Inter- and intra-individual variation in applied force when listening at a surface, and resulting variation in earprints.

We aimed to explore the level of inter- and intra-individual variation in applied force when listening at a surface, and assess the resulting variation in earprints. We further intended to identify possible sources of this variation. Forty subjects each listened twenty-four times at a surface while applied force was recorded. In between efforts the level and frequency of the target sound, and the level of ambient noise were varied. Each listening effort was characterized by two values: the mean of a series of force recordings ('functional force') and the highest force reading of the effort ('peak value'). A mixed model analysis of variance revealed that repetition during multiple efforts of listening and the level of the target sound significantly affected both values for applied force. The frequency of the target sound affected the peak value, but we assume this was due to confounding effects. The level of ambient noise did not affect applied force. To explore the correlation between values for applied force of various efforts by single ear, the intra-class correlation coefficient was calculated. For functional force it was 0.80; for the peak value it was 0.79. To study intra-individual variation in earprints, five prints from each ear were lifted and studied. Variation in prints is discussed.

Evaluation of dental radiographic identification: an experimental study.

The object of this study was to assess the value of dental radiographs for the purposes of personal identification in the absence of tooth restorations. 198 periapical and bitewing radio graphs were taken of teeth contained in 22 dry skulls obtained from the skull collection of the Royal College of Surgeons of Edinburgh. Each selected view was taken three times: by a scientist, a dentist and a dental radiographer. Each operator independently positioned the films, selected the exposure times and positioned the cone of the X-ray machine. Three groups comprising forensic odontologists, dental vocational trainees and dental trainee hygienists attempted to match the randomly mixed radiographs into sets of three. Success rates for matching radio graphs ranged from 63.6 to 100%. The average for forensic odontologists was 93.3%, vocational trainees 85.2% and hygienists 89.7%. Where forensic odontologists had both formal training and experience, or extensive experience without formal training, the success rate was 100%. Where there was formal training but little experience the success rate was lower. Participants believed that root morphology and alignment had been the greatest aid to matching and not crown morphology. The depth of knowledge of the viewer correlated poorly with the number of correct results, although the forensic odontologists achieved the highest success rate. Formal training, although highly desirable, is no substitute for practical experience. Root morphology and alignment were cited most frequently as facilitating matching.

Aromatase, 5-alpha-reductase, and androgen receptor levels in the fetal monkey brain during early development.

Aromatase, 5 alpha-reductase and cytosolic androgen receptor levels were measured in the medial basal hypothalamus (MHB), amygdala (AMG), cerebellum and cerebral cortex of male and female fetal rhesus monkeys on day 70 of gestation. Higher aromatase activities were noted in the MBH and AMG of male than female fetuses. In contrast, no sex differences were found for 5 alpha-reductase and androgen receptor levels. These data suggest that at this early stage of development, differentiation of the MBH and AMG of the male fetus may be more susceptible to androgen modification, by way of aromatization to estrogens, than corresponding areas in the female fetus. Moreover, based upon a comparison of the current data to that published previously for later stages of development, it is suggested that the sex differences in aromatase activity are not the result of androgen stimulation.

Androgen receptors are differentially distributed between right and left cerebral hemispheres of the fetal male rhesus monkey.

In humans there are apparent sex differences in verbal and spatial abilities as well as several cortical pathologies. These differences may arise as the result of prenatal androgen exposure and its effect on the development of the cerebral cortex. With this in mind, we have examined androgen receptor (AR), aromatase (AROM) and 5 alpha-reductase (5 alpha R) levels in the cerebral cortex of Day 70 male and female fetal rhesus monkeys (Macaca mulatta). Receptor and enzyme levels were evaluated in both right (Rt) and left (Lft) temporal (TMP) and frontal (FR) lobes of the cerebral cortex. AR levels in FR-Rt of male subjects were higher than levels in FR-Lft (for each and every subject, P less than 0.05), while in females, there was no consistent pattern in the distribution of the receptor between the two sides of FR. In contrast, AR values in TMP-Lft of male subjects were consistently higher than in TMP-Rt (P less than 0.05). As with the FR, females exhibited no consistent pattern in the distribution of AR between the two TMP sides. AROM and 5 alpha R levels were similar, regardless of sex, between both sides of the two cortical lobes indicating that the AR distribution pattern is not a general biochemical phenomenon. The differential cortical distribution of AR in fetal males versus females lends support to the hypothesis that prenatal androgens from the fetal testes may effect the differentiation of sexually dimorphic, side-specific cortical activity.

Estrogen receptors in the rhesus monkey brain during fetal development.

Estrogen receptor (ER) levels were measured in brain tissue cytosol from fetal male and female rhesus monkeys at Days 70, 100 and 160 postconception. The brain regions which were examined included medial basal hypothalamus (MBH), amygdala (AMG), cerebral cortex (CTX) and cerebellum (CB). For comparison, brain tissues were also obtained from an adult female, and muscle (MUS) and genital tract (GEN, ovaries + uterus) ER values were measured in several Day 70 fetuses. Tissues were dissected and homogenized as previously described. Cytosol was passed through a microcolumn of Lipidex 1000 to remove interfering lipids and incubated with [3H]Moxestrol (4 nM) in the presence or absence of 500 nM Moxestrol. Incubations were carried out for 24 h at 4 degrees C, and free and bound ligand separated by Sephadex LH-20 gel filtration. In one case (Day 160 male fetus), saturation analysis yielded an estimate of apparent Kd of 0.46 x 10(-9) M and indicated that maximal specific binding was achieved at a ligand concentration of 1-2 nM. There was no sex difference at any stage of development (ANOVA). A significant age effect (P less than 0.002) was noted for the MBH and CB but not for any of the other tissues examined. In the MBH the significance of this effect was due to a progressive increase in ER levels with fetal age and into adulthood. In contrast, CB levels exhibited a progressive decline with age. These studies revealed that the ER is present during brain development. Thus any estrogens derived from the aromatization of circulating fetal androgens could potentially exert an influence upon brain development.(ABSTRACT TRUNCATED AT 250 WORDS)

5 alpha-reductase, aromatase, and androgen receptor levels in the monkey brain during fetal development.

To elucidate the metabolic fate and possible role of androgens and their derivatives during primate fetal development, aromatase (AROM), 5 alpha-reductase (5 alpha R), and androgen receptor (AR; cytosolic) levels were assessed in the brain, heart (HRT), lung (LNG), and skeletal muscle (MUS) of fetal rhesus monkeys. Analyses were performed on tissues taken on days 100 and 160 postconception. Five male and four or five female fetuses were examined at each stage. Brain tissues analyzed included medial basal hypothalamus (MBH), amygdala (AMG), cerebellum (CB), corpus callosum (CAL; splenial region), cerebral cortex (CTX), and cingulate cortex (CNG). In the following, enzyme activities are reported as picomoles per mg protein/h, while receptor levels are femtomoles per mg protein. 5 alpha R activity was measurable in all tissues. Analysis of variance revealed significant tissue differences [P less than 0.001, combined stages and sexes; CAL (2.05) greater than MBH (1.08) greater than AMG (0.63) greater than CB (0.4)-CNG-CTX-LNG-HRT-MUS (0.02); -indicates not significantly different]. A significant age x tissue interaction (P less than 0.001) was noted which could be explained by higher MBH and CAL levels in older vs. younger fetuses and higher AMG levels in younger vs. older fetuses. There was also a significant sex x tissue interaction which was attributed to higher female values in the MBH and CAL. AROM activity was detected in all tissues. Levels varied significantly among tissues [P less than 0.001, combined stages and sexes; MBH (0.80)-AMG (0.76) greater than CAL (0.4)-CNG-CB-CTX-LNG-HRT-MUS (0.07)]. Significant age (P less than 0.001) and age x tissue (P less than 0.001) effects were noted, which were due to higher MBH and AMG levels in younger vs. older fetuses. No sex difference in AROM levels was evident in any tissue. AR was measurable in all cases. Although stage and sex differences were not significant, tissue levels varied significantly [P less than 0.001; LNG (2.8)-MUS (2.6)-MBH (2.2) greater than HRT-AMG-CB-CTX-CAL-CNG (0.9)]. These findings indicate that neural and nonneural fetal primate tissues have the potential for transforming androgens to products that could have greater or lesser biological activity. AR were also noted through which dihydrotestosterone or testosterone could effect a genomic response. Since stage, tissue, and sex differences were evident in neural tissues, metabolic and receptor activities may be important for the normal differentiation of sexually dimorphic behavioral systems in monkeys as well as for potential teratogenic changes under abnormal metabolic or physiological conditions.

Excretion of estrone, estradiol, and progesterone in the urine and feces of the female cotton-top tamarin (Saguinus oedipus oedipus).

The excretion of three gonadal steroids was studied in the urine and feces of female cotton-top tamarins (Saguinus oedipus oedipus). Each steroid, 14C-estrone, 14C-estradiol, and 14C-progesterone, was injected into a separate female cotton-top tamarin. Urine and feces were collected at 8 hr intervals for 5 days on the three tamarins. Samples were analyzed to determine the proportion of free and conjugated steroids. Steroid excretion patterns were determined by sequential ether extraction, enzyme hydrolysis, and chromatography. Labeled estrone was excreted in a slow and continuous manner into the urine (57%) and feces (43%) with 90% of the steroid conjugated. The nonconjugated form had an elution profile identical to 3H estrone, but the conjugated portion was not completely hydrolyzed by enzyme. Labeled estradiol was excreted primarily in the urine (87%) and was released rapidly. Over 90% of the injected 14C-estradiol was excreted in urine as a conjugate, of which 41% was converted to an estrone conjugate and the remaining 59% was excreted as a polar estradiol conjugate. Labeled progesterone was excreted primarily in the feces (95%), 61% of which was free steroid. Four to six individual peaks of radioactivity were found when using celite chromatography and high performance liquid chromatography (HPLC), indicating that progesterone is metabolized into several urinary and fecal metabolites. One of these peaks matched 3H-progesterone and others may be pregnanediols, pregnanetriols, and 17-hydroxyprogesterone. These steroidal excretion patterns help explain the atypical hormonal patterns seen during the tamarin ovarian cycle.

Analysis of sex and regional differences in androgen receptors in fetal rhesus monkey brain.

Cytosolic androgen receptor levels were measured in different brain regions of fetal male and female rhesus monkeys (day 135 post-conception). The hypothalamus-preoptic area, amygdala and cerebellum exhibited higher receptor concentration in comparison to the cerebral cortex (parietal, temporal frontal, and occipital lobes), hippocampus and cingulate gyrus (P less than 0.001). No sexual difference in receptor concentrations was found except in the amygdala where fetal males exhibited slightly higher levels than females. The similarity in androgen receptor levels suggests that the developing brain of both sexes could be influenced by circulating androgens under normal or pathological conditions.

FSH-induced aromatase activity in hamster granulosa cells: effect of estradiol-17 beta in vitro.

We have shown previously that estradiol-17 beta (E2) reduces number of ovulations in cyclic rats, induces atresia of the dominant preovulatory follicle in monkeys, and that the initial effects of this treatment include reduced viability and estrogen accumulation in vitro by aspirated granulosa cells (GC) from monkeys and hamsters. The present experiment was designed to determine whether the reduction in estrogen accumulation can be ascribed to a direct action of E2 on the aromatization of androgen to estrogen in vitro. Female hamsters were injected with 30 I.U. pregnant-mare serum gonadotropin i.p. and sacrificed 3 days later. GC were aspirated from the largest follicles and incubated for 48 h ("initial incubation" period) in the presence of human pituitary follicle-stimulating hormone (hFSH, 100 ng/ml). Following initial incubation, GC were further incubated for up to 24 h ("secondary incubation" period). During this subsequent incubation, medium was supplemented with 100 nM 3H-1 beta-androstenedione (3H-A4). Initial incubation with E2 at doses of 10 ng/ml, 100 ng/ml and 1 microgram E2/ml induced variability in GC response, and a maximal depression of approximately 70%. The inhibition by E2 of hamster GC function in vitro parallels that shown in vivo for both hamsters and monkeys, but contrasts with that shown for rats. Thus, hamsters may represent an appropriate model in which to study the atretogenic effects of E2 directly on antral follicle development.

Pulsatile luteinizing hormone (LH) release during the progesterone-induced LH surge in the female rhesus monkey.

LH pulses during the progesterone (P)-induced LH surge were examined in ovariectomized and estrogen-treated female monkeys. Animals received a 2.5-mg P or oil injection 24 h after administration of 30 micrograms estradiol benzoate. The animals were fitted with jugular catheters connected to a tether-swivel system. Blood samples were collected at 10-min intervals starting 3-4 h before and ending 12-20 h after P or oil injection. Plasma LH was measured by both bioassay and RIA. LH pulses were determined by the PULSAR program. P administration induced a BIA-LH surge with a latency of 71 +/- 10 min in all seven animals. The P-induced bioassayable LH (BIA-LH) surge consisted of an ascending phase (204 +/- 24 min), a plateau period (174 +/- 32 min), and a descending phase (376 +/- 60 min). Oil injection did not cause a LH surge (n = 4). BIA-LH release before P and that during the P-induced LH surge were pulsatile. Pulse intervals of BIA-LH before P treatment (57.1 +/- 5.2 min) were not different from those before (55.0 +/- 11.7 min) and after (62.9 +/- 16.3 min) oil injection. In contrast, pulse intervals during the ascending phase (35.0 +/- 4.0 min), plateau period (34.6 +/- 2.6 min), and descending phase (45.0 +/- 3.1 min) were significantly shorter (P less than 0.02) than those before P. Pulse amplitudes of BIA-LH during the ascending phase (125.3 +/- 28.7 ng/ml) and plateau period (253.9 +/- 27.0 ng/ml) were significantly (P less than 0.001) higher than those (44.7 +/- 12.6 ng/ml) before P and during the descending phase (66.9 +/- 11.1 ng/ml). Radioimmunoassayable LH results were quite similar to those for BIA-LH, except that amplitude changes in radioimmunoassayable LH after P treatment were smaller than those in BIA-LH. It was concluded, therefore, that both the frequency and amplitude of pulsatile LH release increase during the P-induced LH surge, especially during the ascending phase and plateau period, in female rhesus monkeys. Furthermore, the present results support our previous conclusion that P facilitates pulsatile LHRH release with increases in frequency and amplitude in ovariectomized and estrogen-treated monkeys.

Androgen receptors in the cerebral cortex of fetal female rhesus monkeys.

The present study characterizes putative androgen receptor activity in the cerebral cortex cytosol of the female fetal monkey (Macaca mulatta) on days 125-135 postconception. Binding activities were compared using tritiated 5 alpha-dihydrotestosterone (DHT) and methyltrienolone (R1881) as ligands. Receptor concentration and association constants (Ka) were estimated from bound/total vs. total ligand binding curves. For R1881 and DHT, Ka values were 4.3 X 10(9) and 7.0 X 10(9) M-1, respectively. Receptor concentrations using the two ligands were estimated to be 5.5 X 10(-15) mol/mg protein (R1881; n = 2) and 1.7 X 10(-15) mol/mg protein (DHT). Analysis of receptor binding on DEAE-cellulose columns (KCl gradient) revealed multiple binding peaks (0.05-0.3 M KCl); similar elution profiles were obtained for the two ligands. Competition with either R1881 or DHT significantly reduced [3H]DHT binding throughout the KCl gradient, while triamcinolone acetonide had no effect. In contrast, [3H]R1881 binding was reduced by all three competitors. Cytosol from fetal male seminal vesicles had [3H]ligand-binding activity that was chromatographically similar to that of cerebral cortex. In contrast, binding in fetal male serum was negligible. Competition of cerebral cortex binding with a variety of hormones, including SCH-16423, progesterone, and cortisol, and analysis of the results on DEAE-cellulose suggested that there may be additional species of ligand-binding molecules. In summary, the findings verify the existence of a specific androgen receptor(s) in the cerebral cortex of fetal female rhesus monkeys. Its presence may be important for understanding both the influence of androgens on central nervous system development and the potential for teratogenic agents to disrupt normal patterns of central nervous system development.

Androgen and estrogen receptors in fetal rhesus monkey brain and anterior pituitary.

In this study, we sought to identify and characterize cytosolic androgen and estrogen receptors in the brain and anterior pituitary gland (AP) of fetal rhesus monkeys using the technique of DNA-cellulose chromatography. Cytosolic extracts were prepared from fetal monkey (days 135-162 of gestation) tissues including hypothalamus-preoptic area/amygdala (HPOA/AMG), cerebral cortex, and AP. Extracts were incubated with [3H]testosterone, [3H]5 alpha-dihydrotestosterone, or [3H] 17 beta-estradiol and applied to DNA-cellulose columns. [3H]Androgen- and [3H]estrogen-binding activities from cytosolic extracts adhered to DNA-cellulose. After elution with a linear salt gradient (10-500 mM NaCl) [3H]androgen-binding activity exhibited elution maxima between 130-150 mM NaCl, while [3H] estrogen-binding activity exhibited elution maxima between 200-220 mM NaCl. These elution patterns were similar in every region examined and were characteristic of putative androgen and estrogen receptors found in other vertebrate species. Additional experiments established the high affinity-low capacity nature of both androgen- and estrogen-binding activities, as well as their inhibition by known competitors of receptor binding. Estimates of binding activity at ligand concentrations that approximated saturation suggested that the concentration (moles specific bound per mg cytosolic protein) of both androgen and estrogen receptor were highest in the AP, intermediate in the HPOA/AMG, and lowest in the cerebral cortex. Comparisons of androgen- and estrogen-binding activities revealed that in the AP, apparent concentrations of the estrogen receptor exceeded those of androgen. Androgen and estrogen receptor concentrations were roughly equivalent in the HPOA/AMG, whereas, in the cerebral cortex, androgen receptor concentration was greater than estrogen. Collectively, these data demonstrate that in the fetal primate brain and AP, distinct androgen and estrogen receptors are present which might mediate the action of gonadal steroids on sexual differentiation.

Estrogen synthesis and metabolism in the hamster blastocyst, uterus and liver near the time of implantation.

The steroidogenic potential of hamster tissues, just prior to implantation of the blastocyst in the uterus, was characterized by incubating blastocysts (14) and pieces of endometrium with [1, 2-3H]-androstenedione for 24 h. [3H]-2-Methoxyestradiol was synthesized, but intermediate estrogens were not found. To obtain a more quantitative assessment and comparison of steroidogenic activity, especially aromatase activity, in these tissues as well as in the uterine myometrium and liver and to increase the possibility of recovering estradiol, microsomes were isolated from 244 blastocysts and portions of the other tissues. Microsomes were incubated with [1 alpha, 2 alpha-3H]-testosterone plus [1 beta,2 beta-3H]-testosterone for 6 h. During this time [3H]-metabolites were synthesized by all tissues as indicated by HPLC. [3H]-Androstenedione was noted and values were higher than control levels (medium alone or microsomes from uterine flush fluid) in all samples but liver. [3H]-Estradiol was detected at an elevated level only in the blastocyst sample; however, addition of unlabeled estradiol during the subsequent incubation of endometrial, myometrial and liver microsomes increased the recovery of [3H]-estradiol. Identities of [3H]-2-methoxyestradiol from the first experiment and [3H]-androstenedione and [3H]-estradiol from the second experiment were confirmed by recrystallization. The formation of 3H2O from [beta-3H]-testosterone was used as an index of aromatase activity. After subtracting control medium values, blastocysts were 24-fold more active (dpm/microgram protein) than the endometrium and myometrium in synthesizing 3H2O. While there was no difference in synthetic potential between endometrium and myometrium, aromatase activity in these tissues was greater than that of the liver. Microsomes from uterine flush fluid displayed no capacity for synthesizing 3H2O indicating that the elevated blastocyst levels were not caused by contaminating endometrial cells. These results indicate that all of the tissues examined have the capacity to metabolize C19-steroids to a variety of hormones, including estrogens, and further, that estrogen metabolism occurs rapidly in these tissues. This capacity may be important for providing a suitable hormonal milieu at the time of implantation.

Patterns of 3 beta-hydroxysteroid dehydrogenase/delta 5-4isomerase activity in the rhesus monkey placenta and fetal adrenal.

3 beta-Hydroxysteroid dehydrogenase/delta 5-4isomerase activity (3 beta-HSDH) was examined in the rhesus monkey (Macaca mulatta) placenta and fetal adrenal at 135 and 155-162 days of gestation. Activity was evaluated in microsomes by the conversion of [3H]pregnenolone to [3H]progesterone. There was a 7-fold increase in enzyme activity in the whole adrenal (minus medulla) between the two stages of development. Combining data from both periods, enzyme activity was greater in the outer than in the inner region of the adrenal. No stage-dependent change in placental activity was evident. The temporal patterns in 3 beta-HSDH activity are consistent with corticoid and progesterone patterns in the circulation. Thus, the level of 3 beta-HSDH activity may be rate limiting in both the fetal adrenal and placenta. Enzyme activity was assessed in incubations which included unextracted, heat-treated, 100,000 g tissue supernatants. In both placental and adrenal incubations, competitive inhibition was noted. Ethyl ether extracts of 100,000 g tissue supernatants also inhibited 3 beta-HSDH in the respective tissues. GLC analysis of these extracts revealed the presence of putative dehydroepiandrosterone. Hormone levels and the nature of the inhibition that were observed are compatible with the conclusion that dehydroepiandrosterone can inhibit the conversion of pregnenolone to progesterone in vivo. The physiological importance of this remains to be determined.

3 beta-Hydroxysteroid dehydrogenase/delta 5-4 isomerase activity in the rhesus monkey placenta and fetal adrenal, testis and ovary during late gestation.

3 beta-Hydroxysteroid dehydrogenase/delta 5-4 isomerase (3 beta-HSDH) was measured in the rhesus monkey (Macaca mulatta) placenta, fetal adrenal (whole organ minus medulla), testis and ovary during late gestation (Days 145-162). Activities were evaluated from the conversion of [3H]-pregnenolone to [3H]progesterone. The maximum enzyme velocity (Vm) in adrenal microsomes (100,000 g pellet) was significantly higher (146 nmoles progesterone/h X mg-1 protein) than in microsomes from the other tissues. Testicular Vm was greater than either ovarian or placental Vm which were not different from one another (11.5 versus 1.9, 1.2 nmoles progesterone/h X mg-1 protein, respectively). Apparent Michaelis-Menten constants in the adrenal, placenta, testis and ovary averaged 1.8, 2.5, 0.27 and 0.16 microM, respectively. In some cases, substrate inhibition was noted. Estimated dissociation constants for pregnenolone were 2.3 microM (adrenal), 2.1 microM (placenta), 0.74 microM (testis) and 0.13 microM (ovary). 3 beta-HSDH was less active in a crude mitochondrial preparation from the fetal adrenal (10,000 g pellet) than in microsomes, whereas activity in the placenta and testis appeared to be equally distributed between mitochondria and microsomes. Rate measurements were consistent with the apparent potentials of these organs to synthesize their characteristic hormones. Thus, 3 beta-HSDH activity may be an important rate determining step in hormone synthesis. The importance of substrate inhibition in progesterone formation remains to be assessed.

Corticoid formation by the monkey fetal adrenal: evaluation of 17-, 21-, and 11-hydroxylase activities.

There is indirect evidence that cortisol synthesis in the fetal rhesus monkey adrenal gland is limited at Day 135 of gestation but increases thereafter. This study was conducted to ascertain whether a reduced synthetic capacity is caused by a deficiency in 17-, 21- or 11-hydroxylase activity. For the sake of comparison 11- and 21-hydroxylases were also estimated in adult adrenals. 11-, 21-Hydroxylases were measured in the entire adrenal by the oxidation of NADPH by mitochondria and microsomes, respectively. 17-Hydroxylase was evaluated in outer and inner regions of the fetal gland by the formation of [3H]17-hydroxyprogesterone, -11-deoxycortisol, -cortisol and -androstenedione from [3H]progesterone. The maximum velocity of both the 11- and 21-hydroxylase was similar in fetal and adult glands indicating that corticoid formation in the fetus is not constrained by levels of these enzymes. [3H]Progesterone was extensively metabolized to -17-hydroxyprogesterone, -androstenedione, -11-deoxycortisol and -cortisol by homogenates from both regions of the fetal adrenal. The ratio of [3H]-cortisol to [3H]11-deoxycortisol was consistently higher in incubations of the inner glandular area. Together, these findings indicate that 17-hydroxylase is also active at Day 135 and that the 11-hydroxylase may be more concentrated in the fetal cortex. These data suggest in addition that the restriction in cortisol formation occurs at a step prior to the metabolism of progesterone to cortisol.

Estrogen synthetase and C17-20lyase activity in the fetal monkey gonad.

In the rhesus monkey (Macaca mulatta) the fetal testis appears to be more active than the fetal ovary in synthesizing steroids. This occurs despite the relative abundance of potential hormone precursors in the circulation. The possibility was investigated that this discrepancy in activity may be related to the activities of two rate-limiting enzymes, estrogen synthetase (ES) and C17-20lyase (LA). ES and LA activities were characterized in monkey fetal gonads during late gestation from the rate of formation of 3H2O from [1,2-3H]-androstenedione (ES) and metabolism of [4-14C]-17-hydroxyprogesterone to [14C]-androstenedione (LA). Ovaries and testes exhibited LA activity with apparent Km values of 3.4 x 10(-6) M and 7.1 x 10(-7) M, respectively. Reaction rate was 1.8 +/- 0.3 x 10(-3) nmol/min x mg-1 protein (n = 3) in the ovary which was significantly less than LA rate in the testis (8.3 +/- 1.6 x 10(-3) nmol/min x mg-1 protein, n = 5). ES activity was detected only in the fetal ovary; it averaged 1.5 +/- 0.4 x 10(-4) nmol/min x mg-1 protein (n = 5). The apparent Km was 5.3 x 10(-8) M. Isolation of the [3H]-estrogens formed revealed the synthesis of estrone and estradiol-17 beta. During the 30 min incubation the amount of 3H2O synthesized diverged from the combined quantity of tritiated reason fetal ovarian synthetic capacity is lower than that of the testis may be due to a low level of LA and ES activity in the ovary and additional metabolism of estrone and estradiol-17 beta.

17-Hydroxyprogesterone metabolism in the monkey fetal adrenal: C17-20lyase and 21-hydroxylase activities.

C17-20Lyase and 21-hydroxylase activities were measured during late gestation in the rhesus monkey (Macaca mulatta) fetal adrenal. Activities were assessed in 10,000 x g supernatants with 17-hydroxyprogesterone and NADPH as substrates. Although conversion of [14C]17-hydroxyprogesterone to [14C]androstenedione was noted, activity was often nonlinear and far less than the rate of hydroxylation which together prevented an accurate estimation of lyase rate, Km and Vmax. 21-Hydroxylase activity was characterized; the mean reaction rate was 1.6 x 10(-3) mumoles NADPH oxidized/min. x mg-1 protein with an apparent Km of 3.6 x 10(-7) M and a Vmax of 2.2 x 10(-3) mumoles/min. x mg-1 protein. These values were similar to data obtained in adrenals from adult monkeys. A relatively high level of hydroxylase activity in the fetal gland might lead to an inadequate supply of precursors for the synthesis of dehydroepiandrosterone sulfate (DHEAS) in the adrenal if it also contained 3 beta-hydroxysteroid dehydrogenase (3 beta-hsdh). However, the fact that the fetal adrenal reportedly is deficient in 3 beta-hsdh may serve to protect both DHEAS and corticoid synthesis.