Synthesizing recombinant rat Prolactin (Prl) in E. coli involves co-inserting the target gene into an expression vector with an N-terminal 6xHis-tag gene, transforming it into E. coli cells, and growing the cells to induce protein expression. The target gene encodes the 30-226aa of the rat Prl. After cell lysis, the rat Prl protein is purified using affinity chromatography. Its purity is evaluated with SDS-PAGE, exceeding 90%.
Rat Prl is a hormone that plays a crucial role in various physiological processes in rats. Research has shown that regulating Prl secretion is complex and varies with the physiological state and time of day [1]. In female rats, Prl is produced by two different cell types, each characterized by distinct secretory granules, indicating a diverse mechanism of Prl synthesis and storage [2]. Studies have demonstrated the presence of Prl receptors in rat hepatocytes, with prolactin exerting sex-dependent effects on the content of these receptors [3].
The production of Prl in rat pituitary tumor cells has been found to differ significantly from that in normal cells, highlighting the diverse mechanisms involved in Prl synthesis [4]. There are sex differences in the neural control of Prl secretion, with male rats showing a tonic release compared to the cyclic pattern observed in females [5].
Prl is also linked to maternal behavior in rats, with studies showing that central Prl infusions stimulate maternal behavior in female rats, an effect that can be modulated by hypophysectomy or bromocriptine treatment [6]. Prl was reported to facilitate female sexual behavior and inhibit copulatory behavior in male rats, indicating a role for Prl in modulating reproductive behaviors [7].
References:
[1] J. Wiersma and J. Kastelijn, Effects of red dim illumination and surgery on prolactin secretion during the estrous cycle and early pseudopregnancy in the rat: different regulatory mechanisms for prolactin secretion, Neuroendocrinology, vol. 42, no. 5, p. 427-435, 1986. https://doi.org/10.1159/000124482
[2] Y. Tong, H. Zhao, F. Labrie, & G. Pelletier, Effects of estrogens on the ultrastructural characteristics of female rat prolactin cells as evaluated by in situ hybridization in combination with immunogold staining technique, Neuroendocrinology, vol. 52, no. 4, p. 309-315, 1990. https://doi.org/10.1159/000125603
[3] G. Mv and K. Ia, Nuclear manifestation of prolactin receptors in rat hepatocytes and effect of prolactin, Bulletin of Experimental Biology and Medicine, vol. 127, no. 5, p. 526-529, 1999. https://doi.org/10.1007/bf02434959
[4] D. Biswas, S. Hanes, & B. Brennessel, Mechanism of induction of prolactin synthesis in gh cells, Proceedings of the National Academy of Sciences, vol. 79, no. 1, p. 66-70, 1982. https://doi.org/10.1073/pnas.79.1.66
[5] J. Wiersma, B. Heijning, & C. Grinten, Electrophysiological evidence for a sex difference in neural regulation of prolactin secretion in rats, Neuroendocrinology, vol. 44, no. 4, p. 475-482, 1986. https://doi.org/10.1159/000124689
[6] R. Bridges, M. Numan, P. Ronsheim, P. Mann, & C. Lupini, Central prolactin infusions stimulate maternal behavior in steroid-treated, nulliparous female rats., Proceedings of the National Academy of Sciences, vol. 87, no. 20, p. 8003-8007, 1990. https://doi.org/10.1073/pnas.87.20.8003
[7] R. Bridges, R. DiBiase, D. Loundes, & P. Doherty, Prolactin stimulation of maternal behavior in female rats, Science, vol. 227, no. 4688, p. 782-784, 1985. https://doi.org/10.1126/science.3969568
