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Biomedical subjects

B L Lasley

Publications and source records attributed to B L Lasley.

At least 127 records · Page 7Linked to original sources
PubMed1987

Comparison of serum estradiol to urinary estrone conjugates in the rhesus macaque (Macaca mulatta).

Paired urine and serum samples were collected daily during fourteen nonconceptive (7 females) and ten conceptive (9 females) ovarian cycles from a total of 12 female rhesus monkeys (Macaca mulatta). Daily urine samples were analyzed for concentrations of estrone conjugates (Ei Conj). Serum samples were evaluated for concentrations of estradiol (E2) and progesterone (P) by radioimmunoassay (RIA), and bioactive luteinizing hormone (bLH) and monkey chorionic gonadotropin (mCG) were analyzed by a mouse Leydig cell bioassay. Linear correlation (r) between urinary E1 Conj and serum E2 (r range = -0.176-0.948) during nonconceptive cycles aligned by the preovulatory E1 Conj peak (Day 0) improved when daily hormone values were realigned to account for an approximately 24-h delay in the excretion of hormonal metabolites in urine (r range = 0.465-0.967). Similarly, correlation between urinary E1 Conj and serum E2 during conceptive cycles aligned by Day 0 (r range = 0.300-0.824) improved when values were offset by 24 h (r range = 0.408-0.876). When conceptive cycles were compared to nonconceptive cycles, serum P levels were significantly elevated over nonconceptive levels by Day +12 (p less than 0.001), and urinary E1 Conj levels by Day +13 (p less than 0.02), whereas serum E2 and bLH were both significantly elevated by Day +14 (p less than 0.0006 and p less than 0.01, respectively). In both nonconceptive and conceptive cycles, urinary E1 Conj paralleled serum E2 and demonstrated incremental increases above baseline levels, which were greater than for serum E2.

Animals↗
PubMed1987

Ovulation induction in anestrous bitches by pulsatile administration of gonadotropin-releasing hormone.

Preliminary studies in anestrous Beagle bitches demonstrated that a single injection of gonadotropin-releasing hormone (150 micrograms) produced a rapid, physiological rise in serum estradiol lasting 1-3 days while progesterone remained below 1 ng/ml, whereas serial injections of FSH rapidly produced greater elevations in estradiol and a rapid rise in progesterone over 2 ng/ml. Consequently, attempts to induce fertile ovulation by means of pulsatile intravenous administration of GnRH (1 pulse/1.5 hours for 6-12 days; 0.04-0.43 micrograms/kg body weight/pulse) were conducted in eight anestrous bitches. Willingness to mate, serum progesterone levels and results of mating were monitored. In six of the eight bitches, vulval and vaginal signs of proestrus occurred by Day 2-4 after initiation of treatment (Day 0); but, two bitches showed negligible responses. In five of the six bitches in which proestrus was induced, behavioral (n = 4) and vaginal (n = 5) correlates of early estrus occurred by Day 5-7 of treatment and breedings occurred over a period of 4-12 days. Following onset of estrus, four of the five bitches had increases in serum progesterone levels between Days 14 and 18 after initiation of treatment (and 4-11 days after cessation of treatment); three of them became pregnant and whelped normal litters (ranging from 9 to 11 pups). The fifth bitch did not have elevated progesterone during the induced estrus, and upon return to estrus one month later was successfully bred and whelped a normal litter of 10 pups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anestrus↗
PubMed1986

Assessment of follicular function in women by measurement of urinary estrogen conjugates.

Daily early morning urine samples from 23 women during their conception cycles were evaluated for urinary estrone (E1) conjugates and pregnanediol-3-glucuronide (PdG) levels and indexed by creatinine (Cr) concentrations. These 23 cycles were classified into two groups according to the rate of E1 conjugates increase following implantation. Urine from 16 nonconception cycles was available for 11 of the women. The two groups differed significantly both before and after, but not during, the midcycle E1 conjugates peak. The length of the follicular phase was significantly shorter in the group of women with the lower E1 conjugate levels. These data suggest that differences in estrogen excretion at times other than the preovulatory estrogen surge represent the endocrine activity of subdominant ovarian follicles. Further, such urinary estrogen profiles may represent useful parameters for defining ovarian follicular populations and/or indicating the effects of hazards to female reproduction.

Embryo Implantation↗
PubMed1986

Monitoring gonadotropin-releasing hormone administration by measurement of urinary steroid conjugates.

The use of measuring urinary steroid conjugates in nontimed, randomly collected morning urine samples expressed as a function of creatinine concentration was assessed to monitor ovarian response to pulsatile administration of gonadotropin-releasing hormone in ambulatory patients. This method of evaluating ovarian steroid production provided a convenient, inexpensive, and noninvasive means of monitoring responses to gonadotropin-releasing hormone treatments and documents that clomiphene-resistant amenorrheic patients can be induced to ovulate with appropriate gonadotropin-releasing hormone therapy. Different ovarian responses in the same woman to similar doses and frequencies of gonadotropin-releasing hormone indicate that discrete adjustments of individual doses may be required to facilitate consistent ovulatory responses. The strategy presented here allows for subsequent gonadotropin-releasing hormone therapy in the individual patient to be determined by an objective and quantifiable ovarian response to an initial treatment.

Adult↗
PubMed1986

Monitoring ovulation and implantation in the cynomolgus macaque (Macaca fascicularis) through evaluations of urinary estrone conjugates and progesterone metabolites: a technique for the routine evaluation of reproductive parameters.

Investigations were undertaken to determine the applicability of recently reported specific radioimmunoassays for urinary estrone conjugates and progesterone metabolites for monitoring ovarian function in the cynomolgus macaque (Macaca fasciularis) and other macaque species. Mean estrone conjugate measurements appear to accurately reflect the preovulatory estrogen peak in both conceptive (n = 5) and nonconceptive (n = 6) cycles, as well as to indicate early pregnancy through increases which are significantly elevated by Day + 15 (p less than 0.049) post estrone conjugates peak. The mean luteal phase levels of these progesterone metabolites are significantly elevated by Day + 14 (p less than 0.012) in conceptive cycles when compared to the mean values for nonconceptive cycles.

Animals↗
PubMed1985

Equol: a contributor to enigmatic immunoassay measurements of estrogen.

The efficacy of radioimmunoassay (RIA) for the measurement of estradiol-17 beta (E2) in murine plasma was investigated. When Sephadex LH-20 or celite column chromatography was used to separate E2 from estrone (E1) and other cross-reacting compounds, the results were erratic if small volumes of mouse plasma were resolved. Assay of a diethyl ether extract of plasma (500 microL) was the most practical method for estimating the concentration of estradiol-17 beta in mice. This method was used to determine the pattern of estrogen secretion during the estrous cycle, on the day of implantation and during pregnancy. No convincing change in estrogen secretion was observed in the diestrous/proestrous mouse. By comparison, estrogen levels were elevated during pregnancy. Taken together, these results implied that cross-reactive components in plasma masked low levels of endogenous estrogen. Further evaluation of mouse plasma and urine using a co-chromatography technique to examine estrogen elution from a reverse-phase HPLC system followed by GC/MS analysis indicated the presence of equol [7-hydroxy-3-(4-hydroxyphenyl)chroman], a phytoestrogen metabolite with a ring structure similar to estradiol-17 beta. Equol and possibly other cross-reactive components of plasma may account for the apparent lack of increased estrogen secretion during the mouse estrous cycle and on the day of implantation as determined by the radioimmunoassay of ether extracts of plasma.

Animals↗
PubMed1985

HPLC separation of anti-estrogen and estrogen receptor binding components of mouse plasma.

Proestrous mouse plasma and urine were subjected to diethyl ether extraction, enzyme hydrolysis and HPLC separation of estrogen components. Radioimmunoassay of the treated proestrous samples with a broad spectrum anti-estrogen serum failed to detect estradiol-17 beta, estrone or estriol. HPLC chromatograms contained two peaks of immunoreactive and estrogen receptor binding material with polarities between those of estriol and estradiol-17 beta. Similar peaks were detected in HPLC chromatograms of urinary extracts from ovariectomized and ovariectomized-adrenalectomized mice. The least polar of the two peaks produced a mass spectrum identical to that of authentic equol [7-hydroxy-3-(4'-hydroxyphenyl)chroman], a phytoestrogen metabolite. The presence of significant quantities of circulating equol in all strains studied, combined with apparently low plasma levels of endogenous classical estrogens during proestrus, confound attempts to study estrogen secretion in the mouse.

Animals↗
PubMed1985

Urinary hormone levels at the time of ovulation and implantation.

Daily early morning urine samples were collected from women receiving donor artificial insemination and were evaluated for estrone conjugates, pregnanediol-3-glucuronide, and human chorionic gonadotropin. All hormone concentrations in urine were indexed by creatinine levels and expressed as the concentration of hormone per milligram creatinine. Composite profiles of 23 women who conceived normal full-term pregnancies were compared with composite profiles obtained from 11 of the same women during nonconception cycles. The endocrine profiles of seven pregnancies that spontaneously aborted and two ectopic pregnancies were also evaluated retrospectively. The combined application of these three urinary hormone indices provides a practical approach for prospective monitoring of the major hormone dynamics during ovulation and implantation and during relatively infrequent events such as spontaneous abortion and ectopic pregnancy. The rise of estrone conjugates which precedes detectable increases of urinary human chorionic gonadotropin at the time of implantation appears to be an early indicator of implantation and may prove to be the best method for detection of occult pregnancy. This method is also suitable for monitoring early pregnancy when exogenous gonadotropins have been employed, as in embryo transfer following in vitro fertilization.

Abortion, Spontaneous↗
PubMed1984

Identification of a non-steroidal estrogen, equol, in the urine of pregnant macaques: correlation with steroidal estrogen excretion.

Macaque urinary estrogens at late pregnancy were separated by high performance liquid chromatography and quantified, both with radioimmunoassay and an in vitro uterine estrogen receptor assay. Five estrogens were measured. Four were steroids: estriol, estrone, 17 beta-estradiol, and 16 alpha-hydroxyestrone. The fifth was a flavonoid, equol, a metabolite of plant isoflavonoids, formononetin and genistein. By mass, estrone and equol were the predominant urinary estrogens, with equol reaching levels of microgram/mg creatinine in three of 8 pregnancies studied. Both quality and quantity of urinary estrogen excretion in the rhesus (Macaca mulatta) was compared to those in 4 other species (Macaca fascicularis, Macaca nemestrina, Macaca radiata and Macaca silenus). All 5 estrogens present in the rhesus were also present in the other 4. Variability in mass of each estrogen excreted appeared no greater between species than within the rhesus. In a longitudinal study, urinary equol levels were most highly correlated with those of estrone, the predominant excretory steroid of macaque pregnancy. We conclude endogenous steroidal estrogen is related to production of equol in macaques, however, equol is not dependent on the feto-placental unit as low levels of equol were also present in male macaque urine.

Animals↗
PubMed1984

A comparison of three methods of hydrolysis for estrogen conjugates.

The efficiencies for estrogen conjugate hydrolysis were compared between enzyme hydrolysis, acid solvolysis and a new method, ammonolysis. Samples included: 1) crystalline 1,3,5(10)-estratriene-3, 17 beta-diol disulfate (estradiol 3,17-disulfate), 2) squirrel monkey urine collected following an intravenous injection of [2,4,6,7-H] 1,3,5(10)-estratriene-3,17 beta-diol (estradiol) and 3) a pool of human pregnancy urine. Ammonolysis demonstrated a significant increase over the other techniques in "free" estrogen yields, specifically, from estradiol 3,17-disulfate.

Ammonia↗
PubMed1984

Characterization of the estrogenic properties of a nonsteroidal estrogen, equol, extracted from urine of pregnant macaques.

Recent reports of substantial urinary levels of equol in pregnant macaques and humans pose a concern, because equol poisoning in the ovine is characterized by an often permanent failure of reproductive processes. Equol (Fig. 1), a metabolite of phytoestrogens, is thought to act through estrogen receptors. The present study made a direct comparison of the estrogenic activity of equol from macaque urine, (+/-) equol and 17 beta-estradiol (E2) in vitro and in vivo. Relative binding affinity of equol for rat uterine receptor was 1% that of E2, and the dissociation rate of equol from the receptor was very high. Consistent with equol's binding properties in vitro, it was ineffective in stimulating rat uterine weight gain and possessed limited ability to increase progesterone receptor. Uterine nuclear receptors after doses of equol sufficient to produce depletion and replenishment of cytosol estrogen receptor were not measurable by exchange assay. No antiestrogenic activity of equol could be demonstrated. Equol's weak potency and lack of antiestrogenic activity are difficult to reconcile with its ability to induce ovine infertility. We conclude species differences at some level other than classical estrogen receptor as defined in the rat model are responsible for variability in equol's impact.

Animals↗
PubMed1984

Testicular androgen and estrogen secretion and benign prostatic hyperplasia in the beagle.

The natural history of benign prostatic hyperplasia (BPH) in the dog is characterized by a slow progression through two phases. The early phase of the disease process is characterized by glandular hyperplasia and occurs as early as 2.5 yr of age. The late phase of the disease is characterized by cystic hyperplasia and occurs after 4 yr. The results of the present study are the first to compare Leydig cell structure and steroidogenic function in dogs with BPH with those in age-matched controls. It was discovered that glandular BPH can occur in young dogs (2.5 yr) in which Leydig cell mass and ultrastructure and maximally stimulated androgen secretion are indistinguishable from those in age-matched controls. These results support the concept that the early phase of BPH (glandular hyperplasia) is not related temporally to some defect in the Leydig cell. In contrast, the late phase of BPH (cystic hyperplasia) in beagles 6 yr of age is associated with diminished smooth endoplasmic reticulum in the Leydig cell and with diminished production of androgens by perfused testes in vitro. During the course of these studies, we discovered that the testes of young beagles with BPH, but not age-matched controls or old beagles with BPH, secrete an unidentified molecule (putative estrogen). This molecule was characterized partially in that it is extractable from testicular venous effluent with diethyl ether, elutes in a discrete fraction in several different high performance liquid chromatographic systems, reacts with an antibody that recognizes 17 beta-estradiol, estrone, and estriol, and competes with 17 beta-[3H]estradiol for the rat uterine estrogen receptor. Based on the elution volume from high performance liquid chromatography, the unknown molecule (putative estrogen) is not estriol, estradiol, or estrone.

Androgens↗
PubMed1984

Musth and urinary testosterone concentrations in the African elephant (Loxodonta africana).

Urine samples were obtained from free-ranging African elephants that were considered to be in and out of musth. Testosterone concentrations, measured by radioimmunoassay were significantly greater in males that were in or around the time of behavioural musth. This study supports a correlation between the observed behavioural characteristics of musth and urinary testosterone levels.

Animals↗
PubMed1983

Estrogen-behavior correlates in the reproductive physiology and behavior of the ruffed lemur (Lemur variegatus).

The animal subjects of this study consisted of seven male-female pairs, living an open-air, off-exhibit area of the San Diego Zoo. Daily urinary estrogen levels in each of five females were measured and daily behavioral observations of the seven pairs were made. Behavioral patterns aligned by objectively determined, discrete physiologic events were analyzed to determine their temporal correlation to changes in estrogen excretion. The data indicate that approximately one-sixth of the female behaviors and one-third of the male behaviors sampled were significantly correlated to urinary estrogen levels in the females (P less than 0.05-0.005). In addition, both attractivity and receptivity were distinguishable and their component behaviors in males and females were found to be related to the estrogen profile. Proceptivity, however, was only weakly identified and its description in this sample population was ambiguous. Mating was observed to occur exclusively on 1 day, presumably the day of ovulation.

Animals↗
PubMed1983

Urinary estrogen excretion during pregnancy in the gorilla (Gorilla gorilla), orangutan (Pongo pygmaeus) and the human (Homo sapiens).

Urinary estrogen components were separated, identified and quantified throughout the pregnancy of the gorilla (Gorilla gorilla) and orangutan (Pongo pygmaeus) and compared to estrogen levels in normal human pregnancies. Fetal and neonatal adrenals from each species were also compared in terms of weight and relative amounts of fetal zone. The results demonstrate that gorillas and chimpanzees excrete 4- to 5-fold less estrogen during pregnancy than the human and orangutan which are similar to each other. The lower estrogen excretion appears to be related to a smaller fetal adrenal in both the gorilla and chimpanzee which reveal both a reduced adrenal weight and increased definitive to fetal zone ratio when compared to either the human or orangutan.

Adrenal Glands↗
PubMed1983

Urinary estrogens during pregnancy of the ruffed lemur (Lemur variegatus).

Pregnancy in the ruffed lemur (Lemur variegatus) was monitored by analyses of urinary estrogens. Urine samples were collected weekly throughout pregnancy (gestation: 100 +/- 1.6 days) from ten females analyzed for total immunoreactive estrogen (Et) and indexed by creatinine (Cr). Maternal urinary total estrogen excretion remained low until the last half of gestation at which time excretion increased steadily, reaching values 1000 times greater than those observed at estrus. Chromatographic separation after enzyme hydrolysis of lemur urine indicates that estrone is the major estrogenic component of pregnancy in the ruffed lemur, with the remaining components consisting of equal amounts of estradiol-17 alpha and -17 beta.

Animals↗
PubMed1983

Monitoring ovulation and implantation in the lion-tailed macaque (Macaca silenus) through urinary estrone conjugate evaluations.

Urine samples were collected daily during ten nonfertile and four fertile ovarian cycles of four adult female lion-tailed macaques (Macaca silenus). Urine was analyzed for concentrations of total immunoreactive estrogen (Et), estrone conjugates, and bioactive luteinizing hormones (LH). The estrone conjugates of selected samples were separated by high-performance liquid chromatography (HPLC) to evaluate the relative proportions of estrone glucuronide (E1 G) to estrone sulfate (E1 S) contributing to the sum total of the conjugate measured in the samples. The estrone conjugate profile was found to accurately reflect the preovulatory estrogen peak in both nonfertile and fertile cycles as well as the early pregnancy increase which was found to be statistically significant on Day + 14 postovulation (P = 0.003). Estrone conjugate levels rose in the early follicular phase from 126.00 +/- 24.07 (SEM) ng/mg creatinine to a preovulatory peak of 471.90 +/- 62.95 ng/mg creatinine. Fertile cycles exhibited a postovulatory climb to a peak of 515.00 +/- 38.00 ng/mg creatinine on Day + 19, in contrast to the secondary rise observed in nonfertile cycles that peaked at 148.11 +/- 13.80 ng/mg creatinine on Day + 10. Bioactive LH evaluations confirmed ovulation and, in the fertile cycles, reflected the subsequent elevation of chorionic gonadotropin on Day + 18. The estrone conjugate profile of fertile cycles and early pregnancy compared favorably to the Et profile: both showed the same time course and increases in estrogen excretion.

Animals↗