Dramatic Elevation of Plasma Metastin Concentrations in Human Pregnancy: Metastin as a Novel Placenta-Derived Hormone in Humans

Abstract

Metastin is a novel peptide that was recently isolated from human placenta as the endogenous ligand of an orphan heptahelical receptor, hOT7T175. Metastin has been shown to suppress the motility of hOT7T175-transfected melanoma cells; however, studies of the physiological function of metastin have begun only recently. To investigate the possibility that metastin is an endocrine peptide, we determined the immunoreactive (ir-) metastin concentration in human plasma using our newly developed, sensitive, and specific two-site enzyme immunoassay. The plasma concentrations of ir-metastin in males and females were 1.30 +/- 0.14 (n = 12) and 1.31 +/- 0.37 fmol/ml (n = 10), respectively. As metastin is known to be abundant in human placenta, the ir-metastin concentration in the maternal plasma was then determined. The ir-metastin concentrations were 1230 +/- 346 fmol/ml (n = 11) in the first trimester, 4590 +/- 555 (n = 16) in the second trimester, and 9590 +/- 1640 (n = 12) in the third trimester. On d 5 after delivery, the ir-metastin concentration returned to nearly the nonpregnant level (7.63 +/- 1.33 fmol/ml; n = 10), suggesting that ir-metastin increases in pregnancy and is derived mainly from the placenta. The plasma from both nonpregnant and pregnant women showed a single ir-metastin peak at the same retention time as authentic metastin on reverse phase HPLC analysis, indicating that the major portion of the circulating metastin, as determined by our two-site enzyme immunoassay, represents endogenous metastin. Histochemical studies of human placenta localized metastin mRNA and immunoreactivity to the syncytiotrophoblasts. The present study provides evidence for metastin as a novel placenta-derived hormone in humans.

Putative Prophylaxes Updated of Placenta Extract and Aloe vera as Biogenic Stimulants

“…Histochemical studies of human placenta localized metastin mRNA and immunoreactivity to the syncytiotrophoblasts. The present study provides evidence for metastin as a novel plasma-derived hormone in humans [24] .…”

Effects of Peripheral Administration of Kisspeptin on Pubertal Maturation and Serum Leptin Levels in Female Rats

“…Kiss pep tin has been re por ted to dra ma ti cally in cre a se in preg nancy. 35 The re may be a ne ga ti ve fe ed back re gu la ti on betwe en kiss pep tin and lep tin sec re ti on. Furt her stu dies are ne e ded to de ter mi ne physi o lo gi cal ro le of kiss pep tin-in du ced lep tin re duc ti on.…”

Prevention of Breast Cancer Could Be a Consequence of Pregnancy: A Review

“…In addition to estrogen and progesterone, newly secreted hormones, such as human growth hormone (hGH), hCG, human placental lactogen (hPL), and inhibin stimulate breast development and differentiation [40,41]. Elevated serum levels of Metastin (KISS1) have been detected during pregnancy [42], but the role of this hormone in breast development has not been identified as of yet. LH, progesterone and hCG are the main hormones driving the initial phase of growth, followed by the secretion of the pituitary hormone prolactin (PRL) that stimulates milk secretion and contributes to the development of the fully differentiated Lob 4 during the last trimester of pregnancy and lactation.…”