Identification and partial characterization of parathyroid hormone-related protein in human and bovine milk

Ratcliffe, W. A.; Green, E.; Emly, Jean F.; Norbury, S; Lindsay, Mitchell; Heath, David A.; Ratcliffe, John G.

doi:10.1677/joe.0.1270167

Cited by 66 publications

(38 citation statements)

References 17 publications

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“…A rumen fistula * Present address: Department of Veterinary Medicine, Punjab Agricultural University, Ludhiana, 141004 India. Ratcliffe, 1990). The specific activity of the tracer was 6-9 MBq/cg.…”

Section: Methodsmentioning

confidence: 95%

The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

Dua¹,

Abbas²,

Care³

1995

Experimental Physiology

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SUMMARYParathyroid hormone-related protein (PTHrP(1-34)) was infused into five sheep, each fitted with a large rumen cannula. After infusion, significant increases were observed in the total and ionized calcium concentrations in plasma but not in saliva. In contrast, significant decreases in the plasma concentrations of phosphate and potassium and corresponding increases in their salivary concentrations and clearance rates were observed. The salivary concentration of endogenous PTHrP(1-34) was significantly greater than that in plasma sampled simultaneously, but during the infusion of PTHrP(1-34) both plasma and salivary concentrations of PTHrP(1-34) increased.

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Section: Methodsmentioning

confidence: 95%

The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

Dua¹,

Abbas²,

Care³

1995

Experimental Physiology

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“…PTHrP was originally cloned from small amounts expressed by tumors causing humoral hypercalcemia of malignancy, and shown to circulate in picomolar amounts in the blood of affected patients. But it later became apparent that 1,000 -10,000 times the concentration of the elusive protein was readily available in milk, whether produced by breastfeeding women or obtained from the corner store (134,208,473,681,742,812). Milk was tested in part because it had been known for some time that hypoparathyroid and aparathyroid women normalize mineral homeostasis or even become hypercalcemic while breastfeeding, which suggested the presence of a PTH-like factor during lactation (see sect.…”

Section: Pthrpmentioning

confidence: 99%

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

Kovacs

2016

Physiological Reviews

383

524

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During pregnancy and lactation, female physiology adapts to meet the added nutritional demands of fetuses and neonates. An average full-term fetus contains ϳ30 g calcium, 20 g phosphorus, and 0.8 g magnesium. About 80% of mineral is accreted during the third trimester; calcium transfers at 300-350 mg/day during the final 6 wk. The neonate requires 200 mg calcium daily from milk during the first 6 mo, and 120 mg calcium from milk during the second 6 mo (additional calcium comes from solid foods). Calcium transfers can be more than double and triple these values, respectively, in women who nurse twins and triplets. About 25% of dietary calcium is normally absorbed in healthy adults. Average maternal calcium intakes in American and Canadian women are insufficient to meet the fetal and neonatal calcium requirements if normal efficiency of intestinal calcium absorption is relied upon. However, several adaptations are invoked to meet the fetal and neonatal demands for mineral without requiring increased intakes by the mother. During pregnancy the efficiency of intestinal calcium absorption doubles, whereas during lactation the maternal skeleton is resorbed to provide calcium for milk. This review addresses our current knowledge regarding maternal adaptations in mineral and skeletal homeostasis that occur during pregnancy, lactation, and post-weaning recovery. Also considered are the impacts that these adaptations have on biochemical and hormonal parameters of mineral homeostasis, the consequences for long-term skeletal health, and the presentation and management of disorders of mineral and bone metabolism.

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“…If milk STC-1 levels were indeed reduced by antibody treatment, this could have negatively affected those enzymes that are responsible for the intestinal absorption of fat. Precedents for the presence of peptide hormones in milk have already been established in the case of parathyroid hormone-related peptide (PTHrP) (7,45) and leptin (11). PTHrP is believed to have positive absorptive effects on the neonate gut by relaxing visceral smooth muscle and increasing luminal gut volume (41).…”

Section: -Test) Bmentioning

confidence: 99%

Passive immunization of lactating mice with stanniocalcin-1 antiserum reduces mammary gland development, milk fat content, and postnatal pup growth

Zaidi¹,

James²,

Wagner³

2006

American Journal of Physiology-Endocrinology and Metabolism

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. Passive immunization of lactating mice with stanniocalcin-1 antiserum reduces mammary gland development, milk fat content, and postnatal pup growth. Am J Physiol Endocrinol Metab 291: E974 -E981, 2006. First published June 13, 2006; doi:10.1152/ajpendo.00601.2005.-During pregnancy and lactation in rodents, stanniocalcin-1 (STC-1) production by the ovaries is upregulated markedly and released into the circulation. The mammary glands are one target of this systemically delivered hormone. The purpose of this study was to lower serum levels of STC-1 in lactating mice through passive immunization so as to monitor the effects on mammary gland function and postnatal pup growth. Passive immunization significantly reduced circulating hormone levels, and pup growth was significantly compromised (30%), even though control and experimental litters had ingested equal amounts of milk. When mammary glands were analyzed, the alveolar area was significantly reduced in antibody-treated mothers. An analysis of milk composition revealed no changes in lactose, protein, or electrolyte levels but an ϳ40% reduction in triglyceride levels. The latter was due to a significant reduction in mammary gland lipoprotein lipase activity and led to a significant buildup of triglycerides in the serum. Body fat content was also significantly reduced in pups from antibody-treated mothers, whereas pup fecal fat content was increased. In mothers, passive immunization also caused significant behavioral effects, in particular, increased locomotor and hindleg rearing activities. Collectively, the results suggest that systemically derived STC-1 has important effects on mammary gland development and the transfer of serum-based triglycerides into milk. Locomotor effects suggest that STC-1 also has a role in maternal behavior. development; lipoprotein lipase; behavior IN RODENTS, THE OVARIES HAVE THE HIGHEST LEVELS of stanniocalcin-1 (STC-1) gene expression. The gene is expressed predominantly by androgen-producing theca cells and interstitial cells. During nonpregnancy, ovarian STC-1 appears to be targeted locally to nearby corpus luteal cells, which contain high levels of receptors and where the ligand has pronounced inhibitory effects on progesterone release (38). An endocrine pathway becomes operative during pregnancy and lactation. In the pregnant mouse, the levels of ovarian STC-1 gene expression are upregulated 15-fold (10). Expression levels drop at parturition and then rise and remain high throughout the lactation phase. In parallel, serum levels of STC-1 rise and fall in concert with the changing levels of ovarian expression (10).During lactation, the high levels of ovarian STC-1 expression are sustained by the sucking stimulus, implying that the hormone is being targeted to the mammary glands. This notion has recently been given credence in studies on virgin, pregnant, and lactating rats (16). The virgin rat mammary gland has high levels of STC-1 receptors and also expresses the STC-1 gene. The majority of receptors are on microsomal membranes ...

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Identification and partial characterization of parathyroid hormone-related protein in human and bovine milk

Cited by 66 publications

References 17 publications

The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

Passive immunization of lactating mice with stanniocalcin-1 antiserum reduces mammary gland development, milk fat content, and postnatal pup growth

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