Phosphorylation of heat shock protein-90 by TSH in FRTL-5 thyroid cells.

Context: Although it is well established that thyrotropin (TSH) initiates signal transduction systems resulting in protein kinase(s) activation, the phosphorylated targets have not been fully characterized.

Objective/design: In FRTL-5 thyroid cells, we used two-dimensional (2D) gel images of silver-stained proteins isolated from FRTL- 5 thyroid cells following TSH stimulation to identify potential phosphorylation targets.

Results: We characterized a 90 kDa protein that had undergone a pH shift and subsequently identified it as heat shock protein-90 (hsp-90) following in-gel trypsin digestion and mass spectroscopy.

Identification and purification of parathyroid hypertensive factor from organ culture of parathyroid glands from spontaneously hypertensive rats.

Parathyroid hypertensive factor (PHF) is a newly described hypertensive factor isolated from the plasma of spontaneously hypertensive rats (SHR). Recent studies have suggested that the primary origin of PHF is the parathyroid gland (PG). In the present investigation, PG from spontaneously hypertensive rats (SHR), as well as from normotensive rats, were isolated and maintained in culture.

Rainbow trout corpuscles of Stannius: stanniocalcin synthesis in vitro.

In fresh-water rainbow trout, Oncorhynchus mykiss (formerly called Salmo gairdneri), experimentally induced mild hypercalcemia results in release of immunoreactive stanniocalcin from the corpuscles of Stannius (CS) and stimulated synthetic and releasing activities of the glands as measured in vitro. Pulse-chase experiments showed that stanniocalcin (STC) is a 56-kDa glycoprotein, processed from a 64-kDa precursor, prostanniocalcin (PSTC). PSTC and STC are homodimeric molecules that are readily split into monomers in the presence of reducing agents such as 2-mercaptoethanol.

Localization of calcitonin gene-related peptide in the small intestine of various vertebrate species.

Calcitonin gene-related peptide (CGRP) was found extensively in the small intestine of both non-mammalian and mammalian vertebrates using radioimmunoassay and immunocytochemistry. By radioimmunoassay, the levels of CGRP in rats, mice, chickens, bullfrogs and rainbow trout were found to range from 91.5 to 419.