Pituitary Tumors and Their Management
Demetrius Pertsemlidis, William B. Inabnet III, Michel Gagner in Endocrine Surgery, 2017
Acromegaly or gigantism results from the hypersecretion of GH. The term acromegaly, derived from the Greek akron (extremity) and megale (large), describes only one aspect of the clinical features of the disease process. Harvey Cushing is credited with relating the overproduction of GH from a pituitary source [50]. GH is a polypeptide, 191 amino acids long, normally produced and released by the somatotropic cells found in the anterior pituitary in response to hypothalamic GH-releasing factor (GRF) [51]. Somatostatin is a 14-amino acid cyclic peptide-releasing factor that inhibits GH release [52]. Three or four bursts of GH secretions occur per day, punctuating a basal state of minimal activity [53]. Sleep, physical exertion or stress, hyper- and hypoglycemia, and a variety of pharmacologic agents can also precipitate GH release. Circulating GH results in the secretion from the liver of a family of peptides called somatomedins. Somatomedin-C (insulin-like growth factor 1 [IGF-1]) is the most familiar somatomedin measured. These secondary hormones, in turn, produce a variety of anabolic effects throughout the body and mediate the effects of GH at the end-organ level. Unlike GH, the somatomedins do not exhibit significant diurnal variation in serum levels, and therefore may be a better means of evaluating patients [54].
Exercise and Neutrophil Activity: A Possible Neuroendocrine Connection
Alan J. Husband in Psychoimmunology CNS-Immune Interactions, 2019
Further work is needed to explore the possibility that growth hormone is the connecting link between moderate exercise and increased neutrophil microbicidal activity. We are currently testing this hypothesis by blocking the growth hormone response to exercise (by consumption of a 5% glucose solution32) and plan to also investigate neutrophil responses in patients on growth hormone therapy. Recent work has shown that somatomedin-C (the agent responsible for the growth-promoting effects of growth hormone) is also immunostimulatory.6Figure 7 is a speculative attempt to place the exercise effect on neutrophil behaviour in a more general physiological/endocrinological context. If the ideas presented in this paper are borne out by further experimentation, it may be possib le to recommend suitable measures of exercise as part of a therapeutic program to ameliorate immune dysfunction associated with ageing27 (where the daily output of growth hormone and somatomedin-C are reduced28), or, perhaps, with AIDS patients, to provide a positive neuroendocrine stimulus to a deteriorating immune system.29-31
The Effects of Growth Hormone and Related Hormones on the Immune System
Istvan Berczi in Pituitary Function and Immunity, 2019
Specific receptor sites for somatomedin, distinct from insulin receptor sites, have been described on circulating human mononuclear cells, on cord blood lymphocytes, and on the IM-9 human leukemia cell line.57–59 Fetal lymphocytes bound more 125I-somatomedin C than did adult lymphocytes. Somatomedins are similar structurally and functionally to insulin, and for this reason they are also called insulin-like growth factors (IGF-I, IGF-II). Insulin competed for the IGF-I receptor on IM-9 insulin receptor with displacement of 125I-insulin, which was concentration dependent. Insulin and somatomedin peptides not only bind to each other’s receptors, but regulate each receptor, which is proportional to their ability to occupy that receptor.58,59
Impaired Placentation and Early Pregnancy Loss in Patients with MTHFR Polymorphisms and Type-1 Diabetes Mellitus
Published in Fetal and Pediatric Pathology, 2019
Rumeysa Hekimoglu Gurbuz, Pergin Atilla, Gokcen Orgul, Atakan Tanacan, Anil Dolgun, Ayse Nur Cakar, Mehmet Sinan Beksac
IGF-1 (somatomedin-C/mechano growth factor) is a 7649 kDa single chain polypeptide (proinsulin analog) activating DNA synthesis and trophoblast proliferation [26]. It is controlled by growth factors, and it activates and supports decidualization [35]. It has six IGF-binding proteins [26]. In our study, IGF-1 expression was found to be reduced in the superficial and glandular cells of the decidua and in decidual cells in both MTHFR and type-1 DM groups. Its expression was also found to be reduced in the interstitial trophoblasts, while it was increased in the villous cytotrophoblasts which may indicate impaired placentation.
Extending Phenotypic Spectrum of 17q22 Microdeletion: Growth Hormone Deficiency
Published in Fetal and Pediatric Pathology, 2021
Ceren Damla Durmaz, Şule Altıner, Elifcan Taşdelen, Halil Gürhan Karabulut, Hatice Ilgın Ruhi
To detect the etiology of short stature of patient, Somatomedin C levels was evaluated and was low, 20 ng/ml (49–171 ng/ml). The patient was diagnosed with growth hormone deficiency and growth hormone (GH) replacement treatment was started. After two years of treatment, the Somatomedin C levels are now within the expected reference range. Laboratory tests that were performed to detect an inborn error of metabolism were normal.
Clinical relevance of insulin-like growth factor-1 to cardiovascular risk markers
Published in The Aging Male, 2020
Ko Harada, Yoshihisa Hanayama, Mikako Obika, Koichi Itoshima, Ken Okada, Fumio Otsuka
Insulin-like growth factor-1 (IGF-1), also called somatomedin C, is a hormone with a similar molecular structure to insulin, which is mainly produced in the liver. In addition to mediating of GH-independent anabolic responses in many cells and tissues, IGF-1 functions as the major mediator of growth hormone (GH)-related somatic growth [1].
Related Knowledge Centers
- Anabolism
- Protein
- Protein Tertiary Structure
- Amino Acid
- Liver
- Insulin
- Hormone
- Gene
- Growth Hormone
- Mecasermin