CIRCANNUAL VARIATION OF INTESTINAL CELL PROLIFERATION IN BDF-1 MALE MICE ON 3 LIGHTING REGIMENS
CIRCANNUAL VARIATION OF INTESTINAL CELL PROLIFERATION IN BDF-1 MALE MICE ON 3 LIGHTING REGIMENS
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DOI：
10.3109/07420528409063895
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发表时间：
1984-01-01
影响因子：
2.8
通讯作者：
WHITE M
中科院分区：
文献类型：
--
作者：
HAUS E;LAKATUA D J;WHITE M
研究人员在冬季、春季、夏季和秋季对 BDF1 雄性小鼠进行了 24 小时的研究。研究前 3 周，.apprx。将 1/3 的动物饲养在 8 小时光照与 16 小时黑暗交替的照明方案下 (LD 8:16)，约 1/3。 1/3 采用 LD 12:12 照明方案，其余采用 LD 16:8 照明方案。在每项研究中，采用所有 3 种照明方案的动物亚组在 24 小时内每隔 4 小时被处死一次。处死前20分钟，动物每20克体重接受5μCi的[3H]-胸苷/0.2ml。研究结肠和小肠 DNA 中胸苷的摄取作为细胞增殖的指标。保持在 LD 8:16 和 LD 12:12 的动物的昼夜节律在末期和振幅方面相似。在 LD 16:8 的小鼠中，在所有 4 个季节中，结肠 DNA 中的 [3H]-胸苷摄取也存在统计学上显着的昼夜节律。然而，这种节奏的末端阶段变化很大，表明自由奔跑。小肠中[3H]-胸苷摄取的昼夜节律不太一致。然而，在采用所有 3 种照明方案的动物中，发现结肠和小肠中 DNA 中 [3H]-胸苷摄取量存在逐年变化，夏季摄取量最高。这项研究表明，LD 16:8 的照明方案不能可靠地同步结肠和小肠中该功能的昼夜节律，在被宰杀前，在 3 种照明方案（LD 8:16、12:12 和 16:8）下持续保持 3-4 周。
BDF1 male mice were studied over a 24-h span in winter, spring, summer and fall. For 3 wk prior to study, .apprx. 1/3 of the animals were kept under a lighting regimen of 8 h light alternating with 16 h of darkness (LD 8:16), .apprx. 1/3 on a lighting regimen of LD 12:12 and a remainder on a lighting regimen of LD 16:8. During each study, subgroups of animals on all 3 lighting regimens were killed at 4-h intervals over a 24-h span. Twenty minutes prior to being killed, the animals received 5 .mu.Ci of [3H]-thymidine/0.2 ml per 20 gm of body wt. The thymidine uptake in the DNA of the colon and of the small intestine were studied as an index of cell proliferation. A circadian rhythm was similar in acrophase and amplitude in the animals kept on LD 8:16 and LD 12:12. In the mice on LD 16:8, there was also a statistically significant circadian rhythm of [3H]-thymidine uptake in the DNA of the colon during all 4 seasons. The acrophases of this rhythm, however, varied widely suggesting free running. A ciradian thythm of [3H]-thymidine uptake in small intestine was less consistent. In animals on all 3 lighting regimens, however, a circannual variation of [3H]-thymidine uptake in DNA in colon and small intestine was found with the highest uptake during summer. This study indicates that a lighting regimen of LD 16:8 does not reliably synchronize the circadian rhythm of this function in the colon and in the small intestine which persists under 3 lighting regimens (LD 8:16, 12:12 and 16:8) maintained for 3-4 wk prior to being killed.