Klugmann T, Mons I, Wenzel B E
Zell- und Immunbiologisches Labor, Medizinische Universität zu Lübeck, Germany.
Acta Endocrinol (Copenh). 1992 Jun;126(6):535-40. doi: 10.1530/acta.0.1260535.
Pulsatile TSH secretion has been described in man. We investigated the effect of discontinuous TSH stimulation on FRTL-5 thyroid cells. FRTL-5 monolayers were pulsed with TSH in 4 h incubation periods with alternate 4 h TSH-free intervals, or continuously incubated with TSH. The cAMP production of cells was measured in the supernatant of monolayers. Expression of a nuclear proliferation antigen in FRTL-5 monolayers was determined by a monoclonal antibody (Ki-67) using the alkaline phosphatase-anti-alkaline-phosphatase staining method. The TSH concentration in the stimulation series ranged from 0.01 to 1.0 U/l medium. Rhythmic cAMP production was observed in both discontinuous and continuous stimulation. With discontinuous stimulation cAMP production peaked after about 24 and 48 h, while in the continuous presence of TSH peaks were observed at 32-40 and 48 h. At all TSH concentrations the effect of discontinuous stimulation was higher than in continuously stimulated cultures. The discontinuous incubation stimulated nuclear proliferation antigen expression of FRTL-5 more intensely and there was a positive correlation with TSH concentration. We conclude that the rhythmic pattern of cAMP production after TSH stimulation is independent of the TSH pulse. The amplitude of stimulation and proliferation of FRTL-5, however, is increased by discontinuous TSH application.
已有研究报道人类存在促甲状腺激素（TSH）的脉冲式分泌。我们研究了间断性TSH刺激对FRTL-5甲状腺细胞的影响。FRTL-5单层细胞在含TSH的培养基中培养4小时，随后间隔4小时无TSH培养，如此交替进行；或者持续在含TSH的培养基中培养。通过测量单层细胞上清液中细胞产生的环磷酸腺苷（cAMP）来评估。采用碱性磷酸酶-抗碱性磷酸酶染色法，利用单克隆抗体（Ki-67）测定FRTL-5单层细胞中核增殖抗原的表达。刺激组中TSH浓度范围为0.01至1.0 U/l培养基。间断性刺激和持续性刺激均观察到有节律的cAMP产生。间断性刺激时，cAMP产生在约24小时和48小时达到峰值；而在持续存在TSH的情况下，峰值出现在32 - 40小时和48小时。在所有TSH浓度下，间断性刺激的效果均高于持续性刺激培养组。间断性培养更强烈地刺激了FRTL-5细胞的核增殖抗原表达，且与TSH浓度呈正相关。我们得出结论，TSH刺激后cAMP产生的节律模式与TSH脉冲无关。然而，间断性应用TSH可增加对FRTL-5的刺激幅度及细胞增殖。
