Related Experiment Video
Updated: Aug 18, 2026

Two Techniques to Create Hypoparathyroid Mice: Parathyroidectomy Using GFP Glands and Diphtheria-Toxin-Mediated Parathyroid Ablation
Published on: March 14, 2017
Parathyroid hormone-related proteins in cultured epithelial cells
H M Docherty1, M J Dixon-Lewis, P G Milton
1Department of Medicine, University of Birmingham, Queen Elizabeth Hospital.
Abstract:
The distribution and molecular characteristics of parathyroid hormone-related protein (PTH-rP) in conditioned media and cell extracts of cultured human keratinocytes, and in media from a variety of both normal and transformed epithelial and non-epithelial cell cultures were studied. PTH-rP of Mr 20,000 was observed in keratinocyte-conditioned media, and a larger form, Mr 29,000, in the keratinocyte cell extract. PTH-like bioactivity was also detected in media from 12 out of 17 epithelial cell cultures, but was not present in media from 14 cell cultures of non-epithelial origin. The molecular size of the PTH-like protein present in the epithelial cell media was approximately 20,000, corresponding with the PTH-rP in keratinocyte-conditioned medium. These observations may explain why hypercalcaemia is most commonly associated with tumours of epithelial origin.
Related Concept Videos
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:
Secondary Messengers in Hormone Action
Many hormones bind to transmembrane G protein-coupled receptors that connect to regulatory G proteins. These G proteins can then activate enzymes such as adenylyl cyclase or phospholipase C. Adenylyl cyclase converts ATP to cAMP, activating...
Synthesis and Functions of Calcitonin
The exact mechanisms by which calcitonin operates in calcium homeostasis remain elusive, but its significance is evident in several vital...
The Parathyroid Glands
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by producing...
Roles of Electrolytes: Calcium and Phosphate
The calcium concentration in blood plasma is primarily regulated...

