Somatropin (recombinant Human Growth Hormone – rDNA origin) is a human growth hormone produced by recombinant DNA technology. It has 191 amino acid sequence and its structure are identical to the dominant form of this human pituitary growth hormone. It has a molecular weight of 22,125 daltons. Somatropin ( rHGH) is a sterile, non-pyrogenic, white lyophilized powder intended for subcutaneous or intramuscular injection, after reconstitution with sterile Water for Injection ( 0,3% m-Cresol)
The primary and most intensively studied action of somatropin is the stimulation of linear growth. This effect is demonstrated in children with GHD.
The measurable increase in bone length after administration of somatropin results from its effect on the cartilaginous growth areas of long bones. Studies in vitro have shown that the incorporation of sulfate into proteoglycans is not due to a direct effect of somatropin, but rather is mediated by the somatomedins or insulin-like growth factors (IGFs). The somatomedins, among them IGF-I, are polypeptide hormones which are synthesized in the liver, kidney, and various other tissues. IGF-I levels are low in the serum of hypopituitary dwarfs and hypophysectomized humans or animals, and increase after treatment with somatropin.
It has been shown that the total number of skeletal muscle cells is markedly decreased in children with short stature lackin endogenous GH compared with normal children, and that treatment with somatropin results in an increase in both the number and size of muscle cells.
Somatropin influences the size of internal organs, and it also increases red cell mass.
Linear growth is facilitated in part by increased cellular protein synthesis. This synthesis and growth are reflected by nitrogen retention which can be quantitated by observing the decline in urinary nitrogen excretion and blood urea nitrogen following the initiation of somatropin therapy.
Hypopituitary children sometimes experience fasting hypoglycemia that may be improved by treatment with somatropin. In healthy subjects, large doses of somatropin may impair glucose tolerance. Although the precise mechanism of the diabetogenic effect of somatropin is not known, it is attributed to blocking the action of insulin rather than blocking insulin secretion.
Insulin levels in serum actually increase as somatropin levels increase. Administration of human growth hormone to normal adults and patients with growth hormone deficiency results in increases in mean serum fasting and postprandial insulin levels, although mean values remain in the normal range. In addition, mean fasting and postprandial glucose and hemoglobin A1c levels remain in the normal range.
Somatropin stimulates intracellular lipolysis, and administration of somatropin leads to an increase in plasma free fatty acids and triglycerides. Untreated GHD is associated with increased body fat stores, including increased abdominal visceral and subcutaneous adipose tissue. Treatment of growth hormone deficient patients with somatropin results in a general reduction of fat stores, and decreased serum levels of low density lipoprotein (LDL) cholesterol.
Administration of somatropin results in an increase in total body potassium and phosphorus and to a lesser extent sodium. This retention is thought to be the result of cell growth. Serum levels of phosphate increase in children with GHD after somatropin therapy due to metabolic activity associated with bone growth. Serum calcium levels are not altered. Although calcium excretion in the urine is increased, there is a simultaneous increase in calcium absorption from the intestine. Negative calcium balance, however, may occasionally occur during somatropin treatment.
-Connective Tissue Metabolism
Somatropin stimulates the synthesis of chondroitin sulfate and collagen, and increases the urinary excretion of hydroxyproline.
- Anti-aging – 0.8-1iu in the morning on an empty stomach or before bedtime as two hours before injection or after it should not consume food containing fats and carbohydrates. Course duration 6-9 months.
- Fat burning – 1-3iu before the morning cardio and / or before another type of workout. A compromise is the night intake before bedtime, but not a dose large than 1.5iu because sleeping disruptions are possible. 2 hours prior to taking and 2 hours after the intake of somatropin must not accept food high in fat or carbohydrates.
- for improvement of sports performance – 1-2 iu in the morning on an empty stomach, before bedtime and / or before training. There are possible more appropriate daily intakes that can be divided into 3 doses. 2 hours before injection and 2 hours after injection must not accept food high in fat or carbohydrates.
- for muscle building – 3-6 iu daily dosage is divided into 2 or 3 doses – before training and before sleep. 2 hours before injection and 2 hours after injection must not accept food high in fat or carbohydrates.
Note: Although listed options for the intake, each case must be examined individually and to consider personal and training characteristics of each person as well as possible interactions if you take other medicines.
Somatropin can be detected for about 4 hours after taking the preparation.
- This product can be used not more than 3 years from the production date ( see box)
- After reconstitution, may be stored for a maximum of 30 days in a refrigerator at 2°C – 8°C.
- Store vials in an upright position.
- Store in a refrigerator (2°C – 8°C). Keep in the outer carton in order to protect from light.
- For one month can be stored at room temperature.