ALTERATION OF SOMATOSTATIN BUT NOT GROWTH HORMONE-RELEASING FACTOR PITUITARY BINDING-SITES IN OBESE ZUCKER RATS
binding site; cells; defect; Endocrinology & Metabolism; growth hormone-releasing factor; hypothalamus; messenger-rna; Physiology; pituitary; secretion; somatostatin; tissue; zucker rat
The present study was designed to determine whether the diminution of growth hormone (GH) secretion that occurs in obese Zucker rats is related to alterations of GH-releasing factor (GRF) or somatostatin (SRIF) pituitary binding sites. Cold saturation studies were performed in pituitary homogenates of 4-month-old lean and obese rats, using [I-125-Tyr-10]hGRF(1-44)NH-2 as radioligand and [I-127-Tyr-10]hGRF-(1-44)NH-2 as competitor, and in pituitary membrane preparations, using [I-125-Tyr-0, D-Trp-8]SRIF14 as radioligand and [I-127-Tyr-0, D-Trp-8]SRIF14 as competitor. In lean rats, analysis of the curves by the Ligand program revealed the presence of two distinct classes of GRF binding sites, the first being of high affinity (0.74 +/- 0.11 nM) and low capacity (118 +/- 31 fmol/mg protein), the second being of lower affinity (880 +/- 240 nM) and higher capacity (140 +/- 35 pmol/mg protein), and of a single class of SRIF binding sites (affinity: 0.40 +/- 0.12 nM; capacity: 24 +/- 6 fmol/mg protein). In obese rats, no difference was observed in GRF binding parameters for both classes of sites, but the concentration of somatostatin binding sites was reduced by 67% when compared to their lean littermates. These findings suggest that the SRIF pituitary receptors are down-regulated in obese Zucker rats and indicate that no alteration of GRF pituitary binding sites contribute to the blunted GH secretion observed in this model of obesity.
Abribat T; Finkelstein J A; Gaudreau P
Regulatory Peptides
1991
1991-10
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/0167-0115(91)90061-k" target="_blank" rel="noreferrer noopener">10.1016/0167-0115(91)90061-k</a>
ACR Appropriateness Criteria(®) Neuroendocrine Imaging.
Diagnosis Differential; Humans; United States; Evidence-Based Medicine; Contrast Media; Societies Medical; Apoplexy; Appropriate Use Criteria; Appropriateness Criteria; AUC; Diabetes insipidus; Pituitary; Pituitary adenoma; Pituitary Diseases/diagnostic imaging; Precocious puberty; Sella turcica
Neuroendocrine dysfunction includes suspected hyper- and hypofunction of the pituitary gland. Causative lesions may include primary masses of the pituitary such as pituitary microadenomas and macroadenomas, as well as extrinsic masses, typically centered in the suprasellar cistern. Clinical syndromes related to hormonal dysfunction can be caused by excessive hormonal secretion or by inhibited secretion due to mass effect upon elements of the hypothalamic-pituitary axis. Additionally, complications such as hemorrhage may be seen in the setting of an underlying mass and can result in hormonal dysfunction. MRI with high-resolution protocols is the best first-line test to evaluate the sella turcica and parasellar region. CT provides complementary information regarding bony anatomy, and may be appropriate as a first-line test in certain instances, but it provides less detail and lesion characterization when compared to MRI. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
Burns J; Policeni B; Bykowski J; Dubey P; Germano IM; Jain V; Juliano AF; Moonis G; Parsons MS; Powers WJ; Rath TJ; Schroeder JW; Subramaniam RM; Taheri MR; Whitehead MT; Zander D; Corey A
Journal of the American College of Radiology
2019
2019-05
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1016/j.jacr.2019.02.017" target="_blank" rel="noreferrer noopener">10.1016/j.jacr.2019.02.017</a>
Initial Urinary Epinephrine And Cortisol Levels Predict Acute Ptsd Symptoms In Child Trauma Victims
catecholamine; catecholamines; children; combat veterans; cortisol; dexamethasone-suppression; Endocrinology & Metabolism; excretion; Neurosciences & Neurology; pituitary; posttraumatic-stress-disorder; psychiatric diagnoses; Psychiatry; PTSD; severity; survivors; trauma; women
Delahanty D L; Nugent N R; Christopher N C; Walsh M
Psychoneuroendocrinology
2005
2005-02
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.psyneunen.2004.06.004" target="_blank" rel="noreferrer noopener">10.1016/j.psyneunen.2004.06.004</a>
TAMOXIFEN TREATMENT OF OVARIECTOMIZED MICE ALTERS DOPAMINE RELEASE FROM STRIATAL TISSUE FRAGMENTS SUPERFUSED IN-VITRO
rat; therapy; Neurosciences & Neurology; estrogen; metabolism; brain; breast-cancer; estradiol; nigrostriatal; pituitary; antiestrogens; uterus; anti-estrogen; caudate nucleus
In this report we examined the effect of tamoxifen upon the nigrostriatal dopaminergic system. Ovariectomized mice were subjected to one of the following treatments: two subcutaneous injections administered on successive days of the sesame oil vehicle (control), estradiol benzoate (EB-10 mu g), tamoxifen citrate (TMX 125 mu g) or a combination of EB + TMX. At 24 h after the second injection, the caudate nucleus was superfused in vitro to evaluate the effects of these treatments upon basal as well as potassium stimulated (30 mM) dopamine release rates. In addition, uteri were weighed from each animal. Basal and total fractional dopamine release rates from the caudate nucleus of control mice were significantly lower than those of the other three treatments, which failed to differ among each other. Potassium minus(-) basal stimulated dopamine release rates failed to differ significantly among the four treatment conditions. Uterine weights of the TMX treated mice were significantly greater than controls, but significantly lower than EB and EB + TMX animals. These data show that TMX can significantly increase caudate nucleus dopamine release to levels observed in EB treated mice. These agonistic effects of TMX upon nigrostriatal dopaminergic function can be contrasted with its relatively weak estrogenic effects upon uterine weights and indicate the discriminatory, system specific effects that can be exerted by this anti-estrogen. This demonstration of TMX's ability to modulate central nervous system function is of particular relevance in light of pending clinical trials for the prophylactic use of TMX in the treatment of women for breast cancer.
McDermott J L; Liu B J; Dluzen D E
Brain Research
1995
1995-11
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/0006-8993(95)00993-z" target="_blank" rel="noreferrer noopener">10.1016/0006-8993(95)00993-z</a>