Houdebine L M
INRA, Unité de Différenciation Cellulaire, Jouy-en-Josas, France.
Reprod Nutr Dev. 1990;30(3):431-8. doi: 10.1051/rnd:19900317.
Prolactin has many different biological functions. It stimulates Nb2 cell multiplication through the kinase C transduction mechanism, casein secretion through the phospholipase A2-arachidonic acid-leukotrienes cascade and milk protein gene expression through an unknown mechanism. Colchicine and other tubulin binding drugs inhibit casein gene expression and DNA synthesis stimulated by prolactin whereas chemical compound which alter microtubule without binding tubulin exert no inhibitory effect. Myo-inositol which suppresses some of the colchicine actions in several biological systems does not restore prolactin action after an inhibition by the drug. These data suggest that a tubulin molecule in the vicinity of the prolactin receptor, rather than actual microtubules, is involved in the transduction of the prolactin message from its receptor to milk protein genes.
催乳素具有多种不同的生物学功能。它通过蛋白激酶C转导机制刺激Nb2细胞增殖，通过磷脂酶A2 - 花生四烯酸 - 白三烯级联反应刺激酪蛋白分泌，并通过未知机制刺激乳蛋白基因表达。秋水仙碱和其他微管蛋白结合药物抑制催乳素刺激的酪蛋白基因表达和DNA合成，而不结合微管蛋白但改变微管的化合物则没有抑制作用。肌醇在几个生物系统中可抑制秋水仙碱的某些作用，但在药物抑制后并不能恢复催乳素的作用。这些数据表明，催乳素受体附近的微管蛋白分子，而非实际的微管，参与了催乳素信号从其受体向乳蛋白基因的转导。
