1 in both control (P<0.05) and diabetic (P<0.01) placenta. We conclude that rat placental ET-1 inhibits NO levels but does not modify PGE(2) concentrations. The elevated levels of ET-1 and PGE(2) in diabetic placenta, potent vasoconstrictors of placental vasculature, are probably related to the induction of placental insufficiency and fetal hypoxia in this pathology.

Membrane-type matrix metalloproteinase-9 activity in placental tissue from patients with pre-existing and gestational diabetes mellitus

The activity of matrix metalloproteinase (MMP)-9 was evaluated in placental tissue from healthy subjects (controls) and from patients with gestational and pre-existing diabetes mellitus (GDM and PDM, respectively). Compared with controls, MMP-9 activity was greater in placental tissue from patients with PDM and lower in placental tissue from patients with GDM. The modulatory role of nitric oxide (NO) and reactive oxygen species (ROS) on MMP-9 activity in placental tissue was evaluated. In healthy placenta, NO synthase inhibitors diminished MMP-9 activity, whereas NO donors enhanced it. The addition of xanthine/xanthine oxidase or hydrogen peroxide to placental incubates enhanced MMP-9 activity, while the addition of superoxide dismutase (SOD) diminished it. In placental tissue from patients with PDM, MMP-9 activity was stimulated by NO and by ROS. In placental tissue from patients with PDM, concentrations of nitrates/nitrites and thiobarbituric acid-reactive substances (TBARS) were enhanced, whereas SOD activity was decreased, suggesting that elevated concentrations of NO and ROS may be related to the enhanced MMP-9 concentrations found in these tissues. In placenta from GDM patients, in which a diminished concentration of MMP-9 were detected, nitrate/nitrite concentrations were increased, but placental MMP-9 activity did not change in the presence of either NO donors or inhibitors. The activity of MMP-9 in placental tissue from patients with GDM was stimulated by ROS donor systems and was inhibited by the addition of SOD; however, TBARS and SOD concentrations were unchanged in these tissues compared with controls. These findings demonstrate that placental MMP-9 activity is modulated by NO and ROS and that, in diabetic pathology, NO and ROS may determine changes in MMP-9 activity, which are probably involved in the structural and functional abnormalities of diabetic placental tissue.

Diminished PGE2 content, enhanced PGE2 release and defects in 3H-PGE2 transport in embryos from overtly diabetic rats

Diminished PGE2 levels in diabetic embryos are related to the development of malformations, and thus the aim of the present study was to determine whether PGE2 levels are modified in rat embryos cultured in diabetic serum during organogenesis, and if PGE2 content and release, and 3H-PGE2 uptake and release, are altered in incubated diabetic embryos. Rats were made diabetic by steptozotocin (60 mg kg(-1)) before mating. Control rat embryos cultured for 24 h (explantation Day 9) in the presence of diabetic serum showed diminished PGE2 levels. When Day 10 diabetic embryos were incubated, embryo PGE2 levels were lower, but the PGE2 released to the incubation media was much higher than in controls. Uptake of 3H-PGE2 by diabetic embryos was initially enhanced (5-10 min), then reached similar levels to controls (20-100 min). Release of 3H-PGE2 previously incorporated during a 60-min incubation was greater in diabetic embryos than in controls. These results show diminished PGE2 content in both diabetic and normal embryos cultured in the presence of diabetic serum, but suggest that diabetic embryos have the capability to produce and release high levels of PGE2. The enhanced release of PGE2 is probably the result of transport abnormalities, and leads to the elevated PGE2 concentrations found in the incubating medium and to the diminished intraembryonic PGE2 levels that alter embryonic development.

Modulation of PGE2 generation in the diabetic embryo: effect of nitric oxide and superoxide dismutase

In this work we assessed NO levels in the control and diabetic embryo during early organogenesis, and the ability of NO and SOD to modify embryonic PGE2 levels. Rats were made diabetic by steptozotocin (60 mg/kg) before mating. Diabetic embryos (day 10 of gestation) show increased nitrate/nitrite levels and enhanced NOS activity. The diabetic embryos release to the incubation medium increased amounts of PGE2 and have diminished PGE2 content. In the control embryo NO modulates PGE2 levels, but this modulatory pathway is not observed in the diabetic embryos. The diminished PGE2 content and the enhanced PGE2 release is prevented by SOD additions, both in the diabetic embryos and in control embryos cultured in the presence of diabetic serum (24 h culture, explantation day 9). The present results show that SOD additions prevent the abnormalities in the accumulation, production and release of PGE2 in diabetic embryos, probably related to the decrease in malformations.

Diminished levels of prostaglandin E in type I diabetic oocyte-cumulus complexes. Influence of nitric oxide and superoxide dismutase

In the present work the prostaglandin E (PGE) production by ovulated, immature and in vitro matured oocyte-cumulus complexes (OCC) was evaluated in a rat model of type I diabetes induced by streptozotocin (60 mg kg(-1)). A diminished number of ovulated OCC were found in the type I diabetic rat. In contrast to the increment in PGE generation found previously in OCC and embryos from type II diabetic rats, it was found that PGE production by type I diabetic OCC was diminished in comparison with the controls. Nitric oxide synthase (NOS) activity is enhanced in proestrous ovaries from type I diabetic rats, but cGMP levels are diminished. SIN-1 (300 microM), a nitric oxide donor, significantly enhanced PGE generation by control OCC, but was unable to modify the PGE levels in type I diabetic OCC. L-NMMA, a nitric oxide inhibitor that diminished PGE values in type II diabetic OCC, did not modify PGE generation in either control and type I diabetic OCC. Superoxide dismutase (SOD, 1000 U mL(-1)), and SOD (1000 U mL(-1)) plus SIN-1 (300 microM), enhanced PGE generation by both control and diabetic OCC. The present results suggest that even when nitric oxide (NO) is overproduced in diabetic ovaries, the NO-PGE pathway is impaired in type I diabetic OCC. As SOD additions are able to increase PGE generation by diabetic OCC, high concentrations of free oxygen radicals might be quenching the NO, impairing its physiological functions.

Regulation of prostaglandin production by nitric oxide in rat smooth muscle myometrial cells

Smooth muscle myometrial cells isolated by an enzymatic method from estrogenized rats were used after 7-10 days of culture. They were incubated for 24 h with two distinct competitive nitric oxide (NO) inhibitors: NG-monomethyl-L-arginine (L-NMMA: 300 microM) and L-nitro-arginine methylester (L-NAME: 600 microM, 5 mM and 10 mM). Afterwards, the supernatants were separated in order to measure nitrite production and prostaglandin PGE synthesis. In the present report, we demonstrate that myometrial cells from estrogenized rats are able to produce NO, since all the inhibitors significantly decrease the production of nitrites in the culture media. Furthermore, we report that both inhibitors inhibited PGE synthesis by myometrial cells. We also used a donor of NO in the incubation medium for 24 h, sodium nitroprusside (NP), obtaining an strong (P< 0.001) increase in both nitrite and PGE production. We conclude that myometrial cells can produce NO and that one possible role of the NO synthetized by this cells may be the modulation of PGE production.

Interaction between nitric oxide and prostaglandin E pathways in rat smooth muscle myometrial cells

Previously, we demonstrated the presence of a nitric oxide (NO) prostaglandin (PG) pathway in myometrial cells obtained from uterine rat tissue. This pathway was modulated by estrogen and one possible function could be to modulate uterine relaxation. In the present study, we investigated the role of progesterone in the regulation of NO synthesis and the uterotonic PGE production by myometrial cells from uterine rat tissue. We worked with two groups of rats: (i) ovariectomizcd (OV) rats, without influence of sex hormones and (ii) OV rats injected with progesterone (4 mg) s.c. Myometrial uterine cells were obtained by a selective enzymatic digestion. In the incubation medium of these cells, nitrite concentration (as a measure of NO production) and PGE production were evaluated. To ensure a specific response, a competitive NOs inhibitor, N(G)-monomethyl-L-arginine; L-NMMA (300 microM) was used. We found that at 48 h of the incubation period, cells obtained from progesterone-primed uterine tissue presented an increase in the nitrite concentration concomitant with a decrease in the PGE production. When L-NMMA was added to the cells, nitrite production and PGE synthesis returned to control values. The fact that this effect had not been observed in the group of cells obtained from OV rats suggests that progesterone was responsible for it. These data provide strong evidence that in spite of the fact that estrogen and progesterone modulate the NO-PG pathway in the uterine rat tissue, the two hormones have opposite effects.

Nitric oxide mediates increased prostaglandin E production by oocyte-cumulus complexes in the non-insulin-dependent diabetic rat

Previous work described an increase in prostaglandin E (PGE) production by oocyte-cumulus complexes (OVA) obtained from non-insulin-dependent diabetic rats. More recently, it has been found that in control OVA nitric oxide (NO) mediates hCG-induced PGE secretion. To determine whether increases in PGE secretion by diabetic OVA are mediated by NO, the present study has evaluated the secretion of PGE by diabetic OVA, cultured in the absence or presence of hCG, NO donors (sodium nitroprusside (NP) and 3-morpholino-sydnonimine-hydrochloride (SIN-1)), and a NO synthase inhibitor (N(G)monomethyl-L-arginine; L-NMMA). hCG, NP and SIN-1 increased PGE secretion by diabetic OVA. L-NMMA did not modify basal secretion of PGE by control OVA but lowered PGE production in diabetic OVA to control values. L-NMMA prevented the hCG-induced PGE accumulation in control and diabetic OVA, and the quantities of PGE produced were similar to those of control OVA but lower than in diabetic OVA incubated in the absence of hCG. The effect of L-NMMA seems to be specific since N(G)monomethyl-D-arginine had no effect. NO synthase activity was higher in diabetic ovaries than in controls. The present results suggest that NO mediates the increased PGE production by diabetic OVA, probably a result of overproduction of NO.

Increased prostaglandin E generation and enhanced nitric oxide synthase activity in the non-insulin-dependent diabetic embryo during organogenesis

Embryonic development, prostaglandin E (PGE) generation and nitric oxide synthase (NOS) activity during organogenesis were evaluated in an experimental rat model of non-insulin-dependent diabetes (NIDD) generated by neonatal administration of streptozotocin. Gross malformations were detected in 5% of NIDD embryos and these embryos were all non-viable; in the other 95%, growth was retarded but no congenital abnormalities were found. Control embryos were all alive and not malformed. The NIDD 11-day embryos secreted more PGE into the incubation medium than did controls. The NO donor SIN-1 increased PGE production in both control and NIDD embryos. A NOS inhibitor (L-NMMA) reduced PGE generation in both experimental groups, suggesting a modulatory role of NO on embryonic PGE production. Activity of NOS was higher in NIDD 11-day embryos than in controls. Treatment in vivo of control and NIDD rats (Days 7-11 of gestation) with a NOS inhibitor (L-NAME; 5 mg kg(-1) i.p.) reduced embryonic PGE production and induced a higher resorption rate and an increase in neural-tube defects. The results suggest that NO modulates PGE generation in the organogenetic embryo. In the NIDD model, overproduction of NO is observed, this NO probably enhancing embryonic PGE production. The relationship between PGE generation and the appearance of congenital abnormalities is discussed.

Nitric oxide mediates human chorionic gonadotrophin-induced prostaglandin E generation in rat oocyte-cumulus complexes

To determine whether nitric oxide (NO) generation mediates human chorionic gonadotrophin (hCG)-induced prostaglandin E (PGE) secretion by oocyte-cumulus complexes (OCC), the secretion of PGE by cultured rat OCC in the presence of NO donors and NO synthase (NOS) inhibitors was characterized. NO donors (sodium nitroprusside and 3-morpholino-sydnonimine-hydrochloride) increased PGE accumulation in OCC to values similar to those obtained in the presence of hCG. The three NOS inhibitors tested (NG-nitro-L-arginine methyl ester, NG-monomethyl-L-arginine and aminoguanidine) prevented the hCG-induced PGE accumulation in cultured OCC. This effect appears to be specific since D-enantiomers NG-nitro-D-arginine methyl ester and NG-monomethyl-D-arginine had no effect. The present results suggest that NO mediates the hCG-induced accumulation of PGE in rat OCC, a process which may occur in vivo in preovulatory follicles prior to ovulation.

Altered prostanoid production by cumulus-oocyte complexes in a rat model of non-insulin-dependent diabetes mellitus

Ovulation, oocyte maturation and PGE and PGF2 alpha production by oocyte-cumulus complexes were evaluated in rats with non-insulin-dependent diabetes induced by neonatal streptozotocin. Diabetic rats had normal estrous cycles, but ovulated a lower number of oocytes at estrus. When oocytes from control and diabetic rats obtained at proestrus were matured "in vitro" during 1, 2 or 4 hours (hr) of culture, differences were not found in the percent of germinal vesicle breakdown between both experimental groups. PGE and PGF2 alpha accumulation was higher in ovulated oocyte-cumulus complexes when compared to immature or "in vitro"-matured oocyte-cumulus complexes in both normal and diabetic rats. When control and diabetic rats are compared, more PGE and PGF2 alpha accumulation was observed in immature, "in vitro"-matured and in ovulated oocyte-cumulus complexes. A lower number of oocytes ovulated and increased oocyte-cumulus complexes prostaglandin production has been observed in this mildly diabetic experimental model. These abnormalities are similar to those previously found when 10 day embryos were evaluated in non-insulin-dependent diabetic rats.

Eicosanoid production, metabolism and contractile activity in the isolated uterus from non-insulin-dependent diabetic rats during late pregnancy

Eicosanoid production, glucose (Glu), glycogen (Gly) and triglyceride (TG) metabolism, spontaneous contractile activity, PGF2 alpha and oxytocin-induced contractions have been studied in uterine tissue obtained from control (C) and non-insulin-dependent diabetic (D) rats prior to parturition. Parturition occurs on day 22 of gestation in control animals, whereas a 24 hr delay was observed in diabetic rats. Production of PGE2, PGE1, 6-keto-PGF1 alpha, PGF2 alpha, TXB2 and LTB4 was similar in uterine tissue obtained from control and diabetic rats on day 21 of pregnancy. Uterine metabolism, on day 21 of pregnancy, based on the production of 14CO2 from U14C-glucose was lower in tissues obtained from diabetic rats than in controls. Levels of TG were similar at 0 hr and after 60 min incubation in Glu or Glu-free medium in both experimental groups. Initially Gly levels in diabetic and control uteri were similar. After 60 minutes of incubation, levels of Gly in control tissue decreased only in the absence of Glu in the incubation medium. In contrast, in diabetic uterine strips, levels of Gly decreased after 60 minutes of incubation either in Glu or Glu-free medium. "In vitro" isometric-developed tension (IDT) evaluated on day 21 (C and D) and 22 (D) of pregnancy was similar at 0 hr in control and diabetic uterine preparations, but IDT in both diabetic groups was decreased after a 40 minute incubation when compared to controls. Alterations in PGF2 alpha-induced uterine responses were not seen in 21 or 22 days pregnant diabetic uterine tissue when compared to controls. In contrast, impaired oxytocin responses were observed in diabetic uteri on day 21 of gestation, but they were similar to control responses of uterine tissue from day 22 diabetic rats. We conclude that in the non-insulin-dependent late pregnant rat, there are no alterations in uterine tissue eicosanoid production, but metabolic and contractile abnormalities are present. Involvement of these alterations in the delayed initiation of parturition is discussed.

Eicosanoid production and phospholipase A2 activity in uterine tissue from castrated rats with non-insulin dependent diabetes mellitus

In uterine tissue obtained from castrated control and non-insulin dependent diabetic (NIDDM) rats, eicosanoid production and its regulation by glucose levels and by the activity of phospholipase A2 (PLA2) was assessed. Basal outputs of prostaglandins (PGs) PGE2, PGE1, PGF2 alpha, 6-keto-PGF1 alpha (indicating the production of prostacyclin), thromboxane B2 (TXB2) (indicating the generation of TXA2) and leukotriene B4 (LTB4) were similar in control and NIDDM uterine preparations as assessed by RIA. When uterine conversion of labelled arachidonate into different prostanoids was evaluated, generation of 6-keto-PGF1 alpha, PGE2 and PGF2 alpha was similar in control and NIDDM uterine tissue, while TXB2 production was higher in the diabetic group. Moreover, when control tissue was incubated in the presence of elevated concentrations of glucose (22 mM) and compared to control tissue incubated in concentrations of glucose 11 mM, similar generation of 6-keto-PGF1 alpha, PGE2 and PGF2 alpha was observed, and higher concentrations of TXB2 were found, similar to those observed in diabetic uterine tissue. When NIDDM uterine tissue was incubated in the presence of glucose 22 mM, no difference in any prostanoid evaluated was observed when compared to values obtained in the presence of glucose 11 mM. In this work we have observed in NIDDM uterine tissue a normal TXA2 production when evaluated by RIA from endogenous arachidonic acid (AA) and a higher TXA2 generation from exogenous labelled AA. In addition PLA2 activity was found diminished in the NIDDM uteri in comparison to control uteri. A role of the diminished PLA2 as a protective mechanism that avoids TXA2 overproduction in uterine tissue from NIDDM rats is discussed.

Hyperglycemia promotes elevated generation of TXA2 in isolated rat uteri

The relationship between high glucose concentrations and arachidonic acid metabolism in uterine tissue from control and diabetic ovariectomized rats was evaluated. Uterine tissue from diabetic rats produced amounts of PGE2 and PGF2 alpha similar to controls, while a lower production of 6-keto-PGF1 alpha (indicating the production of prostacyclin) and a higher production of TXB2 (indicating the generation of TXA2) was found in the diabetic group. A group of diabetic rats was treated with phlorizin to diminish plasma glucose levels. Phlorizin treatment did not alter production of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha in the diabetic group. A diminished production of TXB2 was found in the treated diabetic uteri when compared to the non-treated diabetic group. Moreover, a positive correlation between plasma glucose levels and uterine TXB2 generation was observed. When control uterine tissue was exposed in vitro to high concentrations of glucose (22 mM) and compared to control tissue incubated in the presence of glucose 11 mM alterations in the generation of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were not found, but a higher production of TXB2 was observed and values were similar to those obtained in the diabetic tissue. Alteration in the production of the prostanoids evaluated were not observed when diabetic tissue was incubated in the presence of high concentrations of glucose. These results provide evidence of a direct relationship between plasma glucose levels and uterine production of TXA2.

Influence of prostaglandins on glucose transport in isolated rat uterus

Glucose transport by uterine strips from ovariectomized estrogenized rats was explored. Sugar transport was significantly different from saccharose values (non-specific diffusion) only after 60 min of incubation. The addition of cytochalasin B demonstrated that we are measuring a specific mechanism for glucose transport. Insulin-enhanced sugar transport only at 0.5 or 0.25 U/ml prostaglandin E1 (PGE1), PGE2 and PGF2 alpha (10(-7) M) significantly improved glucose transport, but indomethacin (10(-6) M) failed in modifying this parameter in either control nor insulin-treated tissues. We did not observe an additive or synergistic action between PGE2 (10(-7) M) and insulin (used at maximal or submaximal concentration).

Glucose metabolism, triglyceride and glycogen levels, as well as eicosanoid production in isolated uterine strips and in embryos in a rat model of non-insulin-dependent diabetes mellitus during pregnancy

Spontaneous contractile activity, glucose (Glu), glycogen (GLY), triglyceride (TG) metabolism and eicosanoid production, was evaluated in isolated uterine strips from control and non-insulin-dependent diabetic rats on day 10 of pregnancy. Metabolism of Glu, levels of GLY and TG and eicosanoid production were also studied in day 10 embryos obtained from both experimental groups. "In vitro" isometric developed tension (IDT), was similar at 0 hr in control and diabetic uterine preparations, but IDT was decreased after a 60 min incubation in the diabetic group. The frequency of contractions (FC) was similar at 0 hr and after 60 min incubation in both experimental groups. On the other hand, the production of 14CO2 from U14C-glucose was lower in isolated uteri and embryos obtained from diabetic rats than in controls. Initial TG levels were similar in uteri isolated from control and diabetic rats, and higher in embryos obtained from diabetic mothers than in controls. Levels of TG in uterine strips suspended in Glu or Glu-free medium did not differ at 0 hr or at 60 min either in controls or in diabetic rats. On the contrary GLY levels in uterine strips from diabetic animals were higher than in controls, whereas in embryos from diabetic mothers GLY levels were similar to controls. Levels of GLY in uterine strips from controls and diabetic animals decreased after 60 min incubation only in the absence of Glu in the incubation medium. Production of PGE2, PGE1, 6-keto-PGF1 alpha, PGF2 alpha, TXB2 and LTB4 was studied in uterine strips and embryos obtained from control and diabetic rats. No differences were found between control and diabetic uterine prostanoid production, but lower production of LTB4 was observed in diabetic uteri. However production of PGE2 and PGF2 alpha was greater in embryos obtained from diabetic mothers than in controls. In this study, we observed lower uterine metabolic alterations than in the pancreatectomized diabetic rat model studied previously, but important anomalies in the embryos obtained from non-insulin-dependent diabetic mother were found.

Glucose, glycogen and triglyceride metabolism, as well as prostaglandin production in uterine strips and in embryos from diabetic pregnant rats. Influences of the presence of substrate in the incubation medium

"In vitro" isometric developed tension (IDT) and frequency of contractions (FC), glucose (Glu), glycogen (GLY) and triglyceride (TG) metabolism, as well as prostaglandin PGE2 and PGE1 production, were studied in uterine strips and in embryos isolated from controls and diabetic rats at day 10 of pregnancy. The IDT and the FC, at 0 time or after a 60 min incubation, were not different in controls and in preparations from diabetic animals when the uterine strips were incubated in glucose or in glucose-free medium (p > 0.05). The production of 14CO2 and 14C-lactate from 14C-glucose were lower in the diabetic group than in controls (p < or = 0.05). Indomethacin (10(-6) M), an inhibitor of prostaglandin synthesis, failed to modify these results. Labelled Glu metabolism by isolated embryos was similar (p > 0.05) in controls and in embryos obtained from diabetic mothers. On the other hand, the initial TG and GLY levels were higher (p < or = 0.05) in diabetic uterine tissues than in controls. However, the values of TG and GLY in embryos obtained from both experimental groups were similar (p > 0.05). TG levels in uterine strips suspended in Glu or in Glu-free medium did not differ (p > 0.05) at 0 time (postisolation) and at 60 min, either in controls or in diabetic rats. However, Gly levels in uterine strips from diabetic animals, decreased significantly at 60 min in tissues incubated in Glu or in Glu-free medium (p < or = 0.05). In controls, uterine Gly content decreased (p < or = 0.05) only at 60 min time when the strips were incubated in Glu-free medium. Finally, uterine tissue from controls as well as from diabetic pregnant rats release more PGE2 than PGE1 into the incubation medium (p < or = 0.001). Nevertheless, secretion of PGE2 and PGE1 was similar in both experimental groups and was not modified by the presence or absence of glucose. In summary, we found differences in uterine metabolism of glucose, glycogen and triglycerides in controls and in diabetic rats, but metabolic differences have not been detected between embryos obtained from controls and from diabetic mothers.

Acute effects of a single ethanol injection on in vitro rat uterine spontaneous motility, on uteri prostaglandin production and on tissue metabolism of triglycerides

The acute effects of ethanol (ETOH), injected at 3 g.kg-1i.p. on spontaneous contractions, on prostaglandin (PG) production and on the metabolism of triglycerides (TGs), have been studied in uterine strips obtained from rats at diestrus and suspended in glucose-containing or glucose-free solution. The absolute values of isometric developed tension (IDT: expressed in mg) recorded at 0 time (initial or post isolation determinations) and the frequency of contraction (FC), expressed as the number of contraction cycles during 20 min, were similar for uterine strips from controls and from ETOH treated rats. The uterine IDT and the FC expressed as percent changes from internal controls (0 time values) were explored during 180 min in uteri suspended in glucose medium. The magnitude of IDT decreased, as time progressed, both in controls as well as in ETOH-treated rats. Afterwards, uterine strips from controls exhibited a partial recovery of their contractile activity. This pattern of recovery was not observed in uterine strips from ETOH-treated rats. The uterine IDT, in the ETOH-injected animals after 180 min of activity, were significantly smaller than those of controls. On the other hand, the FC decreased progressively up to the end of the experimental period both in controls as well as in ETOH-treated rats. In glucose-free medium, the IDT of uterine strips from ETOH-injected animals diminished significantly more than controls from 100-180 min following isolation and mounting. In addition, the FC of uterine strips from the ETOH group of rats were significantly smaller than in controls suspended in glucose-free solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of prostaglandins and of leukotriene C4 on the metabolism of labelled glucose in uteri isolated from ovariectomized-diabetic rats. Influences of 17-beta-estradiol and of insulin

The influences of exogenous PGE1, PGE2, PGF2 alpha, LTC4 and insulin (INS) on glucose oxidation in uterine strips isolated from ovariectomized-diabetic (OVD) and ovariectomized-estrogenized-diabetic (OVED) rats, were studied. The spayed animals were made diabetic by a single injection of streptozotocin (65 mg.kg-1 body weight). The effects of prostaglandins were studied in the presence of indomethacin (INDO) in the incubation medium and the effects of LTC4 in the presence of INDO and nordihydroguaretic acid (NDGA). These procedures were followed in order to avoid the possible influences of endogenous derivatives of arachidonic acid formed by the activity of cyclooxygenase and of lipoxygenases. INDO and NDGA did not modify significantly the formation of 14CO2 from U-14C-glucose in uteri from OVD and from OVED rats. INS (0.5 U.ml-1) augmented significantly labelled glucose metabolism, both in OVD as well as in OVED rats. On the other hand, added PGE1, PGE2, PGF2 alpha or LTC4 failed to alter glucose metabolism in uteri from OVD rats. Only PGE1 was able to increase significantly (p less than 0.05) 14CO2 production from labelled glucose in uterine strips from OVED rats. In OVD rats the stimulatory action of INS on uterine glucose metabolism was significantly enhanced by exogenous PGE1, but not modified by PGE2, by PGF2 alpha or by LTC4. PGE1, PGE2 and LTC4 sensitized uterine strips obtained from OVED rats to the effects of INS. The possible importance of PGE1 in improving uterine glucose metabolism in diabetic animals is discussed.

Effect of chronic alcohol consumption on rat uterine spontaneous motility, prostaglandin production and triglyceride metabolism

The spontaneous isometric developed tension (IDT), the synthesis and release of prostaglandins (PGs) into the incubating medium and the metabolism of triglycerides (TGs) in uterine strips isolated from controls and chronic ethanol fed rats, were studied. In order to observe how the uterus of rats fed alcohol reacts during a situation of metabolic emergency, the above mentioned studies were done in the presence or in the absence of glucose in the incubating medium. The decrement of IDT as time progressed was significantly greater in strips obtained from rats which had been drinking 20% ETOH than in controls. Nevertheless, the absolute magnitude of the initial IDT was similar in both groups. On the other hand, the decline of the frequency of contractions (FC) of uterine strips isolated from controls and from ETOH-exposed rats, after 60 min of spontaneous activity was similar. When the uterine strips isolated from ETOH-exposed and from control rats were suspended in glucose-free solution they exhibited the same decrement of IDT and FC after 60 min of activity. The basal release of PGE1 and PGE2 was similar in control tissues incubated in medium containing glucose, but the output of PGE2 was significantly smaller than that of PGE1 in uterine strips isolated from ETOH-exposed rats. The production of PGE1 and PGE2 by uteri suspended in glucose-free medium was similar in control preparations. On the contrary the release of both PGs differs in uterine strips from ETOH-exposed rats, i.e. the output of PGE2 was significantly smaller than in controls and the release of PGE1 increased around 4-fold in comparison with controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Uptake and incorporation of arachidonic acid and of dihomogamma-linolenic acid into tissue lipids in uterine strips isolated from ovariectomized and from ovariectomized-diabetic rats. Effects of 17-beta-estradiol

The uptake of 14C-arachidonic acid (14C-AA) and 14C-dihomogamma-linolenic acid (14C-DGLA) into phospholipids (PLs) and neutral lipids (NLs) in uterine tissue obtained from ovariectomized controls (C) and from ovariectomized-diabetic rats (D) was studied. Uterine strips from D rats incorporate significantly less (P less than 0.05) 14C-AA into PLs than C rats. On the other hand the uptake of 14C-AA into NLs is significantly smaller (P less than 0.05) in uterine tissue from C than from D animals. The estrogenization of the C animals did not modify the incorporation of 14C-AA into PLs or NLs. On the contrary, uterine tissue obtained from D rats treated with 17-beta-estradiol incorporated significantly more labelled AA (P less than 0.05) into PLs and significantly less 14C-AA (P less than 0.05) into NLs than untreated D animals. The incorporation of 14C-DGLA into PLs shows similar pattern in uterine tissue obtained from C and D animals. Estrogenization increased significantly (P less than 0.01) in both cases, the incorporation into PLs. Regarding the incorporation of 14C-DGLA, it was clearly shown that DGLA is taken up significantly more (P less than 0.01) by NLs than by PLs, both in C and D rats. The estrogenization of C and D rats induces a significant decrease in the incorporation of 14C-DGLA into NLs in both experimental groups. The distribution of 14C-AA into the different subfractions of PLs is not uniform.(ABSTRACT TRUNCATED AT 250 WORDS)

On possible different mechanisms subserving the release of arachidonic and di-homo-gamma-linolenic acids for the formation of monoenoic and bisenoic prostaglandins in uteri from ovariectomized rats

The uptake of arachidonic acid (AA) and of di-homo-gamma-linolenic acid (DGLA) and their incorporations into phospholipids (PLs) and into neutral lipids (NLs) of uteri isolated from spayed rats and the effect of inhibiting triglyceride (TG) metabolism with 4-pentenoic acid (4-PEA) on tissue TG levels and the output of prostaglandins (PGs), were explored. Attempts were also made to determine whether the acylation of labelled AA and of labelled DGLA into PLs and TGs is different and to confirm possible correlations between the synthesis of PGE1 and the degradation of TGs. Uterine PLs incorporated significantly less DGLA than AA (P less than 0.05). AA was acylated mainly into the phosphatidylinositol (PI) and into phosphatidylcholine (PC) subfractions of rat uteri, whereas the incorporation of DGLA into these two subfractions was significantly smaller than that of AA. The acylation of labelled DGLA into NL fractions, mainly into triacylglycerol, almost doubled that of labelled AA. The levels of TGs in isolated rat uteri suspended in glucose-free medium during a period of 60 minutes were significantly less than immediately after isolation (P less than 0.001). PGE1 released from uteri into the incubating solution, was significantly higher than that of PGE2. Moreover, the presence of 4-PEA (1.0 mM), added after tissue isolation, prevented the decrement of TGs observed following 60 minutes of incubation and simultaneously diminished significantly (P less than 0.001) the enhanced output of PGE1, without altering that of PGE2. Results presented herein suggest that PLs are not normal precursors for the synthesis of PGE1.(ABSTRACT TRUNCATED AT 250 WORDS)

The influences of leukotriene C4 on the metabolism of labelled glucose in uteri isolated from ovariectomized and from ovariectomized-estrogenized rats. Effects of indomethacin

The effects of leukotriene C4 (LTC4), nordihydroguaiaretic acid (NDGA) and FPL-55712, on the metabolism of labelled glucose (U14C-glucose) in uteri isolated from spayed rats and from spayed-estrogenized rats, incubated in the presence and in the absence of indomethacin, were explored. Indomethacin (10(-6)M), enhanced significantly 14CO2 formation from labelled glucose, both in uteri from ovariectomized rats and in uteri from ovariectomized-estrogenized animals. In uteri from spayed not-estrogenized rats, expose 'in vitro' to indomethacin, NDGA (10(-5)M), an inhibitor of the 5-lipoxygenase, as well as FPL-55712 (10(-5)M), a LT antagonist, reduced significantly the enhanced metabolism of glucose evoked by indomethacin, an inhibitor of the cyclo- oxygenase. On the other hand, LTC4 (10(-7)M), augmented the metabolism of labelled glucose, reaching values even greater than those induced by indomethacin. In the spayed-estrogenized group LTC4 (10(-10)-10(-7)M) enhanced the formation of labelled CO2 from labelled glucose as much as indomethacin (10(-6)M) did, whereas neither NDGA nor FPL-55712 were effective. In addition, in uteri from ovariectomized-estrogenized rats, incubated with indomethacin, NDGA and FPL-55712, decreased the augmenting action of indomethacin on glucose metabolism, whereas LTC4 (10(-10)-10(-7)M) evoked a complete reversal of the inhibitory influence of NDGA on the formation of 14CO2. The force-going results suggest that tissue 5-lipoxygenase products, particularly LTC4, are involved in the metabolism of labelled glucose by rat uteri, mainly when the cyclo-oxygenase pathway is inhibited by indomethacin and the tissue is deprived of estradiol.(ABSTRACT TRUNCATED AT 250 WORDS)

Electric field stimulation alters the outputs of prostaglandins from isolated rat urinary bladder preparations. Influences of papaverine and tetradotoxin

The effects of electric field stimulation (EFS) on the outputs of prostaglandins (PGs) E1, E2 and F2 alpha from isolated contracting rat urinary bladders, were explored. Also, the influences of papaverine (5.10(-6) M) and of tetradotoxin (TTX = 5.10(-7) M) on PGs released by spontaneously contracting or electrically driven preparations, were tested. The basal control outputs of the three PGs in spontaneously contracting urinary bladders, had a comparable magnitude. On the contrary, in electrically stimulated preparations the output of PGE2 rose significantly; that of PGF2 alpha presented a significant reduction and the release of PGE1 was similar to that in controls. Papaverine failed to modify the profile of basal control PG release in non-stimulated bladders, abolished contractile responses to EFS and blocked the augmented output of PGE2 elicited by EFS. The presence of TTX in the suspending solution had no action on the basal control release of PGs from non-stimulated spontaneously contracting preparations, depressed between 80-90% the inotropic responses triggered by EFS and completely antagonized the enhanced output of PGE2 evoked by EFS. Results are discussed in terms of the relative participations of the evoked inotropism of the detrusor muscle or by the stimulation of nerve endings, accounting for the greater release of tissue PGE2 after EFS.

Prostaglandin E2 alters the metabolism of labelled glucose in uteri isolated from ovariectomized rats. Effects of 17-beta estradiol and indomethacin

The effects of prostaglandins (PGs) E1, E2 and F2 alpha on the oxidation of labelled glucose in uterine strips from ovariectomized rats, were explored. Moreover, the influences of in vivo estrogenization of spayed rats and the presence in vitro of indomethacin (10(-6)M) on labelled glucose metabolism by isolated uteri, were also determined. PGE2 (10(-7)M), but not PGE1 or PGF2 alpha, enhanced significantly the formation of 14CO2 from U14C-glucose in uteri from spayed rats. After the injection of 17-beta estradiol to castrated animals prior to sacrifice the three PGs augmentated in vitro uterine glucose metabolism. In uterine strips from spayed non-estrogenized rats incubated with indomethacin, only PGE2 (10(-7) and 10(-6) M) incremented the formation of 14CO2 from labelled glucose, whereas PGE1 and PGF2 alpha were devoid of action, whereas in uteri from ovariectomized-estrogenized animals also incubated with indomethacin, PGE1, PGE2 and PGF2 alpha enhanced significantly the metabolism of labelled glucose, as was observed in the absence of indomethacin. However, in the presence of indomethacin the magnitude of the stimulation evoked by PGs in vitro was 3 to 4 times greater than without the inhibitor of the cyclo-oxygenase. The role of estradiol modulating the actions of PGE2 and PGF2 alpha on uterine glucose metabolism and possible reasons subserving the influence of indomethacin incrementing the effects of PGs on glucose oxidation in uteri from spayed-estrogenized rats, are discussed.

A novel anti-lipolytic action of norepinephrine in uteri isolated from spayed rats appears subserved by the activation of alpha 1-adrenoreceptors diminishing the generation and release of lipolytic prostaglandins

The effects of norepinephrine (NE: 3 x 10(-6) M) on the outputs of prostaglandins (PGs) E1, E2 and F2 alpha, from uterine horns isolated from ovariectomized rats and suspended in solutions with or without exogenous glucose, were explored. The releases of the different PGs into the external medium were determined after incubating for one hour uterine preparations, mounted within a tissue bath and receiving a constant preload tension. In glucose-containing solutions, NE enhanced the basal output of PGE2 and failed to alter the basal releases of PGE1 or of PGF2 alpha. In glucose-free media, the basal output of PGE2 was comparable to that detected in presence of exogenous glucose, and its augmentation following added NE was again evident. However, the basal outputs of PGE1 and of PGF2 alpha, greater in glucose-free solutions than in glucose-containing media, were significantly diminished by added NE. Uterine triglyceride (TG) levels were also explored, both immediately after sacrifice (0 min) or following suspending uterine segments during one hour (60 min) in solutions containing exogenous glucose or not. In glucose-containing media, tissue TGs did not differ at 0 min or at 60 min, neither in controls, nor in NE-challenged preparations, whereas in glucose-free solutions, TGs were significantly smaller at 60 min than at 0. interestingly, the addition of NE completely prevented the dimunition of uterine TGs, present at 60 min in glucose-free medium. Neither propranolol nor yohimbine (10(-6) M) altered this sparing action of added NE on tissue TGs, but phentolamine or prazocin (10(-6) M), effectively antagonized the preventive effect of the agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of experimental diabetes on spontaneous contractions, on the output of prostaglandins and on the metabolism of labelled arachidonic acid, in uteri isolated from ovariectomized rats. Influences of estradiol

Spontaneous changes in isometric developed tension (IDT) as a function of time after isolation (contractile constancy) in uteri from control-castrated and castrated chronic streptozotocin-diabetic rats, were explored. The effects of injecting 17-beta estradiol (Eo) were also studied. No differences in the minor changes of contractile constancy, between control and diabetic preparations, during a period of 60 min, were detected, whereas uteri from non-diabetic Eo injected animals (0.5 + 1.0 ug, prior to sacrifice), exhibited a profound reduction of IDT, significantly greater than in tissues obtained from Eo injected-diabetic rats. Moreover, basal generation and outputs into the suspending solution of prostaglandins (PGs) E1, E2 and F2 alpha, were explored in the same groups, at 60 min following tissue isolation. The basal outputs of these three PGs were similar in castrated control rats, but preparations from castrated-diabetics released significantly more PGE1. The administration of Eo to castrated-diabetics, failed to alter the releases of the three PGs explored. In addition, the metabolism of labelled arachidonic acid (AA) into different prostanoids (6-keto-PGF1, PGF2, PGE2 and thromboxane B2-TXB2), was also investigated. The non-diabetic spayed rat uterus converted AA into these four prostanoids, the transformation into 6-keto-PGF1 alpha (as an index of PGI2 formation) being the most prominent. In preparations from diabetic rats the formation) being the most prominent. In preparations from diabetic rats the formation of 6-keto-PGF1 alpha, PGF2 alpha and PGE2, was significantly smaller than in controls, whereas a greater % of TXB2 formation (as an index of TXA2), was detected. On the other hand uterine preparations from non-diabetic spayed rats injected with Eo formed less 6-keto-PGF1 alpha and PGE2 and similar amounts of PGF2 alpha or of TXB2 from AA, than Eo injected controls, whereas uteri from castrated diabetic animals injected with Eo, formed a similar % of 6-keto-PGF1 alpha, PGF2 alpha and PGE2 from AA, than tissue preparations from non-estrogenized controls. However, the enhanced transformation of the labelled fatty acid precursor (AA) into TXB2 in the diabetic group, was significantly reduced by the steroid. The role of the augmented generation and release of PGE1 in uteri from diabetic rats is discussed in terms of precedents indicating the relevance of PGs type E supporting rat uterine motility. In addition the influence of Eo is attractive, because its reducing effect on TX production, in diabetes, a disease known to be accompanied by enhanced synthesis of vasoconstrictor and platelet aggregation TXA2, and by frequent obstructive circulat

Norepinephrine alters PGE2/PGE1 output ratio in isolated uterus from ovariectomized rats

The rat uterus generates and releases prostaglandins (PGs) of the series 2 as well as PGs of the series 1. The main purposes of the present study are to compare the effects of norepinephrine (NE) on the production and outputs of PGE1, PGE2 and PGF2 alpha by the uterus isolated from ovariectomized rats, treated or not with 17-beta-estradiol and to explore also, whether the effects of NE on PG synthesis are mediated through alpha, beta or both types of adrenoreceptors. Segments of control uterine horns obtained from ovariectomized rats generated and released into the incubating solution, equal amounts of PGE1, PGE2 and PGF2 alpha and propranolol (10(-6) M) or phentolamine (10(-6) M) failed to alter this basal production of PGs. Norepinephrine (3 X 10(-6) M) significantly depressed the outputs of PGE1 and PGF2 alpha but enhanced, also significantly, the release of PGE2. In the presence of the beta-adrenoreceptor blocker, propranolol, the reduction induced by NE on the output of PGE1 was not altered, but the stimulatory influence of NE on the release of PGE2 as well as the depression on the output of PGF2 alpha, were abolished. On the other hand the diminution evoked by NE on the release of PGF1 and PGF2 alpha as well as the increment induced on PGE2 output, were inhibited by the presence of phentolamine in the incubating solution. Uterine horns from ovariectomized rats treated with 17-beta-estradiol released into the incubating solution significantly more PGF2 alpha than PGE1 or PGE2. NE, either alone of in the presence of alpha 0 or beta-adrenoceptor blockers, did not modify this pattern of PG production. A possible mechanism(s) of action for NE on PG synthesis is discussed.

Sow (Sus scrofa) follicular fluid: prostaglandin content and effect on the motility of isolated oviducts

The present study provides information regarding the effects of the sow follicular fluid (FF) on the motility of isolated segments of swine and rabbit oviducts. In addition, the concentration of prostaglandins (PGs) F2 alpha, E2 and E1 in the follicular fluid of sow ovaries isolated at different stages of the sex cycle as well as the generation of the same PGs by walls of ovarian follicles in early and late proestrus, in estrus, in metestrus and in diestrus, were explored. The stimulatory contractile effect of proestrous FF in isolated segments of sow fimbria was antagonized by polyphloretin phosphate (PPP), a PG receptor blocker and by indomethacin, an inhibitor of PG synthesis. The positive inotropism evoked by the FF was mimiked by bradykinin and the influences of both interventions were similarly antagonized by PPP. It appears plausible that the inotropic effect of the preovulatory FF on the sow fimbria could be not only by PGs already present in the fluid, but also by the stimulation of the synthesis of tubal PGs by follicular fluid bradykinin. The FF also stimulated the ampullary tubal segments isolated from proestrous sows whereas the same volume of FF depressed significantly the isometric developed tension of rabbit ampulla. The total concentration of the three PGs in the FF from late proestrous follicles was significantly greater than that of the same PGs in the other two stages of the sex cycle (early proestrus and diestrus), whereas the concentration of each PG (PGE2, PGF2 alpha or PGE1), did not differ within any of the stages of the cycle. Furthermore, the total amount of the three PGs produced by the walls of follicles from late proestrous ovaries was also significantly greater than that generated by ovarian follicles from early proestrus, estrus, metestrus and diestrus. In summary the results document that the concentration of each one of the PGs measured (E2, E1 or F2 alpha) attained maximal values at the time of ovulation. The results regarding the effects of FF on the inotropic activity of fimbrial and ampullary segments of sow oviducts also suggest that the fluid might play a physiological role, favouring the capture and transfer of ova into the oviducts at the moment of ovulation.

Sex hormones and the motility of and prostaglandin output from, uterine horns of immature rats

The effects of injecting estradiol, progesterone or both hormones to immature rats, on the spontaneous contractions of isolated uterine horns and on prostaglandin (PG) E and F-like materials released into the bathing medium, were studied. The in vitro contractile decrement detected both in controls as well as in the group receiving progesterone (P4) alone, was only minor. On the other hand, preparations from rats treated with 17-beta-estradiol (E2) exhibited a significant and progressive reduction of spontaneous motility. Coincident with these smaller contractions a significant diminution of PGE-output accompanied by an enhancement of the release of PGF-like material into the suspending solution, were found. The initial (postisolation) isometric developed tension (IDT) of uterine preparations from immature rats injected with sex hormones was significantly higher than that of tissues from untreated control animals. Neither the initial contractile frequency (CF) nor its constancy changed following hormonal treatment (E2 or P4), except in the case of uteri from animals treatment (E2 or P4), except in the case of uteri from animals administered with P4, which showed a smaller decrement of CF than controls. Furthermore, tissue preparations obtained from animals injected with P4 released into the bathing media similar amounts of PGE-like material as controls, but significantly more PGF. It is interesting that the injection of E2 plus P4 increased the output of PGE-like material but did not modify that of PGE i. e., the depressive effect of estradiol on the release of PGE into the bathing media was abolished by the administration of P4. On the other hand, the addition of indomethacin or acetylsalicylic acid to the bath solution reduced significantly contractions of uterine horns isolated from immature animals. The foregoing results, supporting our previous findings on the effect of P4 on PGF release from the rat uterus, are in keeping with the hypothesis holding that better spontaneous motility correlates well with a greater release of PGE and that E2 injection coincides with a depression of both PGE output and myometrial contractions.

Role of endogenous and exogenous prostaglandins on the contractile functioning of isolated sow (Sus scrofa) oviducts

The output of prostaglandins (PGs) E1, E2 and F2 alpha, from ampullary and isthmic portions of sow oviducts isolated during proestrus, estrus and metestrus, was explored. Moreover, in vitro cumulative dose-response curves for the contractile effect of these three PGs, on identical oviductal segments, were constructed. Isthmic preparations from proestrous and metestrous animals released more PGE1 and PGF2 alpha than PGE2 "like material". During estrus, the outputs of PGE1, PGE2 and PGF2 alpha were similar, whereas, oviducts from proestrous and metestrous sows released less PGE1 and PGF2 alpha than during estrus. Although the output of PGE2 "like material" from isthmic and ampullary segments did not differ significantly during the three stages of the sex cycle, ampullary metestrous preparations released more PGE1 and PGF2 alpha, than estrous or proestrous ones. The addition of PGE1, PGE2 or PGF2 alpha, consistently stimulated the amplitude of contractions of isthmic oviductal segments isolated from proestrous and metestrous sows. Within the concentration-range explored, dose-response curves for PGE2 and PGE1 were to the left of those for PGF2 alpha in the isthmus obtained before ovulation (proestrus) but not in segments isolated at later times (2-3 days) of the cycle (metestrus). The stimulatory dose-response curves for PGE1, or PGE2, in isthmic segments of metestrous preparations incubated with phentolamine (10(-6)M) were shifted to the right of controls not exposed to the adrenoreceptor blocker, whereas, the curve for PGF2 alpha without phentolamine, was identical to that obtained in its presence. PGE1 and PGE2 did not evoke significant contractile effects on oviductal ampullary portions from proestrous sows, whereas, PGF2 alpha was clearly stimulatory at concentrations of 10(-9)M and higher. In ampullary segments isolated after ovulation (metestrus) the threshold for contractile enhancement following PGF2 alpha was greater than during proestrus, whereas, PGE1 elicited a significant inhibition of contractions. The spontaneous contractile pattern exhibited by isthmic and ampullary oviductal regions, prior to and after ovulation, is discussed in terms of tissue PG generation and output and is compared with results regarding tubal motility following the exposure to exogenous PGs.

Metabolic factors regulating the generation of prostaglandins E1 and E2 by isolated rat uterus

The generation and output of PGE2 and PGE1 by isolated rat uterus incubated with or without glucose as well as the influence of different metabolic substrates and selective enzyme inhibitors on tissue formation and release of PGE material of the 1 and 2 series, were explored. The output of PGE2 was comparable with glucose, fructose, lactate or pyruvate as the substrate but diminished significantly in citrate-containing solution. In substrate-free media uteri released more PGE2 than in the presence of glucose or other substrates. The PGE1 liberated was similar in glucose, fructose, lactate or pyruvate and decreased significantly in citrate or without substrate. 2-deoxy-D-glucose (2-DG), fluoride or arsenite failed to alter significantly the release of PGE2 whereas 2,4-dinitrophenol (DNP) evoked augmentation. The uterus released less PGE1 after 2-DG or fluoride but not following the addition of DNP or arsenite. The results suggest that the synthesis and release of PGE2 and PGE1 in the isolated rat uterus appear to be selectively modulated by different tissue metabolic pathways.

Progesterone enhances the output of prostaglandin F2-alpha by uterine horns isolated from adult ovariectomized and immature rats

The output of prostaglandin (PG) F and PGE-like material into the solution bathing uterine horns isolated from adult ovariectomized and immature rats under the influence of progesterone, was studied. The injection of progesterone (0.5; 1.0; 2.0 or 4.0 mg) 6 hours prior to sacrifice enhanced significantly the release of PGF-like substance without modifying that of PGE. The augmentation of PGF was detected as early as one hour after injecting 4.0 mg of progesterone and remained elevated at 2,4,6, 12 and 24 hours, following the treatment. Puromycin (50 mg/Kg), injected 6 hours before killing, failed to alter the release of PGF-like substance but clearly blocked the stimulating effect of the hormone. In addition, progesterone also enhanced significantly the release of PGF-like material by horns isolated from immature animals. The results suggest that progesterone receptors do not appear to be important for the described effect of the hormone because the preparations employed in the present study have a very small content of these receptors. Alternatively, it can be hypothesized that only a reduced number of progesterone receptors are sufficient for the action of the hormone augmenting the output of PGF-like material from the uterus.

Sonography of fetal urinary tract anomalies

Experience with 13 cases and a review of 41 cases in English literature indicate that anomalous development of the fetal urinary system can be detected in utero using sonography. Anomalies not compatible with extrauterine life (bilateral renal agenesis, infantile polycystic and bilateral multicystic kidney disease) have distinctive sonographic features that can be detected early enough to allow elective termination. Megacystis, either as a primary finding or secondary to urethral obstruction, can be detected and usually portends a poor fetal outcome. Obstruction at the ureterovesical junction has a distinctive sonographic appearance, but ureteropelvic junction obstruction cannot be differentiated from some cystic renal lesions, particularly when it is unilateral. Even when a precise diagnosis cannot be established in utero, the detection of a fetal renal anomaly may significantly affect obstetric and neonatal management of the benefit of both mother and fetus.