Search PubMed⌕ Search

Biomedical subjects

C A Flood

Publications and source records attributed to C A Flood.

14 recordsLinked to original sources
PubMed1993

Plasma dehydroepiandrosterone sulfate serves as a prehormone for 48% of follicular fluid testosterone during treatment with menotropins.

Evidence has suggested that dehydroepiandrosterone sulfate (DS) is a prehormone for ovarian steroidogenesis. To study this hypothesis, combined 6-h infusions of [3H]dehydroepiandrosterone sulfate and [14C]testosterone ([14C]T) were performed in four normal women treated with menotropins who were undergoing medically indicated surgery, and the data were compared to those from nine normal women. The concentrations of tracer and nonisotopic DS, androst-5-ene-3 beta,17 beta-diol sulfate (delta 5diolS), androst-5-ene-3 beta,17 beta-diol (delta 5diol), dehydroepiandrosterone (D), androstenedione (delta 4A), and T were determined in arterial and venous blood and in follicular fluid. From these data, the concentrations and fractions of steroids in the follicular fluid that were derived from DS were calculated from the specific activity of intravascular DS and the concentrations of follicular fluid tracer steroids and their specific activities. The fractions of T (0.48), delta 5diol (0.31), delta 5diolS (0.42), and D (0.25) in follicular fluid arising from circulating DS were similar and were not significantly different from that of follicular DS arising from circulating DS (0.32). However, the fraction of follicular fluid delta 4A (0.041) was significantly less (P < 0.01), and the fractions of intrafollicular estrone and estradiol arising from DS were both less than 0.04. The mean MCR of DS in the women treated with menotropins of 22.0 +/- 3.5 L/day (mean +/- SE) was significantly higher than the normal control value. These findings elucidate an important mechanism of adrenal/ovarian interaction at the level of steroidogenesis; circulating DS serves as a prehormone for the production of intrafollicular delta 5diolS, delta 5 diol, D, and T.

Adult↗
PubMed1993

Testosterone, a follicular regulator: key to anovulation.

To study the interrelationships of steroids within the follicle, combined 6-h infusions of [3H]dehydroepiandrosterone sulfate and [14C] testosterone ([14C]T) were performed in four normal women treated with menotropins who were undergoing medically indicated surgery. The concentrations of tracer and/or nonisotopic dehydroepiandrosterone sulfate, androst-5-ene-3 beta,17 beta-diol sulfate, androst-5-ene-3 beta,17 beta-diol, dehydroepiandrosterone, androstenedione, T, dihydrotestosterone, estrone (E1), and estradiol (E2) were determined in arterial and venous blood and follicular fluid. The log-transformed product/precursor ratio of [3H]dihydrotestosterone/[3H]T in follicular fluid was negatively correlated with the log-transformed follicular concentrations of E1 (P = 0.01) and E2 (P = 0.02), suggesting a reciprocal relationship between 5 alpha-reductase and follicular E1 and E2. E2 and T were positively correlated in follicular fluid (r = 0.84; P = 0.0003), suggesting a stimulatory action of follicular T on aromatase. These findings along with extensive published data suggest that follicular T functions as a follicular regulator, enhancing follicular aromatase activity when adequate amounts of FSH are available. These conclusions have important implications with regard to mechanisms for selecting the dominant follicle and producing atresia in the remaining cohort of follicles, and they describe a final common path in the pathophysiology of anovulation.

Anovulation↗
PubMed1991

Metabolic clearance rate of dehydroepiandrosterone sulfate, its metabolism to testosterone, and its intrafollicular metabolism to dehydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone in vivo.

At the time of surgery, women were infused with [3H]dehydroepiandrosterone sulfate ([3H]DS)/[14C]testosterone ([14C]T) for 6 h; blood samples were obtained from an artery the ovarian veins, and a peripheral vein; and fluid was obtained from ovarian follicles. Both blood and follicular fluid samples were analyzed for radioactivity as DS, dehydroepiandrosterone (D), androstenedione (delta 4A). T, and dihydrotestosterone (DHT), and the blood was also analyzed for the concentration of nonisotopic DS by RIA. In other subjects the concentrations of D and DS were measured in paired samples of blood and follicular fluid. From these data, values of 13.6 +/- 0.69 L/day four (mean +/- SE; n = 4) for MCRDS, 607 +/- 90 L/day (n = 3) for MCRT, and 0.0190 +/- 0.0089 (n = 3) for [p]DS-T (fraction of plasma DS metabolized to plasma T) were obtained. The ratio of the concentration of the tracer-labeled steroid in the follicular fluid to the concentration in the arterial plasma sample was elevated significantly above 1 for three 3H-labeled and three [14C-labeled metabolites: [3H]D (21-fold; P less than 0.001), [3H]T (81-fold; P less than 0.001), [3H]DHT (19-fold; P less than 0.001), [14C]T (4-fold; P less than 0.025), [14C]DHT (21-fold; P less than 0.01), and [14C]delta 4A (50-fold; P less than 0.001). The estimated concentrations of steroids in follicular fluid derived from DS based on specific activity calculations were as follows: [geometric mean (95% confidence limits; n)]: DS, 5600 (4800-6500 nmol/L; 12); D, 370 (88-1500 nmol/L; 10); delta 4 A, 120 (67-220 nmol/L; 12); T, 130 (39-450 nmol/L; 10); and DHT, 64 (35-120 nmol/L; 8). Comparison of these data to known follicular fluid steroid concentrations shows that DS from the intravascular pool can be used as an ovarian prehormone.

Adult↗
PubMed1991

Metabolism of dehydroepiandrosterone sulfate (DS) in normal women and women with high DS concentrations.

In order to determine the contribution of serum dehydroepiandrosterone sulfate (DS) to estrone (E1) production in normal women and the effect of chronic elevation of the serum DS concentration on DS metabolism, four normal women and four women with high endogenous serum DS were infused with [3H]DS and [14C]E1 or [14C]testosterone for 6 h. Blood samples were analyzed for radioactivity as DS, dehydroepiandrosterone (D), androstenedione, testosterone, and dihydrotestosterone. Urine was collected for analysis of creatinine, 17-ketosteroids (17-KS), and radioactivity as estrone (E1). The serum DS of 12.4 +/- 1.44 mumol/L (mean +/- SE) in the group with high DS was higher than that of 3.96 +/- 1.0 mumol/L (1.46 +/- 0.37 micrograms/mL) in the normals (P less than 0.005). Those with high DS also had increased 17-KS (13.2 +/- 2.0 vs. 5.68 +/- 0.68 mg/day, P less than 0.025) and a higher blood production rate of DS (PBDS) (126 +/- 21 (n = 3) vs. 54.3 +/- 13.8 mmol/day, P less than 0.05) but a lower MCRDS (10.94 +/- 0.61 (n = 3) vs. 13.8 +/- 0.27 L/day, P less than 0.01) than that in normals. In the four normal women the fraction of infused DS converted to estrone ( [rho]BMDS E1) was 0.00078 +/- 0.00018, the amount of E1 produced from serum DS was 41.3 +/- 15 nmol/day, the basal plasma E1 was 102 +/- 18 pmol/L, the MCRE1 was 1340 +/- 181 L/day, the value for blood production of E1 (PBE1) was 129 +/- 12 nmol/day, and the portion of E1 derived from DS was 30.4 +/- 9.4%. Correlation analysis of the data from these eight subjects showed that 17-KS, PBDS, and the serum DS were all correlated with body surface area, body weight, and ponderal index and that 17-KS excretion, PBDS, and serum DS were all correlated with one another. The most important predictors of 17-KS excretion were serum DS (P less than 0.001) and the ponderal index (P less than 0.05).

17-Ketosteroids↗
PubMed1989

Metabolic clearance rate (MCR) of dehydroepiandrosterone sulfate (DS), its metabolism to dehydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone, and the effect of increased plasma DS concentration on DS MCR in normal women.

The combined infusion of [3H]dehydroepiandrosterone sulfate [( 3H]DS) and [14C]estrone (E1) for 6 h in four normal women in the follicular phase of the cycle demonstrated values of 13.77 +/- 0.27 L/day (mean +/- SE) for the DS MCR (MCRDS) and 1343 +/- 206 L/day for MCRE1. The fraction of DS metabolized to dehydroepiandrosterone (D), [rho]DS-D, was 0.285 +/- 0.044, and the fraction of D arising from DS (delta D) was 0.318 +/- 0.096, determined using isotopic techniques. Raising the plasma DS concentration by 8.6 micrograms/mL (23 mumol/L) by infusing DS iv increased the MCRDS to 24.49 L/day in the first subject, and raising the plasma DS by 11.40 +/- 0.33 micrograms/mL (30.94 +/- 0.90 mumol/L) in the next three subjects raised the MCRDS to 35.7 +/- 1.3 L/day (P less than 0.01) without changing the MCRE1. The increase in MCRDS produced by increasing plasma DS makes it difficult to accurately measure the MCRDS in effect at the subject's endogenous plasma DS concentration by infusion of nonisotopic DS. Determination of the fractions of D, androstenedione (delta delta 4A), and testosterone (T) arising from DS using the increase in the plasma concentrations of these steroids produced by infusion of nonisotopic DS gave the following estimates: delta D = 0.262 +/- 0.042, delta delta 4A = 0.089 +/- 0.046, and delta T = 0.273 +/- 0.14.

Adult↗
PubMed1978

Serum lysozyme, serum proteins, and immunoglobulin determinations in nonspecific inflammatory bowel disease.

The serum levels of lysozyme, serum electrophoresis, and serum immunoglobulins were determined prospectively in 101 patients with ulcerative colitis, ulcerative proctitis, Crohn's disease, or nonclassifiable nonspecific inflammatory bowel disease. Although the mean serum lysozyme concentration of patients with Crohn's disease (10.5 +/- 6.8 microgram/ml) and ulcerative colitis (9.6 +/- 4.1 microgram/ml) performed by a standardized lysoplate method was significantly greater than normal controls (6.0 +/- 1.5 microgram/ml), the results did not correlate with the diagnosis nor with the degree of disease activity. Individually separated protein fractions and serum immunoglobulins also did not correlate with the serum lysozyme levels. This study indicates that measurement of the level of serum lysozyme in individual patients is not helpful in determining the cause or degree of activity of nonspecific inflammatory bowel disease.

Adult↗
PubMed1965

Esophagitis.

Explore the source record for details and available documents.

Deglutition Disorders↗