Northern analysis revealed that the mink prolactin receptor probe hybridized with multiple transcripts of 3.4, 4.4, and 10.5 kb. This pattern compares to rat long form with three transcripts of 2.5, 3.0, and 5.5 kb; the rabbit with three major transcripts of 2.7, 3.4, and 10.5 kb and one minor transcript of 6.2 kb; and the human with transcripts of 2.5, 3.0, and 7.3 kb. Tissue distribution analysis revealed a strong prolactin receptor hybridization signal in mink ovary and testes, and longer exposure of the blot indicated a signal in the uterus, adrenal, kidney, and liver. ventolin 100 mcg
The wide tissue distribution of prolactin receptor mRNA is not unexpected, since prolactin has a spectrum of biological activity. The binding of the prolactin receptor probe to follicles and stroma as well as to CL in the mink ovary agrees with findings in the mouse and rat. In this study, there was a correlation between [125I]prolactin binding to ovarian membranes and the abundance of prolactin receptor mRNA, suggesting that the mRNA abundance values are indicative of expression of the receptor protein. The prolactin receptor in the mink ovary is of physiological significance because of the important luteotropic role of this hormone in this species. The current experiment demonstrates that the abundance of prolactin receptor mRNA and receptor binding in the whole ovary and CL were low during the delay phase of gestation and did not increase during the early stages of CL reactivation.