Comparison of meat composition from offspring of cloned and conventionally produced boars.

This study compares the meat composition of the offspring from boars produced by somatic cell nuclear transfer (n=4) to that of the offspring from conventionally produced boars (n=3). In total, 89 commercial gilts were artificially inseminated and 61 progressed to term and farrowed. All of the resulting piglets were housed and raised identically under standard commercial settings and slaughtered upon reaching market weight. Loin samples were taken from each slaughtered animal and shipped offsite for meat composition analysis. In total, loin samples from 404 animals (242 from offspring of clones and 162 from controls) were analyzed for 58 different parameters generating 14,036 and 9396 data points from offspring of clones and the controls, respectively. Values for controls were used to establish a range for each parameter. Ten percent was then added to the maximum and subtracted from the minimum of the control range, and all results within this range were considered clinically irrelevant. Of the 14,036 data points from the offspring of clones, only three points were found outside the clinically irrelevant range, two of which were within the range established by the USDA National Nutrient Database for Standard Reference, Release 18, 2005; website: (www.nal.usda.gov/fnic/foodcomp/search/). The only outlier was the presence of Eicosadienoic acid (C20:2) in one sample which is typically present in minute quantities in pork; no reference data were found regarding this fatty acid in the USDA National Nutrient Database. In conclusion, these data indicated that meat from the offspring of clones was not chemically different than meat from controls and therefore supported the case for the safety of meat from the offspring of clones.

Mifepristone modulation of ACTH and CRH regulation of bovine adrenocorticosteroidogenesis in vitro.

Mifepristone (RU486), bovine corticotropin-releasing hormone (CRH), arginine vasopressin (VP), adrenocorticotropin (ACTH1-24), and protein kinase activators (forskolin, [FSK]; phorbol 12-myristate 13-acetate [PMA]) were used in vitro to investigate their direct effect on adrenocorticosteroidogenesis. Bovine adrenocortical fasciculata/reticularis cells (2 x 10(5) viable cells/well) were cultured for 3 d in medium supplemented with 10% fetal calf serum. After incubation for an additional 24 hr in serum-free medium, cells were treated with serum-free medium alone (Control) or various concentrations of ACTH, CRH, VP, FSK, PMA, RU486, and/or various concentrations for 1, 2, 4, or 24 hr. Medium content of cortisol and progesterone were determined by radioimmunoassays. ACTH, CRH, FSK, and PMA each stimulated (P < 0.05) secretion of cortisol in time- and dose-related manners. Although these agents stimulated (P < 0.05) secretion of progesterone in a dose-related manner, medium content of progesterone declined (P < 0.05) over time. The minimal effective doses of ACTH and CRH required to stimulate (P < 0.05) secretion of cortisol relative to the Control over a 4-hr culture period were 0.01 nM and 3 nM, respectively. Relative to observations at 1 hr posttreatment, 24-hr treatment with ACTH or CRH increased the medium content of cortisol by an additional 19.8- and 48-fold, respectively (whereas content of progesterone declined over that time period). VP-stimulated secretion of cortisol was time- (P < 0.05) but not dose-related. Specifically, by 24-hr posttreatment, the medium content of cortisol was increased (P < 0.05) 4.6-fold relative to the quantity of cortisol secreted by 1-hr postaddition of VP (0.01 to 1 microM). Co-treatment with RU486 (1 microM) decreased (p < 0.05) FSK-, ACTH- and CRH-stimulated secretion of cortisol by 77, 27, and 56%, respectively. Similarly, the stimulatory effects of ACTH and CRH on progesterone secretion were reduced (P < 0.05) by 40 and 22%, respectively, by co-addition of RU486. The inhibitory action of RU486 on production of cortisol was no longer apparent by 24 hr after treatment. These observations indicate that RU486 can act as a steroid agonist and as well as an antagonist. These data characterize time- and dose-related direct actions of ACTH, CRH, and RU486 on adrenocorticosteroidogenesis. This information will assist efforts to clarify complex intra-adrenal interactions of neurohormones, growth factors, and endogenous steroids.