Pasley J N, Barnes C L, Rayford P L
Prog Clin Biol Res. 1987;227A:371-8.
Fluctuations in serum gastrin and plasma cholecystokinin (CCK) over a 24-hr period were examined in fasted and freely fed adult BALB/c mice and Sprague Dawley rats. Eighty-four mice and 84 rats were caged in groups of (six) each and placed in separate isolation chambers with light from 0600 to 1800 hr (CST) daily (LD 12:12). After standardization for 30 days, one-half of the animals were fasted 24 hr prior to circadian sampling, and the remainder were allowed continuous access to food. Animals were removed and killed by rapid cervical dislocation every 4 hr beginning at 0800 hr for seven time points. Blood was collected and serum gastrin and plasma CCK were measured by specific radioimmunoassays. The data document a circadian bioperiodicity for serum gastrin and plasma CCK. The parameters of the rhythms, evaluated by cosinor rhythmometric methods, are characterized by an acrophase that occurs in the dark period for both fed and fasted rodents and a mesor that is higher in fed than fasted animals. Circadian sampling time and nutritional status appear to be important in studies involving serum levels of gastrin and plasma CCK in rodents.
在禁食和自由进食的成年BALB/c小鼠和Sprague Dawley大鼠中，研究了24小时内血清胃泌素和血浆胆囊收缩素（CCK）的波动情况。84只小鼠和84只大鼠每6只一组关在笼中，每天置于单独的隔离室，光照时间为06:00至18:00（中部标准时间）（光照-黑暗周期为12:12）。标准化30天后，一半动物在昼夜采样前禁食24小时，其余动物可连续进食。从08:00开始，每隔4小时处死一组动物，共七个时间点，通过快速颈椎脱臼法将动物处死。采集血液，用特异性放射免疫分析法测定血清胃泌素和血浆CCK。数据证明血清胃泌素和血浆CCK存在昼夜生物节律。通过余弦节律测定法评估的节律参数的特征是，进食和禁食的啮齿动物的高峰相位均出现在黑暗期，且进食动物的中值比禁食动物更高。在涉及啮齿动物血清胃泌素水平和血浆CCK水平的研究中，昼夜采样时间和营养状况似乎很重要。
