Somatostatin growth hormone increased

Growth hormone. Mood disorders have been related to alterations in the activity of the growth-hormone axis. A blunted growth-hormone response to clonidine, an a2 receptor agonist, has been consistently found in depression. Increased growth-hormone secretion during the day and decreased nocturnal growth-hormone secretion have also been observed in depressed patients. Depressed patients have lower CSF concentrations of somatostatin, compared to those with schizophrenia and normal controls. While lower CSF somatostatin is a state-dependent marker of depression, it occurs in a number of unrelated nonpsychiatric conditions, and thus appears to be relatively nonspecific. 

Modifications designed to enhance the enzyme resistance and prolong the activity of SS derivatives have been quite successful. The use of D-amino acids instead of the normal L-enantiomers (e.g., in Trp ), or replacement of the disulfide link by a nonreducible ethylene bridge, leads to an increased duration of activity, approaching 3 hours. Several analogs show a greatly increased effect, like the [D-Ala, D-Trp ]somatostatin, which has 20 times the activity of SS on growth hormone release. The NH-terminal outside the cyclic dodecapeptide is not essential for activity. Selectivity of action results from... 

Sonntag WE, Xu X, Ingram RL, D Costa A. Moderate caloric restriction alters the subcellular distribution of somatostatin mRNA and increases growth hormone pulse amplitude in aged animals. Neuroendocrinol. 1995 61 601-608. 

The growth hormone (STH) or the human growth hormone 87) (HGH), a linear peptide hormone made up of 191 amino acids with 2 intrachain disulfide bridges, is formed under the control of somatostatin and influences the maturation process during the growth period (e.g. the increase in protein substance and in height). 

McMahon CD, Chapin LT, Lookingland KJ, Tucker HA (1998) Stimulation of dopamine D, receptors increases activity of periventricular somatostatin neurons and suppresses concentrations of growth hormone. Dom Anim Endocrinol 75 257-265. 

Epinephrine, norepinephrine, cortisol, somatostatin, and growth hormone also have contrainsular activity. Thyroid hormone also must be classified as an insulin counterregulatory hormone because it increases the rate of fuel consumption and also increases the sensitivity of the target cells to other insulin counterregulatory hormones. 

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