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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of this study was to investigate changes in expression of mRNAs encoding FSH receptor (FSHr), LH receptor (LHr), cytochrome P450 side-chain cleavage (P450(scc)), cytochrome P450 17alpha-hydroxylase (P450(c17)), and cytochrome P450 aromatase (P450(arom)) during recruitment and selection of bovine ovarian follicles. Dairy heifers (4-5 per group) were ovariectomized at 12, 24, 36, 48, 60, 72, 84, or 96 h after initiation of the first follicular wave following estrus as determined by ultrasonography (Time 0 = initiation of follicular wave; mean +/- SEM = 42.0 +/- 2.6 h after estrus). Expression of mRNAs encoding FSHr, LHr, P450(scc), P450(c17), and P450(arom) was detected by in situ hybridization and quantified by image analysis. Antral follicles were classified as healthy or atretic. Healthy follicles expressed higher (p < 0.01) amounts of mRNAs for gonadotropin receptors and steroidogenic enzymes than did atretic follicles, and expression of LHr, FSHr, P450(scc), P450(c17), and P450(arom) increased (p < 0.01) with follicular size and stage of the follicular wave. Expression of mRNAs for P450(scc), P450(arom), and LHr was time- and size-dependent during recruitment and selection. During recruitment, expression of mRNAs for P450(scc) and P450(arom) was first detected in granulosa cells of 16 of 21 of the follicles 4-6 mm in diameter at 12 h. At 24 and 36 h, almost all follicles 6-9 mm in diameter, but not those 4-5 mm in diameter, expressed both P450(scc) and P450(arom) mRNA in the granulosa cells. At 48 h and thereafter, P450(scc) and P450(arom) mRNA were expressed predominantly in one healthy large follicle per cow with a few exceptions. Expression of LHr mRNA was first detected in granulosa cells at 36 h and was always found in granulosa cells of one follicle > or = 8 mm per cow with exception of one cow at 36 h (no expression) and another two cows, one each at 36 and at 84 h (expression in 2 follicles). In addition, LHr mRNA expression in the granulosa cell layer was limited to follicles that also expressed mRNAs for P450(scc) and P450(arom) in the granulosa cells. In summary, follicular recruitment in cattle was associated with expression of P450(scc) and P450(arom) mRNA within granulosa cells, and the process of follicular selection was associated with initiation of LHr mRNA expression in granulosa cells.
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PMID:Changes in messenger ribonucleic acid encoding luteinizing hormone receptor, cytochrome P450-side chain cleavage, and aromatase are associated with recruitment and selection of bovine ovarian follicles. 916 Jul 14

We have shown previously that long-term testosterone secretion, which decreases when human Leydig cells are cultured alone, increases when purified human Leydig and Sertoli cells are cultured together. In this work, human Leydig cell functions were studied further during in vitro culture, either alone or with human Sertoli cells, on a basal membrane derived from bovine corneal endothelial cells. The secretion of testosterone increased during the first week of co-culture and remained elevated up to day 12 of culture. In one prolonged co-culture, testosterone secretion decreased progressively after day 12 and, after 1 month of culture, was at a level similar to that observed during the first 48 h. After culture for 48 h, testosterone secretion in the co-culture was enhanced by 162 +/- 5% (p < 0.0001) compared with values observed when Leydig cells were cultured alone (42.6 +/- 10.6 ng/10(6) Leydig cells/48 h; mean +/- SEM). This change was associated with increase in mRNA levels for 3 beta-hydroxysteroid dehydrogenase delta 5-delta 4-isomerase (2.49 +/- 0.58-fold), cytochrome P450c17 (2.81 +/- 0.99-fold), cytochrome P450scc (5.20 +/- 0.13-fold) and cytochrome P450 aromatase (1.73 +/- 0.21-fold) when Leydig cells were co-cultured with Sertoli cells (p < 0.05 for each enzyme). IGF-I mRNA levels were higher (2.77 +/- 0.72-fold for 7.6 kb and 1.41 +/- 0.07-fold for 1.1-1.3 kb transcripts) in the Leydig-Sertoli cell co-cultures than the sum of the levels in Leydig and in Sertoli cells cultured alone. Both basal and hCG-induced testosterone secretion were enhanced by treatment of the co-culture with human recombinant FSH (50 mIU/mL). For basal testosterone secretion, this increase amounted to 163 +/- 5% compared with Leydig cells cultured alone (p < 0.0001) and by 112 +/- 4% compared with non-FSH treated co-cultures (p < 0.01); for hCG-stimulated testosterone secretion this increase was 220 +/- 12% compared with Leydig cells cultured alone (p < 0.0001) and 132 +/- 8% compared with non-FSH treated co-cultures (p < 0.01). This study confirms the enhancement of long-term testosterone secretion by adult human Leydig cells by co-culture with adult human Sertoli cells and shows that this effect is associated with an enhancement of the expression of several steroidogenic enzymes; it might be mediated, as in other species, through increased production of IGF-I by co-culture.
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PMID:Enhancement of long-term testosterone secretion and steroidogenic enzyme expression in human Leydig cells by co-culture with human Sertoli cell-enriched preparations. 966 97

In the present study, it was hypothesized that the adrenocorticotrophin hormone receptor (ACTH-R) would be up-regulated in the adrenal gland of the sheep fetus following infusion of physiological amounts of ACTH, as shown for adrenal cortical cells in culture. In chronically catheterized sheep, an intravenous infusion of ACTH(1-24) was given to 6 fetuses for 24 h at a rate of 0.5 microg h(-1), starting on Day 126 or 127 of gestation (term approximately 147 days). Four control fetuses received an infusion of vehicle (saline). Total RNA was extracted from the fetal adrenal glands by the guanidinium thiocyanate method. Expression of specific mRNAs was determined by ribonuclease protection assay using cRNA probes directed against: ACTH-R; the steroid enzymes side-chain cleavage (P450scc), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 17apha-hydroxylase (P450c17) and 21beta-hydroxylase (P450c21); and beta-actin. Ratios of mRNA expression to beta-actin mRNA expression (arbitrary units) were calculated to correct for differences in RNA quality between samples. The concentration (mean +/- SEM) of immunoreactive cortisol in fetal plasma was greater after ACTH infusion than after vehicle infusion (47 +/- 3 v. 13 +/- 2 ng mL(-1) respectively; P<0.001). Adrenal expression of P450scc and P450c21 mRNA increased after ACTH infusion (P<0.05), whereas expression of P450c17 and 3beta-HSD mRNA was unchanged. There was no difference in ACTH-R mRNA expression between ACTH- and vehicle-infused fetuses (254 +/- 48 v. 305 +/- 76 arbitrary units respectively). It was concluded that ACTH is able to increase plasma cortisol concentrations in the sheep fetus by up-regulating cortisol synthesis in the adrenal gland, but that in vivo this does not require up-regulation of ACTH-R mRNA.
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PMID:Adrenocorticotrophic hormone (ACTH) stimulation of sheep fetal adrenal cortex can occur without increased expression of ACTH receptor (ACTH-R) mRNA. 1205 14

In this work, to improve the mechanical stability of electrodes based on P450scc for LDL-cholesterol detection and measure, anodic porous alumina (APA) was used. This inorganic matrix, which pores can be tuned in diameter modifying the synthesis parameters, was realized with cavities 275 nm wide and 160 microm deep (as demonstrated with AFM and SEM measurement), to allow the immobilization of P450scc macromolecules preserving their electronic sensitivity to its native substrate, cholesterol. Even if the sensitivity of the APA+P450scc system was slightly reduced with respect to the pure P450scc system, the readout was stable for a much longer period of time, and the measures remained reproducible inside a proper confidentiality band, as demonstrated with several cyclic voltammetry measures. To optimize the adhesion of P450scc to APA, a layer of poly-L-lysine, a poly-cathion, was successfully implemented as intermediate organic structure.
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PMID:Anodic porous alumina as mechanical stability enhancer for LDL-cholesterol sensitive electrodes. 1776 1


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