IMMUNOCHARACTERISTICS OF OESTROGEN AND ANDROGEN TARGET CELLS IN THE ANTERIOR PITUITARY GLAND OF THE CHICK EMBRYO AS DEMONSTRATED BY A COMBINED METHOD OF AUTORADIOGRAPHY AND IMMUNOHISTOCHEMISTRY

1980 ◽  
Vol 86 (2) ◽  
pp. 245-NP ◽  
Author(s):  
J.-M. GASC ◽  
M. SAR ◽  
W. E. STUMPF
Keyword(s):  
Chick Embryo ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Feedback Regulation ◽  
Anterior Pituitary Gland ◽  
Target Cells ◽  
Combined Method ◽  
Gonadotrophin Secretion ◽  
Positive Immunoreactivity ◽  
Autoradiographic Technique

The distribution of oestrogen and androgen target cells in the anterior pituitary gland of the chick embryo on days 10, 12 and 15 of incubation was studied 1 h after the injection of tritium-labelled steroid hormone using the thaw–mount autoradiographic technique. Oestradiol target cells were localized in the caudal zone that corresponds to the so-called 'caudal lobe', while androgen target cells were found throughout the rostral and caudal lobes of the anterior pituitary gland. With a combined autoradiography and immunohistochemistry technique, most of the oestrogen target cells showed immunoreactivity to turkey LH antiserum but not to adrenocorticotrophin (1–24) and β-thyrotrophin antisera. In contrast, androgen target cells did not show positive immunoreactivity to the three antisera used. The results suggested a direct and early involvement of oestrogens but not of androgens in the feedback regulation of pituitary gonadotrophin secretion in the chick embryo.

Pituitary and testicular responses in sexually mature bulls after intravenous injections of graded doses of LH-releasing hormone

1984 ◽  
Vol 103 (3) ◽  
pp. 371-376 ◽  
Author(s):  
M. J. D'Occhio ◽  
B. P. Setchell
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Limiting Factor ◽  
Releasing Hormone ◽  
Intravenous Injections ◽  
Gonadotrophin Secretion ◽  
Lh Release ◽  
Lh Releasing Hormone ◽  
Sexually Mature

ABSTRACT The capacity of the anterior pituitary gland and testes in mature bulls (705±9 (s.e.m.) kg body wt, n = 4) to respond to graded doses of LH-releasing hormone (LHRH) was assessed relative to endogenous profiles of LH and testosterone secretion. Endogenous hormone profiles were determined by bleeding bulls at 20-min intervals for 12 h. Responses to LHRH were assessed on successive days after single intravenous injections of 1, 5, 10, 50 or 100 ng LHRH/kg body wt. Blood samples were taken at −40, −20, 0, 10, 20, 30, 40, 60 and 120 min relative to LHRH injection. During a 12-h bleed bulls showed spontaneous pulses of LH and testosterone which had peak amplitudes of 2·6±0·5 μg/l and 44·5 ± 7·1 nmol/l respectively. Respective peak LH (μg/l) and testosterone (nmol/l) responses to LVRH were as follows: 1 ng LHRH (3·0±0·7: 47·3±4·1); 5 ng LHRH (8·0±1·2; 52·8 ± 6·2); 10 ng LHRH (11·1±2·3; 57·7 ± 9·1); 50 ng LHRH (19·2±2·8; 47·9±8·6); 100 ng LHRH (19·1±4·7; 43·9 ±6·4). A dose of 1 ng LHRH/kg produced LH and testosterone responses which were comparable in amplitude to spontaneous peaks in the respective hormone. There was a linear (y = 0·28x+5·72; r = 0·81) increase in the LH response to doses of LVRH between 1 and 50 ng/kg; corresponding testosterone responses showed no relationship with the dose of LHRH. The capacity of the anterior pituitary gland to release amounts of LH eight to ten times in excess of those secreted during spontaneous peaks suggests that (1) there exists a large releasable store of LH in the anterior pituitary gland and (2) hypothalamic LHRH is a limiting factor in gonadotrophin secretion. In contrast to LH release, the androgenic response of the testes to acute gonadotrophic stimulation is determined largely by prevailing steroidogenic activity. J. Endocr. (1984) 103, 371–376

PROGESTERONE AND 20α-HYDROXYPREGN-4-EN-3-ONE LEVELS IN OVARIAN VEIN BLOOD OF THE RAT THROUGHOUT LACTATION

1969 ◽  
Vol 44 (1) ◽  
pp. 101-106 ◽  
Author(s):  
H. TOMOGANE ◽  
K. ÔTA ◽  
A. YOKOYAMA
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Venous Blood ◽  
Anterior Pituitary Gland ◽  
Ovarian Vein ◽  
High Concentration ◽  
Gonadotrophin Secretion ◽  
Rat Ovary ◽  
Secretory Pattern

SUMMARY Changes in the rate of progesterone and 20α-hydroxypregn-4-en-3-one (20α-OH-P) secretion by the rat ovary during the course of lactation were investigated. The level of progesterone in the ovarian vein blood, which was very low on day 1 of lactation, increased progressively up to day 8 (355 μg./100 ml. blood), then declined to day 18 (45·5 μg./100 ml.) and day 21 of lactation. A high concentration of 20α-OH-P in blood was observed on day 1 and day 21 of lactation, but from day 4 to day 18 the secretion of this steroid was relatively low. The ratio of progesterone to 20α-OH-P exceeded unity from day 4 to day 16, and in the middle of lactation the concentration of progesterone in ovarian venous blood was about four times greater than that of 20α-OH-P. These changes in the secretory pattern of progestins during lactation are discussed in connexion with the effects of the suckling stimulus on prolactin and gonadotrophin secretion from the anterior pituitary gland.

scholarly journals Alteration of Extracellular Matrix Components in the Anterior Pituitary Gland of Neonatal Rats Induced by a Maternal Bisphenol A Diet during Pregnancy

2021 ◽  
Vol 22 (23) ◽  
pp. 12667
Author(s):  
Bumpenporn Sanannam ◽  
Sasikarn Looprasertkul ◽  
Songphon Kanlayaprasit ◽  
Nakarin Kitkumthorn ◽  
Tewarit Sarachana ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bisphenol A ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Treated Group ◽  
Anterior Pituitary Gland ◽  
Target Cells ◽  
Tissue Inhibitors Of Metalloproteinase ◽  
Extracellular Matrix Components ◽  
Adverse Effect Level

The extracellular matrix (ECM) plays crucial roles in the anterior pituitary gland via the mechanism of cell–ECM interaction. Since bisphenol A (BPA), a well-known endocrine disruptor, can cross through the placenta from mother to fetus and bind with estrogen receptors, cell populations in the neonatal anterior pituitary gland could be the target cells affected by this chemical. The present study treated maternal rats with 5000 µg/kg body weight of BPA daily throughout the pregnancy period and then investigated the changes in ECM-producing cells, i.e., pericytes and folliculostellate (FS) cells, including their ECM production in the neonatal anterior pituitary at Day 1. We found that pericytes and their collagen synthesis reduced, consistent with the increase in the number of FS cells that expressed several ECM regulators—matrix metalloproteinase (MMP) 9 and the tissue inhibitors of metalloproteinase (TIMP) family. The relative MMP9/TIMP1 ratio was extremely high, indicating that the control of ECM homeostasis was unbalanced. Moreover, transmission electron microscopy showed the unorganized cell cluster in the BPA-treated group. This study revealed that although the mother received BPA at the “no observed adverse effect” level, alterations in ECM-producing cells as well as collagen and the related ECM balancing genes occurred in the neonatal anterior pituitary gland.

UPTAKE AND BINDING OF ANDROGENS BY THE ANTERIOR PITUITARY GLAND, HYPOTHALAMUS, PREOPTIC AREA AND BRAIN CORTEX OF RATS

1974 ◽  
Vol 76 (3) ◽  
pp. 417-430 ◽  
Author(s):  
Oddvar Næss ◽  
Arne Attramadal
Keyword(s):  
Pituitary Gland ◽  
Muscle Tissue ◽  
Anterior Pituitary ◽  
Brain Cortex ◽  
Preoptic Area ◽  
Anterior Pituitary Gland ◽  
Radioactive Material ◽  
Ventral Prostate ◽  
Target Cells ◽  
The Brain

ABSTRACT [1,2-3H] testosterone was given intramuscularly to castrated adult male and female rats. The concentration of radioactivity in the anterior pituitary gland, hypothalamus, preoptic area, brain cortex, ventral prostate and muscle tissue was measured at different time intervals. In the ventral prostate a preferential concentration and retention of radioactivity was recorded. In the anterior pituitary, hypothalamus, preoptic area and brain cortex, however, the maximum uptake was observed 7½ min after the injection of the hormone. Thereafter the radioactivity rapidly declined. Non-labelled testosterone was found to compete with the radioactive testosterone for the binding sites in the anterior pituitary, hypothalamus and preoptic area. High doses of non-labelled testosterone caused a slight, and statistically insignificant reduction of the radioactivity in the brain cortex. The concentration of radioactivity in the muscle tissue was not affected by any of the doses of non-radioactive testosterone given. Filtration of serum on Sephadex G-25 columns showed that considerable amounts of radioactivity were associated with macromolecules. Therefore in order to get a valid record of the binding of androgens to the specific molecules of the target cells, perfusion of the vascular system was essential. In vivo and in vitro experiments revealed that considerable amounts of radioactive material were bound to macromolecules in the cytosol fractions of the anterior pituitary gland, hypothalamus, preoptic area and brain cortex. Thus for the first time a binding of androgens by macromolecules in the cytosol fraction of the preoptic area and brain cortex has been found. Since association of androgens with plasma constituents can be excluded, the radioactive material is most likely bound to specific binding molecules present in the target cells of the anterior pituitary gland, hypothalamus, preoptic area and the brain cortex.

Effects of estrogens on the characteristics of [3H]spiroperidol and [3H]RU24213 binding in rat anterior pituitary gland and brain

1979 ◽  
Vol 16 (2) ◽  
pp. 99-112 ◽  
Author(s):  
Thérèse Di Paolo ◽  
Réjean Carmichael ◽  
Fernand Labrie ◽  
Jean-Pierre Raynaud
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland
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