In the isotonic medium (300 mOsm), there was a significant difference (p < 0.05) in the SZ cell volumes and aspect ratios between intact cartilage samples and cartilage explants. Changes in cell volumes at both short-term (2 min) and long-term (2 h) time points after the hypotonic challenge (180 mOsm) were significantly different (p < 0.05) between the groups. Further, proteoglycan content was found to correlate significantly (r (2) = 0.63, p < 0.05) with the cell volume changes selleck chemicals in cartilage

samples with intact surfaces. Collagen content did not correlate with cell volume changes. The results suggest that the biomechanical behaviour of chondrocytes following osmotic challenge is different in intact cartilage and in click here cartilage explant. This indicates that the mechanobiological responses of cartilage and cell signalling may be significantly

dependent on the integrity of the mechanical environment of chondrocytes.”
“Effect of ractopamine hydrochloride (RH) and zilpaterol hydrochloride (ZH) on LM shear force and sensory attributes was determined using pens (n = 40) British x Continental crossbred steers randomly allocated to one of the following treatments: control; RH fed at 200 (RH 200) or 300 mg . steer(-1) . d(-1) (RH 300), or 400 mg . steer(-1) . d(-1) (RH 400) top-dressed for the final 30 d of feeding; or ZH fed at 7.5 mg/kg, beginning 23 d before slaughter with a 3-d withdrawal. Two replicates (pens) per treatment were represented in four blocks. Eighteen carcasses per pen were randomly selected and one 5-cm LM sample was removed from both carcass sides to be used for shear force and sensory evaluation. Samples were aged for 14 d, frozen at

-28.8 degrees C, and cut into 2.5-cm steaks. All steaks were cooked to an internal temperature of 71.1 degrees C before being evaluated for Warner-Bratzler shear force (WBSF), slice shear force (SSF), or being fed to trained sensory panelists. Increasing dose and potency of beta-agonist DAPT increased WBSF by 4 to 17% and SSF by 5 to 24% (P smaller than 0.05). Steaks from steers fed ZH had higher WBSF and SSF values compared with all other treatments (P smaller than 0.05), whereas steaks from controls and steers fed RH 200 were not different (P bigger than 0.05). Probability of steaks failing to meet shear force standards to be certified tender (WBSF smaller than 4.4 kg, SSF smaller than 20 kg) was increased from an initial probability of smaller than 0.06 in steaks from steers in the control treatment to 0.10 to 0.20 in steers fed RH 400 or ZH (P smaller than 0.05). No difference was detected in panel ratings for overall tenderness of steaks from steers fed RH 200 compared with controls (P bigger than 0.05). Steaks from steers fed RH 300 and RH 400 were comparable for all sensory attributes; however, both RH 300 and RH 400 were rated lower for overall tenderness than controls (P smaller than 0.05).