Kininogen present in rat reproductive tissues is apparently synthesized by the liver, not by the reproductive system.

OBJECTIVE

The purpose of this study was to determine the source(s) of the reproductive tract kininogen and to assess whether kininogen transcription is influenced by reproductive conditions.

STUDY DESIGN

Rats in various reproductive states (immature, mature, ovulatory, luteal phase, pregnancy, parturition, postpartum) were used to obtain reproductive tissues (follicles, corpora lutea, oviduct, uterus, testes) and liver. Complementary deoxyribonucleic acid probes for rat prekininogens were used to quantify kininogen messenger ribonucleic acid synthesis.

RESULTS

The T-prekininogen complementary deoxyribonucleic acid probe detected a single 1.6 kb message, whereas the k-prekininogen complementary deoxyribonucleic acid probe identified two messages, an abundantly expressed 1.6 kb band and a 2.2 kb band. The source of all the three prekininogen messages appears to be the liver. Naturally occurring reproductive conditions such as ovulation, implantation, and parturition, did not turn on prekininogen message transcription in the rat gonad or genital tract. Only decidualization of the uterus was associated with the induction of kininogen transcription in the liver.

CONCLUSION

There appears to be little, if any, contribution of local gene expression to the kininogen present in the reproductive tissues. Apparently, the reproductive tract increases uptake of kininogen from plasma as needed.