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The effect of a high fat, low carbohydrate, low protein diet on the in vivo oxidation of 17 beta-estradiol was studied using radiometric methods. Five male chimpanzees were fed a normal (13%) fat diet or a high (65%) fat diet for 8 weeks. After a 4-week rest period, the animals were fed the alternative diet. The mean percent oxidation of 16 alpha-[3H]estradiol-17 beta 24 h after injection was 3.8 +/- 1.3% (+/- SD) on the normal diet vs. 18.4 +/- 4.7% on the high fat diet (P less than 0.01). In contrast, the mean percent oxidation of 2-[3H]estradiol 24 h after injection was 31.6 +/- 3.8% (+/- SD) on the normal diet vs. 20.0 +/- 3.5% on the high fat diet (P less than 0.05). These results suggest that the oxidation of 17 beta-estradiol to estriols relative to that to catechol estrogens is increased by a high fat diet.

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Previous studies have indicated that serum levels of follicle-stimulating hormone rise with age during the female reproductive life, but the effect on other hormones is not clear. We studied the effects of age, independent of pregnancy, by comparing serum hormone levels in two groups of nulliparous, premenopausal women aged 18 to 23 and 29 to 40 years. We found that increased age during reproductive life is accompanied by a significant rise in both basal and stimulated serum follicle-stimulating hormone levels. This was accompanied by an increase in the serum level of estradiol-17 beta and the urine levels of estradiol-17 beta and 17 beta-estradiol-17-glucosiduronate. The serum level of estrone sulfate decreased with age. Serum and urine levels of other estrogens were unchanged. The basal and stimulated levels of luteinizing hormone were also unchanged. There was a significant decrease in basal and stimulated serum prolactin levels. Serum levels of dehydroepiandrosterone and dehydroepiandrosterone sulfate decreased with age, but serum testosterone was unchanged. It is concluded that significant age-related changes in the female hormonal environment occur during the reproductive years.

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An early (but not a late) first pregnancy is known to be protective for breast cancer. This effect might be mediated through a long term change in the hormonal environment caused by the early first pregnancy. To investigate the possibility of such a change we carried out a prospective longitudinal study of serum and urinary estrogens and serum androgens in four groups of women, namely early (age, 18-23 yr) first pregnancy (n = 15), early control (n = 20), late (age, 29-40 yr) first pregnancy (n = 9), and late control (n = 20). The pregnancy groups were studied before (initial visit) and 7-19 months after a first pregnancy (return visit). The control groups were similarly studied, but without an intervening pregnancy. The following were measured: serum estrone (E1), 17 beta-estradiol (E2), estriol (E3), and E1 sulfate; urinary total E1, E2, E3, and glucosiduronates of these three estrogens; and serum testosterone, dehydroepiandrosterone sulfate (DHAS), and dehydroepiandrosterone (DHA). There was no significant change between the initial and return visits in serum E1, E2, E1 sulfate, or any of the urinary estrogens in either pregnancy group or in the corresponding control groups. There was, however, a significant increase in serum E3 between initial and return visits for both pregnancy groups compared with the control values. There was no significant change in serum testosterone. There was a marked significant decrease in both serum DHAS and DHA between initial and return visits in both pregnancy groups compared with the corresponding control group values. There was also a significant increase in the serum E3 to DHA ratio in both pregnancy groups. A cross-sectional study (measuring serum DHAS and DHA only) was then carried out in a series of parous and nulliparous women. The serum DHAS and DHA levels were markedly and significantly lower in parous than in nulliparous women, as expected. There was no significant relationship between serum DHAS or DHA levels and months elapsed (up to 150) since last delivery, indicating that the changes last at least for this period of time. There was no significant relationship between serum DHAS or DHA levels and parity (one to three previous pregnancies), indicating that the changes occur only after a first pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)

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An early first pregnancy is known to protect against subsequent breast cancer. We speculated that this effect may be mediated by a long-term depression of prolactin secretion after pregnancy. We therefore measured basal and post-stimulation serum levels of prolactin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in two groups--15 women 18 to 23 years of age and 9 women 29 to 40--before and after a first full-term pregnancy, and in 40 appropriate nulliparous controls. We observed no significant change in basal levels of serum LH or FSH or in the levels stimulated by gonadotropin-releasing hormone in any group. A significant decrease was seen, however, in basal and perphenazine-stimulated levels of prolactin after pregnancy in both the younger and older first-pregnancy groups but not in the controls. In a separate cross-sectional study, we compared basal serum prolactin levels in 29 parous and 19 nulliparous women of similar age. The serum prolactin levels were significantly lower in the parous group but were not related to the number of pregnancies (one to three) or the time elapsed (12 to 150 months) since the last delivery. We conclude that a first pregnancy leads to a long-term decrease in serum prolactin secretion, lasting at least 12 to 13 years.

PIP: On the theory that early pregnancy may protect women against breast cancer by a long-term depression of prolactin secretion, basal and perphenazine-stimulated release of prolactin, as well as basal and GnRH- stimulated release of LH and FSH were assayed in women before and after their 1st full term pregnancy, and in groups of parous and nulliparous women. The study groups were 15 women aged 18-23 and 9 women aged 29- 40. All hormone samples were taken at 0800 in the early follicular phase on women who had never taken oral contraceptives, or in the cross section survey, women who had not been exposed for at least 6 months. There were no significant differences in LH or FSH basal or stimulated levels for 100 minutes after GnRH. In contrast after term pregnancy both basal and stimulated prolactin levels were significantly lower than comparable levels in nulliparous controls. Parous women returned for their second prolactin assay from 5-11 months after delivery. The cross-section basal prolactin levels were done from 12-150 months after delivery, with no evidence of an effect of age, parity or elapsed time. These results are appropriate for a protective factor against breast cancer, and prolactin is known to stimulate breast neoplasm in rodents.

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Although several phenothiazines are known to stimulate prolactin (PRL) secretion, only chlorpromazine is in general use for this purpose in humans. However, chlorpromazine has severe sedative and hypotensive effects. Therefore, the effects of perphenazine on human PRL release and on blood pressure were evaluated. Perphenazine was administered orally (8mg) and intramuscularly (5mg and 2mg) to determine the optimal route and dose for evaluating PRL release. The postural hypotensive effect of perphenazine was evaluated with the 2mg intramuscular (IM) dose. The mean time of peak PRL response (hr +/- SD) was significantly shorter (p less than 0.05) for the 5mg IM (1.7 +/- 0.4) than the oral (4.5 +/- 0.6) route. Also, the mean ratio of peak/baseline PRL was significantly greater for the 5mg IM (8.87 +/- 5.69) than the oral (5.12 +/- 2.90) route. The major side-effect produced by perphenazine was drowsiness, which was moderate to severe with the 5mg IM dose. A lower IM dose (2 mg) retained PRL releasing activity, reduced drowsiness, and did not produce hypotension. For clinical testing, intramuscular perphenazine is preferred over oral perphenazine because of the shorter latency period and the higher PRL levels. Intramuscular perphenazine (2 mg) is preferred to chlorpromazine since it did not produce a clinically significant hypotensive effect. This is the first report on the dynamic responses of PRL and blood pressure to intramuscular perphenazine in humans.

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The metabolism of estradiol-17ß is primarily an oxidative process at either carbon-2 or carbon-16 in the human. The objective of this study was to determine the relative importance of these two oxygenation pathways in the chimpanzee. The rate of oxidation of estradiol-17ß at each position was determined by measuring the release of tritium into body water from carbon-2 or carbon-16. [2-3H]-Estradiol-17ß or [16-3H]-estradiol-17ß was injected intravenously into three adult male chimpanzees, and blood samples were obtained at several time intervals between 1 and 48 hr. The blood was lyophilized, and the release of tritium from the specifically labeled estrogens into the body fluid pool was determined. The release of tritium from the 16α-position was very low and did not exceed 3% in any animal. The release of tritium from the carbon-2 was much faster, amounting to 29%, 34%, and 35%, respectively, by 24 hr. The ratio of tritium released from carbon-2:carbon-16 was 5.0, 13.2 and 16.9, respectively, at 24 hr after injection of the specifically labeled estradiol-17ß. These results demonstrate clearly that the major pathway for oxidative metabolism of estradiol-17ß in the chimpanzee is via oxygenation at carbon-2, with the formation of catechol estrogens, as in the human.

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The interrelationship between sex skin swelling and the urinary excretion of luteinizing hormone and sex steroids was investigated during ovulatory menstrual cycles in adult female chimpanzees. Estrone was excreted in two peaks, one during the preovulatory and the other during the midluteal phase. Maximum swelling of the sex skin was attained several days before the preovulatory estrone peak. The LH surge preceded or accompanied beginning detumescence of the sex skin which, in turn, was closely correlated with a rising excretion of pregnanediol. Urinary measurements provide integrated estimates of the concentration of fluctuating hormones and, in addition, are safer and easier to make than blood measurements in this species.

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The urinary excretion of estrone glucosiduronate, 17 beta-estradiol-17-glucosiduronate, and estriol-16 alpha-glucosiduronate in men and throughout the menstrual cycle in women was measured by specific radioimmunoassay. In 9 men the mean +/- SE excretion of these conjugates was 15.9 +/- 1.4, 2.7 +/- 0.3, and 3.2 +/- 0.2 microgram/24 h respectively. In 15 women studied in the midfollicular phase (day 8) of the menstrual cycle, the excretion was 19.4 +/- 1.7, 2.9 +/- 0.2, and 5.4 +/- 1.3 micrograms/24 h. Excretion of each conjugate was significantly (P less than 0.01) elevated in the midluteal phase (day 22) to 41.9 +/- 3.9, 6.3 +/- 0.8, and 12.2 +/- 1.5 micrograms/24 h respectively (n = 14). The mean excretion of estriol-16 alpha-glucosiduronate was greater than that of 17 beta-estradiol-17-glucosiduronate in the luteal phase (P less than 0.05) but not in the follicular phase or in men (P greater than 0.05). The excretion of each of these specific conjugates measured throughout the menstrual cycle in 7 women was characterized by a sharp midcycle peak and a lower, broader luteal phase peak. The ratios of estriol-16 alpha-glucosiduronate to 17 beta-estradiol-17-glucosiduronate, estrone glucosiduronate to 17 beta-estradiol-17-glucosiduronate, and estriol-16 alpha-glucosiduronate to estrone glucosiduronate throughout the menstrual cycle were analyzed. When the mean ratio during the follicular phase was set at 1, a significant increase (P less than 0.01) occurred in the mean luteal phase ratio in each case: 1.00 +/- 0.03 to 1.66 +/- 0.09, 1.00 +/- 0.04 to 1.30 +/- 0.04, and 1.00 +/- 0.03 to 1.24 +/- 0.04 (mean +/- SE) respectively. The marked alteration in the proportions of these urinary estrogen conjugates may be due to altered metabolism of 17 beta-estradiol, but it more likely reflects a change in the pattern of estrogen secretion or production between the two phases of the menstrual cycle.

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The effect of the drug sulfobromophthalein (BSP) on plasma estrogens in the dog were studied during intravenous infusions of 3H-labeled estrogens. During [3H]estrone infusion, BSP administration caused a marked increase in arterial plasma levels of the radioactive conjugated estrogens, estrone glucosiduronate, estradiol-17 beta glucosiduronate(s), and estrone sulfate. Levels of the unconjugated estrogens, estrone and estradiol-17 beta, were substantially unaltered. Possible mechanisms were investigated. Splanchnic extraction of the conjugates did not change significantly during BSP administration, and renal excretion rose promptly in proportion to the plasma levels, thus virtually excluding decreased biliary or renal excretion. There was no net discharge of estrogen glucosiduronate radioactivity from adipose tissue or muscle following BSP. During [3H]estrone glucosiduronate infusion, BSP again caused an increase in plasma estrone glucosiduronate, thus excluding increased formation (of this conjugate, at least). BSP caused decreased extraction of estrone glucosiduronate by the hindlimb, indicating that decreased metabolism was the probable cause of the elevated plasma levels. BSP also caused decreased formation of unconjugated estrogens by the lungs, indicating that the decreased metabolism includes decreased hydrolysis of estrogen glucosiduronates.

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Specific RIAs requiring ether extraction only were established for estrone and 17 beta-estradiol both in plasma and in urine from the nonpregnant female. These assays were used to measure the renal clearance rates of estrone and of 17 beta-estradiol in eight ambulatory women in the follicular and in the luteal phases of the menstrual cycle. The mean (+/-SE) for the renal clearance rate of estrone was 0.71 +/- 0.058 ml/min in the follicular phase and 1.26 +/- 0.35 ml/min in the luteal phase. The mean (+/-SE) renal clearance rate of 17 beta-estradiol was 0.44 +/- 0.055 ml/min in the follicular phase and 0.29 +/- 0.043 ml/min in the luteal phase. There was no significant difference in the renal clearance rates of either estrone or of 17 beta-estradiol between the follicular and luteal phases of the cycle. The renal clearances of estrone and 17 beta-estradiol were highly correlated (r = 0.84; P less than 0.01). The renal clearance rate of estrone was significantly greater than that of 17 beta-estradiol in both phases of the cycle (P less than 0.01).

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Estrone sulfate, quantitatively the most important estrogen in plasma, has previously been determined only after hydrolysis and chromatography. An antiserum raised against estrone glucosiduronate-bovine thyroglobulin was found to be suitable for the specific RIA of estrone sulfate both in plasma and urine. Plasma levels were measured after solvent extraction without hydrolysis or chromatography. The mean (+/-SE) was 972 +/- 79 pg/ml (range, 537-1581) in 15 women in the follicular phase, 1806 +/- 160 pg/ml (range, 814-3358) in 15 women in the luteal phase, and 922 +/- 62 pg/ml (range, 461-1238) in 13 men. The urinary excretion of estrone sulfate, measured after simple chromatographic separation, ranged from 0.8-7.9 micrograms/24 h in men and 5.1-18.7 micrograms/24h in nonpregnant women. This was generally one-seventh to one-half the simultaneous estrone glucosiduronate excretion rate. An approximate mean renal clearance of estrone sulfate calculated from the above values was 2.7 ml/min. The low clearance rate is taken to reflect extensive binding of estrone sulfate by plasma proteins. The splanchnic extraction of estrone sulfate measured in 6 patients undergoing hepatic vein catheterization for diagnostic purposes was 29.8 +/- 11.1%, indicating net uptake of this compound by the splanchnic area.

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A direct radioimmunoassay which does not require hydrolysis or chromatography has been developed for estriol-16alpha-glucosiduronate in pregnancy plasma and urine. The antigen used in the development of this antiserum was prepared by joining the carboxylic acid group of estriol-16alpha-glucosiduronate covalently to the epsilon-amino group of the lysine residues in bovine serum albumin. Results indicate that the direct radioimmunoassay yields levels of estriol-16alpha-glucosiduronate in late pregnancy urine that are comparable to those obtained by mroe elaborate procedures involving chromatographic separation of the estriol conjugates, followed by enzymic hydrolysis and measurement of the freed estriol. In addition, good correlation was found between the total estrogen values in urine obtained by currently used chemical procedures and urinary levels of estriol-16alpha-glucosiduronate. The renal clearance of estriol-16alpha-glucosiduronate was determined in eight normal women during the third trimester, and the mean value +/- S.D. was 404 +/- 81 ml. per minute (range, 248 to 494). This method is suitable for the evaluation of variations in the plasma and urine levels of estriol-16alpha-glucosiduronate in pregnancy and offers significant advantages over the presently used chemical methods for monitoring fetal well-being.

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High pressure liquid chromatography using a prepacked commercial strong anion exchanger column (mu Partisil 10 SAX, 25 cm x 4.6 mm) was used to separate a mixture of eight estrogen conjugates. Chromatographic conditions using a 0.01 M potassium phosphate or 0.1 M NaCl as solvent in the isocratic mode are described for the separation of estrone glucosiduronate, 17beta-estradiol-3-glucosiduronate, 17beta-estradiol-17-glucosiduronate, estriol-3-glucosiduronate, estriol-16alpha-glucosiduronate, estriol-17-glucosiduronate, estrone sulfate and 17beta-estradiol-3-sulfate. This system gives high resolution of the estrogen conjugates in small eluent volumes in less than 30 min. The advantages of this high pressure liquid chromatographic system over other methods of separation are discussed.

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Direct radioimmunoassay are described for the measurement of each of three specific estrogen glucosiduronates: estrone glucosiduronate, 17 beta-estradiol-17-glucosiduronate and estriol-16 alpha-glucosiduronate in urine. Each assay utilizes a specific antiserum prepared by complexing the carboxylic acid group of the appropriate glucosiduronate to the epsilon-amino group of lysine in bovine serum albumin or bovine thyroglobulin. The antisera showed little or no cross reactivity toward other estrogens that might be present in significant amounts in urine. These antisera were used for the direct assay of the conjugates in urine from normal men and nonpregnant women without prior extraction or chromatography. The values were similar to those obtained after extraction, chromatographic purification on DEAE-Sephadex and subsequent immunoassay; The following mean values +/- SE (microgram/g creatinine) were obtained: estrone glucosiduronate, male 10.1 +/- 0.6, follicular phase female 17.3+/- 1.6, luteal phase female 31.8 +/- 2.5; 17 beta-estradiol-17-glucosiduronate, male 1.7 +/- 0.3, follicular phase female 2.4 +/- 0.1, luteal phase female 4.2 +/- 0.4; estriol-16 alpha-glucosiduronate, male 1.8 +/- 0.2, follicular phase female 4.7 +/- 0.9, luteal phase female 10.0 +/- 1.6.

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A method for the preparation of radioactive estradiol-17 beta, 17-glucosiduronate by incubating 3H-estradiol with rhesus monkey liver microsomal preparation in the presence of uridine diphosphoglucuronic acid is described. Small but significant amounts of the conjugate were also obtained from the 150,00 pellet and cytosol fractions. The addition of NADPH to the incubation media increased the yield of radioactive-estradiol-17 beta, 17-glucosiduronate perhaps by preserving the integrity of the C-17-hydroxyl group. As expected, the effect of the reduced nucleotide was more pronounced in the fractions other than the microsome. The biosynthesized conjugate was isolated and purified by multiple column chromatography and the structure was confirmed by derivative formation, enzyme hydrolysis and crystallization of the aglycone.

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Basal body temperature (BBT) was measured continuously by radiotelemetry throughout 14 chimpanzee menstrual cycles and correlated with daily observations of the sexual skin swelling. A biphasic BBT shift from a pre-nadir mean of 36-12 degrees C to a post-nadir mean of 36-67 degrees C was observed in 12 cycles. The temperature nadir showed a close temporal relationship with detumescence of the sexual skin swelling (an early luteal event), but the rate of temperature rise after the nadir was variable. In 3 normal cycles studied, the temperature nadir occurred the day after a urinary oestrone peak, but there was no consistent temporal association between BBT rise and pregnanediol increment. Progesterone secretion is therefore probably not the sole determinant of the BBT shift; the changing oestrogen/progestin ratio may be the more important factor regulating body temperature during the luteal phase.

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Estrone glucosiduronate, 17beta-estradiol-3-glucosiduronate, 17beta-estradiol-17-glucosiduronate and estriol-16alpha-glucosiduronate have been biosynthesized in substantial yield by incubation of radioactive estrone, 17beta-estradiol, estriol and uridine diphosphoglucosiduronic acid with rhesus monkey liver homogenates. The metabolites were characterized by chromatography on Celite and DEAE-Sephadex, enzyme hydrolysis, derivative formation and crystallization to constant specific activity. The percent conversion to 17beta-estradiol-17-glucosiduronate from 17beta-estradiol ranged between 56-71%; from estrone, the conversion was 49-54%. Other metabolites formed from estradiol were estrone glucosiduronate (12-21%) and 17beta-estradiol-3-glucosiduronate(5-12%). The same metabolites derived from estrone accounted for 18-28% and 10-14% respectively. After estriol incubation, more than 90% of the steroid was converted to estriol-16alpha-glucosiduronate with no detectable estriol-3-glucosiduronate. This report represents the first time that 17beta-estradiol-17-glucosiduronate has been reported as a metabolite in the rhesus monkey and this is the only known species which forms 17beta-estradiol-17-glucosiduronate as the predominant metabolite of either estrone or estradiol in vitro. Rhesus monkey liver is similar to the human and baboon in that it metabolizes estriol exclusively to estriol-16-glucosiduronate.

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