Some in vitro Effects of Synthetic Thyrotrophin Releasing Factor on the Secretion of Thyroid Stimulating Hormone from the Anterior Pituitary Gland of the Domestic Fowl

1974 ◽  
Vol 15 (1) ◽  
pp. 1-9 ◽  
Author(s):  
C.G. Scanes
PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 948-950
Author(s):  
David R. Brown ◽  
J. Michael McMillin

We have previously reported a case of anterior pituitary insufficiency in a 14-year-old girl following closed head trauma.1 Endocrine evaluation one year after her accident revealed hypopituitarism manifested by cachexia, hypothyroidism, hypogonadism, and hypoadrenocorticism. Laboratory studies demonstrated deficiencies of adrenocorticotropic hormone, thyroid-stimulating hormone (TSH), growth hormone, and gonadotropic hormones (follicle-stimulating hormone and luteinizing hormone). We postulated that her hypopituitarism was due to anterior pituitary gland destruction rather than stalk section or hypothalamic damage. We have recently measured her serum prolactin concentrations following provocative stimulation with thyrotropin-releasing hormone (TRH), and these results strengthen the evidence for direct anterior pituitary gland destruction and provide a more complete delineation of her endocrinologic function.


REPORTS ◽  
2021 ◽  
Vol 335 (1) ◽  
pp. 39-46
Author(s):  
V.G. Semenov ◽  
V.G. Tyurin ◽  
D.A. Baimukanov ◽  
E.P. Simurzina ◽  
S.G. Kondruchina ◽  
...  

The research was performed to identify the most effective bio immunostimulant. We used PS-2 and Prevention-N-E biologicals developed on the basis of the Chuvash State Agrarian University, as well as widely used in veterinary practice - PDE and E-selenium. Injection of PS-2 and Prevention-NE preparations to dry cows at a dose of 10.0 ml three times 45-40, 25-20 and 15-10 days before calving, as well as PDE and E-selenium at a dose of 20.0 and 10.0 ml 20 days before calving, respectively, prevents postpartum diseases. The mechanism of action of the PS-2 and Prevention-N-E drugs developed and tested by us is manifested, first of all, due to the consecutive processes of macrophage activation, as a result of the action of polysaccharide corpuscles and drug components on macrophage receptors. Secondly, information from the receptors of macrophages and chemoreceptors is transmitted along the afferent pathway to the cerebral cortex, then the signals go to the hypothalamus, which leads to liberin secretion by the nuclei of the ashen tuber of the hypothalamus. Liberins, in turn, increase the release of hormones by the anterior pituitary gland - the adenohypophysis. The anterior pituitary gland releases tropic hormones: somatotropic hormone, adrenocorticotropic hormone, thyroid-stimulating hormone, follicle-stimulating hormone, etc. These hormones are involved in metabolic processes in the body. Under the influence of preparations, in cows the time of membranes sweep was reduced, the risk of uterus subinvolution and endometritis decreased. In cows, the timing of the onset of estrus, the insemination rate, and the service period were shortened, and the conception rate increased in one estrus. In such a way, against the background of the use of biologicals with the help of nonspecific adaptive reactions, the body retains the relative constancy of the internal environment necessary for life - homeostasis, and it actively resists the adverse effects of the external environment, increasing its phylactic power. Consequently, new opportunities are opening up for the implementation of the reproductive and productive qualities of cattle due to the body immunoprophylaxis with complex biological products of a new generation.


1984 ◽  
Vol 100 (2) ◽  
pp. 219-226 ◽  
Author(s):  
S. A. Nicholson ◽  
T. E. Adrian ◽  
B. Gillham ◽  
M. T. Jones ◽  
S. R. Bloom

ABSTRACT The effect of six hypothalamic peptides on the basal release of ACTH and that induced by arginine vasopressin (AVP) or by ovine corticotrophin releasing factor (oCRF) from fragments of the rat anterior pituitary gland incubated in vitro was investigated. Dose–response curves to AVP and to oCRF were obtained, and the response to a low dose of oCRF was potentiated by a low dose of AVP. Basal release of ACTH was not affected by any of the peptides in concentrations in the range 10−12 to 10−6 mol/l, and only substance P (SP) and somatostatin (SRIF) inhibited significantly the response to oCRF in a dose-related manner. The responses to a range of doses of oCRF or AVP were reduced by 10−8 and 10 − 6 mol SP or SRIF/1, and to a greater extent by the higher dose. Except in the case of 10−6 mol SRIF/1 on the response to AVP, the response was not further diminished by preincubation of the tissue with the peptide before the stimulating agent was added. The inhibition of the responses to AVP or oCRF by 10−9 mol SP/1 was not potentiated by its combination with either 5 × 10−10 or 10−8 mol SRIF/1; the inhibitory effects were merely additive. The results suggest that although SRIF and SP are able to modulate the release of ACTH from the anterior pituitary gland, they do so only at a high concentration. In the case of SRIF these concentrations are several orders of magnitude higher than those reported to be present in the hypophysial portal blood and therefore a physiological role for this peptide in the control of ACTH secretion is unlikely. J. Endocr. (1984) 100, 219–226


1975 ◽  
Vol 67 (2) ◽  
pp. 469-476 ◽  
Author(s):  
WH Fletcher ◽  
NC Anderson ◽  
JW Everett

The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions.


2016 ◽  
Vol 35 (4) ◽  
pp. 463-475 ◽  
Author(s):  
Sonia A. Ronchetti ◽  
María S. Bianchi ◽  
Beatriz H. Duvilanski ◽  
Jimena P. Cabilla

Inorganic arsenic (iAs) is at the top of toxic metalloids. Inorganic arsenic-contaminated water consumption is one of the greatest environmental health threats worldwide. Human iAs exposure has been associated with cancers of several organs, neurological disorders, and reproductive problems. Nevertheless, there are no reports describing how iAs affects the anterior pituitary gland. The aim of this study was to investigate the mechanisms involved in iAs-mediated anterior pituitary toxicity both in vivo and in vitro. We showed that iAs administration (from 5 to 100 ppm) to male rats through drinking water increased messenger RNA expression of several oxidative stress-responsive genes in the anterior pituitary gland. Serum prolactin levels diminished, whereas luteinizing hormone (LH) levels were only affected at the higher dose tested. In anterior pituitary cells in culture, 25 µmol/L iAs significantly decreased prolactin release in a time-dependent fashion, whereas LH levels remained unaltered. Cell viability was significantly reduced mainly by apoptosis evidenced by morphological and phosphatidylserine externalization studies. This process is characterized by early depolarization of mitochondrial membrane potential and increased levels of reactive oxygen species. Expression of some key oxidative stress-responsive genes, such as heme oxygenase-1 and metallothionein-1, was also stimulated by iAs exposure. The antioxidant N-acetyl cysteine prevented iAs-induced effects on the expression of oxidative stress markers, prolactin release, and apoptosis. In summary, the present work demonstrates for the first time that iAs reduces prolactin release both in vivo and in vitro and induces apoptosis in anterior pituitary cells, possibly resulting from imbalanced cellular redox status.


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