Introduction
Gonadotropin-releasing hormone 1 (GNRH1), also called Luteinizing-hormone releasing hormone (LHRH), is a hormone that triggers the release of other hormones, namely follicle-stimulating hormone (FSH) and luteinizing hormone (LH), from the pituitary gland. GNRH1 itself is produced and released by a part of the brain called the hypothalamus.
When GNRH1 reaches the pituitary gland, it stimulates the production and release of FSH and LH. The pattern of GNRH1 release, in terms of the amount and frequency, influences how much FSH and LH are released. Additionally, hormones like androgens and estrogens also provide feedback that affects this process. Low-frequency pulses of GNRH1 mainly lead to FSH release, while high-frequency pulses primarily trigger LH release.
The way GNRH1 is secreted differs between males and females. In males, GNRH1 is released in pulses at a consistent frequency. However, in females, the frequency of these pulses changes throughout the menstrual cycle, with a significant surge in GNRH1 right before ovulation.
The pulsatile release of GNRH1 is essential for proper reproductive function in all vertebrates. This single hormone plays a crucial role in a complex series of events in females, including the growth of follicles (which contain eggs), the release of an egg (ovulation), and the maintenance of the corpus luteum (a structure that forms after ovulation). In males, GNRH1 is vital for the production of sperm.
Description
Synthetic human Lutenizing Hormone Releasing Hormone is a single chain molecule, not containing any sugar molecules, composed of 10 amino acids. Its molecular weight is 1182.2 Daltons, and its chemical formula is C55H75N17O13.C2H4O2. It is uniquely identified by the CAS Number 71447-49-9.
Physical Appearance
It appears as a white powder, sterilized by filtration and dried by freezing (lyophilized).
Formulation
The LHRH, in a concentrated solution of 1 mg/ml, undergoes a freeze-drying process to remove water, resulting in a powder form. No additional substances are added during this process.
Solubility
To reconstitute the freeze-dried LHRH, it is recommended to dissolve it in sterile water with a pH of 9 (adjusted using sodium hydroxide) at a concentration not less than 100 micrograms per milliliter. This solution can then be diluted further with other aqueous solutions if needed. Alternatively, LHRH can also be dissolved in a 1% solution of glacial acetic acid.
Stability
Lyophilized LHRH, though stable at room temperature for up to 3 weeks, should ideally be stored in dry conditions at a temperature below -18°C. Once reconstituted, LHRH can be stored at 4°C for 2-7 days. For longer storage periods, it should be kept at or below -18°C.
To further enhance long-term storage stability, adding a carrier protein like 0.1% HSA or BSA is recommended.
Repeated cycles of freezing and thawing should be avoided.
Purity
The purity is determined to be greater than 98.0% using a technique called Reverse Phase High Performance Liquid Chromatography (RP-HPLC).
Synonyms
Progonadoliberin-1, Progonadoliberin I, LHRH, GRH, GNRH, LNRH.
Amino Acid Sequence
Pyr-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2.
