Animal physiology : from genes to organisme

23a,759 p .; 30 cm

A radioimmunoassay for serum rat thyroglobulin. Physiologic and pharmacological studies.

A double antibody radioimmunoassay has been developed to measure thyroglobulin in rat (RTg) serum. The lowest detectable quantity measurable was 5.0 ng/ml. Specificity was documented by: (a) fall in serum RTg to undetectable levels after thyroid ablation; (b) the fact that L-thyroxine, D-thyroxine, L-triiodothyronine, D-triiodothyronine, triiodothyroacetic acid, tetraiodothyroacetic acid, triiodothyropropionic acid, moniodotyrosine, diiodotyrosine, and human thyroglobulin (HTg) in concentrations up to 40,000 ng per tube did not cross-react in the assay; (c) the demonstration that constant levels of serum RTg were observed while varying amounts of serum (criterion of parallelism) were introduced in the assay. The mean RTg concentration in tail vein blood of adult Sprague-Dawley rats were 101.5 +/- 13.0 ng/ml (SEM) (n=21); values ranged from 12.0 to 258.0 ng/ml. Chronic administration of a high-iodine diet (HID) did not affect serum thyroglobulin levels. Chronic administration of a low-iodine diet (LID) and propylthiouracil (PTU) led to a statistically significant increase in serum RTg that was accompanied by a significant rise in serum thyrotropin (rTSH). Serum thyroxine (T4) administered to normal rats for 14 days (20 mug/day subcutaneously) depressed serum RTg concentration from a mean level of 119.4 +/- 17.5 ng/ml (n=19) to a mean of 35.0 +/- 0.27 ng/ml (n=19) (P less than 0.001). While rats were on continuous T4 suppression, bovine thyroid-stimulating hormone (bTSH) given intravenously (2 IU) resulted in a mean maximal increment of RTg of 332.0 +/- 81.5 ng/ml (n=6) at 24 h. IgC-(LATS) long-acting thyroid stimulatory injected intravenously resulted in a mean maximal increment of RTg concentration at 96 h of 87.2 +/- 14.3 ng/ml (n=5). Normal IgG had no statistical significant effect of RTg levels at any time after the injection

Health status and population demographics of free-living endangered black cockatoos (Calyptorhynchus spp.) in Western Australia

The three species of black cockatoo endemic to the south-west of Western Australia (Carnaby's Black Cockatoo Calyptorhynchus latirostris, Baudin's Black Cockatoo Calyptorhynchus baudinii and Red-Tailed Black Cockatoo Calyptorhynchus banksii naso) face population declines as a result of several threatening factors including habitat loss and fragmentation, poaching for the pet trade, competition with other species for nesting hollows, vehicle strikes, shootings and extreme weather events. A research project to determine the health status and population demographics of wild black cockatoos is currently being undertaken by Murdoch University as a collaborative project with the Department of Environment and Conservation, Perth Zoo and University of West Virginia, with support from Newmont Boddington Gold, BHP Billiton Worsley Alumina and the Department of Environment and Conservation (DEC). Whilst this initial research project has funding for a three year period, it is hoped that this project will be able to be conducted over the long-term

Effects of a Phytogenic Feed Additive Versus an Antibiotic Feed Additive on Oxidative Stress in Broiler Chicks and a Possible Mechanism Determined by Electron Spin Resonance

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