Discordant patterns of hyperprolactinaemia and galactorrhoea in secondary amenorrhoea

There were 123 patients with functional secondary amenorrhea of at least 6 months' duration. The upper normal serum prolactin level was 3 ng/ml as measured by radioimmunoassay. Hyperprolactinemia was found in 40 of the 123 patients (33%). Those with peak levels of 60 ng/ml often also had some normal levels. Patients with levels over 120 had demonstrable galactorrhea in 38% of cases. Galactorrhea was found in 10 patients with normal prolactin values. The 5 patients with anorexia nervosa had normal prolactin values and no galactorrhea. 14 of 61 (23%) patients with self-induced weight loss had hyperprolactinemia but galactorrhea was rare. Hyperprolactinemia was found in 4 of 13 patients with stress-related amenorrhea. Amenorrhea after use of oral contraceptives was related to hyperprolactinemia in 10 of 28 patients and 5 had galactorrhea. There were 4 patients with the Chiari-Frommel syndrome; their mean serum prolactin level was 435 ng/ml. 5 patients had pituitary tumors; galactorrhea was present in 3 of them. All of these 5 patients had high serum prolactin levels ranging from 145 to 620 ng/ml. Mild hyperprolactinemia was present in 16 patients with idiopathic amenorrhea but no galactorrhea. 5 of the 9 patients who were hirsute had elevated prolactin. Results show that galactorrhea is not a reliable sign of hyperprolactinemia. The prolactin assay is helpful in the management of patients with amenorrhea.     

Twenty-four-hour prolactin secretory patterns in women with galactorrhea, normal menses, normal random prolacting levels and abnormal sellar tomograms

During a systematic study of women with idiopathic galactorrhea, we observed several patients with normal random serum prolactin (PRL) levels and normal menses, but abnormal sellar tomograms characteristic of a pituitary adenoma. To test the hypothesis that these women might have intermittent PRL hypersecretion, we studied PRL secretion by sampling blood every half hour for 24 h in 10 patients and for 17.5 h in another, and compared the findings to those of a group of 5 normal women. The mean 24-h PRL of the 10 patients (16.8 +/- 7.8 ng/ml; mean +/- SD) was not significantly different from that of the normal women (13.6 +/- 3.2 ng/ml), and each patient showed a normal sleep-associated PRL increment. Three individuals exhibited an abnormally elevated 24-h PRL (greater than 20 ng/ml). Increased PRL secretion occurred primarily at night or in the afternoon. Thyrotropin releasing hormone (TRH) administration caused normal or exaggerated PRL responses in all patients tested. High resolution CT scanning of two of the hypersecretors suggested a microadenoma in one case. In another case whose PRL was normal over 17.5 h, transsphenoidal surgery, carried out because of the tomographic findings and the symptom of headaches, demonstrated a 5-mm chromophobe adenoma that did not contain PRL by immunohistochemistry. Postoperatively the galactorrhea persisted. We conclude that most women with galactorrhea, normal PRL, normal menses, and abnormal tomograms have normal PRL secretion. However, a minority of patients with this syndrome do demonstrate intermittent PRL hypersecretion. The etiology of intermittent PRL hypersecretion and its relevance to galactorrhea have not been determined.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pituitary enlargement with suprasellar extension in functional hyperprolactinemia due to lactotroph hyperplasia: a pseudotumoral disease

Beside the well characterized PRL-secreting adenomas, a wide spectrum of functional hyperprolactinemic states exists. We describe here five women, 21-38 yr old, all suspected of having a PRL-secreting adenoma because of a pseudotumoral appearance of the pituitary on computerized tomographic (CT) scan or magnetic resonance imaging (MRI). Four had oligomenorrhea with or without galactorrhea, one had amenorrhea with galactorrhea, and two complained of infertility. In the same patient, basal plasma PRL levels were variable on different days, sometimes normal (mean +/- SEM, 11.3 +/- 1.5 micrograms/L), sometimes elevated (49 +/- 7 micrograms/L), but in all cases, a PRL response of large amplitude to TRH (6- to 8-fold increase in the basal value) was observed. Basal plasma levels of estradiol were within luteal phase normal values (0.41 +/- 0.13 pmol/L), while progesterone levels were low (1.92 +/- 0.47 nmol/L). CT scan or MRI showed an intrasellar mass with suprasellar extension, suggesting a tumoral process. However, the signal intensity was homogeneous, and on coronal views, the suprasellar extension was pyramidal and symmetrical, and the pituitary stalk was always in the midline. The five patients were operated on by the transsphenoidal route, but no adenoma was found. Surgical biopsies were taken in four cases, and lactotroph hyperplasia, i.e. enlarged cell cords consisting mainly of PRL cells, was found in three of them. One case displayed a continuum between areas of lactotroph hyperplasia and adenomatous PRL cells. We conclude that functional hyperprolactinemia may mimic on CT scan or MRI a PRL-secreting adenoma.     

Long term follow-up of women with surgically treated prolactin-secreting pituitary tumors

To examine the long term effectiveness of transsphenoidal microsurgery for patients with PRL-secreting pituitary tumors, we studied 54 women at yearly intervals after transsphenoidal surgery. Five years after surgery, 19 women (35%) had normal serum PRL concentrations, and 23 (43%) had persistent hyperprolactinemia. Hyperprolactinemia recurred in 12 of 31 patients (39%) who had normal PRL concentration 6 weeks after surgery. None of the patients with recurrent hyperprolactinemia had radiographic evidence of tumor regrowth, and only 3 of 12 had amenorrhea. A serum PRL level below 6 ng/ml 6 weeks after surgery occurred more frequently in cured patients than in those who had a recurrence. PRL responses to TRH were normal in cured patients 1 and 5 yr after surgery and abnormal in those who had recurrent hyperprolactinemia. The PRL responses to chlorpromazine- and insulin-induced hypoglycemia were blunted in patients with normal as well as elevated PRL levels. Patients with recurrent, as well as those with persistent, hyperprolactinemia had no nocturnal rise in serum PRL 5 yr after surgery. The 39% recurrence rate of hyperprolactinemia and persistent abnormalities in pituitary-hypothalamic regulation of PRL secretion after transsphenoidal surgery raise important questions about the choice of primary therapy for patients with PRL-secreting tumors.     

Pituitary autonomy in hyperprolactinemic secondary amenorrhea: results of hypothalamic-pituitary testing.

Twenty-seven women with secondary amenorrhea of greater than six months duration were subjected to multiple testing of hypothalamo-pituitary function. They were divided into normo-prolactinemic (Group 1 mean serum prolactin (PRL) 9.8 ng/ml; range 6.8 to 13.0 ng/ml; n=9) and hyperprolactinemic (Group 2 mean 37.5 ng/ml; range 19.2 to 93.7 ng/ml; n=18) groups on the basis of 4 weekly baseline determinations. Group 2 had significantly (P less than .05) lower serum LH and urinary pregnanediol levels than did Group 1; there was no statistical difference between the groups in serum FSH, T4, T3 or urinary estrogen measurements. Two women in Group 2 were found to have a pituitary chromophobe adenoma. Group 2 women showed no significant rises in serum PRL following stimulation tests with thyrotropin releasing hormone (TRH, 200 microng iv) and metoclopramide (10 mg orally), which caused significant responses in Group 1. The TSH response to TRH was, however, preserved in Group 2, while it was subnormal in Group 1 subjects. Both groups showed similar FSH and LH responses to luteinizing hormone-releasing hormone (LHRH, 25 microng iv). No significant suppression of serum PRL was seen in Group 2 patients given L-Dopa (500 mg orally),, which produced a significant response (P less than 0.05) in Group 1 subjects, while all patient showed marked reduction in serum PRL values following 2-bromo-alpha-ergocryptine (CB-154, 2.5 mg orally). When compared with other Group 2 members, the 2 cases with proven pituitary adenomata gave similar responses to the stimulation-inhibition tests and were not clearly distinguished on this basis. We conclude: 1. The pattern of PRL responses to dynamic tests, although of pathophysiological interest an autonomous pituitary lesions in patients with hyperprolactinemic secondary amenorrhea. 2. Such dynamic tests, although a pathophysiological interest, provide no clinical information additional to that provided by the mean basal serum PRL value. 3. In clinical practice, such dynamic tests should be confined to patients with mean serum PRL levels at around the upper limit of the normal range.     

Nonpuerperal lactation and normal prolactin regulation.

Prolactin secretion was evaluated in 11 consecutive patients referred with nonpuerperal lactation who did not have clinical evidence of pituitary tumors. Six patients had normal fasting prolactin (PRL) levels, 13.8 plus or minus 1.8 ng per ml (Group I), and the other 5 women had elevated basal serum PRL concentrations, 182 plus or minus 72 ng per ml (Group II). All Group II patients had amenorrhea; however, 5 of 6 Group I patients had menstrual periods. The 24-h mean serum PRL concentrations were 12.8 plus or minus 1.2 (SEM), 13.3 plus or minus 0.7, and 165 plus or minus 62 ng per ml for the controls and Group I and II, respectively. A pattern of intermittent PRL discharge during the day characterized each group; however, a normal sleep related increase in serum PRL concentration was absent in the Group II patients. Chlorpromazine produced greater than two-fold increases in serum PRL concentrations in the controls and Group I patients; however, this response was absent in Group II. L-Dopa produced appropriate suppression of serum PRL concentrations in the normals and both patient groups. Normal serum growth hormone, thyroxine, and plasma cortisol characterized each group. Serum estrogen and/or LH and FSH were decreased in 3 of 5 Group II patients; however, the serum concentrations of these hormones were normal in 5 of 6 Group I patients. Short term L-dopa therapy was effective in suppressing lactation in 3 of 5 Group II patients, and it also decreased lactation in the 4 treated Group I patients without significantly altering 24-h mean serum PRL concentrations in the latter group. Conclusion: hypothalamic-pituitary dysfunction was present in certain patients with nonpuerperal lactation who had elevated 24-h mean PRL concentrations and no PRL release following chlorpromazine and sleep. Frequently, however, nonpuerperal lactation is associated with normal prolactin secretion.     

Prolactin secretion in acromegalic patients before and after selective adenomectomy

PRL secretion before and after transsphenoidal adenomectomy was studied in 13 patients with acromegaly. Six patient had elevated basal serum PRL levels before surgery, while 7 patients had normal levels. In every patient, the basal serum GH level decreased to less than 5.0 ng/ml after surgery. In the group (group A) with high basal serum PRL levels (mean +/- SD, 41.3 +/- 5.8 ng/ml) before surgery, the PRL levels decreased significantly (P less than 0.0002) to less than 10.0 ng/ml (4.8 +/- 3.6 ng/ml) after the operation. However, in the group (group B) with normal levels (10.8 +/- 4.4 ng/ml) before surgery, PRL levels changed little (7.8 +/- 3.1 ng/ml) after the operation. In group A, the increment of PRL after TRH injection decreased or disappeared (P less than 0.02; 4.1 +/- 2.4 ng/ml) after surgery compared with that before surgery (39.2 +/- 25.9 ng/ml). On the other hand, in group B, the increment of PRL after TRH injection was nearly unchanged (17.1 +/- 7.0 ng/ml) after surgery compared with that before surgery (19.3 +/- 8.0 ng/ml). The results indicate that PRL is secreted from the pituitary adenoma in acromegalic patients with hyperprolactinemia, while PRL secretion from the normal part of the pituitary gland is decreased.     

Bone density in amenorrheic women with and without hyperprolactinemia

To determine whether decreased bone density in patients with PRL-secreting pituitary tumors is specifically related to hyperprolactinemia or is a consequence of disordered pituitary-gonadal function common to all amenorrheic states, we measured the bone mineral content of the radius by photon absorptiometry in normal subjects, in women with amenorrhea and normal serum PRL levels, and in women with PRL-secreting pituitary tumors. The women did not differ significantly in mean age, height, weight, or serum calcium, phosphorous, gonadotropin, testosterone, vitamin D, or PTH concentrations, and all had normal renal and thyroid function. The bone mineral content in women with amenorrhea and normal serum PRL levels (0.91 +/- 0.02 g/cm) was not significantly different from that in control subjects (0.88 +/- 0.01 g/cm). Patients with PRL-secreting tumors studied 2-5 yr after transsphenoidal surgery had significantly diminished bone mineral content whether they were cured (0.82 +/- 0.02 g/cm) or had persistent amenorrhea and hyperprolactinemia (0.81 +/- 0.02 g/cm). Serum estradiol concentrations did not differ significantly in the four groups, and there was no correlation between estradiol concentration and bone mineral content or between PRL concentration and bone mineral content in the amenorrheic women. The presence of decreased bone mineral content in hyperprolactinemic patients suggests that PRL may have a direct effect on bone and may be another indication for early treatment of PRL-secreting pituitary tumors.     

Subnormal prolactin responsiveness to thyrotropin-releasing hormone (TRH) in women with primary empty sella syndrome

Basal prolactin (PRL) levels and PRL responsiveness to thyrotropin-releasing hormone (TRH) were studied in 10 women with primary empty sella (PES) syndrome (mean age 38.2 yr). Hyperprolactinemia (34 to 72 ng/ml) was found in 5 patients (hyperprolactinemic PES, H-PES), whereas 5 patients showed normal (9.5 to 19 ng/ml) PRL levels (normoprolactinemic PES, N-PES). The results were compared with those obtained in 10 healthy women (mean age 32.8 yr, PRL = 7 to 15 ng/ml) and in 8 women with a PRL-secreting pituitary microadenoma (MA) (mean age 37.5 yr, PRL = 39 to 85 ng/ml). The mean basal levels of PRL were significantly higher in patients with H-PES (50.8 +/- 13.2 ng/ml) or MA (64.0 +/- 18.3 ng/ml) than in the control group (10.9 +/- 2.6 ng/ml, p less than 0.02) and in the patients with N-PES (13.9 +/- 3.7 ng/ml, p less than 0.02). In contrast, the relative maximum response (RMR) of PRL to TRH (peak PRL/basal PRL) was significantly lower in the patients with PES (both H-PES and N-PES) or MA (1.4 +/- 0.4, 2.3 +/- 0.7 and 1.2 +/- 0.2, respectively) than in the control subjects (3.6 +/- 1.1; p less than 0.02, less than 0.05 and less than 0.02, respectively). Our results show that the pituitary responsiveness to the acute stimulation with TRH is significantly decreased both in patients with a PRL-secreting pituitary MA and in those with PES. Therefore, the clinical value of the TRH test in distinguishing the PES syndromes from prolactinomas seems to be questionable.     

Clinical profile and long term follow up of children and adolescents with prolactinomas

We report clinical presentation, response to medical treatment, and long-term follow-up of 39 children and adolescents with prolactinoma (F:M; 30:9) (30 macro and 9 microadenoma) diagnosed at the age of 9–20 years. Mean duration of follow up was 56 months. All patients were treated with bromocriptine (BC) at doses ranging from 2.5 to 20 mg/day or by cabergoline at doses ranging from 0.5 to 2 mg/week orally. Two patients received external conventional radiotherapy after surgery. In patients with macroprolactinoma (F:M; 21:9), headache and/or visual defects were the first symptoms. All females had primary or secondary amenorrhea. Growth arrest was not observed in any patient and pubertal development was appropriate for their age. Spontaneous or provocative galactorrhea was observed in 23 patients (all females) and none of male patient had gynecomastia. Mean serum prolactin (PRL) concentration at the time of diagnosis was 322.50 ng/ml in patients with microadenoma, 522.38 ng/ml in patients with macroadenoma and 2,294.86 ng/ml in patients with macroadenoma with suprasellar extension. In 25 patients, BC normalized PRL levels and caused variable, but significant, tumor shrinkage. Cabergoline normalized PRL concentrations in 14 patients. Pregnancy occurred in 6 patients while on treatment. Pregnancies were uncomplicated, and the patients delivered normal newborns at term. Impairment of other pituitary hormone secretion was documented at the time of diagnosis in only one patient. Postoperatively six patients had other pituitary hormone deficiencies. In conclusion, the medical treatment with dopaminergic compounds is effective and safe in patients with prolactinoma with onset in childhood, allowing preservation of the anterior pituitary function.     

Acquired prolactin deficiency in patients with disorders of the hypothalamic-pituitary axis

Acquired PRL deficiency occurs when the anterior pituitary is functionally destroyed, and it usually accompanies other pituitary hormone deficiencies. We retrospectively investigated in an outpatient endocrine clinic of a major tertiary medical center the prevalence and clinical characteristics of acquired PRL deficiency in patients with diseases of the hypothalamic-pituitary axis. The study included 100 consecutive patients, 61 men and 39 women, aged 4-79 yr at diagnosis. Patients were divided by PRL level to normal (>5 ng/ml), mild (3-5 ng/ml), and severe deficiency (<3 ng/ml). Twenty-seven patients (27%) had PRL deficiency, 13 mild deficiency and 14 severe deficiency. Patients with severe PRL deficiency tend to be younger at diagnosis (mean age, 37.5+/-21.8 yr) than patients with normal PRL (46+/-18.5 yr; ns). Underlying diseases including pituitary apoplexy, non-functioning pituitary adenoma, craniopharyngioma, and idiopathic hypogonadotropic hypogonadism were associated with PRL deficiency. The incidence of severe PRL deficiency rose with an increase in the number of other pituitary hormone deficits (ACTH, TSH, gonadotropin, vasopressin), from 0 in patients with no other deficits to 38% in patients with 4 deficits (p=0.006). Patients with severe deficiency had a mean of 3 hormone deficits compared to 1.8 in the other groups (p=0.006). PRL deficiency was significantly associated with TSH, ACTH and GH deficiency. CONCLUSIONS: PRL deficiency is common in patients with hypothalamic-pituitary disorders, especially pituitary apoplexy and craniopharyngioma. Acquired severe PRL deficiency can be considered a marker for extensive pituitary damage and a more severe degree of hypopituitarism.     

Primary empty sella, galactorrhea, hyperprolactinemia and renal tubular acidosis.

Discussed here is a 41 year old woman with galactorrhea associated with the empty sella syndrome and mild renal tubular acidosis. Basal serum prolactin (PRL) levels were normal, but a 24 hour serum PRL secretory profile demonstrated an increased mean PRL concentration. Serum PRL was appropriately suppressed by the administration of L-dopa; however, chlorpromazine stimulation resulted in a blunted serum PRL response. Pituitary luteinizing hormone, follicle stimulating hormone, ACTH and thyroid stimulating hormone levels were normal. Thus, galactorrhea associated with an enlarged sella does not establish the diagnosis of a pituitary tumor, and pneumoencephalography must be performed to exclude the empty sella syndrome.     

Return of gonadal function in men with prolactin-secreting pituitary tumors

Gonadal function was evaluated in 10 men [33 +/- 17 (SD) yr] with pituitary tumors and hyperprolactinemia (47-2550 ng/ml) using nocturnal penile tumescence (NPT), semen analysis, urinary LH and FSH excretion, and diurnal variation of serum testosterone and PRL. Results were compared to 16 normal subjects (33 +/- 13 yr). NPT was decreased in tumor patients as demonstrated by reduced maximum circumference change (P less than 0.01) and total tumescence time (P less than 0.05). Semen analysis was examined in 5 patients able to produce specimens. All seminal parameters were significantly abnormal as demonstrated by oligospermia, asthenospermia, teratospermia , and elevated fructose. Urinary LH [570 +/- 72 (SE) vs. 838 +/- 22 mIU/h; P less than 0.01] and serum testosterone (235 +/- 60 vs. 625 +/- 63 ng/dl; P less than 0.01) were decreased in 9 tumor patients, all of whom had serum PRL levels above 50 ng/ml. Diurnal variation of serum PRL was absent in hyperprolactinemic patients whereas all had normal circadian changes in serum testosterone, although at a lower set point. Eight patients were followed for 6-13 months after reduction of serum PRL by surgery and/or drug therapy. Serum PRL reached normal levels in six men after 6 months of treatment. Selected individuals had an increase in serum LH after 2 months of treatment. Significant rises in serum testosterone occurred as early as 3 months and normal levels were found in six patients after 6-8 months of treatment. Only two subjects, however, demonstrated a normal semen analysis. These data suggest that men with serum PRL levels above 50 ng/ml maintain a normal diurnal pattern of serum testosterone at a lower set point, and demonstrate hypogonadism with reduced urinary LH excretion and NPT. In addition, routine seminal parameters are clearly abnormal and are both delayed and incomplete in their recovery.     

The natural history of untreated hyperprolactinemia: a prospective analysis

This report describes the results of a long term prospective study of 30 women with hyperprolactinemia who were not treated and who underwent yearly clinical, hormonal, and radiographic evaluation for an average of 5.2 yr (range 3-7 yr). At entry into the study 18 women had amenorrhea, 8 had oligomenorrhea, and 4 had regular menstrual periods. The initial mean serum PRL levels did not differ in women grouped according to menstrual function. Nine women (35%) had improvement in clinical symptoms. Serum PRL decreased, and menstrual periods normalized more often in those who initially had oligomenorrhea or regular menstrual periods. In most amenorrheic women serum PRL levels did not decline, and menstrual symptoms did not improve. Six of 30 women had an increase in serum PRL, 14 had no change, and 10 had a decrease, in 6 of whom serum PRL was normal at the last observation. Twenty-seven women had serial radiographic studies. Four (15%) of the 13 women with initially abnormal radiographic findings had normal studies later, 2 had tumor progression, and 7 no change. Four of 14 women who had normal radiographic studies initially developed radiographic evidence of a pituitary tumor, although the radiographic changes were minimal, and no patient developed a macroadenoma or pituitary hypofunction. Increases or decreases in serum PRL did not accurately predict changes in tumor size. Prior estrogen use and previous pregnancies did not increase the likelihood of tumor appearance or enhance tumor growth. The clinical presentation of the patient was an important factor in predicting which patients had a decline in serum PRL and resolution of symptoms. We conclude that patients with hyperprolactinemia are unlikely to have progression of their disease and may, in fact, have clinical and radiographic improvement.     

Twin pregnancy following bromocriptine in an acromegalic patient staying sterile after removal of a pituitary adenoma. Immunocytochemical study of the tumor (author's transl)]

A pituitary adenoma was removed from a young woman who had acromegaly with galactorrhea-amenorrhea. Postoperatively, the dysmorphic acromegalic syndrome and galactorrhea decreased but amenorrhea, elevated serum GH and PRL concentrations remained. After Bromocriptine administration (5 mg daily) GH and PRL levels became normal, vaginal bleeding ensued within 3 months and a twin pregnancy was induced. An immunocytochemical study of the pituitary adenoma revealed the presence of two well defined, distinct cell types, each secreting one hormone with large preponderance of GH cells.     

Normal pregnancies after treatment of hyperprolactinemia with bromoergocryptine, despite suspected pituitary tumors.

Bromocryptine treatment was administered to 15 patients with amenorrhea and galactorrhea (AG) and to 1 patient with amenorrhea. All of them had increased plasma PRL levels. Of these 16 patients, 4 had a normal sella turcica (ST; group STO), 4 had a slight enlargement (group ST+), and 7 had a clear enlargement of ST (ST++) but no evidence of suprasellar extension. Ovulation was restored in 15 patients by bromocryptine treatment only. In one patient, ovulation resumed only after human pituitary gonadotropin treatment in combination with bromocryptine. There was no correlation between basal prolactinemia, PRL stimulability or suppressibility, the size of ST, or the efficiency of bromocryptine treatment. Every patient with normal LH response to either LRH or clomiphene or both resumed ovulation. Ovulation resumed in 3 patients among the 4 with abnormal LH response to either LRH or clomiphene or both. Among the 14 who desired pregnancy, 13 became pregnant. To date, 12 patients (ST++, 5; ST+, 3; STO, 4) have delivered normal babies. The courses of pregnancy were normal. During pregnancy, no change of ST was noted on lateral and frontal skull x-ray performed in every patient at trimonthly intervals. There was no change in the sellar index in 10 patients after pregnancy, as compared to the pretreatment status. In the presence of a pituitary adenoma or in patients with hyperprolactinemia and amenorrhea and galactorrhea, bromocryptine treatment may cure sterility without pituitary complication during pregnancy.     

Serum prolactin response to thyrotropin-releasing hormone and metoclopramide in patients with prolactin-secreting tumors before and after transsphenoidal surgery.

Seven female patients with amenorrhea, galactorrhea, and hyperprolactinemia were examined before and after selective transsphenoidal removal of a PRL-secreting microadenoma. Before adenomectomy, metoclopramide (MCP; 10 mg orally) and TRH (200 micrograms iv) did not increase PRL blood levels in any of the seven patients. On the contrary, after oral administration of 10 mg MCP, a positive response was noted in a group of eight lactating women 3 days postpartum. After surgery, serum PRL level returned to normal in all patients. A positive PRL response to MCP and TRH was found in six of the seven patients 1 month after surgery. One patient, who had the lowest PRL level, failed to show a PRL increase after both stimuli. These findings indicate that hypothalamic pituitary function can be restored to normal after transsphenoidal removal of PRL-secreting pituitary tumors.     

Study on galactorrhea-amenorrhea syndrome (GAS) with special reference to normoprolactinemic GAS

In order to clarify the mechanism(s) which causes galactorrhea and amenorrhea in patients with Galactorrhea-Amenorrhea Syndrome (GAS) (Group A, n = 20), composed of Chiari-Frommel Syndrome (CFS) (Subgroup I, n = 3), Argonz-del Castillo Syndrome (ADCS) (Subgroup II, n = 5) and Drug-induced Galactorrhea-Amenorrhea (DIG) (Subgroup III, n = 12), we analysed basal plasma prolactin (PRL) and gonadotropin levels and their responsiveness to TRH and LH-RH, respectively in GAS patients. In addition, another group of galactorrhea patients without amenorrhea (Group B, n = 29) was selected, and further divided into three subgroups; subgroup I (n = 7) with persisting postpartum lactation, subgroup II (n = 7) of idiopathic galactorrhea, and subgroup III (n = 15) induced by drug administration. There were found unexpectedly high frequencies of normoprolactinemic patients (less than 23.7 ng/ml) in 40% of GAS (66.7% in CFS, 40% in ADCS, and 33.3% in DIG). The PRL responsiveness to TRH, evaluated by % delta PRL (peak PRL - basal PRL/basal PRL X 100), tended to be high in ADCS and DIG (group after discontinuation of drugs) compared with those of normal subjects (n = 12) and patients with primary hypothyroidism (n = 21). PRL response was almost normal in CFS or DIG (group during drug administration). Basal level of plasma gonadotropin in GAS was comparable to that of normal subjects. However, responsiveness of gonadotropin to LH-RH in GAS tended to be high compared with that of normal subjects. The patients in group B (subgroup I-III) demonstrated almost parallel responses of PRL and gonadotropin, respectively, to those of corresponded subgroups in group A. From the present results, we concluded that; 1) It seems likely that frequency of normoprolactinemic patients in GAS (Group A) is surprisingly high. 2) A still unclarified mechanism(s) for the occurrence of galactorrhea, not explained solely by plasma radioimmunoassayable PRL level and/or hyperresponsiveness of PRL to stimuli, may operate on a considerably large number of group A patients. 3) Decreased gonadotropin secretion at pituitary level seems not to be a main cause of menstrual abnormality in group A patients. 4) The same mechanism(s) as in group A patients may cause galactorrhea in group B patients.     

The effects of pyridoxine on pituitary hormone secretion in amenorrhea-galactorrhea syndromes

Six patients with amenorrhea, five of whom had galactorrhea and elevated PRL levels, were evaluated on a metabolic ward. All had normal sella tomograms, normal thyroid functions, and routine laboratory evaluations. None of the patients had taken any medication in the previous 6 months. On alternate days, five patients received 500 microgram of TRH iv with the measurement of PRL, TSH, FSh, LH, and hGH; 500 mg L-dopa orally with the measurement of PRL, FSH, and LH; a bolus infusion of 300 mg pyridoxine (B6) with measurement of PRL, hGH, TSH, FSH, and LH; and 25 mg chlorpromazine (CPZ) im with the measurement of PRL, LH, and FSH. The patients were then discharged on 600 mg oral pyridoxine/day and were readmitted for a repeat of the complete protocol 21 days later. The patients were continued on 600 mg oral pyridoxine for 3-4 months with monthly evaluations of serum PRL, LH, and FSH levels. These evaluations continued for 3 months after discontinuing pyridoxine. There was no demonstrable change in serum PRL after acute or chronic B6 therapy, mor was there a significant change in the response of PRL to CPZ, L-dopa, or TRH. The mean basal PRL was 97.5 +/- 9.7 ng/ml and after 3-4 months of oral pyridoxine was 97.1 +/- 14.8. In addition, there was no significant change in LH or FSH levels in response to acute or chronic B6, TRH, L-dopa, or CPZ. Neither acute B6 infusion nor chronic B6 therapy had any effect on TSH or the TSH response to TRH. Finally, acute B6 infusion had no effect on hGH levels and there were no paradoxical hGH responses to TRH. Two patients began having regular menses while on chronic pyridoxine. Their hormonal responses did not differ from those of the group, however.     

Hypoglycemia as a provocative test of prolactin release

Insulin-induced hypoglycemia has been traditionally used to test growth hormone (GH) and cortisol reserve. In order to determine its usefulness as a provocative test for prolactin (PRL) release, 31 healthy men and women, 38 patients with definite pituitary abnormalities (pituitary tumors, 17; hypopituitarism [other causes]—complete, 4, or partial, 17), and 17 patients with suspected pituitary dysfunction (delayed puberty, 5; short stature, 4; secondary amenorrhea, 6; empty sella, 2, received regular i.v. insulin (0.05–0.15 U/kg), and the plasma was assayed serially for PRL, GH, cortisol, and glucose. In the 31 healthy subjects, PRL increased from 16.3 ± 1.8 ng/ml (mean ± SEM) to 45.5 ± 7.9 (p < 0.001) at 60 min and was still elevated at 120 min (25.8 ± 3.1 ng/ml). The maximal rise to 52.2 ± 8.0 ng/ml occurred between 40 and 90 min. There was no significant sex difference in the maximal PRL increase, maximal increment, or concentration at any time. In 21 of the 31 subjects, PRL increased at least 10 ng/ml with a doubling of baseline levels—criteria for a positive response. In addition, 12 of the healthy subjects received thyrotropin-releasing hormone (TRH) (500 μg i.v.) while 5 received chlorpromazine (50 mg i.m.). There was no significant difference among the maximal prolactin increments following insulin (36.7 ± 7.9 ng/ml), TRH (46.4 ± 6.3 ng/ml), or chlorpromazine (63.4 ± 21.9 ng/ml). In patients with definite pituitary abnormalities, 28 of 38 had diminished PRL release after insulin. Of these 28, 23 also had inadequate GH and 13 impaired cortisol release. In the 10 partially hypopituitary subjects with normal PRL responses, GH increased normally in 7 and cortisol in all. Thirteen of the 17 patients with suspected pituitary dysfunction had adequate PRL increases, while the GH and cortisol responses were intact in 16 and 17 subjects, respectively. Overall, the PRL response was concordant with changes in GH in 44 of 55 patients and in cortisol in 32 of 55 patients. It is concluded that insulin-induced hypoglycemia (1) releases PRL in most normal subjects and (2) is useful in determining the integrity of the hypothalamic pituitary axis for PRL release in patients with suspected abnormalities of pituitary function. Moreover, in combination with TRH, it may aid in localizing the site of abnormality in patients with these disorders.