酵母多糖对环磷酰胺所致免疫损伤大鼠的拮抗作用

为研究酵母多糖(YP)对环磷酰胺(CTX)所致免疫损伤大鼠的拮抗作用,本实验将80只雄性SD大鼠随机分为YP(50 mg/kg)+CTX组、YP(100 mg/kg)+CTX组、YP(200 mg/kg)+CTX组、CTX对照组和正常对照组。YP+CTX组按剂量灌胃并称重,CTX和正常对照组则灌胃给予等量生理盐水,连续给药10 d;在第8 d、9 d,除正常对照组外,其余4组腹腔注射CTX 100 mg/kg。第11 d采血及对相关的免疫器官组织进行检测。结果显示,YP(100 mg/kg)组平均日增重和饲料报酬比正常对照组显著增加(p<0.05);胸腺指数,血清中IgA、IgG、表皮生长因子(EGF)、碱性磷酸酶(AKP)含量及空肠SIgA水平显著(p<0.05)或极显著(p<0.01)高于CTX对照组;结肠壁中前列腺素E2(PGE2)含量与CTX对照组相比显著降低(p<0.05)。以上结果表明,YP能提高大鼠的生长性能;YP对CTX所致免疫损伤具有一定的拮抗保护作用,其中100 mg/kg剂量的YP效果最为显著。     

A Marine Mineral Supplement Alters Markers of Bone Metabolism in Yearling Arabians

This study tested whether the supplement (Aquacid), high in calcium and other minerals, can alter markers of bone metabolism and mineralization of the equine third metacarpus bone. Radiographs were taken of the left third metacarpus of 14 yearlings. Radiographic bone aluminum equivalence (RBAE) of each cortex was calculated to estimate mineral content. Blood samples were also taken at this time. Horses were ranked according to RBAE and gender, were pair-matched, and randomly assigned to two treatment groups. Each group was provided one of two mineral supplements in addition to their normal diet. The treated group (Aq) received 75 g Aquacid/horse/d, which provided an additional 15 g of calcium. The control group (Co) received 39.5 g of limestone to provide similar amounts of calcium. The study lasted for 112 days, with blood being taken every 28 days. At day 56 and 112, additional radiographs was taken to track changes in RBAE. Blood was analyzed for osteocalcin (a bone formation marker) and serum C-telopeptide crosslaps of type I collagen (a bone resorption marker) to detect alterations in bone metabolism. Using day 0 values as a covariate for bone markers, there was a trend (P = .07) for osteocalcin concentrations to be greater in Aq horses than in Co. Likewise, C-telopeptide crosslaps of type I collagen concentrations were greater (P < .0001) in Aq horses than in Co. There were minimal differences in RBAE values. These findings suggest Aquacid, while not altering bone mass, increases bone turnover and may aid in repairing damaged bone and preventing injuries.