Light Victoria A, Montgomery Ron D, Akingbemi Benson T
Department of Anatomy, Auburn University, Auburn, AL 36849, USA.
Am J Vet Res. 2012 Aug;73(8):1186-93. doi: 10.2460/ajvr.73.8.1186.
To investigate the effects of gonadectomy on collagen homeostasis in cranial cruciate ligaments of male rabbits.
30 sexually immature (16-week-old) male New Zealand White rabbits.
Rabbits were randomly assigned to 5 groups of 6 rabbits each: sexually intact, placebo (control group); castrated, placebo; castrated, testosterone; castrated, dihydrotestosterone; and castrated, 17β-estradiol (E(2)). Control rabbits underwent a sham operation, and all other rabbits underwent gonadectomy. At the time of gonadectomy, the placebo and sex hormones were administered via slow-release pellets implanted subcutaneously as assigned. After 21 days of hormone supplementation, measurements were obtained of serum testosterone and E(2) concentrations, ligament collagen characteristics, and androgen receptor, estrogen receoptor α, and matrix metalloproteinase expression.
Following gonadectomy and hormone supplementation, the treatment groups differed in serum testosterone and E(2) concentrations to various degrees. Collagen concentrations were lower and fiber diameters higher in the absence of sex hormones, in association with the degrees of estrogen receptor a and androgen receptor expression. Although differences were detected among the groups in matrix metalloproteinase expression, these differences were not significant.
Sex hormones appeared to play a role in cranial cruciate ligament homeostasis in male rabbits. Physiologic changes triggered by the lack of sex hormones following gonadectomy in sexually immature rabbits may potentially predispose those rabbits to orthopedic injuries.
研究去势对雄性兔颅交叉韧带中胶原稳态的影响。
30只性未成熟（16周龄）雄性新西兰白兔。
将兔子随机分为5组，每组6只：性成熟、安慰剂组（对照组）；去势、安慰剂组；去势、睾酮组；去势、双氢睾酮组；去势、17β-雌二醇（E₂）组。对照兔接受假手术，其他所有兔均接受去势手术。在去势时，按照分组通过皮下植入缓释微丸给予安慰剂和性激素。激素补充21天后，测定血清睾酮和E₂浓度、韧带胶原特性以及雄激素受体、雌激素受体α和基质金属蛋白酶的表达。
去势和激素补充后，各治疗组血清睾酮和E₂浓度有不同程度差异。在缺乏性激素的情况下，胶原浓度较低而纤维直径较高，这与雌激素受体α和雄激素受体的表达程度有关。尽管各组间基质金属蛋白酶表达存在差异，但这些差异不显著。
性激素似乎在雄性兔颅交叉韧带稳态中起作用。性未成熟兔去势后因缺乏性激素引发的生理变化可能使这些兔子易发生骨科损伤。
