IW Caple

TL;DR: Perfusion in situ of the placenta of intact or previously parathyroidectomized fetal lambs has been used to assess the ability of three mid‐molecule fragments of the humanParathyroid hormone‐related protein (PTHrP) molecule to stimulate the placental transport of calcium and magnesium.

TL;DR: Perfusion in situ of the placenta of previously thyroparathyroidectomized fetal lambs has been used to compare the ability of various forms of parathyroid hormone-related protein to stimulate placental calcium transport, and it is suggested that post-translational processing of PTHrP (1-141) may occur as an activating step in thePlacenta in vivo.

TL;DR: It is suggested that in the ovine fetus, parathyroid hormone promotes the active transport of calcium from mother to fetus, so that in its absence the fetus must obtain its calcium for growth by reducing its calcaemia and thereby allow net diffusion of calcium to replace the action of the placental calcium pump.

TL;DR: The ovine fetal PTHrP may be responsible for maintaining the fetus hypercalcaemic relative to the mother, the humoral hyperCalcaemic factor associated with malignancy in man.

TL;DR: It was concluded that a mid‐molecule portion of PTHrP can stimulate a putative placental pump which is responsible for the gradients of both calcium ions and magnesium across the ovine placenta.