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Biomedical subjects

A Kambegawa

Publications and source records attributed to A Kambegawa.

At least 37 records · Page 2Linked to original sources
PubMed1989

Sex-specific effects on the fetal neuroendocrine system during acute stress in late pregnancy of rat and the influence of a simultaneous treatment by tyrosine.

It is well-known that prenatal chronic intermittent stress affects the reproductive system of both sexes. Investigating the effects of an acute maternal stress on the fetal neuroendocrine system, parameters such as hypothalamic catecholamines. CRF, GRF, LH-RH, beta-endorphin, hypophysial beta-endorphin and beta-LPH as well as plasma LH, corticosterone and androstenedione were measured. Pregnant rats of Wistar strain were exposed to restraint stress at day 22 of gestation or to forced immobilization at day 20 of gestation, respectively, and were sacrificed before stress and 10, 30, 60, and 120 min after starting stress. A decrease of fetal hypothalamic catecholamines and an increase of LH-RH content of the hypothalamus as well as of plasma catecholamines were observed under stress on day 22 of gestation. On day 20 of gestation hypothalamic beta-endorphin was depleted in male and unchanged in female fetuses under stress. A depletion of hypothalamic CRF was observed in male fetuses, whereas female fetuses showed an increase of hypothalamic CRF. An increase of GRF was found in fetuses of both sexes. Pituitary opioid content increased in fetuses of both sexes initially, but was depleted secondarily in male fetuses. The LH plasma level was markedly reduced in male, the corticosterone level was elevated in fetuses of both sexes as well as the androstenedione level in female fetuses. A simultaneous treatment of mother animals with tyrosine--a catecholamine precursor--prevented the depletion of hypothalamic and pituitary beta-endorphin as well as in part the reduction of plasma LH levels in male fetuses. Hypothalamic GRF content does not increase under tyrosine treatment in male fetuses, whereas in female fetuses the stress-induced increase of GRF content was rather pronounced under tyrosine than attenuated. These results indicate that fetal hypothalamic neurotransmitters and neurohormones (such as LH-RH, CRF, GRF and opioids) are involved in changing circulating hypophysial and adrenal hormones in fetuses exposed to maternal stress in late pregnancy, whereby sex-specific different pathways might be effective in fetal stress processing. The prenatal administration of tyrosine prevented at least in part--those neurohormonal changes which are affecting the sex-specific brain differentiation.

Androstenedione↗
PubMed1989

Contragestive effects of the antigestagenic agent, RU486, in rats and rabbits.

The contragestive effects of the antiprogesterone RU486 in pregnant rats and rabbits were investigated. Administrations of increasing doses of RU486 in intact or castrated pregnant rats induced abortion in a dose dependent manner. RU486 had less effect when administered on the 16th day of gestation. Antiestrogens (tamoxifen, clomiphene citrate), an inhibition of 3 beta-hydroxysteroid dehydrogenase (epostane) showed a synergistic effect when used in combination with RU486. A decrease in serum progesterone levels was observed after RU486 administration. A larger dose of RU486 was necessary to induce abortion in pregnant rabbits compared to rats. The maximum blood concentration was greater and the area under the plasma level curve was larger in rats than in rabbits following administration of RU486.

Abortifacient Agents↗
PubMed1989

The inhibitory effect of synthetic steroids on proestrous gonadotropin release in the rat.

This study was performed to evaluate the inhibitory effect of synthetic steroids on the hypothalamo-pituitary axis. Six synthetic steroids, used for contraception or other gynecologic indications, were injected to female rats on diestrus 2 (2 mg/kg, sc), and the animals were sacrificed in the afternoon of proestrus. Serum levels of LH, FSH and progesterone, the pituitary contents of LH and FSH, and LH-RH in the median eminence were measured by radioimmunoassays. Among the synthetic steroids tested in this study, norethisterone, d-norgestrel, 3-keto-desogestrel and gestrinone completely blocked the gonadotropin surge on proestrus, showing stronger antigonadotropic activity than progesterone. Desogestrel did not affect proestrous gonadotropin release at this dose. The suppressive effect of danazol could be seen only in a larger dose (20 mg/kg). These findings reconfirmed previously reported results, which demonstrated that the hypothalamo-pituitary complex was a major site of action of these steroids.

Animals↗
PubMed1989

Radioimmunoassay of 2-hydroxyesterone using antisera raised against antigenic complexes obtained by convenient methods.

Antigenic complexes of 2-hydroxyestrone (2-OHE1) were obtained by Mannich reaction of 2-OHE1 and bovine serum albumin (BSA) and by coupling of 2-OHE1 1-glutathione thioether to BSA using glutaraldehyde. Antiserum raised against the antigen obtained by the Mannich reaction had high affinity (Kd = 3.8 x 10(9) M-1) and relatively high specificity; cross reactivities for estrone, 4-hydroxyestrone and 2-methoxyestrone were 2.1%, 10% and 1.5%, respectively. The other antiserum also had high affinity (4.5 x 10(9) M-1) but its cross reactivities for the above three steroids were more than 100%. Concentrations of 2-hydroxyestrone in human plasma were determined by radioimmunoassay with the more specific antiserum and Sephadex LH-20 chromatography to be less than a minimum detectable amount (less than 10 pg/ml) (men), 20.9 pg/ml (women, proliferation) and 26.0 pg/ml (women, periovulation).

Adult↗
PubMed1989

Steroid hormone receptors in the uterus and ovary of immature rats treated with gonadotropins.

We administered either saline (group A) or 10 IU of pregnant mare serum gonadotropin (PMS; groups B and C) to female immature rats. Fifty-three hours later, the rats were injected with saline (groups A and B) or 30 IU of human chorionic gonadotropin (hCG; group C). The rats were decapitated 17 h after the last treatment, and the serum levels of progesterone (P4) and estradiol (E2) were measured by specific radioimmunoassays (RIA). The receptor levels of progesterone (PR) and estrogen (ER) in the uterus and ovaries were measured and the dissociation constant (Kd) of PR was obtained. The highest serum level of P4 was found in group C and that of E2 in group B. Cytosol levels of PR and ER in the uterus and ovary of the group B were the highest. It was indicated that the PMS treated-group (B), which had developing follicles in the ovary and the high serum level of E2, showed the highest concentration of ER and PR in both the ovary and the uterus. In the PMS and hCG-treated group (C), the uterine and ovarian steroid receptors decreased probably because of the luteinization and the high serum level of P4. The Kd uterine PR value was less than that of ovarian PR.

Animals↗
PubMed1989

Inhibition of rat ovarian 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17 alpha-hydroxylase and 17,20 lyase by progestins and danazol.

The site of action of synthetic progestins or danazol in the treatment of endometriosis is considered to be mainly the hypothalamo-pituitary level, but the direct action to the uterine endometrium and the ovary is also suggested. We investigated the effect of these synthetic steroids to rat ovarian steroidogenic enzymes. The effect of norethisterone, levonorgestrel, danazol, gestrinone, desogestrel and 3-keto-desogestrel was studied in vitro. The sources of the enzymes were prepared from ovaries of immature rats treated either with pregnant mare serum gonadotropin (PMS) and human chorionic gonadotropin (hCG) for 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD), or with PMS for 17 alpha-hydroxylase and 17,20 lyase. The substrates used were pregnenolone (P5) for 3 beta-HSD, progesterone (P4) for 17 alpha-hydroxylase, and 17 alpha-hydroxy-progesterone (17 alpha-OH-P4) for 17,20 lyase. The substrates were incubated with the enzyme sources and coenzymes, and the products formed were measured. All the steroids inhibited 3 beta-HSD, and the inhibition by gestrinone (Ki = 3.0 microM) and 3-keto-desogestrel (17.5 microM) was particularly marked. Only desogestrel (Ki = 30.3 microM) and danazol (168 microM) inhibited 17 alpha-hydroxylase. All the steroids inhibited 17,20 lyase, and the inhibition by desogestrel (Ki = 0.70 microM), danazol (0.80 microM), and gestrinone (30 microM) was particularly marked.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Serum 17-hydroxypregnenolone and 17-hydroxypregnenolone sulfate concentrations in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Serum concentrations of 17-hydroxypregnenolone, 17-hydroxypregnenolone sulfate and 17-hydroxyprogesterone were measured simultaneously in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, using a combined radioimmunoassay method. All these precursor steroids were found to be markedly elevated in the sera of untreated patients with a salt-losing form of the disease, whereas, in untreated patients with a simple virilizing form, only the concentration of unconjugated steroids was increased and the 17-hydroxypregnenolone sulfate concentration remained within the normal range. Among the patients with a salt-losing form under maintenance therapy, these steroids were all still significantly increased in those on insufficient control, whereas only 17-hydroxyprogesterone was significantly but slightly increased in those on adequate control. Although the mechanism whereby the serum 17-hydroxypregnenolone sulfate concentration is not increased in the untreated simple virilizers is unknown, both a milder degree of 21-hydroxylase deficiency and a role of 17-hydroxypregnenolone sulfate in adrenal steroid production as a kind of supplier are suggested as possible explanations, especially in the neonatal period and early infancy. Thus, this study showed the serum concentrations of 17-hydroxypregnenolone and its sulfate together with 17-hydroxyprogesterone in patients with 21-hydroxylase deficiency in various conditions.

17-alpha-Hydroxypregnenolone↗
PubMed1988

Age-related changes in serum 17-hydroxypregnenolone and 17-hydroxypregnenolone sulfate concentrations in human infancy and childhood.

In order to clarify some of the developmental processes of the human adrenal cortex or steroidogenesis in infancy and childhood, serum concentrations of 17-hydroxypregnenolone, 17-hydroxypregnenolone sulfate and 17-hydroxyprogesterone were measured by means of a combined radioimmunoassay method, and the age-related changes in these steroids were also examined. The actual ranges of serum concentrations of 17-hydroxypregnenolone, 17-hydroxypregnenolone sulfate and 17-hydroxyprogesterone in umbilical cord blood were 27.1-80.5, 1,560-5,030 and 53.3-304 nmol/l, respectively. These values subsequently decreased to nadirs of 0.95-2.09 nmol/l of 17-hydroxypregnenolone in subjects 1 to 2 years old, 0.93-7.03 nmool/l of 17-hydroxypregnenolone sulfate in subjects 3 to 6 years old and 0.18-0.78 nmol/l of 17-hydroxyprogesterone in subjects 1 to 2 years old, respectively, and they were followed by gradual increases to the adult levels. This study thus revealed the age-related changes in 17-hydroxypregnenolone and its sulfate concentrations in infancy and childhood and indicated that, in the process in which the adrenal cortex was differentiated to the definitive form, the decrease in the activity of steroid sulfotransferase in infancy and childhood occurred more slowly than the increase in that of 3 beta-hydroxysteroid dehydrogenase.

17-alpha-Hydroxypregnenolone↗
PubMed1987

A sensitive bridge heterologous enzyme immunoassay of progesterone using geometrical isomers.

A sensitive bridge heterologous enzyme immunoassay of progesterone using geometrical isomers of progesterone 3(O-carboxymethyl)oxime(E/Z) was developed. Isomers were separated by synthesis of N-hydroxysuccinimide esters. Progesterone 3(Z)(O-carboxymethyl)oxime N-hydroxysuccinimide ester bound with beta-galactosidase in an appropriate molar ratio provided a conjugate suitable for an enzyme immunoassay. The antiserum was raised in rabbits by immunizing the animals with the progesterone 3(E)(O-carboxymethyl)oxime-bovine serum albumin conjugate. This bridge heterologous enzyme immunoassay proved to have sufficient sensitivity equivalent to radioimmunoassay and excellent specificity.

Antigens↗
PubMed1985

[Age-related changes of serum 17 alpha-hydroxypregnenolone and 17 alpha-hydroxypregnenolone sulfate concentrations in infancy and childhood].

In order to clarify a part of the developmental processes of the human adrenal cortex or steroidgenesis in infancy and childhood, serum concentrations of 17 alpha-hydroxypregnenolone (17-OH-delta 5 P), 17 alpha-hydroxypregnenolone-3-sulfate (17-OH-delta 5 P-S) and 17 alpha-hydroxyprogesterone (17-OH-delta 4 P) were measured using a combined radioimmunoassay method previously reported, and age-related changes of these steroids were evaluated. In addition to the serum concentrations, a ratio of 17-OH-delta 5 P-S to 17-OH-delta 5 P (S/delta 5 P ratio) and that of 17-OH-delta 4 P to 17-OH-delta 5 P (delta 4 P/delta 5 P ratio) were also estimated as the indices of the activities of steroid sulfokinase (SK) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), respectively. Serum 17-OH-delta 5 P, 17-OH-delta 5 P-S and 17-OH-delta 4 P concentrations in umbilical cord blood were 13.5 +/- 6.02 (Mean +/- SD) ng/ml, 965 +/- 363 ng/ml and 46.3 +/- 21.1 ng/ml, respectively. These values decreased consecutively to the nadirs which were 0.47 +/- 0.16 ng/ml in subjects 1 to 2 years old, 1.26 +/- 0.82 ng/ml in subjects 3 to 6 years old and 0.17 +/- 0.007 ng/ml in subjects 3 to 4 months old, respectively, and they were followed by gradual increases up to the adult levels. S/delta 5 P ratio also showed the same profile.(ABSTRACT TRUNCATED AT 250 WORDS)

17-alpha-Hydroxypregnenolone↗
PubMed1985

[A combined radioimmunoassay method for the determination of 17 alpha-hydroxypregnenolone, 17 alpha-hydroxypregnenolone sulfate and 17 alpha-hydroxyprogesterone in human blood].

It is well recognized that in the fetal adrenal cortex, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity is lower and in fetal tissues, steroid sulfokinase (SK) is higher than in the adult. In order to clarify a part of the development processes of the adrenal cortex or steroidgenesis in humans, a combined radioimmunoassay (RIA) method to estimate serum 17 alpha-hydroxypregnenolone (17-OH-delta 5 P), 17 alpha-hydroxypregnenolone sulfate (17-OH-delta 5 P-S) and 17 alpha-hydroxyprogesterone (17-OH-delta 4P) was devised. The method consisted of the following procedures: 1) diethyl ether extraction and chromatographic separation of unconjugated steroids (17-OH-delta 5P and 17-OH-delta 4P), 2) enzymatic hydrolysis of 17-OH-delta 5P-S using the residue of diethyl ether extraction for a material, 3) diethyl ether extraction and chromatographic purification of hydrolyzed 17-OH-delta 5P-S, and 4) RIAs for 17-OH-delta 5-P to estimate 17-OH-delta 5P and 17-OH-delta 5P-S concentration, and for 17-OH-delta 4P. Extracted 17-OH-delta 5P was well separated from 17-OH-delta 4P by Sephadex LH-20 microcolumn chromatography, using a benzene/methanol = 95/5 (v/v) solvent as a mobile phase. Several procedures for hydrolysis or solvolysis of 17-OH-delta 5P-S were compared using available tritiated delta 5-3 beta-hydroxysteroids including dehydroepiandrosterone (DHA), DHA sulfate (DHA-S) and 17-OH-delta 5P, and it was found that the most suitable method was an enzymatic hydrolysis by arylsulfatase from Helix Pomatia in an appropriate condition in which the percent hydrolysis was 92.9 +/- 1.2 (mean +/- SEM)%. The final percent recoveries were 88.7 +/- 1.2% in 17-OH-delta 4P, 90.7 +/- 1.4% in 17-OH-delta 5P and 78.1 +/- 2.1% in 17-OH-delta 5P-S, respectively. A suitable antiserum and its final dilution titer for RIA of 17-OH-delta 5P (hydrolyzed 17-OH-delta 5P-S also) was 1:12,000 dilution of anti-17-OH-delta 5P-3-succinate-BSA serum. An anti-7-oxo-17-OH-delta 5P-7-carboxymethyloxime-BSA serum was considered to be unsuitable for the measurement of hydrolyzed 17-OH-delta 5-P-S, presumably because of a significant cross-reactivity with a large amount of unknown steroid sulfates simultaneously hydrolyzed.(ABSTRACT TRUNCATED AT 400 WORDS)

17-alpha-Hydroxypregnenolone↗
PubMed1985

Involvement of gonadotrophin and steroid hormones in spermiation in the amago salmon, Oncorhynchus rhodurus, and goldfish, Carassius auratus.

Effects of intraperitoneal injections of chum salmon gonadotrophin (SGA) and various steroid hormones (17 alpha, 20 beta-dihydroxy-4-pregnen-3-one; 17 alpha,20 beta-diOHprog, 17 alpha-hydroxy-progesterone, testosterone, 11-ketotestosterone) on the induction of in vivo spermiation were examined in nonspermiating amago salmon (Oncorhynchus rhodurus) and goldfish (Carassius auratus). A single injection of SGA to amago salmon and two successive injections to goldfish induced strong spermiation responses. Similarly two successive injections of 17 alpha,20 beta-diOHprog caused precocious spermiation in both species; however, the response to 17 alpha,20 beta-diOHprog was of lesser magnitude than that to SGA. The spermiation response of goldfish to 17 alpha-hydroxyprogesterone was similar to that of 17 alpha,20 beta-diOHprog. Neither testosterone nor 11-ketotestosterone were effective in inducing spermiation in amago salmon, but these steroids were found to be slightly effective in goldfish. Effects of a single injection of SGA on changes in serum levels of 17 alpha,20 beta-diOHprog and 11-ketotestosterone were also examined in nonspermiating amago salmon. Serum levels of 17 alpha,20 beta-diOHprog dramatically increased after treatment and peaked on Day 2 and thereafter declined quickly. Similarly, 11-ketotestosterone peaked on Day 2, but the levels remained high throughout the experimental period. Considered together, these findings are consistent with the suggestion that 17 alpha, 20 beta-diOHprog is involved in the process of spermiation in teleosts. It is further suggested that this hormone is a testicular steroidal mediator of gonadotrophin-induced spermiation in amago salmon.

Animals↗
PubMed1985

A new radioimmunoassay for serum 16 alpha-hydroxyandrost-4-ene-3,17-dione with specific antiserum.

A radioimmunoassay system for serum 16 alpha-hydroxyandrost-4-ene-3,17-dione was developed with the use of rabbit antiserum against 16 alpha-hydroxyandrost-4-ene-3,17-dione-3-(O-carboxymethyl)oxime which was conjugated with bovine serum albumin. The antiserum was highly specific for 16 alpha-hydroxyandrost-4-ene-3,17-dione, with cross reactions to other steroids being less than 0.8% except for androst-4-ene-3,17-dione(3.4% cross reaction). Use of LH-20 column chromatography, however, clearly separated these two steroids. Pregnancy sera were measured with this assay system after an addition of labelled internal standard, extraction and separation by column chromatography. The lower limit of detection for 16 alpha-hydroxyandrost-4-ene-3,17-dione was 2 pg/tube. The mean recovery rate of the added standard was 98.3 +/- 8.8% (mean +/- SE). Intra- and inter-assay coefficients of variation were 8.6% (n = 6) and 12.1% (n = 7), respectively.

Amniotic Fluid↗
PubMed1984

Relationship between the anti-inflammatory effects and intrapleural accumulations of anti-inflammatory drugs in rats carrageenin pleurisy.

We simultaneously determined the time course of the anti-exudative effects of three types of anti-inflammatory drug and their concentrations in serum and pleural exudate in carrageenin-induced pleurisy in rats. Dexamethasone (DM, steroidal anti-inflammatory drug, 0.1 mg/kg, p.o.) in spite of the gradual decline of DM concentration in the pleural exudate with time and its actual loss at 16 h after carrageenin, showed an anti-exudative effect throughout the period of testing after carrageenin which was more marked in the relatively late phase than in the relatively early phase. Mepirizole (MP, non-acidic, non-steroidal antiinflammatory drug, 100 mg/kg, p.o.) showed an anti-exudative effect only at 3 h after carrageenin and not thereafter, although MP concentration in exudate was the same between 3 and 6 h after carrageenin and then declined gradually. Ketoprofen (KP, acidic, non-steroidal anti-inflammatory drug, 1 mg/kg, p.o.) showed an anti-exudative effect for 6 h after carrageenin and not thereafter, while KP concentration in exudate reached the peak at 3 h after carrageenin and then declined with time. However, at the relatively late phase (10 h after carrageenin) the twice administration of KP resulted in an increase in its exudate concentration enough to show an anti-inflammatory effect, but did not result in any more anti-exudative effect than the single administration of KP. Therefore, these differences in the anti-exudative effects of three types of anti-inflammatory drug can not be explained by the change in their concentrations in the inflamed tissue, but may reflect the difference in their intrinsic anti-inflammatory activities. The anti-inflammatory drugs accumulated in the inflamed pleural cavity independently of their ability to bind to plasma proteins, because the ratio of concentrations of three types of drug in exudate to those in serum were similar in spite of marked differences in protein binding capacities among these drugs.

Animals↗
PubMed1984

Radioimmunoassay of diethylstilbestrol in plasma of patients with prostatic carcinoma.

A method for the radioimmunoassay of diethylstilbestrol (DES) was established and it was used to measure the plasma concentration of DES in patients with prostatic carcinoma receiving intravenous drip infusion of 500 mg of diethylstilbestrol diphosphate (DES-DP). The sensitivity of this assay system was 40 pg per tube, with a recovery of 98%. The cross reactivity of the anti-DES antibody with estradiol, testosterone, and ethynylestradiol was less than 0.01% of DES, and that with DES-DP was 0.7%. In patients with prostatic carcinoma, plasma DES concentration at 6 and 24 hr after was declined to 10.2% and 4.4% of the level at the termination of intravenous administration of DES-DP, respectively; however, the concentration in patients with renal dysfunction was higher than that in ones with normal renal function.

Diethylstilbestrol↗