PTH (1-84) N15 Human

Parathyroid Hormone (PTH) is a critical hormone secreted by the parathyroid glands. The specific form, Parathyroid Hormone (1-84) N15 Labeled (Human Recombinant), is a recombinant version of the full-length human PTH, consisting of 84 amino acids. This version is labeled with the stable isotope Nitrogen-15 (N15), which is often used in research to track and study the hormone’s behavior and interactions .

PTH (1-84) N15 is produced in Escherichia coli (E. coli) as a single, non-glycosylated polypeptide chain. It has a molecular mass of approximately 9550 Daltons . The hormone is purified using proprietary chromatographic techniques to ensure high purity, typically greater than 97% as determined by RP-HPLC and SDS-PAGE analysis .

PTH plays a crucial role in regulating calcium levels in the blood. It acts on three primary sites in the body:

1. Bones: PTH enhances the release of calcium from bones by stimulating osteoclasts indirectly. It binds to receptors on osteoblasts, which then increase the expression of RANKL, leading to the formation and activation of osteoclasts .
2. Kidneys: PTH increases the reabsorption of calcium in the distal tubules and the thick ascending limb of the nephron .
3. Intestines: PTH indirectly increases calcium absorption in the intestines by stimulating the production of active vitamin D (1,25-dihydroxy vitamin D), which enhances calcium uptake .

PTH is one of the primary hormones involved in calcium homeostasis, along with calcitonin and vitamin D. It is secreted in response to low blood calcium levels and works to increase calcium concentration by mobilizing calcium from bones, increasing renal reabsorption, and enhancing intestinal absorption . The secretion of PTH is tightly regulated by the calcium-sensing receptors on the parathyroid glands .

The N15-labeled version of PTH (1-84) is particularly valuable in research settings. The stable isotope labeling allows for detailed studies of the hormone’s kinetics, interactions, and metabolic pathways. This can provide insights into the hormone’s role in various physiological and pathological conditions, including osteoporosis and hypoparathyroidism .

Lyophilized PTH (1-84) N15 is stable at room temperature for up to three weeks but should be stored desiccated below -18°C for long-term storage. Upon reconstitution, it should be stored at 4°C for short-term use (2-7 days) and below -18°C for long-term use. It is recommended to add a carrier protein, such as 0.1% HSA or BSA, to prevent freeze-thaw cycles .