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Biomedical subjects

A L Southren

Publications and source records attributed to A L Southren.

At least 19 recordsLinked to original sources
PubMed1996

Decreased 3 alpha-hydroxysteroid dehydrogenase activity in peripheral blood lymphocytes from patients with primary open angle glaucoma.

The purpose of the present study was to determine whether peripheral blood lymphocytes (PBL) from primary open angle glaucoma (POAG) patients have reduced 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) activity as was previously found in POAG-derived cultured trabecular meshwork cells. The availability of PBL from both POAG and control patients makes this a useful system for studying the association of decreased 3 alpha-HSD activity with POAG. PBL were isolated from the venous blood of 17 POAG patients and 22 non-glaucoma controls and assayed for 3 alpha-HSD activity with tritiated 5 beta-dihydrocortisol as a substrate. The mean 3 alpha-HSD activity +/- S.E.M., expressed in comparable units of specific activity, of the POAG derived PBL was 13.8 +/- 1.3 U as compared to 32.8 +/- 2.0 U for control cells. This reduction (> 50%) was statistically significant (P < 0.001). Quantitative immunoblot analysis of PBL indicated that the POAG and control cells, despite their difference in 3 alpha-HSD activity, had nearly identical amounts of 3 alpha-HSD protein. The molecular weight of PBL 3 alpha-HSD from both groups of patients was 38,000, the same as previously reported for human liver. The results of this study show an association of decreased PBL 3 alpha-HSD activity and POAG which was not related to antiglaucoma therapy. The reduced levels of 3 alpha-HSD activity in the readily obtainable PBL may serve as a marker for POAG or those at risk for developing the disease.

3-Hydroxysteroid Dehydrogenases↗
PubMed1994

Treatment of glaucoma with 3 alpha, 5 beta-tetrahydrocortisol: a new therapeutic modality.

The effectiveness of 3 alpha, 5 beta-tetrahydrocortisol (3 alpha, 5 beta-THF), a metabolite of cortisol, in lowering intraocular pressure (IOP) in rabbits made ocular hypertensive with glucocorticoids suggested its use in patients with Primary Open Angle Glaucoma (POAG). Patients with well-documented POAG were treated with a 1% suspension of 3 alpha, 5 beta-THF administered to one eye four times daily for up to six weeks. Eight out of nine patients experienced an appreciable decrease in IOP in the treated eye (average decrease 4.9 mm Hg). There was no conjunctival irritation, corneal pathology, visual field changes, alteration in liver or renal function tests or blood count during the treatment period. The present study demonstrates that 3 alpha, 5 beta-THF, a naturally occurring steroid metabolite, is effective in lowering IOP in patients with POAG. Antiglucocorticoids may represent a new therapeutic modality for the management of POAG.

Administration, Topical↗
PubMed1992

Human hepatic 3 alpha-hydroxysteroid dehydrogenase: possible identity with human hepatic chlordecone reductase.

3 alpha-Hydroxysteroid dehydrogenase is a cytosolic, monomeric, NADPH-dependent oxidoreductase which reduces 3-keto-5-dihydrosteroids to their tetrahydro products. We present here the first partial amino acid sequence data for the human liver enzyme and show these sequences to be identical to the deduced amino acid sequence for human hepatic chlordecone reductase. In addition, these two enzymes exhibit similar substrate and cofactor specificities and immunological reactivity. The results suggest that the natural substrates for chlordecone reductase are 3-keto-5-dihydrosteroids and that these two proteins may be identical.

3-Hydroxysteroid Dehydrogenases↗
PubMed1992

Purification and properties of human hepatic 3 alpha-hydroxysteroid dehydrogenase.

3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) was purified greater than 500-fold from human liver cytosol. The purification was monitored using 5 beta-[3H]dihydrocortisol (5 beta-DHF) as substrate. Electrophoretically homogeneous enzyme was obtained using a procedure that involved ammonium sulfate precipitation and three successive column chromatography steps: DEAE-cellulose, hydroxylapatite and Blue-Sepharose. The enzyme is a monomer since the native molecular weight was found to be 37,000, using a calibrated Sephadex G-75 column, and the denatured subunit molecular weight was determined to be 38,500, by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The enzyme had a pI of 5.6-5.9. The 3-ketosteroids: cortisol, testosterone, progesterone and androstenedione, were not substrates for 3 alpha-HSD indicating that a saturated 4,5 double bond was required for substrate activity. The conformation at the 5 position, however, did not influence substrate activity since 5 alpha- and 5 beta-DHF and 5 alpha-dihydrotestosterone were all reduced at similar rates. The purified enzyme preferred NADPH to NADH as a cofactor and showed a broad peak of activity in the pH range of 6.8-7.4. The apparent Km for 5 beta-DHF was 18 microM. The enzyme was markedly stabilized by 50 mM phosphate buffer containing 10 to 20% glycerol at 4 degrees C. Freezing and thawing of the enzyme resulted in a large loss of activity during early stages of the purification. This is the first report of the purification to homogeneity of 3 alpha-HSD from human tissue.

3-Hydroxysteroid Dehydrogenases↗
PubMed1991

5 alpha-dihydrocortisol in human aqueous humor and metabolism of cortisol by human lenses in vitro.

Glucocorticoids have long been implicated in the etiology of primary open-angle glaucoma (POAG) and cataract. Cortisol metabolites have biologic activity and may affect aqueous humor dynamics. This study was done to determine whether these metabolites are found in human aqueous humor and can be produced by ocular tissues. Radioimmunoassays (RIA) were developed for 5 alpha-dihydrocortisol (5 alpha-DHF) and 5 beta-dihydrocortisol (5 beta-DHF). These assays, as well as a cortisol RIA, were used to quantify these three steroids in 20 surgically derived aqueous humor specimens from patients with and without POAG. The mean concentrations of cortisol and 5 alpha-DHF were 2.5 and 1.3 ng/ml, respectively. In the small group studied, there was no statistically significant difference between the aqueous humor steroid levels in patients with and without POAG. The amount of 5 beta-DHF was at the lower limits of detection of the assay system and could not be uniquivocally shown. Human lenses metabolized cortisol in vitro to 5 alpha-DHF and 3 alpha,5 alpha-tetrahydrocortisol (3 alpha,5 alpha-THF). There was no 5 beta-DHF or cortisone formed. The 5 alpha-DHF and 3 alpha,5 alpha-THF were identified by their positions on thin-layer chromatography, their retention times on high-performance liquid chromatography, and recrystallization with authentic standards to constant specific activity. The data suggest that the lens is the source of 5 alpha-DHF in aqueous humor.

Aged↗
PubMed1990

Human hepatic cortisol reductase activities: enzymatic properties and substrate specificities of cytosolic cortisol delta 4-5 beta-reductase and dihydrocortisol-3 alpha-oxidoreductase(s).

The metabolism of cortisol by human liver homogenates has been studied. Cortisol delta 4-reductase and dihydrocortisol-3-oxidoreductase activities were distributed in all subcellular fractions. The products of the soluble enzymes were identified. Cortisol and 5 beta-dihydrocortisol were reduced to 3 alpha,5 beta-tetrahydrocortisol, and 5 alpha-dihydrocortisol was reduced to 3 alpha,5 alpha-tetrahydrocortisol. The soluble enzymes showed a wide range of substrate specificity. The 21 substituted cortisol derivatives were not metabolized. The apparent Km values of cortisol delta 4-5 beta-reductase and dihydrocortisol-3 alpha-oxidoreductase for their substrates (cortisol, 5 alpha-dihydrocortisol, and 5 beta-dihydrocortisol) all ranged from 18 to 27 microM. Dexamethasone inhibited the reduction of all of these substrates and the inhibition was abolished by 21 substitution of the dexamethasone. Testosterone was a competitive inhibitor of the reduction of cortisol, 5 alpha-dihydrocortisol, and 5 beta-dihydrocortisol with a Ki ranging from 11 to 32 microM. NADPH was the preferred cofactor for the cortisol delta 4-5 beta-reductase and dihydrocortisol-3 alpha-oxidoreductase. No end product inhibition was observed.

Chromatography, High Pressure Liquid↗
PubMed1989

Dexamethasone induces specific proteins in human trabecular meshwork cells.

Previous studies have demonstrated the presence of high-affinity, glucocorticoid-specific receptors in explants of human outflow tissue and in cultured trabecular meshwork. Glucocorticoid-induced responses of scleral fibroblasts and trabecular meshwork cells were evaluated in this study. Incubation of human trabecular meshwork (HTM) and scleral fibroblast (HS) cells with 10(-7) M dexamethasone (DEX) results in a 60% inhibition of prostaglandin production. The effects of glucocorticoid treatment on cellular and secreted proteins using [35S] methionine incorporation were evaluated. Treatment of HTM cells cultured from two normal individuals with DEX induced the expression of [35S] methionine-labelled cellular proteins of 35, 65 and 70 kD, and secreted proteins of 40, 90 and 100 kD. Under the same experimental conditions, a 70 kD molecular weight cellular protein was induced in the HS cells. There were no apparent DEX-induced alterations in HS-secreted proteins. Since a functional common response to glucocorticoid treatment in both HS and HTM cells was inhibition of prostaglandin production, the dexamethasone-induced expression of the 70 kD protein in these cells may be related to this effect. Further studies are required to elucidate specific roles of the steroid-induced proteins in the effects of glucocorticoids on HTM and HS cells.

Cells, Cultured↗
PubMed1988

Bromocriptine in polycystic ovarian disease: a controlled clinical trial.

Bromocriptine and placebo were given to a group of 20 polycystic ovarian disease patients on a double-blind, cross-over basis. Patients were studied for three cycles: a baseline cycle without any medication, a placebo-treated cycle, and a bromocriptine-treated cycle with multiple plasma samples taken during the different phases of the menstrual cycle. The clinical response to bromocriptine was compared with that of a placebo for the following hormones: prolactin (PRL), luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio, testosterone, androstenedione, estradiol-17 beta (E2), estrone (E1), and progesterone. Patients were divided into two subgroups: hyperprolactinemic (basal PRL greater than 20 ng/mL) and normoprolactinemic (basal PRL less than 20 ng/mL), and the response of both subgroups to bromocriptine was compared. Prolactin, LH/FSH ratio, testosterone, and E1 showed a significant drop with bromocriptine, whereas E2 significantly increased. Two out of nine amenorrheic polycystic ovarian disease patients menstruated during bromocriptine treatment, and three patients showed evidence of ovulation.

Adolescent↗
PubMed1987

Ovarian follicular fluid beta-endorphin levels in normal and polycystic ovaries.

The possibility of local ovarian production of beta-endorphin prompted us to measure beta-endorphin levels in 19 follicular fluid samples obtained from normal ovaries and compare them with beta-endorphin plasma levels in 19 women with normal ovulation. beta-Endorphin was extracted through Sepharose-treated chromatography columns and assayed with a specific anti-beta-endorphin antibody. Follicular fluid beta-endorphin levels (21.3 +/- 10.8 pg/ml) were significantly higher (p less than 0.01) than the plasma levels (15.5 +/- 3.35 pg/ml). There was no significant correlation between plasma and follicular fluid beta-endorphin concentrations. Follicles greater than 1 cm in size contained more beta-endorphin than follicles less than 1 cm in size (22.7 +/- 3.5 versus 18.7 +/- 4.4 pg/ml, p less than 0.05). Five follicular fluid samples were obtained from polycystic ovaries. The mean beta-endorphin content (45.1 +/- 7.7 pg/ml) in these follicles was significantly higher than that of normal ovaries (p = 0.001). It is concluded that the ovaries produce beta-endorphin and that polycystic ovaries produce more beta-endorphin than normal ovaries.

Endorphins↗
PubMed1987

A controlled clinical trial for the effect of bromocriptine on the adrenal contribution in polycystic ovarian disease.

Adrenal involvement in polycystic ovarian disease was assessed by measuring dehydroepiandrosterone sulphate in 20 polycystic ovarian disease patients. The response of dehydroepiandrosterone sulphate to bromocriptine treatment was compared to that of placebo, both being given for one cycle on a double-blind, cross over basis. The mean basal DHEA-S was above the upper limit of the normal range (6793 nmol/l) in three patients. The mean basal dehydroepiandrosterone sulphate in the polycystic ovarian disease group was significantly higher than the mean of the normal control group (P less than 0.01). Dehydroepiandrosterone sulphate showed a significant drop with bromocriptine as compared to placebo (P less than 0.001) and a significant correlation with prolactin both before (P less than 0.001) and after treatment with bromocriptine (P less than 0.001). These findings support the hypothesis of adrenal involvement in polycystic ovarian disease and prove the significant effect of bromocriptine on the adrenal which might be of therapeutic value.

Adolescent↗
PubMed1987

Intraocular hypotensive effect of a topically applied cortisol metabolite: 3 alpha, 5 beta-tetrahydrocortisol.

3 alpha, 5 beta-tetrahydrocortisol, previously considered an inactive metabolite of cortisol, was found to lower significantly the intraocular pressure (IOP) of rabbits made ocular hypertensive with dexamethasone alone or with threshold levels of dexamethasone plus 5 beta-dihydrocortisol. The ocular hypotensive effect appeared within 3-7 days after the metabolite was started and persisted through the duration of the experiments. The metabolite did not lower the IOP of ocular normotensive untreated animals. Thus, 3 alpha,5 beta-tetrahydrocortisol is a naturally occurring steroid antagonist, which may be of use in the treatment of primary open-angle glaucoma.

Animals↗
PubMed1987

Human trabecular meshwork cells in culture: morphology and extracellular matrix components.

This study demonstrates the presence of laminin and collagen type IV in the extracellular space of human trabecular meshwork (HTM) cells in culture and its absence in cultures of fibroblasts from sclera adjacent to the outflow pathway. These basement membrane components can be detected by standard immunohistochemical techniques. Positive staining for these macromolecules is found only after the HTM cells have reached confluence. The presence of laminin and human collagen type IV in the early passages can serve as additional criteria for identification of HTM cells in culture. These cells provide a useful experimental system for studying the effects of drugs and other factors on the synthesis of components of the extracellular matrix.

Adolescent↗
PubMed1986

Correlation of the ultrasonic appearance of the ovaries in polycystic ovarian disease and the clinical, hormonal, and laparoscopic findings.

The ovarian ultrasonic appearance in 20 patients with polycystic ovarian disease was studied and correlated to the clinical, hormonal, and laparoscopic findings. Ultrasound studies showed that both ovaries were enlarged in 15 patients (15.46 +/- 2.5 cm3). Maximum ovarian surface area was 9.75 +/- 3.38 cm2. Three ultrasonic patterns were detected: (1) isoechoic, with no discernible cysts (four patients); (2) hypoechoic, with multiple small cysts of less than 1 cm (11 patients); (3) hypoechoic, with single cyst of greater than 1 cm (five patients). Ultrasonic estimation of ovarian size was superior to clinical assessment and equal to that of laparoscopic examination. Subtle differences existed between the ultrasonic appearance of the ovaries in hyperprolactinemic subgroups of polycystic ovarian disease compared to normoprolactinemic ones. However, no significant relationship was found between the ovarian size and any of the hormones studied. Obesity, amenorrhea, hirsutism, hyperprolactinemia, and elevated testosterone and dehydroepiandrosterone sulfate levels were more common in the group with enlarged ovaries, whereas oligomenorrhea, elevated luteinizing hormone/follicle-stimulating hormone ratio, and elevated androstenedione and estrone levels occurred more frequently in the group with normal-sized ovaries. The value of ultrasound studies in the management of polycystic ovarian disease is emphasized.

Adolescent↗
PubMed1986

Prostaglandin synthesis and release from cultured human trabecular-meshwork cells and scleral fibroblasts.

Human trabecular-meshwork (HTM) cells in culture convert arachidonic acid to two products: PGE2 and 6-keto PGF1 alpha. Prostaglandin PGE2 was the major product of arachidonic-acid metabolism. The synthesis and release of PGE2 and 6-keto PGF1 alpha was inhibited by a 15-min pre-treatment with indomethacin (5 X 10(-6) M) or a 4-24-hr incubation with 10(-7) M dexamethasone. The effects of dexamethasone could be prevented by cycloheximide (0.5 micrograms ml-1), or actinomycin D (2 micrograms ml-1). Prostaglandin E2 synthesis and release by these HTM cells from two different individuals could be stimulated by bradykinin, arachidonic acid and the calcium ionophore, A23187.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Potentiation of collagen synthesis in explants of the rabbit eye by 5 beta-dihydrocortisol.

The biologic effect of 5 beta-dihydrocortisol on collagen synthesis was evaluated. The metabolite was found to potentiate subthreshold levels of dexamethasone in increasing 3H-proline incorporation in cells of the outflow region of the rabbit. Digestion of the tissue with highly purified collagenase indicated that the 3H-proline was incorporated into collagen type protein. This study demonstrates another biologic activity of 5 beta-dihydrocortisol, a metabolite found to accumulate in cells cultured from trabeculectomy specimens from patients with primary open angle glaucoma.

Animals↗
PubMed1985

Direct radioimmunoassay (RIA) of salivary testosterone: correlation with free and total serum testosterone.

Simple and sensitive direct RIA for determination of salivary testosterone was developed by using RSL NOSOLVEX TM (125 1) kit produced by Radioassay System Laboratories (Carson, California). In addition, a relationship between salivary and serum free and total testosterone concentrations was studied in randomly selected 45 healthy subjects, 5 females on oral contraceptive pills and 28 hypertensive patients on various treatment regimens. The lowest weight of testosterone detectable by our modified method was equivalent to 1 pg/ml of saliva, taking into account analytical variability. Intra- and interassay coefficients of variation were 5.09 +/- 2.7% and 8.2 +/- 5.9% respectively. Statistically significant correlations were found between salivary and serum free testosterone (r = 0.97) and salivary and serum total testosterone concentrations (r = 0.70-0.87). The exception to this was a group of hypertensive females in which no correlation (r = 0.14) between salivary and total serum testosterone was found. It is also of interest that, while salivary testosterone was significantly increased in subjects taking oral contraceptives and most of the hypertensive patients the total serum testosterone concentration was in normal range. Our findings suggest that determination of salivary testosterone is a reliable method to detect changes in the concentration of available biologically active hormone in the circulation.

Adult↗