EFFECT OF PROLACTIN INHIBITORY AGENTS ON THE ECTOPIC ANTERIOR PITUITARY AND THE MAMMARY GLAND IN RATS

1977 ◽  
Vol 85 (2) ◽  
pp. 267-278 ◽  
Author(s):  
K.-J. Gräf ◽  
R. Horowski ◽  
M. F. El Etreby

ABSTRACT The purpose of the present study was to investigate the biological effectiveness of two highly potent prolactin (PRL) inhibitors, lisuride hydrogen maleate (LMH) and 2-Br-α-ergocryptine (CB-154), in the absence of hypothalamic factors acting directly at the level of the anterior pituitary. Hypophysectomized female rats bearing 4 transplanted pituitaries beneath the kidney capsules were treated with oestradiol benzoate (OeB) and progesterone (P) with or without simultaneous administration of LHM or CB-154 for 22 days in order stimulate or inhibit lobulo-alveolar growth of the mammary glands. In addition to the investigation of the mammary glands by DNA determination and assessment of the histological pictures, the aim of this study was directed towards the influence of the substances tested at the level of the anterior pituitary remote from the hypothalmus. In this connection the changes in the different cells within the ectopic pituitaries as revealed by immunoenzyme-cytochemical studies were investigated. The results obtained support the classical view of a neuroendocrine regulation of mammary gland growth and the importance of oestrogens, P and PRL within this system. Both ergot derivatives LHM and CB-154 were able to antagonize the stimulatory effect of OeB combined with P on the mammary gland. With regard to the mechanism of action of LHM and CB-154 it is concluded that both substances act via a direct action on dopaminergic receptors within the ectopic anterior pituitary.

1978 ◽  
Vol 77 (3) ◽  
pp. 319-323 ◽  
Author(s):  
HIROSHI NAGASAWA ◽  
REIKO YANAI

The mammary gland synthesizes little DNA during lactation in mice. The effects of daily injections of oestradiol benzoate (OB) between days 9 and 11 of lactation, and/or grafting with three isologous anterior pituitary glands on day 1, on the growth of the litter and the development and function of mammary glands were studied on day 12 of lactation in C3H/He mice. The level of prolactin in the plasma of mice with pituitary grafts was raised, but mammary gland function was not affected. The synthesis and content of mammary gland RNA was depressed after injection of 0·5 μg OB/day; at a dose of 10 μg/day, OB also depressed litter growth and mammary DNA content, but increased the synthesis of DNA and the level of prolactin in the plasma. Pituitary grafting enhanced the effect of 10 μg OB/day on DNA synthesis. These findings suggest that one of the causes of the low level of DNA synthesis in the mammary gland during lactation in mice is a low level of oestrogen in the circulation.


Author(s):  
I.C. Murray

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.


2019 ◽  
Vol 11 (1) ◽  
pp. 101-105
Author(s):  
NAJDA RIFQIYATI ◽  
ANA WAHYUNI

Abstract. Rifqiyati N, Wahyuni A. 2019. Fennel (Foeniculum vulgare) leaf  infusion effect on mammary gland activity and kidney function of lactating rats. Nusantara Bioscience 11: 101-105. Fennel (Foeniculum vulgare Mill) leaf, traditionally, is believed to have a potential in increasing and smoothing breast milk production. This study aimed to determine the effect of fennel leaf infusion on milk production and to know the side effects of its use. The material used in the research was infusion of fennel leaves (Foeniculum vulgare Mill) collected from Kopeng, Central Java. The research utilized 12 female rats each with 5 newborns off springs. The experiment was designed in Completed Random Design (CRD) with 4 treatments and 3 replications. Histological preparation of mammary glands was set using paraffin method with HE staining. Kidney function was observed through uric acid level in the blood. The results showed that the diameter of lactiferous ducts and of its lumen diameter were significantly influenced by 15 days fennel leaf infusion treatment. The largest lactiferous duct diameter observed was on P3 treatment group (452.97 ± 75.033 µm) and the smallest was observed in control groups (273.17 ± 38.746 µm). The numbers of active alveoli observed in treatment groups, i.e., in P1 (20 g/300  mL), P2 (40 g/300  mL), and P3 (60 g/300  mL), increased than inactive alveoli. The blood uric acid level observed was 4.0-4.6 mg/dl. The results suggested that the infusion of fennel leaf with a treatment dose of 60 g infusion in 300  mL distilled water administered for 15 days can significantly increase the diameter of lactiferous lumen of female rat mammary glands, and increase the diameter of the alveoli and the number of active alveolar mammary glands. Histological picture of mammary gland also showed that the female rats treated with dose of 60g infusion per 300  mL aquadest increased milk secretion and than the other treatment groups. The treatment also showed no significant side effects.  


1977 ◽  
Vol 74 (2) ◽  
pp. 315-NP ◽  
Author(s):  
A. DANGUY ◽  
J. L. PASTEELS ◽  
F. ECTORS

A single injection of 1 mg of a complex of testosterone esters on day 5 of life was used to prepare constantly oestrous rats. Such androgenized female rats were then ovariectomized and submitted to stereotaxical implantation of 1 μg oestradiol benzoate, 5 μg testosterone isobutyrate or, as a control, 10 μg cholesterol in the anterior hypothalamic areas. The effects of the steroids on plasma and pituitary FSH and LH were assessed by radioimmunoassay. As reported previously by us in normal female and male rats, the preoptic–suprachiasmatic area (POA) was able to control synthesis and secretion of both gonadotrophins and did not lose its sensitivity to oestradiol and testosterone in androgenized rats. Evidence for enhanced prolactin secretion in androgenized rats was derived from immunofluorescence studies of the pituitary gland and from histology of the mammary glands. In this respect the condition of the androgenized females was opposite to that of the males. The present work demonstrated that stimulation of prolactin secretion in androgenized female rats resulted from oestrogen action due to permanent oestrus rather than from impairment of hypothalamo-hypophysial relationships. Indeed, prolactin stimulation was suppressed when the androgenized rats were ovariectomized and restored when they were subsequently implanted with oestradiol in the POA.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhenqiang You ◽  
Junying Sun ◽  
Feng Xie ◽  
Zhiqin Chen ◽  
Sheng Zhang ◽  
...  

Fermented papaya extracts (FPEs) are obtained by fermentation of papaya by Aspergillus oryzae and yeasts. In this study, we investigated the protective effects of FPEs on mammary gland hyperplasia induced by estrogen and progestogen. Rats were randomly divided into 6 groups, including a control group, an FPE-alone group, a model group, and three FPE treatment groups (each receiving 30, 15, or 5 ml/kg FPEs). Severe mammary gland hyperplasia was induced upon estradiol benzoate and progestin administration. FPEs could improve the pathological features of the animal model and reduce estrogen levels in the serum. Analysis of oxidant indices revealed that FPEs could increase superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, decrease malondialdehyde (MDA) level in the mammary glands and serum of the animal models, and decrease the proportion of cells positive for the oxidative DNA damage marker 8-oxo-dG in the mammary glands. Additionally, estradiol benzoate and progestin altered the levels of serum biochemical compounds such as aspartate transaminase (AST), total bilirubin (TBIL), and alanine transaminase (ALT), as well as hepatic oxidant indices such as SOD, GSH-Px, MDA, and 8-oxo-2′-deoxyguanosine (8-oxo-dG). These indices reverted to normal levels upon oral administration of a high dose of FPEs. Taken together, our results indicate that FPEs can protect the mammary glands and other visceral organs from oxidative damage.


1965 ◽  
Vol 33 (3) ◽  
pp. 491-499 ◽  
Author(s):  
F. DÖCKE ◽  
G. DÖRNER

SUMMARY To study the positive feed-back mechanism by which oestrogen induces corpus luteum formation, electrolytic lesions were placed in different parts of the anterior hypothalamus of prepubertal female rats which were then injected with oestradiol benzoate. Ovarian luteinization did not occur when the main parts of the suprachiasmatic nuclei or of the medial preoptic area had been destroyed. Oestradiol benzoate was implanted stereotaxically into the brain and the anterior pituitary of immature female rats. Whereas 1/25 of the subcutaneously effective dose had to be implanted into the anterior hypothalamus, 1/100 of the peripherally effective dose introduced into the adenohypophysis was sufficient to induce corpus luteum formation in most of the treated animals. The results suggest that, although the anterior hypothalamus is necessary for this positive feed-back mechanism, the anterior pituitary may be the main site of action of oestrogen. Oestrogen may increase the hypophysial sensitivity to the hypothalamic gonadotrophin-releasing factor. Thus an enhanced gonadotrophin secretion may result, sufficient for the induction of ovulation. The possibility is discussed that this positive feed-back mechanism is also essential for the induction of ovulation in women.


1978 ◽  
Vol 89 (2) ◽  
pp. 251-262 ◽  
Author(s):  
G. Aumüller ◽  
R. Wagner ◽  
K. J. Gräf

ABSTRACT Adult intact female rats were injected with norethisterone oenanthate (NOe), with or without simultaneous administration of CB-154, or with oestradiol benzoate (OeB). The ultrastructure of prolactin (PRL) cells due to the various treatment regimens was investigated and compared with the situation found in controls. Both after treatment with NOe or NOe plus CB-154, the number of PRL cells increased and displayed various ultrastructure signs of stimulation. The determination of serum PRL levels coincides with these morphological findings. In all treated animals mammary gland DNA content was significantly increased. The results presented indicate that proliferative changes in the rat mammary gland depend predominantly on the presence of progestogenic activities additionally to PRL, whereas the effect of oestrogens was regarded as an indirect effect via their PRL-stimulatory action.


1962 ◽  
Vol 40 (2) ◽  
pp. 265-276 ◽  
Author(s):  
K. Ahrén ◽  
L. Hamberger

ABSTRACT Testosterone propionate in arachis oil was applied locally to the skin over the third left thoracic mammary gland (= experimental gland) of castrated male and female rats. Arachis oil was applied to the third right thoracic mammary gland (= control gland). After 21–23 days of local applications the development of the experimental and control glands was studied on whole mount preparations. It was found that small doses of testosterone (0.15 mg daily) stimulated slight but definite lobule-alveolar development in the experimental glands, while the control glands did not show any alveoli. Applications of higher doses of testosterone propionate (0.30 and 0.75 mg daily) stimulated extensive lobule-alveolar development in the experimental glands, while only few alveoli were produced in the control glands. It may therefore be concluded that the effect of testosterone on the rat mammary gland is not mediated through other endocrine glands, but is a direct, local effect on the mammary gland structures. The result is discussed in relation to our present knowledge of the hormonal control of different growth processes within the mammary glands.


2020 ◽  
Vol 28 (4) ◽  
pp. 429-436
Author(s):  
Svetlana A. Anisimova ◽  
Janna A. Svirina ◽  
Denis A. Maksaev

Nowadays, hormonal imbalance is proven to be a factor that influences initiation of malignant and benign breast tumors. To study the aspects of participation of sex hormones in damage to organs and tissues, it may be necessary to model a common womens pathology fibrocystic disease of mammary glands characterized by the most pronounced effects of this pathogenetic factor, on experimental animals. Aim. To create a model of fibrocystic disease of mammary gland with the subsequent possibility of studying morphological manifestations of the disease in natural and drug-induced pathomorphism. Materials and Methods. The pathology was induced by intramuscular injection of 0.5 ml of 2% synestrol and 0.5 ml of 2.5% progesterone to virgin female rats on the 1st, 7th, 14th, 21st, 28th and 35th days of the experiment. For examination, histological preparations of inguinal mammary glands were made. The preparations were described and studied using morphometric analysis. Results. In the result of the experiment, pronounced macro- and microscopic alterations of mammary glands were found. Microscopic picture was similar to that observed in fibrocystic mastopathy in women. Almost all the morphometric parameters underwent reliable alterations in correspondence with the given pathology. Conclusion. A model of fibrocystic disease of mammary gland was obtained that may be used for further study of morphogenesis and methods of correction.


1965 ◽  
Vol 49 (2) ◽  
pp. 231-238 ◽  
Author(s):  
T. Swelheim

ABSTRACT A single injection of 50 μg oestradiol benzoate, administered at 11 a.m. to adult female rats which had been spayed 14 days previously and had since been treated with 0.5 μg oestradiol benzoate daily, led to an increase in the ICSH-content of the serum, which was determined 29 hours after the injection. In an identical experimental design a decrease in the ICSH-content of the serum was found in adult male rats. ICSH-determinations were carried out by the ventral prostate assay. A stimulating effect upon the ventral prostate of oestrogen present in the serum used for the above determinations was excluded. At the time when the changes in the serum were established, there were no demonstrable changes in the ICSH-content of the anterior pituitary gland in both sexes. The existence of a fundamental sex difference in the response to a single high dose of oestrogen is suggested.


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