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Single Amino Acids
Published in Luke R. Bucci, Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
Ornithine is a key intermediate in the urea cycle, which is involved with conversion of ammonia derived from amino acid (protein) or nitrogen catabolism into urea for safe excretion of nitrogen, since ammonia is a toxic substance in the body.331–333 Ornithine is also capable of somatotropin release after intravenous administration334–336 and after oral administration of 170 mg/kg of ornithine hydrochloride to bodybuilders.337 Lower oral doses of ornithine hydrochloride (40, 100 mg/kg),337 a 1:1:1 mixture of arginine to ornithine to lysine (2 g each per d for 4 d),338 a mixture of arginine (1.8 g), ornithine (1.2 g), methionine (0.48 g), and phenylalanine (0.12 g),339 and a combination of ornithine (1.1 g) and tyrosine (0.75 g)340 all failed to promote release of somatotropin in athletic subjects. Thus, a threshold of effect for oral induction of somatotropin release appears to exist. An acute dose of at least 10 g or more of a single amino acid known to induce somatotropin release from intravenous studies, such as ornithine, is needed before there is a possibility of somatotropin release. However, at the highest dose tested, 170 mg ornithine per kg, osmotic diarrhea was noted in almost every subject.337 Therefore, further research is necessary in order to justify the potential use of high-dose amino acids for somatotropin release.
The Endocrine System and Its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
Pituitary hypersecretion of the growth hormone somatotropin during the period of skeletal development results in giantism, an abnormal increase in the length of skeletal structures causing unusually large body size (hence the name). Acromegaly (acro = extremity, plus megaly, large), a form of gigantism that affects adults, is often caused by a pituitary tumor that produces excess growth hormone after skeletal development is normally complete. Rather than affecting skeletal length, its effects are seen as thickening of cartilage and bone with widening of the jaw, hands, feet, eyebrow ridges, and soft tissue. Conversely, hyposecretion of somatotropin results in dwarfism, the condition seen in dwarfs and midgets. Dwarfism can also result from a deficiency in thyroid hormones.
Somatotropin
Published in Paul V. Malven, Mammalian Neuroendocrinology, 2019
A population of cells in the pars anterior (or pars distalis) that stain with acidic dyes (i.e., cells are acidophilic) synthesize and secrete somatotropin for delivery to its receptors located in several tissues of the body. The first known action of somatotropin was to increase growth in body size of normal as well as hypophysectomized rats. For this reason, the hormone is sometimes called growth hormone and abbreviated GH. The present chapter will discuss the endocrinology of GH secretion as well as the neurohormonal regulation and neuroendocrine integration of adenohypophysial release of GH. A final section will address some clinical disorders involving GH-related hormones in humans and the practical applications of GH biotechnology in agricultural animals.
The triple function of the capsaicin-sensitive sensory neurons: In memoriam János Szolcsányi
Published in Temperature, 2023
Erika Pintér, Zsuzsanna Helyes, Éva Szőke, Kata Bölcskei, Angéla Kecskés, Gábor Pethő
Although SOM injection is used in certain acute cases, this agent is not suitable for the role mentioned above. When given by infusion, SOM has been shown to be an effective agent for the treatment of excessive secretion from endocrine tumors of the gastrointestinal tract and for the treatment of acute, severe gastrointestinal bleeding. There are also stable octapeptide analogs on the market, the best known of which is octreotide (Sandostatin) used for the symptomatic treatment of endocrine tumors [21]. Analysis of the function of SOM receptor types (SST1–5) revealed that the endocrine effects are mediated by members of the somatotropin release inhibiting factor (SRIF) SRIF1 group of receptors (SST2, SST3 and SST5), whereas the anti-inflammatory and analgesic effects are mediated by members of the SRIF2 group (SST1 and SST4). As SOM analogs are also considered antitumor agents due to their antiproliferative activity, a number of stable analogs have been synthesized [20].
Occurrence of Hypopituitarism in Tunisian Turner Syndrome patients: familial versus sporadic cases
Published in Gynecological Endocrinology, 2021
M. Mnif-Feki, W. Safi, N. Bougacha-Elleuch, G. Abid, M. Moalla, M. Elleuch, D. H. Ben Salah, N. Rekik, N. Belguith, F. Abdelhedi, T. Kammoun, M. Hachicha, N. Charfi, F. Mnif, H. Kammoun, H. Hadj Kacem, F. Hadj-Kacem, M. Abid
TS is known to be associated with congenital abnormalities, yet association with Hypopituitarism is an unfamiliar finding. The first case of a pituitary deficiency co-occurring with gonadal dysgenesis owing to a TS was described by Efstathiadou in 2000 [7]. At the onset, the patient was diagnosed with somatotropin, thyrotropin, and gonadotropin deficiencies. Afterward, with the ascertainment of several clinical characteristics and the absence of ovarian tissue on ultrasound, karyotype was carried out. Results revealed concrete gonadal dysgenesis secondary to TS with no evidence of mosaicism. MRI showed a hypoplastic pituitary gland and an ectopic localization of neuro-hypophysis. So far, only nine cases of TS associated with Hypopituitarism have been reported in the literature (Table 3). Three congenital cases with such an association were already reported in 2016 by our team, as described in Table 1 (cases 4, 5, and 6) [4]. Up to date, only 12 cases with Hypopituitarism associated with TS are described (half of them are reported in our series). Interestingly, the familial occurrence of this association is seen in 5 out of 12 patients.
Inhibitory effects of somatostatin analogue in bleomycin-induced pulmonary fibrosis
Published in Experimental Lung Research, 2021
Tatsuya Hosono, Masashi Bando, Yoshiko Mizushina, Masafumi Sata, Koichi Hagiwara, Yukihiko Sugiyama
Recently, several studies showed an increased uptake of radiolabeled somatostatin analogue in the lung in patient with IPF when compared to control patient and its uptake correlated with severity of pulmonary fibrosis.13 Somatostatins, which are known as somatotropin-release inhibiting factors (SRIFs), form a family of cyclopeptides that mainly produced by normal endocrine, gastrointestinal, immune and neuronal cells, as well as by certain tumors.14 Lung fibroblasts expressed somatostatin receptors.13,15,16 In addition, somatostatin analogue inhibits the expression of transforming growth factor (TGF)-β, insulin-like growth factor (IGF)-I, platelet-derived growth factor (PDGF), and basic fibroblast growth factor (b-FGF).17–19 The purpose of this study is to evaluate the effects of somatostatin analogue on bleomycin (BLM)-induced pulmonary fibrosis in mice.