this study aimed to explore and validate a new juvenile osteopenic (jo) rat model then examine the efficacy of moghat (glossostemon bruguieri) as an alternative reversal therapy for jo. phytochemical screening analysis showed that moghat contains 5.8% alkaloids, 1.5% flavonoids and 13.2% total phenols. juvenile osteopenia was induced in 15 days old sprague- dawley female rats by feeding them fr...

Biologic effects of large C-terminal parathyroid hormone (PTH) fragments, opposite to those of N-terminal PTH, have been demonstrated. C-terminal PTH fragments are co-secreted with N-terminal PTH from the parathyroids. The aim of our study was to examine whether C-terminal PTH 7-84 regulates secretion of PTH 1-84 and affects the expression of genes of relevance for parathyroid function, PTH, ca...

Partially purified bovine parathyroid hormone (PTH) produced two kinds of antisera, GP-100 reacting with 125I-labeled bovine PTH (b-PTH 1-84) alone and GP-M reacting with 125I-labeled synthetic N-terminal portion of bovine PTH (b-PTH 1-34) as well as b-PTH 1-84. Rat serum PTH reacted with the latter but not in the former, suggesting a similarity to b-PTH 1-34. Rat serum PTH became undetectabl...

Highly purified bovine parathyroid hormone (b-PTH 1-84) and its synthetic N-terminal peptide (b-PTH 1-34) were labelled with 125-I and incubated with rat kidney homogenate at 37 degrees C for 1 hour to assess the degree of hydrolysis of the iodinated peptides through measurement of the increase of trichloroacetic acid soluble 125-I fraction. Rat kidney homogenate rapidly hydrolyzed b-PTH 1-84 b...

The parathyroid hormone (PTH) 2 receptor is potently activated by tuberoinfundibular peptide (TIP39). Rat and human PTH2 receptors differ considerably in their PTH responsiveness. PTH weakly stimulates cAMP accumulation via the rat receptor, and here we show it did not detectably increase intracellular calcium ([Ca2+]i) and bound with low affinity (450 nM). For the human PTH2 receptor PTH was a...

The Cbfa1/Runx2 (referred to herein as Cbfa1) transcription factor has been shown to be essential for osteoblast differentiation and bone formation during embryogenesis. PTH given intermittently is a proven bone anabolic agent. Here, we investigated whether PTH regulates the expression and/or activity of Cbfa1 in osteoblastic cells and in a rat metatarsal organ culture assay. PTH was found to r...

Secondary hyperparathyroidism is a major complication of chronic kidney disease (CKD). In experimental models of secondary hyperparathyroidism induced by hypocalcemia or CKD, parathyroid hormone (PTH) mRNA levels increase due to increased PTH mRNA stability. K-homology splicing regulator protein (KSRP) decreases the stability of PTH mRNA upon binding a cis-acting element in the PTH mRNA 3' UTR ...

PTH is a major regulator of renal proximal tubule 1,25(OH)2D3 biosynthesis. However, the intracellular pathways involved in PTH activation of the mitochondrial 25-hydroxyvitamin D3-1 alpha-hydroxylase (1-OHase) remain unknown. PTH can activate both the adenylate cyclase/protein kinase A (PKA) and the plasma membrane phospholipase C/protein kinase C (PKC) pathways. The present study was undertak...

Parathyroid hormone (PTH) inhibits proximal tubular reabsorption of P(i) by retrieval of type IIa Na-P(i) cotransporters (NaPi-IIa) from the brush-border membrane (BBM). We analyzed by immunohistochemistry whether PTH analogs, signaling through either protein kinase A (PKA) and C (PKC; 1-34 PTH) or only PKC (3-34 PTH), elicit in rat kidney in vivo or in the perfused murine proximal tubule in vi...

The humoral hypercalcemia of malignancy (HHM) is caused by tumor cells that release a circulating factor which stimulates osteoclastic bone resorption. Recently, it has been reported that tumors associated with HHM contain factors that stimulate renal and bone cell adenylate cyclase. The activity was inhibited by parathyroid hormone (PTH) antagonists, and this led to the hypothesis that hyperca...