Aromatization and the induction of male sexual behavior in male, female, and androgenized female hamsters

Eight weeks after gonadectomy male, female, and androgenized [10 μg testosterone propionate (TP), 24 hr after birth] female hamsters were given daily treatment with: 150 μg dihydrotestosterone (DHT), 5 μg estradiol benzoate (EB), 150 μg DHT + 5 μg EB, 150 μg DHT + 1 μg EB, 30 μg DHT + 5 μg EB, 30 μg DHT + 1 μg EB, or the oil vehicle. Treatment of castrated male hamsters with 5 μg EB fully restored mounting but relatively few of these animals intromitted and none ejaculated. Treatment with 150 μg DHT restored all components of male sexual behavior but only in a small proportion of the males. Combined treatment with EB and DHT restored mounts, intromissions, and ejaculations in the majority of the males. Although as little as 30 μg DHT + 1 μg EB restored the full complement of male behavior, the males which received 150 μg DHT + 5 μg EB or 150 μg DHT + 1 μg EB required fewer intromissions to achieve ejaculation than the males which received 30 μg DHT + either dose of EB. The response of the androgenized females was similar to that of the males except that the androgenized females had lower intromission rates and none ejaculated. Relatively few of the nonandrogenized females responded to EB and DHT treatment and those that did mounted only a few times each test. These results demonstrate that both EB and DHT can stimulate male sexual behavior in the hamster and that the sensitivity to EB and DHT for copulatory behavior is determined by early postnatal androgen exposure.     

Hysterectomy-induced facilitation of lordosis behavior in the rat

The present study investigated the effect of hysterectomy on hormone-induced lordosis behavior. Lordosis quotients (LQ) were measured in hysterectomized-ovariectomized (HO) and ovariectomized-sham hysterectomized (OSH) rats after several treatments including either estradiol benzoate (EB) alone or EB plus progesterone (P) 44 hr later. Testing consisted of placing the females with sexually active males 48 hr after EB. In Experiment 1, HO animals treated with 5 μg/kg EB and 0.5 mg P had significantly higher LQs than OSH animals; groups treated with 10 μg/kg plus P were not different. Experiment 2 showed that a single injection of 50 μg/kg EB resulted in equally high levels of receptivity in both groups. The LQs of HO animals injected with 3 μg/kg for 4 days did not differ from those of OSH animals; however, the administration of 0.5 mg P 24 hr after the fourth EB injection resulted in significantly higher LQs in the HO group (Experiment 3). In Experiment 4, HO rats injected with 5 μg/kg EB and 0.1 mg P 44 hr later displayed higher levels of lordosis behavior than OSH animals. It was concluded that hysterectomy facilitated the lordosis behavior of ovariectomized rats injected with both EB and P and that the mechanism for this potentiation remains to be determined.     

A single injection of 17β-estradiol facilitates sexual behavior in castrated male mice

Sexual behavior was assessed in castrated adult CD-1 male mice given exogenous steroids under various treatment regimens. Castrated mice maintained on 20 μg testosterone (T) daily for 1 week, but given 250 μg testosterone propionate (TP) on the day of testing showed higher levels of copulatory activity than intact mice or the males receiving an additional dose of 20 μg T on the test day, although plasma testosterone levels were not different at the time of behavioral testing. Castrated males given 50, 125, or 250 μg TP for 1 week including the day of testing showed higher levels of sexual behavior than males receiving the same doses of TP only once, on the test day. A single injection of 17β-estradiol (E₂) completely restored the male copulatory pattern, including ejaculation, in castrated mice under every condition examined. Testosterone and dihydrotestosterone (DHT) were less effective than E₂, as was the combination of E₂ and DHT. The relative efficacy of a single dose of T, DHT, and E₂ plus DHT was dependent upon factors such as the delay between steroid administration and testing, as well as whether or not the castrated mice received androgen replacement prior to testing. Estradiol benzoate (E₂B) was not capable of restoring sexual behavior in castrated mice in this study. The comparison of results obtained with TP, T, E₂, and E₂B suggests that an appreciable, but not necessarily sustained, elevation of E₂ levels in the brain may be critical in the facilitation of male copulatory behavior in mice.     

Effects of estradiol benzoate, estrone, and propionates of testosterone or dihydrotestosterone on sexual and related behaviors of ovariectomized rhesus monkeys

Ovariectomized adult rhesus monkeys were injected daily for 10 days with either 1 mg of dihydrotestosterone propionate (DHTP), 1 mg of testosterone propionate (TP), 10 μg of estradiol benzoate (EB), or 500 μg of estrone (El). On the 5th and 10th days of treatment, females received two 24-min behavioral tests with each of two adult males. All females received every hormonal treatment during the course of the study, with the order of treatments counterbalanced. Prior to the initiation of an hormonal treatment, each subject received two tests with no hormone treatment (NORX). Three behaviors related to female proceptivity were recorded. Treatment with DHTP had no influence on any aspect of proceptivity measured, in comparison to the NORX condition, whereas El or TP treatment augmented the frequencies of two of the proceptive behaviors and EB increased all three. The response of the male toward the female was influenced by the female's hormonal condition. Treatment with TP or DHTP did not increase the frequency of male contact or the mount rate in comparison to the NORX condition, whereas EB or El treatment did. In addition, DHTP was the only steroid which failed to increase the percentage of tests with intromission or ejaculation when compared to NORX. Female receptivity, as measured by acceptance or rejection of male contacts, was not different for the NORX-, TP-, EB-, or El-treated conditions. DHTP treatment, however, reduced female receptivity in comparison to all other conditions. Treatment with DHTP or TP resulted in an increase in the frequency of female yawning behavior, whereas neither estrogen treatment showed any effect on this behavior. The influences of TP on female proceptive and male sexual behavior were never duplicated or even approximated by treatment of females with the nonaromatizable DHTP. Nor was there any evidence that TP inhibited female receptivity below the level characteristic of NORX females, as was true for DHTP.     

The regulation of precopulatory behavior by ovarian hormones in the female Mongolian gerbil

The hormonal regulation of precopulatory behavior in the female Mongolian gerbil was studied using two groups (N = 6) of sexually experienced females. A novel testing procedure was used which involved females living continuously with test males for several days. The test males showed either full sexual behavior (copulating males, C) or only precopulatory behavior (noncopulating males, NC). Experiment 1 investigated changes during the estrous cycle and following ovariectomy in females. Experiment 2 studied the effects of hormonal treatment of these ovariectomized females with 6 micrograms estradiol benzoate (EB) followed by 0.4 mg progesterone (P) or by 0.04 ml arachis oil. When tested with NC males, females displayed a greater range of precopulatory behavior. The patterns could be classified into three groups according to the manner of response to ovariectomy and hormone treatment. Group I patterns (approach, leave, and olfactory investigation of the male's head) were affected by neither ovariectomy nor EB treatment relative to Day 3 levels (Day 3, day preceding estrus; Day 4, estrus), but they were increased to estrous levels by EB and P. Group II patterns (darting, foot-stomping, and the present and piloerection postures) appeared only during estrus, did not appear after ovariectomy, and reappeared only after sequential EB and P treatment. Group III patterns (investigation of the male's anogenital area, allogrooming, ventral gland marking, and sand-rolling) were reduced relative to both estrus and Day 3 levels by ovariectomy and increased above Day 3 levels by EB alone; EB and P treatment further increased Group III patterns to the level of estrus. It is suggested that female precopulatory behavior patterns differ in their responsiveness to ovarian hormones. Estrogen appears to affect those patterns associated with the earliest stages of estrus (Group III).     

Control system for detection of the illegal use of naturally occurring steroids in calves

Within the scope of the National Plan for Hormone Control in The Netherlands, a study was performed to develop a system for control of the illegal use of three naturally occurring hormones [oestradiol-17β (E₂-17β), testosterone (T), progesterone (P)] for fattening purposes in animal production. Using a specific high-performance liquid chromatographic—radioimmunoassay method, reference values were established for concentrations of E₂-17β, T and P and some of their metabolites in blood plasma and urine from untreated male and female veal calves. E₂-17β levels of both male and female calves were <0.01 μg/l in blood plasma and <0.2 μg/l in urine. For male veal calves levels of T and epitestosterone (epiT) in blood plasma and urine varied widely. The P levels were <0.1–0.3 μg/l in blood plasma and <0.6–10 μg/l in urine from both male and female calves. To investigate the effect of anabolic treatment on the hormone levels in plasma and excreta, male veal calves were injected, subcutaneously into the dewlap, with a solution containing 20 mg of E₂-17β benzoate and 200 mg of T propionate in 5 ml of arachis oil. Only the levels of E₂-17β and E₂-17α in blood plasma and excreta were elevated until about one week after injection, compared with the untreated control calves and the reference values. T and epiT levels were similar in plasma and excreta from both untreated and treated animals.     

Ovarian hormones and the duration of sexual receptivity in the female golden hamster

The induction of sexual receptivity and its maintenance after copulation in ovariectomized female golden hamsters (Mesocricetus auratus) was found to be a function of the levels of ovarian hormones administered. Various combinations of estradiol benzoate (between 0.6 and 666 μg) and progesterone (between 0.05 and 5.0 mg) were administered in two experiments. Although some animals responded at 0.6 μg, higher levels of estradiol benzoate (1–6 μg or more) were more effective in inducing levels of lordosis equivalent to those seen in intact females in natural estrus. After mating, a depression in lordosis was observed in both ovariectomized and intact females. However, in ovariectomized females (excluding animals that did not respond initially) the duration of postcopulatory receptivity was a function of the level of progesterone administered. High levels of progesterone tended to prolong slightly the duration of postcopulatory receptivity.     

Central and peripheral action of testosterone propionate on scent gland morphology and marking behaviour in the Mongolian gerbil

Scent gland size and activity and frequency of marking under standard conditions were compared in five groups of male and female gerbils: (1) intact, sham-operated controls, (2) intact with scent glands excised, (3) gonadectomized, (4) gonadectomized injected with 1000 μg testosterone propionate (TP) on alternate days, and (5) gonadectomized with a low dose (25 μg) TP applied topically to the ventral scent gland on alternate days. The animals were housed in individual cages and tested for marking in an open field arena with plastic pegs.The scent gland is not required in either sex for the behavioural act of marking. Topical application of a dose of TP too low to exert a systematic effect restored the scent gland but not marking. Injection of sufficient TP to restore seminal vesicle weight restored marking, as well as the scent glands.It was concluded that in the male, both marking behaviour and scent gland size are controlled by the testes. The effect of androgens on marking is mediated directly through the central nervous system, and not through peripheral stimulation of the glands.Females have smaller glands and mark less than males. The ovaries appear to have little control over marking frequency, and some control over scent gland size. It is possible to stimulate marking behaviour to supernormal levels by TP injection, but not by topical application.     

Sexual behavior in male rats treated with estrogen in combination with dihydrotestosterone

Male rats castrated at 30 days of age were treated with estradiol benzoate (dose range: 0.05–50 μg EB for 26 days) and dihydrotestosterone (1 mg DHT for 36 days) as adults. The combined EB and DHT treatments resulted in display of male sexual behavior which did not differ from the behavior shown by intact untreated males or castrated, testosterone propionate (1 mg TP for 26 days) treated males. EB alone or DHT alone were relatively ineffective in activating male behavior in castrated males.     

Assessment of possible luteolytic effect of intra-ovarian injection of prostaglandin F2α in the human

A group of five patients awaiting laparoscopic tubal diathermy were followed by daily assay of luteinising hormone (LH) and progesterone. Between five and eight days after the LH peak, prostaglandin F_2α (PGF_2α) was injected into either the corpus luteum or the ovarian stroma. Doses of 100 μg into the corpus luteum, 1000 μg into the adjacent stroma and 500 μg into an indeterminate ovarian structure had no effect on peripheral plasma progesterone levels or uterine bleeding.An injection of 500 μg or 1000 μg given unequivocally into the corpus luteum produced a rapid and profound fall in plasma progesterone levels, the nadir coinciding with the onset of uterine bleeding which commenced 24 hours after the injection and persisted for more than seven days. Injection of 100 μg in the same volume of saline had no such effect. Despite continued bleeding plasma progesterone levels returned to normal luteal levels for three days and then fell again.     

Biosynthesis of prostaglandins and thromboxane B2 by fetal lung homogenates

The conversion of arachidonic acid to prostaglandins (PG's) and thromboxane B₂ (TXB₂) was investigated in homogenates from fetal and adult bovine and rabbit lungs. Adult bovine lungs were very active in converting arachidonic acid (100 μg/g tissue) to both PGE₂ (10.7 μg/g tissue) and TXB₂ (6.2 μ/g tissue). Smaller amounts of PGF_2α (0.9 μ/g) and 6-oxoPGF_1α were formed. Homogenates from fetal calf lungs during the third trimester of pregnancy were quite active in converting arachidonic acid to PGE₂, but formed very little TXB₂, PGF_2α or 6-oxoPGF_1α. Homogenates from rabbit lungs converted arachidonic acid (100 μg/g) mainly to PGE₂, both before and after birth. The amount of PGE₂ formed increased during gestation to a maximum of about 6 μg/g tissue at 28 days of gestation. It then decreased to a minimum (1.5 μg/g) which was observed 8 days after birth, followed by an increase to about 4 μg/g in older rabbits.     

Hormonal Modulation of the Cutaneous Initiation of Lordosis in Infant and Adult Rats

The purpose of these experiments is to compare the regional specificity (Experiment 1) and the hormonal modulation (Experiment 2) of the cutaneous initiation of lordosis in 4- to 6-day-old male and female rats (infants) and in 60- to 90-day-old female rats (adults). In Experiment 1, subjects were primed with 100 μg estradiol benzoate (EB) and 0.5 mg progesterone (P) and were denervated on the Waist (dermatomes L1-L3), Midriff (dermatomes T10-L3), Flanks (dermatomes L4-L6), or Sides (dermatomes T10-L6). In infants, there were no significant differences between males and females. Denervation of the Waist. Midriff, or Sides but not of the Flanks significantly decreased the percentage of subjects displaying lordosis, lordosis quotient (LQ), and mean lordosis duration; no significant differences were obtained among Waist-, Midriff-, or Sides-denervated infants. In contrast, denervation of the Sides but not of the Waist significantly decreased LQ and mean lordosis intensity among adults. In Experiment 2, Waist-denervated infants and their surgical Controls were treated either with 100 μg EB and 0.5 mg P or with the oil vehicle; Waist-denervated adults and their surgical Controls received either 100 or 10 μg EB (no P). Regardless of hormone treatment, denervation of the Waist significantly decreased LQ and lordosis duration in infants and decreased LQ and lordosis intensity in adults. In infants, the only effect of priming with EB and P was to increase the percentage of pups showing lordosis and lordosis duration among the surgical Controls. In contrast, priming with 100 μg EB significantly increased the percentage of rats displaying lordosis, LQ, and lordosis intensity among Waist-denervated adults. These data suggest that cutaneous input from the Waist is important for eliciting lordosis in both infant and adult rats, and that the importance of this input is modulated by hormone priming in adult but not infant rats.     

A Single Neonatal Injection of Ethinyl Estradiol Impairs Passive Avoidance Learning and Reduces Expression of Estrogen Receptor α in the Hippocampus and Cortex of Adult Female Rats

Although perinatal exposure of female rats to estrogenic compounds produces irreversible changes in brain function, it is still unclear how the amount and timing of exposure to those substances affect learning function, or if exposure alters estrogen receptor α (ERα) expression in the hippocampus and cortex. In adult female rats, we investigated the effects of neonatal exposure to a model estrogenic compound, ethinyl estradiol (EE), on passive avoidance learning and ERα expression. Female Wistar-Imamichi rats were subcutaneously injected with oil, 0.02 mg/kg EE, 2 mg/kg EE, or 20 mg/kg 17β-estradiol within 24 h after birth. All females were tested for passive avoidance learning at the age of 6 weeks. Neonatal 0.02 mg/kg EE administration significantly disrupted passive avoidance compared with oil treatment in gonadally intact females. In a second experiment, another set of experimental females, treated as described above, was ovariectomized under pentobarbital anesthesia at 10 weeks of age. At 15–17 weeks of age, half of each group received a subcutaneous injection of 5 μg estradiol benzoate a day before the passive avoidance learning test. Passive avoidance learning behavior was impaired by the 0.02 mg/kg EE dose, but notably only in the estradiol benzoate-injected group. At 17–19 weeks of age, hippocampal and cortical samples were collected from rats with or without the 5 μg estradiol benzoate injection, and western blots used to determine ERα expression. A significant decrease in ERα expression was observed in the hippocampus of the estradiol-injected, neonatal EE-treated females. The results demonstrated that exposure to EE immediately after birth decreased learning ability in adult female rats, and that this may be at least partly mediated by the decreased expression of ERα in the hippocampus.     

Effect of insulin-induced hypoglycemia on the serum concentrations of thyroxine,triiodothyronine and reverse triiodothyronine

The effect of insulin-induced hypoglycemia on serum thyroid hormone concentrations was studied in nine healthy individuals. Before, during and after the hypoglycemia blood samples were taken for measurement of the concentrations of glucose, thyroxine (T₄), triiodothyronine (T₃), reverse triiodothyronine (rT₃), catecholamines and pituitary hormones.There was no change in the mean serum T₄ level (± the standard error of the mean) of 67 ± 2 μg/l. However, the T₃ concentrations rose from a mean basal level of 1.86 ± 0.06 μg/l to a mean peak of 2.51 ± 0.21 μg/l (P < 0.01) at 45 minutes after the insulin injection, and the rT₃ concentrations fell from a mean basal level of 0.184 ± 0.008 μg/l to a mean nadir of 0.171 ± 0.022 μg/l (not a significant change). The mean peak epinephrine level was 545 ± 103 ng/l and it occurred between 30 and 45 minutes after the insulin injection; the mean peak norepinephrine level was 584 ± 114 ng/l and it occurred between 30 and 90 minutes after the injection. The growth hormone levels reached a mean peak of 26.1 ± 4.8 μg/l and the plasma cortisol levels rose to 215 ± 9 μg/l. The mean basal prolactin level was 8.5 ± 0.9 μg/l; in five subjects there was a rise to a mean peak of 50.6 ± 14.6 μg/l, whereas in the remaining four no significant increase occurred. No correlation was found between the changes in the serum T₃ concentration and any of the other factors studied.It was concluded that acute hypoglycemia is associated with a rapid increase in the serum T₃ concentration.     

Effects of prostaglandins E1 and F2α on serum luteinizing hormone concentration and on some sexual functions in male rabbits

PGE₁(50μg/animal) and PGF_2α (250 μg/animal) caused a transient in serum LH at 5 min after injection. PGE₁ (250 μg/animal) had a biphasic effect on serum LH. A small peak was obtained at 5 min, and a second, larger peak at 60 min after injection. It is suggested that the first peak is a result of the stress associated with injection of the PGs, whereas the second peak represents a physiological effect of PGE. Subcutaneous injection of PGE₁ (1 mg in arachis oil b.i.d.) for 10 days did not affect the concentration of LH in serum, the function of the accessory sexual glands or the sexual activity. PGF_2α, given at the same dose and in the same manner, increased the sexual activity but left all other variables unaffected. The pituitary responsiveness to LH-RH was unaltered by the treatment with PGE₁ and PGF_2α.     

Restorative effect of various androgens on copulatory behavior of the male golden hamster

Adult male hamsters were castrated, and four weeks later, after a single mating test, began receiving daily 100 μg injections of testosterone (T), androstenedione (AD), or testosterone propionate (TP). Mating tests were conducted at regular intervals during the eight week treatment period. Results indicated the superiority of TP in reinstating intromissions and ejaculations. The T and AD groups did not differ on any of the measures, a result which agrees with previous similar experiments using rats.     

Critical Periods of Sensitivity of Sexually Dimorphic Spinal Nuclei to Prenatal Testosterone Exposure in Female Rats

Male rats normally have more neurons than do females in two nuclei of the lumbar spinal cord, the spinal nucleus of the bulbocavernosus (SNB) and the dorsolateral nucleus (DLN). Female rats exposed to testosterone propionate (TP) on the 2 days of gestation (Days 18 and 19) when males normally experience a surge in plasma testosterone showed a maximal increase in both SNB and DLN neuronal number. TP exposure just prior to, or following, Days 18 and 19 led to smaller increments. Administration of a small (5 μg) dose of TP after birth, while having no effect by itself, synergized with prenatal TP to enhance the number of SNB neurons. DLN neurons were less responsive to postnatal TP. The somal and nuclear size of SNB, but not DLN, neurons was increased by perinatal TP. Paradoxically, the number of DLN neurons with large somas (1358 μm²or larger) was reduced by perinatal TP, a finding congruent with a previous report that females and feminized males have more of these large DLN neurons than control males. Our data suggest an exquisite sensitivity of the developing spinal nuclei to the timing of hormonal surges normally found in fetal males. Exposure to androgens during a brief prenatal period is needed to assure responsiveness to the low amounts of androgen circulating during neonatal ontogeny, when the process of sexual differentiation is completed.     

Therapeutic Potential of Date Palm Pollen for Testicular Dysfunction Induced by Thyroid Disorders in Male Rats

Hyper- or hypothyroidism can impair testicular function leading to infertility. The present study was designed to examine the protective effect of date palm pollen (DPP) extract on thyroid disorder-induced testicular dysfunction. Rats were divided into six groups. Group I was normal control. Group II received oral DPP extract (150 mg kg^-1), group III (hyperthyroid group) received intraperitoneal injection of L-thyroxine (L-T4, 300μg kg^-1; i.p.), group IV received L-T4 plus DPP extract, group V (hypothyroid group) received propylthiouracil (PTU, 10 mg kg^-1; i.p.) and group VI received PTU plus DPP extract. All treatments were given every day for 56 days. L-T4 or PTU lowered genital sex organs weight, sperm count and motility, serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone (T), testicular function markers and activities of testicular 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD). Moreover, L-T4 or PTU increased estradiol (E2) serum level, testicular oxidative stress, DNA damage and apoptotic markers. Morphometric and histopathologic studies backed these observations. Treatment with DPP extract prevented LT4- or PTU induced changes. In addition, supplementation of DPP extract to normal rats augmented sperm count and motility, serum levels of LH, T and E2 paralleled with increased activities of 3β-HSD and 17β-HSD as well as testicular antioxidant status. These results provide evidence that DPP extract may have potential protective effects on testicular dysfunction induced by altered thyroid hormones.     

Nevirapine,Sodium Concentration and HIV-1 RNA in Breast Milk and Plasma among HIV-Infected Women Receiving Short-Course Antiretroviral Prophylaxis

Introduction

Risk factors for breast milk transmission of HIV-1 from mother to child include high plasma and breast milk viral load, low maternal CD4 count and breast pathology such as mastitis.

Objective

To determine the impact of nevirapine and subclinical mastitis on HIV-1 RNA in maternal plasma and breast milk after intrapartum single-dose nevirapine combined with either 1-week tail of Combivir (zidovudine/lamivudine) or single-dose Truvada (tenofovir/emtricitabine).

Methods

Maternal plasma and bilateral breast milk samples were collected between April 2008 and April 2011 at 1, 4 and 6 weeks postpartum from HIV-infected Tanzanian women. Moreover, plasma samples were collected at delivery from mother and infant.

Results

HIV-1 RNA was quantified in 1,212 breast milk samples from 273 women. At delivery, 96% of the women and 99% of the infants had detectable nevirapine in plasma with a median (interquartile range, IQR) of 1.5 μg/mL (0.75–2.20 μg/mL) and 1.04 μg/mL (0.39–1.71 μg/mL), respectively (P < 0.001). At 1 week postpartum, 93% and 98% of the women had detectable nevirapine in plasma and breast milk, with a median (IQR) of 0.13 μg/mL (0.13–0.39 μg/mL) and 0.22 μg/mL (0.13–0.34 μg/mL), respectively. Maternal plasma and breast milk HIV-1 RNA correlated at all visits (R = 0.48, R = 0.7, R = 0.59; all P = 0.01). Subclinical mastitis was detected in 67% of the women at some time during 6 weeks, and in 38% of the breast milk samples. Breast milk samples with subclinical mastitis had significantly higher HIV-1 RNA at 1, 4 and 6 weeks (all P < 0.05).

Conclusion

After short-course antiretroviral prophylaxis, nevirapine was detectable in most infant cord blood samples and the concentration in maternal plasma and breast milk was high through week 1 accompanied by suppressed HIV-1 RNA in plasma and breast milk.     

Intrauterine injection of 15(S)-15-methyl-prostaglandin F2α for termination of early pregnancy in out-patient

15-me-PGF_2α was administered as single intrauterine injection for interruption of very early pregnancy in 30 out-patients. After 2 weeks, abortion was complete in 60 % induced with 125 or 200 μg and 80 % induced with 300 μg. After 3 weeks, abortion was complete in 90 % induced with 125 μg, in 70 % induced with 200 μg and in 100 % induced with 300 μg. One failure occurred in patients treated with 200 μg and 2 curettages were performed because of incompleteness of abortion. No serious complications occurred. Compared with our previous results it appears that 15-me-PGF_2α is as effective as natural PGF_2α in inducing abortions during very early pregnancy but causes somewhat fewer side-effects.