Roesink J M, Konings A W, Terhaard C H, Battermann J J, Kampinga H H, Coppes R P
Department of Radiotherapy, University of Utrecht, The Netherlands.
Int J Radiat Oncol Biol Phys. 1999 Sep 1;45(2):483-9. doi: 10.1016/s0360-3016(99)00185-6.
To study the ability of a prophylactic pilocarpine administration to preserve the rat parotid gland function after unilateral irradiation with graded doses of X-rays.
The right parotid gland of male albino Wistar rats was irradiated with single doses of X-rays (10-30 Gy, at 1.5 Gy min(-1)). Pilocarpine (4 mg/kg) was administered intraperitoneally, 1 hour prior to irradiation. Saliva samples of both left and right parotid gland were collected by means of miniaturized Lashley cups 4 days before and 3, 7, 10, and 30 days after irradiation. The parotid salivary flow rate (microl/min) was used as a parameter for the assessment of parotid gland function.
Our data confirm that a single prophylactic treatment of pilocarpine can attenuate radiation-induced loss of gland function. Surprisingly, the effect of pilocarpine was not restricted to the irradiated gland only. Pilocarpine also enhanced the flow rate in the contralateral, nonirradiated gland. The latter effect was found for all doses above 10 Gy and became apparent around 7 days after the radiation treatment. The effectiveness of pilocarpine to attenuate function loss in the irradiated gland decreased with increasing dose and was lost after single doses of 30 Gy.
Our data provide direct evidence that increasing the compensatory potential of the nondamaged gland, at least in part, underlies the "radioprotective effect" of pilocarpine in case of unilateral radiation. The ability of pilocarpine to ameliorate the early radiation-induced impairment of the parotid gland function in the irradiated gland may therefore be dependent on the remaining number of functional cells, and thus on the volume of the gland that lies within the radiation portal.
研究预防性给予毛果芸香碱对大鼠腮腺在单侧分次X射线照射后功能的保护作用。
雄性白化Wistar大鼠的右侧腮腺接受单次X射线照射（10 - 30 Gy，1.5 Gy/min）。在照射前1小时腹腔注射毛果芸香碱（4 mg/kg）。在照射前4天以及照射后3、7、10和30天，通过小型Lashley杯收集左右腮腺的唾液样本。以腮腺唾液流速（微升/分钟）作为评估腮腺功能的参数。
我们的数据证实，单次预防性给予毛果芸香碱可减轻辐射诱导的腺体功能丧失。令人惊讶的是，毛果芸香碱的作用并不局限于受照射的腺体。毛果芸香碱还提高了对侧未受照射腺体的流速。在所有高于10 Gy的剂量下均发现了后一种效应，并且在放射治疗后约7天变得明显。毛果芸香碱减轻受照射腺体功能丧失的有效性随剂量增加而降低，在单次给予30 Gy后丧失。
我们的数据提供了直接证据，即增加未受损腺体的代偿潜力至少部分是毛果芸香碱在单侧辐射情况下“辐射防护作用”的基础。因此，毛果芸香碱改善受照射腺体早期辐射诱导的腮腺功能损害的能力可能取决于功能性细胞的剩余数量，进而取决于位于辐射野内的腺体体积。
