Dennis W. Matt

Interleukin-1β, human leukocyte antigen HLA-DRα, and transforming growth factor-β expression in endom trium, placenta, and placental membranes

Maternal immune recognition of the fetal semiallograft appears to be necessary and beneficial for fetal survival and growth. Interleukin-1 beta and human leukocyte antigen HLA-DR are important for foreign antigen recognition by the immune system, whereas transforming growth factor-beta inhibits many of the immunostimulatory properties of interleukin-1 beta. In this study we found that first-trimester decidua and term placental membranes expressed significantly higher levels of interleukin-1 beta, interleukin-1 beta messenger ribonucleic acid, and human leukocyte antigen HLA-DR alpha messenger ribonucleic acid expression. All tissues found at the maternal-fetal interface, including first-trimester decidua, placenta, and placental membranes, contained transforming growth factor-beta and expressed transforming growth factor-beta 1 messenger ribonucleic acid. On the basis of these findings, we suggest that the increase in decidual interleukin-1 beta and human leukocyte antigen HLA-DR alpha during pregnancy may be involved in maternal recognition of the fetal semiallograft and that transforming growth factor-beta production may regulate the local maternal immune response and prevent rejection of the fetus.

Coculture cells that express leukemia inhibitory factor (LIF) enhance mouse blastocyst developmentin vitro

PurposeLeukemia inhibitory factor is a cytokine that plays an important role in implantation and enhances mouse preimplantation embryo development in vitro.Since leukemia inhibitory factor enhances early embryo development, we tested the hypothesis that coculture cells that express leukemia inhibitory factor would enhance mouse blastocyst development in vitro.In this study, Northern analysis for leukemia inhibitory factor was performed on total RNA extracted from Vero cells, human embryonic, fibroblasts, and human placental fibroblasts.MethodsTwo-cell mouse embryos were cultured to blastocyst in Hams F-10 with 15% human cord serum (control) or with the coculture cells. Northern analysis demonstrated expression of LIF mRNA in Vero cells and embryonic fibroblasts but not in placental fibroblasts. Development to blastocyst was significantly enhanced in two-cell embryos cultured with Vero cells (86%, 140/163) and embryonic fibroblasts (83%, 118/142) when compared to controls (71%, 67/94, P<0.05) or placental fibroblasts (71%, 95/134), P<0.05).ConclusionThese data suggest that coculture cells that express leukemia inhibitory factor may be superior to nonleukemia inhibitory factor expressing cells for early preimplantation embryo development.

Dehydroepiandrosterone Reduces Plasma Plasminogen Activator Inhibitor Type 1 and Tissue Plasminogen Activator Antigen in Men

Dehydroepiandrosterone (DHEA) may help prevent heart disease in men. To test the hypothesis that DHEA might exert its effects by enhancing endogenous fibrinolytic potential, a double-blind, placebo-controlled study was conducted that assessed the effects of DHEA administration on plasma plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) antigen. Eighteen men received 50 mg DHEA orally and 16 men received a placebo capsule thrice daily for 12 days. Serum DHEA-sulfate and plasma PAI-1 and tPA antigen were measured before and after treatment. In the DHEA group, serum DHEA-sulfate (from 7.5 +/- 1.2 micromol/L to 20.2 +/- 1.5 micromol/L (P < 0.0001), androstenedione (from 2.6 +/- 0.2 nmol/L to 4.0 +/- 0.4 nmol/L; P < 0.005) and estrone (from 172 +/- 21 pmol/L to 352 +/- 28 pmol/L; P < 0.005) increased, whereas plasma PAI-1 (from 55.4 +/- 3.8 ng/mL to 38.6 +/- 3.3 ng/mL; P < 0.0001) and tPA antigen (from 8.1 +/- 1.9 ng/mL to 5.4 +/- 1.3 ng/mL; P < 0.0005) decreased. In the placebo group, serum DHEA-sulfate declined slightly from 8.0 +/- 3.3 micromol/L to 7.3 +/- 3.4 micromol/L (P < 0.05), but no other measured steroid changed. Plasma PAI-1 and tPA antigen did not change in the placebo group. These findings suggest that DHEA administration reduces plasma PAI-1 and tPA antigen concentrations in men.

Suppression of serum insulin level by diazoxide does not alter serum testosterone or sex hormone-binding globulin levels in healthy, nonobese women.

Suppression of serum insulin levels with diazoxide is associated with a decrease in serum testosterone and an increase in serum sex hormone-binding globulin in obese women with the polycystic ovary syndrome. To determine whether physiologic insulin levels play a regulatory role in the androgen status of nonobese women with normal menses, the androgen status of five nonobese normal women was assessed on two occasions: during a control study and after 10 days of oral diazoxide (100 mg, three times daily) administration. Insulin release in response to 100 gm oral glucose administration decreased from 108.0 +/- 28.2 to 49.3 +/- 5.2 nmol.min/L (p = 0.05) after diazoxide administration. However, despite suppression of insulin release, diazoxide administration did not affect serum total testosterone (diazoxide, 0.73 +/- 0.10; control, 0.69 +/- 0.11 nmol/L; p = NS) or sex hormone-binding globulin (diazoxide, 79.7 +/- 16.6; control, 70.2 +/- 12.6 nmol/L; p = NS) concentrations. These observations suggest that physiologic insulin levels in nonobese healthy women do not regulate testosterone metabolism and that diazoxide does not exert a direct or independent effect on serum testosterone or sex hormone-binding globulin levels.

Attenuated proestrous luteinizing hormone surges in middle-aged rats are associated with decreased pituitary luteinizing hormone-β messenger ribonucleic acid expression

OBJECTIVEnThis study determined whether attenuated preovulatory luteinizing hormone surges in aging rats are associated with a decrease in pituitary luteinizing hormone content or luteinizing hormone beta-messenger ribonucleic acid expression on proestrus.nnnSTUDY DESIGNnBlood samples were taken every 90 minutes from 1:30 to 10:30 PM on proestrus in young (n = 8) and middle-aged (n = 12), regularly cyclic rats for plasma luteinizing hormone determination. On the next proestrus at 12 noon, rats were killed and the pituitaries were removed for luteinizing hormone content determination by radioimmunoassay and luteinizing hormone beta-messenger ribonucleic acid expression by dot blot analysis. Results were analyzed by one-way analysis of variance.nnnRESULTSnSeven of the middle-aged rats had attenuated luteinizing hormone surges while the remaining five females had surges similar to those of young rats. On the next proestrus, all rats had similar quantities of pituitary luteinizing hormone. However, luteinizing hormone beta-messenger ribonucleic acid expression in middle-aged rats with attenuated luteinizing hormone surges was lower (p less than 0.05) than that of middle-aged and young rats with normal surges.nnnCONCLUSIONnDecreased luteinizing hormone beta-messenger ribonucleic acid expression, but not pituitary luteinizing hormone content at 12 noon on proestrus is correlated with attenuated luteinizing hormone surges in middle-aged rats.

Alterations in gonadotropin secretion in middle-aged persistent-estrous rats following LHRH agonist treatment

During aging female rats enter an anovulatory condition with chronically elevated circulating levels of estrogen described as persistent estrus (PE). Since this endocrine state is dramatically different from the fluctuating steroid milieu of young regularly cycling females, interpretations of altered neuroendocrine responses in aged rats have been difficult to attribute to aging per se. In the present study, young cyclic and middle-aged PE rats were treated with an LHRH agonist, [DTrp6,Pro9-NHEt]-LHRH, continuously (2.5 micrograms/h) for 12 days to suppress gonadotropin and ovarian steroid secretion. On the evening of the first day of LHRH agonist (LHRH-AG) treatment both young cyclic and middle-aged PE rats showed marked (p < 0.01) increases in plasma LH and FSH followed by progressive decreases in gonadotropin secretion which reached significantly (p < 0.05) lower levels than pretreatment values by day 7. LHRH-AG treatment significantly (p < 0.01) reduced circulating 17 beta-estradiol (E2) levels in both young and PE rats while progesterone concentrations did not change. Following LHRH-AG treatment, ovariectomy (OVX) resulted in increases of plasma LH and FSH that were delayed and attenuated in PE rats as compared to those of young females. When compared to nontreated rats, 12 days of LHRH-AG treatment in both young and PE females had a minimal and transient effect on the post-OVX gonadotropin responses, suggesting that the endocrine status immediately prior to OVX does not profoundly influence the post-OVX responses in young cyclic and middle-aged PE rats. Furthermore, LHRH-AG treatment does not appear to have permanent inhibitory effects on the hypothalamic-pituitary axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Orosomucoid in human pregnancy serum diminishes bioavailability of the progesterone antagonist RU 486 in rats

Bioavailability of the progesterone antagonist RU 486 was examined in vivo by measurement of first-pass uptake by hepatic and uterine tissues in rats. Presence of human pregnancy serum or alpha 1-acid glycoprotein (orosomucoid) in injection vehicles diminished uptake of this steroid, which suggests limited bioavailability. These data indicate that elevated human serum orosomucoid levels may account for some failures of RU 486 in early pregnancy termination.

Comparison of in vivo bioavailability of progestational agents into the rat uterus and liver and the effect of plasma protein binding

The in vivo bioavailabilities of three clinically available progestational agents were evaluated with a previously described rat model. With this model a single-injection, double-isotope technique was performed to calculate and compare the unidirectional extractions of progesterone, 19-nortestosterone, and medroxyprogesterone acetate into the rat uterus and liver. To assess the role of plasma protein binding in the extraction of these agents, steroids were presented in four different vehicles: (1) Ringers solution, 0.1% bovine serum albumin; (2) Ringers solution, 4% bovine serum albumin; (3) Ringers solution, 0.8 mg/ml, alpha 1-acid glycoprotein; (4) human pregnancy serum. The results revealed that liver extraction always exceeded uterine extraction for each progestin, regardless of the vehicle, and that liver extraction was approximately 100% for all steroids. With regard to the uterus, when binding proteins were not present in the injectate, the extraction of the three steroids was similar; the uterine vasculature was relatively permeable to these progestins, and bovine serum albumin and alpha 1-acid glycoprotein had no major effect on the uptake into the uterus. However, when human pregnancy serum was in the injectate, the extractions of progesterone and 19-nortestosterone into the rat uterus were significantly diminished. In contrast, pregnancy serum had no effect on the uptake of medroxyprogesterone acetate into the uterus, with the extraction equal to that of Ringers solution alone. This suggests that, regardless of potential binding proteins, medroxyprogesterone acetate displays greater bioavailability than that of the other progestogens studied.