Geoffrey N. Hendy

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Antidiuretic hormone (arginine vasopressin) binds to and activates V2 receptors in renal collecting tubule cells. Subsequent stimulation of the Gs/adenylyl cyclase system promotes insertion of water pores into the luminal membrane and thereby reabsorption of fluid. In congenital nephrogenic diabetes insipidus (CNDI), an X-linked recessive disorder, the(More)
Targeted deletion of genes encoding the 1,25-dihydroxyVitamin D [1,25(OH)(2)D]-synthesizing enzyme, 25 hydroxyVitamin D-1alpha-hydroxylase [1alpha(OH)ase or CYP27B1], and of the nuclear receptor for 1,25(OH)(2)D, the Vitamin D receptor (VDR), have provided useful mouse models of the inherited human diseases, Vitamin D-dependent rickets types I and II. We(More)
BACKGROUND The regulation of extracellular calcium concentration by parathyroid hormone is mediated by a calcium-sensing, G-protein-coupled cell-surface receptor (CASR). Mutations of the CASR gene alter the set-point for extracellular ionised calcium [Ca2+]o and cause familial hypercalcaemia or hypocalcaemia. The CASR missense polymorphism, A986S, is common(More)
Parathyroid hormone-like peptide (PLP) is a newly discovered novel peptide that interacts with renal and osseous parathyroid hormone (PTH) receptors through its amino-terminal sequence, which is homologous with PTH. Human PLP is the product of a complex single-copy gene, existing in several isoforms which result from alternative exon usage. The peptide was(More)
Familial isolated hyperparathyroidism (FIHP) can result occasionally from the incomplete expression of a syndromic form of familial hyperparathyroidism (HPT), specifically multiple endocrine neoplasia type 1 (MEN1), familial hypocalciuric hypercalcemia, or the hyperparathyroidism-jaw tumor syndrome (HPT-JT). The cause of FIHP has not been identified in the(More)
Previous studies have identified eight variant human GH receptor (hGHR) messenger RNA (mRNAs; V1-V8), that differ in their 5'-untranslated regions (5'UTRs) but splice into the same site just upstream of the translation start site in exon 2; thus, they encode the same protein. Here we report a novel variant, V9, and describe the mapping of all nine 5'UTR(More)
In subprimates, significant onset of growth hormone receptor (GHR) expression occurs only after birth whereas, in the human, GHR mRNA and protein are widely manifest from the first trimester of fetal life. Thus, it is likely that subprimates are not the best models for studying regulation of human GHR gene transcription, especially during early stages in(More)
X-linked nephrogenic diabetes insipidus (NDI) is a rare disease with defective renal and extrarenal arginine vasopressin V2 receptor responses due to mutations in the AVPR2 gene in Xq28. To study the cause of loss of function of mutant V2 receptors, we expressed 12 mutations (N55H, L59P, L83Q, V88M, 497CC-->GG, deltaR202, I209F, 700delC, 908insT, A294P,(More)
Activin, a member of the TGFbeta superfamily, is a negative regulator of cell growth and prolactin (PRL) production in pituitary lactotrope cells. However, the mechanisms by which this growth factor exerts its growth-inhibitory and -repressive effect on PRL remain unclear. In this study, we show that activin negatively regulates PRL expression at the(More)
To determine if molecular and immunohistochemical (IHC) features of the HRPT2/CDC73 gene and its product, parafibromin, predict the natural history of parathyroid malignancy, particularly atypical adenoma, as seen in a single-centre patient cohort. Matched tumor and non-tumor tissues were obtained from 46 patients with parathyroid carcinoma (CA) (n = 15),(More)