Effects of multiple pituitary homografts or progesterone on 7,12-dimethylbenz[a]anthracene-induced mammary tumors in rats.
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In patients with hypogonadism, the exact cause of the deficient androgenisation is not always clinically apparent. The data presented demonstrate that by means of hormone measurements, basally or after stimulation tests, the exact level of the lesion can usually be determined. This allows a decision with regard to appropriate therapy to be made on the basis of an accurate diagnosis. In many instances basal measurements of pituitary and gonadal hormones are all that is required to decide the level of the lesion. Care in interpreting basal levels is required, however, in view of methodological limitations and of known physiological variations with age, time of day and hour-to-hour fluctuations. If the basal hormone levels are borderline, or if the 'reserve function' of part or all of the hypothalamic-pituitary-gonadal axis needs to be assessed, than the appropriate stimulation test should be performed. The indication for these stimulation procedures and results obtained in different conditions are described and problems of interpretation discussed.
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The presence of several hormones in milk occurring either by passive diffusion or by active concentrating mechanism from blood can be of great concern to the neonate. According to Fulkerson [1979] when the clearance rates of the hormones out of blood is considered, this worry is unwarranted. Concerning the steroids, when their levels have been monitored in milk after lactogenesis, the worry for the baby seems to be unfounded. But with the new finding of high level of LH-RH in milk whose concentration far exceeds that of blood, care should be taken to examine in the neonates whether the levels of LH and FSH become disproportionately high and induce the secretion of gonadal steroids at a higher level.
In the present study the Authors consider whether estroprogestins at low dosage may influence the basal levels of plasma Prolactin in a group of patients subdivided on the basis of their different ways of life. The results show that oral contraceptives containing 30 microgrammes of EE do not induce modifications on PRL levels; however these are significantly (p less than or equal to 0.01) lower in the smoker group. It has therefore been hypothesised that smoke may interfere with the regulatory mechanisms of PRL, even if the practical effects of such action in the ambit of the physiopathology of reproduction is not yet clear.
This study investigated prospectively the effect of supplementary breast feeding on the duration of lactational amenorrhoea and serum prolactin levels during prolonged breast feeding in a group of 34 Australian mothers. Although supplementary feeding correlated statistically with the decline in mean serum prolactin levels and the subsequent resumption of menstruation, critical analysis of the data revealed that serum prolactin levels were declining with time before the introduction of supplementary feeding. It was concluded that the resumption of menstruation during prolonged lactational amenorrhoea is associated with the introduction of supplementary infant feeding, but other factors may be more important in this process. The good correlation between the decline in serum prolactin levels and the return of cyclic ovarian activity in individual mothers suggests that measurement of serum prolactin level may be a useful predictive index for returning fertility during breast feeding.
The changes in serum specific hCG and prolactin levels were studied in 20 women after the evacuation of normal pregnancy at 5-10 weeks (group A) and 10 patients after the evacuation of molar pregnancy of 9-16 weeks (group B). The elimination of circulating hCG was faster in group A than in group B, and that in women after term delivery(group C)was faster than in both groups A and B. The half-life of the serum hCG level was 44.4 hrs in group A, 42.7hrs in group B, and 38.9hrs in group C, respectively. The mean level of serum prolactin in group A was 27.4ng/ml at 0 day, 64.5ng/ml at 4-7 days, and 31.9ng/ml at 13-15 days after evacuation, respectively. The surge was statistically significant. Though no regular tendency was found in the prolactin levels in group B, the levels were relatively higher than in group A and nonpregnant women. No correlation was found between hCG and prolactin levels in either group A or group B. The administration of drugs, such as methotrexate, did not affect the prolactin levels. On BBT, the resumption of ovulation tended to occur when the prolactin level, rather than the hCG level, returned to its normal range.
Twenty women whose blood pressure became elevated during oral contraceptive treatment had higher serum prolactin levels (31 +/- 5.3 microgram/liter) than did 20 normotensive pill takers (16.1 +/- 1.8 microgram/liter) and 20 women who were not taking the pill (14 +/- 1.1 microgram/liter), and the higher level was maintained (30 +/- 3.5 microgram/liter) after the pill was discontinued and blood pressure had become normal. This increase in prolactin levels was not related to differences in age or mode of treatment, and it is thought to reflect an alteration in dopaminergic transmission in patients with pill-related hypertension.
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Prolactin levels were evaluated during certain stress conditions, obstetric or gynecologic surgical interventions, labor, and birth. In 68 patients undergoing voluntary abortion, prolactin levels were measured to study the effect of anesthetics and of dilatation and curettage on hormonal secretion. Prolactin levels were evaluated in five patients undergoing elective cesarean section and in five post-menopausal patients undergoing total abdominal hysterectomy with bilateral oophorectomy. Moreover, prolactin concentration in serial samples of blood was estimated in 32 normal patients with spontaneous vaginal delivery at term and in 16 newborns at term after 30-60 and 120 min following birth. Prolactin responsiveness to TRH was evaluated in 12 newborns at the 4th day of life. Plasma prolactin levels rose in all the stress conditions investigated except in labor, during which hormone levels showed a decrease starting 2 h before delivery and reaching the lowest value 1 h prior. From this moment on there was a remarkable rise in prolactin concentration, with a peak 1 h after delivery. The decrease in prolactin levels during labor could possibly be due to an increase in dopaminergic activity. Moreover, the finding of no variation of prolactin levels during induced abortion in a group of patients pretreated with methysergide supports the view that the serotoninergic system also affects prolactin release.
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One hundred women who had been employing combination estrogen/progestin oral contraceptives (OCs) for a minimum of six consecutive months were evaluated for the presence of galactorrhea. It was found in 9%. The incidence did not vary significantly with age, gravidity, duration of OC use of estrogen content. Only six subjects had breast fed previously, preventing assessment of the effect this may have on the incidence of galactorrhea. Twelve OC users with galactorrhea were evaluated for the presence of pituitary microadenomas. Two had radiologic and hormonal findings consistent with the presence of prolactinomas, one had functional hyperprolactinemia, one had an empty sella, one had a partially empty sella, and two with normal basal prolactin levels had both polytomography and computerized axial tomography findings suggestive of pituitary microadenomas. Galactorrhea in OC users who have not breast fed is frequently associated with significant intrasellar pathology and should be an indication for further evaluation.
The purpose of this study was to characterize the effects of two functionally diverse steroids, 17 beta-estradiol and medroxyprogesterone acetate (MPA), on MtTW15 rat mammosomatotropic pituitary tumor growth and hormone production. Steroid responsiveness, as well as the hormonally autonomous nature of the tumor, was studied by treating both male and female tumor-bearing rats for 7 weeks with weekly injections of either 17 beta-estradiol (600 ng/g body weight/week) or MPA (200 microgram/g body weight/week) and, subsequently, comparing both the tumor weights and the in vivo production of growth hormone (GH) and prolactin (PRL) among the treatment groups. Large tumors (6 to 20 gm) were obtained in all treatment groups, indicating hormonal autonomy; however, tumors were markedly smaller, on the average, in untreated males an ovariectomized females. Treatment of such rats with 17 beta-estradiol stimulated tumor growth. Radioimmunoassay of tumor and serum GH and PRL levels in all treatment groups indicated the following: (a) tumors from untreated male or female hosts did not favor the production of one hormone over the other to any great extent; (b) MPA, however, promoted significant increases (p less than 0.05) in GH production in both male and female tumor-bearing rats while having little effect on the production of PRL; and (c) 17 beta-estradiol significantly inhibited (p less than 0.05) GH production and promoted PRL production by tumors borne by either sex. Selected studies utilizing multiple doses of MPA (1 to 500 microgram per gm body weight per week) and 17 beta-estradiol (10 to 800 ng per gm body weight per week) were accomplished and demonstrated that hormone production can be influenced in a dose-related manner. These results indicated that the estrogen-induced MtTW15 rat pituitary tumor is hormonally autonomous, yet divergently responsive to two different classes of steroidal compounds, thus making this tumor line an appropriate model for the study of hormonally responsive pituitary tumor cells.
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The endocrine profile of the midluteal phase was assessed in 29 patients with the post-tubal-ligation syndrome, consisting of pain, bleeding and premenstrual tension. Compared to normal controls, the patients had a high serum estradiol and a low serum progesterone level. This abnormal luteal function may be responsible for the symptoms observed and may also explain the failure to conceive following successful reversal of tubal ligation. It is recommended that patients seeking sterilization reversal be screened for abnormal luteal function preoperatively. Selection of sterilization procedures that minimize alteration in luteal function should be given high priority.
Serum prolactin levels were determined in 123 patients who presented with menstrual irregularities and/or infertility of more than 1 year's duration. Sixty-three patients had hyperprolactinemia with serum prolactin levels of 26 to 843 ng/ml (normal 5 to 22 ng/ml); 44.4% of this group of patients received oral contraceptive for a period of 2 months to 7 years. Sixty patients were normoprolactinemic, with serum prolactin levels of 3 to 22 ng/ml; 33.4% of this group received oral contraceptives for a period of 6 months to 7 years. The age of presentation, onset of symptoms, age at which they started on oral contraceptives, and duration of use were tabulated. The data were analyzed using chi 2 test corrected for continuity. There was no significant difference in age at the time of evaluation between oral contraceptive users and nonusers with hyperprolactinemia. The relative odds developing hyperprolactinemia were 2.64 times greater among women who has used oral contraceptives for more than 1 year and 6.25 times greater if this use started before the age of 25.
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