Cardinali D P, Cutrera R A, Bonacho M G, Esquifino A I
Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
J Pineal Res. 1997 May;22(4):210-20. doi: 10.1111/j.1600-079x.1997.tb00324.x.
Diurnal variations in splenic ornithine decarboxylase and tyrosine hydroxylase activities were examined in rats subjected to pinealectomy, bilateral superior cervical ganglionectomy, or their respective sham operations. Rats were treated with Freund's complete adjuvant or its vehicle 2 days before sacrifice. After immunization, splenic ornithine decarboxylase activity was augmented 5-6-fold. In both immunized and nonimmunized sham-operated rats, significant diurnal variations in ornithine decarboxylase activity were detectable, with a maximum at early morning, acrophases after Cosinor analysis varying from 0845 to 1048h. In pinealectomized or superior cervical ganglionectomized, immunized rats, ornithine decarboxylase activity attained values 22-27% lower than those of immunized sham-operated controls, while amplitude decreased significantly by 27-30%. Administration of melatonin (30 microg/animal s.c. at late evening for 11 days in immunized rats) significantly augmented mesor levels of splenic ornithine decarboxylase activity and increased the amplitude of the diurnal rhythm both in pinealectomized and in superior cervical ganglionectomized rats. Melatonin treatment also augmented rhythm mesor in immunized, sham-ganglionectomized rats, as well as rhythm amplitude in immunized and nonimmunized, sham-ganglionectomized rats. Splenic tyrosine hydroxylase activity attained its maximum at late afternoon and early night, with acrophases varying from 1800 to 2023h. Immunization significantly increased mesor values of splenic tyrosine hydroxylase activity, whereas neither pinealectomy nor superior cervical ganglionectomy affected circadian rhythm parameters. Melatonin treatment augmented mesor values of tyrosine hydroxylase rhythm and increased its amplitude in pinealectomized, ganglionectomized, or sham-operated rats. The results are compatible with the view that the pineal gland plays a role in circadian changes of immune responsiveness in rat spleen via an immunopotentiating effect of melatonin on splenic cell proliferation.
在接受松果体切除、双侧颈上神经节切除或各自假手术的大鼠中，检测脾脏鸟氨酸脱羧酶和酪氨酸羟化酶活性的昼夜变化。在处死前2天，用弗氏完全佐剂或其赋形剂处理大鼠。免疫后，脾脏鸟氨酸脱羧酶活性增加了5 - 6倍。在免疫和未免疫的假手术大鼠中，均可检测到鸟氨酸脱羧酶活性的显著昼夜变化，清晨达到最大值，经余弦分析后的峰值相位在0845至1048h之间变化。在松果体切除或颈上神经节切除的免疫大鼠中，鸟氨酸脱羧酶活性比免疫假手术对照大鼠低22 - 27%，而振幅显著降低27 - 30%。给予褪黑素（免疫大鼠在傍晚皮下注射30μg/只，连续11天）显著提高了松果体切除和颈上神经节切除大鼠脾脏鸟氨酸脱羧酶活性的中值水平，并增加了昼夜节律的振幅。褪黑素治疗还提高了免疫假神经节切除大鼠的节律中值，以及免疫和未免疫假神经节切除大鼠的节律振幅。脾脏酪氨酸羟化酶活性在傍晚和深夜达到最大值，峰值相位在1800至2023h之间变化。免疫显著增加了脾脏酪氨酸羟化酶活性的中值，而松果体切除和颈上神经节切除均未影响昼夜节律参数。褪黑素治疗提高了松果体切除、神经节切除或假手术大鼠酪氨酸羟化酶节律的中值，并增加了其振幅。这些结果与以下观点一致，即松果体通过褪黑素对脾细胞增殖的免疫增强作用，在大鼠脾脏免疫反应性的昼夜变化中发挥作用。
