THE PROLACTIN PRODUCTION AND RELEASE OF A PITUITARY GRAFT AND OF THE HYPOPHYSIS IN SITU

1963 ◽  
Vol 43 (2) ◽  
pp. 271-279 ◽  
Author(s):  
O. L. Wolthuis ◽  
S. E. de Jongh
Keyword(s):  
Direct Action ◽  
List Type ◽  
Portal Circulation ◽  
Prolactin Release ◽  
Kidney Capsule ◽  
Experimental Animals ◽  
Inhibitory Mechanisms ◽  
Hypophysectomized Rats ◽  
Prolactin Content

ABSTRACT In order to compare the prolactin function of a pituitary graft with that of a hypophysis in situ, an attempt was made to make the two groups of experimental animals used comparable with respect to their gonadotrophin and steroid levels. This was done: by autotransplantation of the ovaries into the spleen or by ovariectomy; by supplying excess amounts of exogenous gonadotrophins. It was found that prolactin effects produced by hypophyseal grafts were far greater than those brought about by hypophyses in situ. If small amounts of oestrogens accidentally escaped from the portal circulation, these effects were enhanced both in the grafted animals and in those with the hypophyses in situ. Assays of serum and hypophyseal material of ovariectomized and hypophysectomized rats bearing a hypophyseal graft under the kidney capsule showed that the prolactin content of the graft is lower and the prolactin content of the serum higher when compared to material from ovariectomized sham-operated controls. From these results it is concluded that: The hypothalamus inhibits the prolactin function of the hypophysis in situ. Hypothalamic inhibitory mechanisms affect prolactin release more than prolactin production. Oestrogens enhance prolactin production in the hypophysis, presumably mainly by a direct action on the pituitary gland.

FEEDBACK EFFECTS OF STEROIDS ON GONADOTROPHIN RELEASE IN HYPERPROLACTINAEMIC, OVARIECTOMIZED RATS

1981 ◽  
Vol 89 (3) ◽  
pp. 431-435 ◽  
Author(s):  
D. A. CARTER ◽  
S. A. WHITEHEAD
Keyword(s):  
Direct Action ◽  
Steroid Treatment ◽  
Ovariectomized Rats ◽  
Prolactin Release ◽  
Feedback Effects ◽  
Lh Surge ◽  
Kidney Capsule ◽  
Pituitary Glands ◽  
Hypothalamic Pituitary Axis

The effect of hyperprolactinaemia on the progesterone-induced LH surge which occurs in oestrogen-primed, ovariectomized rats has been investigated. Hyperprolactinaemia was produced by implanting pituitary glands under the kidney capsule and levels of LH and prolactin in the circulation were measured at appropriate times during the steroid treatment. Twenty-four hours after oestrogen administration plasma LH levels were significantly reduced in both hyperprolactinaemic and sham-operated control rats. Progesterone induced a surge of LH which peaked 5 h after injection in both groups of rats. However, the peak LH level in the hyperprolactinaemic rats was less than 50% of that observed in the controls. Differences were also found in the effect of oestrogen on prolactin release in the hyperprolactinaemic rats. It is suggested that prolactin reduces the sensitivity to progesterone by a direct action on the hypothalamic–pituitary axis.

SENSITIVITY OF THE RAT DIAPHRAGM TO GROWTH HORMONE.

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén
Keyword(s):  
Growth Hormone ◽  
Inhibitory Effect ◽  
Rat Diaphragm ◽  
Intracellular Accumulation ◽  
Slight Effect ◽  
Kidney Capsule ◽  
Muscle Tissues ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

A METHOD FOR EVALUATING AN EXPERIMENTAL ATHYREOSIS

1972 ◽  
Vol 70 (2) ◽  
pp. 289-294 ◽  
Author(s):  
K. Schimmelpfennig ◽  
A. Kaul ◽  
U. Haberland
Keyword(s):  
Weight Loss ◽  
Thyroid Tissue ◽  
Cervical Region ◽  
List Type ◽  
Experimental Animals

ABSTRACT A micro-131I-test is presented which allows an easy separation of completely surgically thyroidectomised experimental animals from animals with aberrant or residual thyroid tissue. The application of the method is easy and not time-consuming: the total time spent on one animal is approximately 3 min. The method is based on the principle that the 131I storage is measured over the cervical region. The application of this method gives the following advantages: When performing studies with proven athyroid rats it is not necessary subsequently to demonstrate athyreosis (histologically, BMR, or PBI). Time-consuming experiments with animals which are not definitely athyroid can be avoided. The additional fractionated radio-iodine resection after surgical thyroidectomy, used by many authors to destroy residual thyroid tissue, becomes superfluous. Such a procedure takes 4 to 8 weeks. The animals may be used after a 5-day-period. This excludes secondary changes like weight loss and disturbed development which have to be taken into consideration when using a radio-iodine resection.

scholarly journals Dendrite-Free and Stable Lithium Metal Battery Achieved by a Model of Stepwise Lithium Deposition and Stripping

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tiancun Liu ◽  
Jinlong Wang ◽  
Yi Xu ◽  
Yifan Zhang ◽  
Yong Wang
Keyword(s):  
Reduction Method ◽  
Coulombic Efficiency ◽  
List Type ◽  
Lithium Metal ◽  
Metal Anode ◽  
In Situ Raman ◽  
Unique Model ◽  
Li Metal Anode ◽  
Pyridinic N

Highlights A facile method is adopted to obtain cucumber-like lithiophilic composite skeleton. Massive lithiophilic sites in cucumber-like lithiophilic composite skeleton can promote and guide uniform Li depositions. A unique model of stepwise Li deposition and stripping is determined. Abstract The uncontrolled formation of lithium (Li) dendrites and the unnecessary consumption of electrolyte during the Li plating/stripping process have been major obstacles in developing safe and stable Li metal batteries. Herein, we report a cucumber-like lithiophilic composite skeleton (CLCS) fabricated through a facile oxidation-immersion-reduction method. The stepwise Li deposition and stripping, determined using in situ Raman spectra during the galvanostatic Li charging/discharging process, promote the formation of a dendrite-free Li metal anode. Furthermore, numerous pyridinic N, pyrrolic N, and CuxN sites with excellent lithiophilicity work synergistically to distribute Li ions and suppress the formation of Li dendrites. Owing to these advantages, cells based on CLCS exhibit a high Coulombic efficiency of 97.3% for 700 cycles and an improved lifespan of 2000 h for symmetric cells. The full cells assembled with LiFePO4 (LFP), SeS2 cathodes and CLCS@Li anodes demonstrate high capacities of 110.1 mAh g−1 after 600 cycles at 0.2 A g−1 in CLCS@Li|LFP and 491.8 mAh g−1 after 500 cycles at 1 A g−1 in CLCS@Li|SeS2. The unique design of CLCS may accelerate the application of Li metal anodes in commercial Li metal batteries.

Serotonin stimulates GH secretion through a direct pituitary action: studies in hypophysectomized autografted animals and in perifused pituitaries

1986 ◽  
Vol 113 (3) ◽  
pp. 317-322 ◽  
Author(s):  
F. López ◽  
D. Gónzalez ◽  
E. Aguilar
Keyword(s):  
Plasma Volume ◽  
Direct Action ◽  
Experimental Models ◽  
Male Rats ◽  
Blood Samples ◽  
Kidney Capsule ◽  
Gh Secretion ◽  
Significant Release ◽  
The Right ◽  
Dose Dependent

Abstract. To analyze a possible direct action of serotonin (5-hydroxytryptamine) at pituitary level in GH secretion, two experimental models were used: hypophysectomized autografted rats and perifused pituitaries. Adult male rats were hypophysectomized and their own pituitaries placed under the right kidney capsule. Ten days later an intra-atrial cannula was inserted. The next day, blood samples were obtained before and every 10 min during a 2 h period after the injection of saline or 5-hydroxytryptamin (1 or 2 mg/kg iv). Plasma volume was replaced with saline. Both doses of 5-hydroxytryptamine elicit a strong release of GH, the effect being dose-dependent. In pituitaries perifused with 5-hydroxytryptamine (100 μm during 115 min or 1, 10 and 100 μm during 15 min), a significant release of GH was also observed. These results suggested that 5-hydroxytryptamine may stimulate GH secretion through a direct pituitary action.

scholarly journals THE EFFECT OF EPITHELIAL REMNANT AND WHOLE ORGAN GRAFTS OF THYMUS ON THE RECOVERY OF THYMECTOMIZED IRRADIATED MICE

1969 ◽  
Vol 129 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
Esther F. Hays
Keyword(s):  
Direct Action ◽  
Lymphoid Cells ◽  
Lymphoid Tissues ◽  
Functional Development ◽  
Reticular Cells ◽  
Microscopic Morphology ◽  
Two Parameters ◽  
A Minor ◽  
Cellular Components

Work has been presented which suggests that thymus epithelial reticular cells are not effective in restoring the microscopic morphology of lymphoid tissues and their immunologic capacities. They function in recruiting precursors of thymus lymphocytes from the host animals to produce an organ which, after it becomes architecturally normal, can reconstitute the defective host. Intact thymus grafts in situ from 10–14 days, but not for shorter periods of time, have been shown to result in a return toward normal of these two parameters. Evidence is offered to show that few dividing cellular components in the lymphoid tissue originate from the thymus remnant grafts, and that a minor cellular component is contributed by the intact grafts. These data support the concept that the structural and functional development of the lymphatic tissue in thymectomized animals is dependent on thymus lymphoid cells and/or their products, and that the epithelial-reticular cells do not have a direct action in peripheral lymphoid reconstitution.

scholarly journals Association of Breast Surgeons at the British Association of Surgical Oncology (ABS AT BASO)

2006 ◽  
Vol 9 (S1) ◽  
pp. 28-33
Author(s):  
Keyword(s):  
Clinical Trials ◽  
Ductal Carcinoma ◽  
Randomised Trial ◽  
Surgical Oncology ◽  
British Association ◽  
List Type ◽  
Current Contact ◽  
Trial Testing ◽  
Er Positive

This section provides current contact details and a summary of recent or ongoing clinical trials being coordinated by Association of Breast Surgeons at the British Association of Surgical Oncology (ABS at BASO). Clinical trials include: BASO DCIS II TRIAL: Randomised trial testing observation (no radiotherapy) against radiotherapy in women with low-risk completely excised ER positive ductal carcinoma in situ (DCIS) of the breast on adjuvant endocrine therapy.Neoadjuvant trial of preoperative exemestane or letrozole ± celecoxib in the treatment of ER positive postmenopausal early breast cancer.

An In-Situ Rainwater Collection and Infiltration System to Improve Plant-Available Water and Fine Root Growth for Drought Resistance

2020 ◽  
Vol 36 (5) ◽  
pp. 807-814
Author(s):  
Xiaolin Song ◽  
Xiaodong Gao ◽  
Paul Reese Weckler ◽  
Wei Zhang ◽  
Jie Yao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Root Growth ◽  
Root System ◽  
Drought Resistance ◽  
Fine Roots ◽  
Soil Depth ◽  
List Type ◽  
Available Water ◽  
Plant Available Water

HighlightsAn in-situ rainwater collection and infiltration (RWCI) method is a rainwater catchment utilization techniqueRWCI is advantageous for increasing sustainable plant-avaibale water to increase drought resistanceRWCI significantly increased the amount of water and nutrients in the rhizosphere for uptake by apple tree rootsABSTRACT. A two-year field experiment was undertaken to determine the spatial distribution of plant-available water and roots in soil profiles under two rainfall control systems—an in-situ rainwater collection and infiltration (RWCI) method and a semi-circular basin (SCB)—in apple orchards in the Loess Plateau of China. The results showed that the RWCI treatments with a soil depth of 40 cm (RWCI40), 60 cm (RWCI60), and 80 cm (RWCI80) significantly increased plant-available water in different seasons and depths and increased root growth of apple trees in the experimental soil profile (0–200 cm). At 0–200 cm soil depth, then RWCI treatments had significantly higher (91.86%-110.01%) mean plant-available water storage (PAWS) than the SCB treatment in both study years (2015 and 2016). From 0–120 cm soil depth, the RWCI60 treatment had significantly higher growing season mean PAWS than RWCI40 and RWCI80; however, RWCI80 had the highest from 120–200 cm. From 0–60 cm, the RWCI treatments had 25.84%-36.86% a smaller proportion of root system than the SCB treatment. However, from 60–120 cm, the proportion of root system increased by 131.53% (RWCI40), 157.95% (RWCI60) and 129.98% (RWCI80), relative to SCB. From 0–200 cm, the RWCI treatments had 1.49–1.94 times more root dry weight density than the SCB treatment. The highest concentration of fine roots occurred in the RWCI treatments. Thus, RWCI enabled roots to absorb more water and nutrients from a wider wetted area and improved drought resistance. Keywords: Drought resistance, Fine roots, Loess Plateau, Plant-available water, Spatial distribution.

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