Tyrosine kinase inhibition reduces the plateau phase of the calcium increase in response to progesterone in human sperm

FEBS Letters

Forti, G.¹  Bonaccorsi, L.¹  Baldi, E.¹  Luconi, M.¹ 

[1] Dipartimento di Fisiopatologia Clinica, Unita' di Andrologia, Universita' di Firenze, viale Pieraccini, 6, I-50139 Firenze, Italy

关键词: Spermatozoa;    Progesterone;    Intracellular calcium;    Tyrosine phosphorylation;    Nongenomic steroid effect;   

DOI  :  10.1016/0014-5793(95)00369-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Progesterone (P) has previously been shown to induce a rapid increase in [Ca²⁺]_i as well as tyrosine phosphorylation of proteins in human spermatozoa. Both these effects are essential for induction of the acrosome reaction by P. We investigated a possible relationship between the P-induced calcium increase and tyrosine kinase activation, by evaluating the effect of the tyrosine kinase inhibitor genistein on these two effects. We found that preincubation with genistein abolished P-induced tyrosine phosphorylation of two sperm proteins of 97 and 75 kDa molecular weight and significantly inhibited the plateau phase of P-induced [Ca²⁺]_i increase without affecting the peak phase. Conversely, the plateau phase was enhanced by the tyrosine phosphatase inhibitor Na₃VO₄. The effect of genistein was specific for P, since no inhibition was observed on the [Ca²⁺]_i increase induced by thapsigargin, an inhibitor of endoplasmic Ca²⁺-ATPase previously shown to mobilize Ca²⁺ in spermatozoa. These results indicate that tyrosine kinase activation is involved in the generation of the plateau phase of Ca²⁺ influx induced by P, and suggest the possibility that two different pathways are involved in the induction of Ca²⁺ entry by P in human sperm.

【 授权许可】

Unknown