Potentiation of sulpiride-induced prolactin secretion by sodium deprivation in man

1980 ◽  
Vol 94 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Masatomo Mori ◽  
Isao Kobayashi ◽  
Kihachi Ohshima ◽  
Sakae Maruta ◽  
Yohnosuke Shimomura ◽  
...  
Keyword(s):  
Control Diet ◽  
Normal Subjects ◽  
Sodium Content ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Aldosterone Secretion ◽  
Low Sodium Diet ◽  
Specific Radioimmunoassay ◽  
Prolactin Response ◽  
Pituitary Prolactin

Abstract. Previous studies suggest that prolactin is not an important osmoregulatory hormone in man, while aldosterone is well known to be important in osmoregulation. The present investigation was undertaken to ascertain whether serum osmotic changes affect pituitary prolactin secretion following sulpiride administration. Five normal subjects were placed on a constant isocaloric diet with different sodium content. Serum prolactin and aldosterone level were measured by specific radioimmunoassay. The basal serum level of prolactin was unaffected by changes in sodium content of the diet, in contrast to the basal level of aldosterone. On the other hand, the maximum levels of serum prolactin in response to sulpiride (50 mg, im) were significantly higher on a low sodium diet (3 g of salt/day) than on a control diet (12– 15 g of salt/day). When the content of diet changed from low salt to high salt (25 g of salt/day), sulpiride-induced prolactin response decreased, though it was not significantly lower than that on a control diet. However, sulpiride administration could not stimulate aldosterone secretion under any of the various sodium contents of the diet. The present study provides evidence that lowering of serum osmolarity stimulates serum prolactin response to sulpiride administration in man and this response is not modulated by aldosterone secretion.

ONSET OF OESTROGEN-INDUCED PROLACTIN SECRETION AND DNA SYNTHESIS BY THE RAT PITUITARY GLAND

1977 ◽  
Vol 72 (1) ◽  
pp. 35-39 ◽  
Author(s):  
JOAN JACOBI ◽  
H. M. LLOYD ◽  
J. D. MEARES
Keyword(s):  
Dna Synthesis ◽  
Pituitary Gland ◽  
Prolactin Secretion ◽  
Male Rat ◽  
Serum Prolactin ◽  
Rat Pituitary ◽  
The Times ◽  
Pituitary Prolactin

SUMMARY The times of onset of oestrogen-induced prolactin secretion and DNA synthesis were studied in the pituitary gland of the male rat. At intervals from 3 to 96 h after injection of 10 mg diethylstilboestrol dipropionate, serum and pituitary prolactin concentrations were measured by radioimmunoassay and pituitary DNA synthesis by incorporation of [3H]thymidine in vitro. Serum prolactin was raised significantly from 6 h onwards and DNA synthesis was increased from 30 h onwards. Pituitary prolactin concentration began to increase at 30 h. Significant correlations were obtained between serum prolactin and DNA synthesis from 24 to 72 h but not during the period of prolactin secretion from 6 to 24 h.

THE STIMULATION OF PROLACTIN SECRETION BY SULPIRIDE IN "ADOLESCENT GYNAECOMASTIA"

1977 ◽  
Vol 85 (4) ◽  
pp. 692-697
Author(s):  
R. D'Agata ◽  
S. Andó ◽  
S. Gulizia ◽  
L. Condorelli ◽  
C. Paci ◽  
...  
Keyword(s):  
Baseline Level ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Maximum Increase ◽  
The Mean ◽  
Pituitary Prolactin ◽  
Stimulation Of

ABSTRACT In order to evaluate the function of the hypothalamic-pituitary-prolactin axis in "adolescent gynaecomastia" (AG), sulpiride was administered to 7 normal boys and 7 boys with AG. The maximum increase in serum prolactin (PRL) above the mean baseline level (Δmax) was used as index of response. The sulpiride induced a greater PRL release in boys with gynaecomastia than in the controls. Our data indicate that boys with gynaecomastia may have a greater pituitary prolactin pool. The results also illustrate the usefulness of specific neurotrophic agents such as sulpiride as important tools for evaluating the function of the hypothalamic-pituitary-PRL axis.

DNA SYNTHESIS AND DEPLETION OF PROLACTIN IN THE PITUITARY GLAND OF THE MALE RAT

1978 ◽  
Vol 77 (1) ◽  
pp. 129-136 ◽  
Author(s):  
H. M. LLOYD ◽  
J. M. JACOBI ◽  
J. D. MEARES
Keyword(s):  
Growth Hormone ◽  
Dna Synthesis ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Male Rat ◽  
Serum Prolactin ◽  
Inhibitory Effects ◽  
Pituitary Prolactin

Haloperidol, bromocriptine and diethylstilboestrol dipropionate were given in various régimes to male rats to determine their effects on pituitary DNA synthesis, prolactin secretion and growth hormone secretion. Haloperidol increased serum prolactin but did not stimulate pituitary DNA synthesis or reduce pituitary prolactin concentrations. Haloperidol potentiated the effects of oestrogen on serum prolactin and on pituitary DNA synthesis; pituitary prolactin concentrations were greatly reduced, and growth hormone secretion was slightly inhibited. The inhibitory effects of bromocriptine in oestrogen-stimulated rats were demonstrated by smaller pituitary weights and decreased DNA synthesis; serum prolactin levels were lowered and pituitary prolactin concentrations were increased. Haloperidol, given to rats treated with oestrogen and bromocriptine, reversed the inhibitory effects of bromocriptine on DNA synthesis and serum prolactin; pituitary prolactin concentrations fell to well below normal. The results suggest that the haloperidol potentiation of oestrogeninduced pituitary DNA synthesis may depend upon stimulation of prolactin secretion together with reduction of intracellular prolactin levels.

Lack of effect of chronic hypocalcaemia on serum prolactin response to chlorpromazine

1983 ◽  
Vol 103 (3) ◽  
pp. 321-325 ◽  
Author(s):  
Aydan Usman
Keyword(s):  
Normal Subjects ◽  
Serum Prolactin ◽  
Control Group ◽  
Normal Range ◽  
Serum Parathyroid Hormone ◽  
Stimulation Tests ◽  
The Mean ◽  
Prolactin Response ◽  
Low Serum ◽  
Made In

Abstract. The effects of chronic hypocalcaemia on serum basal and chlorpromazine-stimulated prolactin (Prl) levels were studied in 16 patients with idiopathic or secondary hypoparathyroidism. These results were compared with the results of other chlorpromazine stimulation tests which were made in the normocalcaemic state after treatment with vitamin D, and in normal subjects. In hypocalcaemic and normocalcaemic states (mean serum Ca 5.8 ± 0.24 mg/dl and 9.5 ± 0.11 mg/dl, respectively) basal Prl levels were within the normal range and during stimulation the maximal stimilated levels in each state were not significantly different from each other. Also, the mean serum Prl levels obtained from a control group were not different from values in the normocalcaemic state. It is concluded that chronic hypocalcaemia does not inhibit Prl secretion and low serum parathyroid hormone levels do not affect basal and chlorpromazine-stimulated Prl secretion.

Metoclopramide Effect on Faltering Milk Production by Mothers of Premature Infants

PEDIATRICS ◽  
1986 ◽  
Vol 78 (4) ◽  
pp. 614-620
Author(s):  
Richard A. Ehrenkranz ◽  
Barbara A. Ackerman
Keyword(s):  
Milk Production ◽  
Breast Feeding ◽  
Premature Infants ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Breast Feed ◽  
Increase Milk Production ◽  
Daily Milk Production ◽  
Prolactin Response ◽  
Daily Milk

Metoclopramide treatment has been shown to augment milk production by stimulating prolactin secretion in women in whom lactational insufficiency develops after a full-term pregnancy. The effect of metoclopramide therapy in 23 women who were delivered of premature infants (birth weight 1,314 ± 115 g, gestational age 30.4 ± 0.7 weeks) and who were having difficulty maintaining milk production with milk expression was evaluated. Each woman had noted a gradual decrease in the total daily volume of expressed milk during the first several weeks of lactation. Maternal metoclopramide therapy was started at a mean of 32.0 ± 3.7 days postpartum, after a review of diet and milk expression technique and an increase in the number of expressions per day failed to increase milk production. Daily milk production increased significantly from 93.3 ± 18.0 mL/d to 197.4 ± 32.3 mL/d between the first and seventh day of therapy. This increase was associated with significantly increased basal serum prolactin levels, from 18.1 ± 3.3 ng/mL to 121.8 ± 21.5 ng/mL. Although milk expression resulted in a variable increase in serum prolactin levels prior to metoclopramide treatment, milk expression did not produce any additional prolactin response in the treated women, with mean basal levels of 157.8 ± 15.4 ng/mL v mean peak levels of 144.5 ± 12.2 ng/mL. No major side effects were reported by the women, and no untoward effects were noted in the infants fed milk expressed while their mothers were being treated with metoclopramide. After treatment with metoclopramide, 15 of the 23 women were able to successfully maintain lactation, were breast-feeding at the time their infants were discharged from the hospital, and continued to breast-feed afterward. These data suggest that the increased daily milk production seen with metoclopramide treatment is related to a significant increase in the basal prolactin level, and they demonstrate that metoclopramide treatment can permit a successful breast-feeding experience in women who deliver prematurely and have difficulty maintaining lactation.

EFFECT OF AGE AND SEX ON CIRCULATING AND PITUITARY PROLACTIN LEVELS IN HUMAN

1976 ◽  
Vol 83 (4) ◽  
pp. 711-719 ◽  
Author(s):  
T. Yamaji ◽  
K. Shimamoto ◽  
M. Ishibashi ◽  
K. Kosaka ◽  
H. Orimo
Keyword(s):  
Human Subjects ◽  
Quantitative Difference ◽  
Age Groups ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Elderly Subjects ◽  
Pituitary Glands ◽  
Prolactin Response ◽  
Effect Of Age ◽  
Female Subjects

ABSTRACT In an attempt to determine whether age or sex affects prolactin secretion in the human, basal levels of serum prolactin, and its response to TRH administration as well as the pituitary content of this hormone were compared between both sexes and among the different age groups. In 315 adult subjects of various ages, the mean basal levels of prolactin were found to be higher in women than in men of the same age groups with the exception of the sixth decade. The effect of age on serum prolactin concentrations, on the other hand, was not demonstrated. Similarly, the prolactin response to intravenous injections of 500 μg of TRH was significantly greater in female subjects than in males of both young and aged groups. No relationship between the prolactin response and the day of menstrual cycle in young women was apparent. Although quantitative difference in TRH-induced prolactin release was not observed between young and elderly subjects, the occurrence of prolactin peak and the elimination of the circulating prolactin following TRH administration were delayed in the aged groups. Taken together with the demonstration of a higher content of this hormone in female pituitary glands compared with those of males, it was concluded that prolactin secretion is enhanced in female subjects throughout life after puberty and that aging, per se, is not associated with an alteration in the rate of secretion of this hormone in human subjects.

scholarly journals Loss of Hypothalamic Dopaminergic Control of Prolactin Secretion in the Hyperprolactinaemic Rat

1982 ◽  
Vol 35 (2) ◽  
pp. 207 ◽  
Author(s):  
GA Smythe ◽  
JE Bradshaw ◽  
M Duncan
Keyword(s):  
Inhibitory Control ◽  
Chronic Administration ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Clinical Tool ◽  
Prolactin Release ◽  
Highly Active ◽  
Prolactin Response ◽  
Normal Controls ◽  
Different Doses

The possibility that chronic hyperprolactinaemia results in loss of the ability of hypothalamic dopamine activity to inhibit prolactin secretion was studied in rats. Two degrees of hyperprolactinaemia (moderate and gross) were induced in the animals following the chronic administration of two different doses of oestradiol valerate. In rats with high chronic serum prolactin concentrations (approximately 20 times normal) there was a profound increase in prolactin secretion following inhibition of brain dopamine (DA) synthesis by 3-iodo-L-tyrosine, indicating intact and highly active hypothalamic DA-inhibitory control of prolactin release. However, the degree of hypothalamic inhibition of prolactin release relative to normal controls was significantly reduced. In animals with grossly elevated chronic serum prolactin concentrations (approximately 100 times normal) a prolactin response to DA synthesis inhibition was absent despite a highly significant reduction in hypothalamic DA concentrations induced by 3-iodo-L-tyrosine. These observations show that chronic and gross hyperprolactinaemia in the rat results in loss of hypothalamic DA inhibitory control of prolactin secretion. The use of 3-iodo-L-tyrosine to block brain DA synthesis in these studies has provided significant new data relating to prolactin control in hyperprolactinaemic states and indicates that this compound could be a useful clinical tool in the study of human hyperprolactinaemia.

INHIBITION OF PITUITARY PROLACTIN SECRETION BY HUMAN PLACENTAL LACTOGEN IN RATS

1976 ◽  
Vol 71 (1) ◽  
pp. 115-120 ◽  
Author(s):  
HIROSHI NAGASAWA ◽  
REIKO YANAI ◽  
KOREHITO YAMANOUCHI
Keyword(s):  
Prolactin Secretion ◽  
Female Rats ◽  
Placental Lactogen ◽  
Ovariectomized Rats ◽  
Serum Prolactin ◽  
Corpora Lutea ◽  
Human Placental Lactogen ◽  
Vaginal Smears ◽  
Pituitary Prolactin

SUMMARY Intact female rats given twice daily injections of 1 mg human placental lactogen (HPL) showed continued dioestrous vaginal smears and their ovarian corpora lutea were found to be hypertrophied and functional. The serum prolactin level was significantly lower in these rats than in the controls at dioestrus as well as at pro-oestrus. Twice-daily injections of 0·5 or 2 mg HPL to ovariectomized rats decreased serum and pituitary levels of prolactin and increased hypothalamic activity of prolactin inhibiting hormone, although the effect was less at the lower dose. Human placental lactogen had no direct effect on pituitary prolactin secretion in vitro. These findings have demonstrated that HPL, like prolactin itself, inhibits prolactin secretion by acting indirectly on the pituitary through the hypothalamus.

Prolactin secretion in man following acute and long-term cimetidine administration

1980 ◽  
Vol 93 (4) ◽  
pp. 392-395 ◽  
Author(s):  
A. Masala ◽  
S. Alagna ◽  
R. Faedda ◽  
A. Satta ◽  
P. P. Rovasio
Keyword(s):  
Duodenal Ulcer ◽  
Healthy Volunteers ◽  
Normal Subjects ◽  
Term Treatment ◽  
Prolactin Secretion ◽  
Serum Prolactin ◽  
Prolactin Release ◽  
Long Term Treatment ◽  
Pre Treatment

Abstract. In 20 patients with duodenal ulcer we measured serum prolactin levels following acute and long-term cimetidine administration. In addition, in 20 healthy volunteers we studied the effect of pre-treatment with bromocriptine, metergoline, nomifensine and cyproheptadine on cimetidine-induced prolactin release. Intravenous cimetidine stimulated prolactin secretion in patients and in normal subjects. In the latter, bromocriptine and metergoline pre-administration blunted the release of prolactin in response to iv cimetidine whereas nomifensine and cyproheptadine were ineffective. Long-term treatment with cimetidine (1.2 g daily for 3 months) had no effect on prolactin secretion in the 20 patients studied. No incidence of gynaecomastia, galactorrhoea or disorders of the menstual cycle was observed.

Sign in / Sign up

Export Citation Format

Share Document