Abstract
Recent evidence suggests that galanin, may regulate prolactin (PRL) secretion during lactation. In this article, we describe the regulation of anterior pituitary galanin and PRL gene expression during pregnancy and after parturition in the rat. Expression of galanin and PRL in the anterior pituitary were significantly higher at d 20 of pregnancy compared to diestrus. One day after parturition, galanin mRNA levels increased a further 4.5-fold. This post partum increase in gene expression was not observed for PRL. The increase in galanin gene expression was maintained above the diestrous level for at least 10 d after parturition. PRL mRNA expression, on the other hand, was largely unchanged after parturition. Although the increase in galanin gene expression 1 d after parturition was independent of suckling, subsequently, galanin, gene expression was significantly higher in nursing mothers. Anterior pituitary galanin gene expression was 12-fold higher in nursing mothers compared with those that were not, 3 d after parturition. Similarly, PRL gene expression was significantly lower in mothers who were not suckling their pups 3 d after parturition. Initiation of suckling alone was insufficient to stimulate galanin and PRL expression. Despite suckling for 2 d, removal of the suckling stimulus subsequently resulted in a rapid decrease in galanin gene expression. Hence, the stimulatory effect of suckling on galanin expression requires a sustained suckling stimulus. In conclusion, the data support the hypothesis that anterior pituitary galanin plays an important role during lactation, likely acting to amplify lactotroph stimulation through paracrine and autocrine mechanisms.
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Tatemoto, K., Rokaeus, A., Jornvall, H., McDonald, T. J., and Mutt, V. (1983). FEBS Lett. 164, 124–128.
Ottlecz, A., Synder, G. D., and McCann, S. M. (1988). Proc. Natl. Acad. Sci. USA 85, 9861–9865.
Maiter, D. M., Hooi S. C., Koenig, J. I., and Martin, J. B. (1990). Endocrinology 126, 1216–1222.
Koshiyama, H., Kato, Y., Inoue, T., Murakami, Y., Ishikawa, Y., and Imura, H. M. (1987). Neurosci. Lett. 75, 49–54.
Nordstrom, O., Melander, T., Hokfelt, T., Bartfai, T., and Goldstein, M. (1987). Neurosci., Lett. 73, 21–26.
Hooi S. C., Maiter, D. M., Martin, J. B., and Koenig, J. I. (1990). Endocrinology 127, 2281–2289.
Sahu, A., Crowley, W. R., Tatemoto, K., Balasubramaniam, A., and Kalra, S. P. (1987). Peptides 8, 921–926.
Vrontakis, M. E., Peden, L. M., Duckworth, M. L., and Friesen, H. G. (1987). J Biol. Chem. 262, 16,755–16,758.
Kaplan, L. M., Spindel, E. R., Isselbacher, K. J., and Chin, W. W. (1988). Proc. Natl. Acad. Sci. USA 85, 1065–1069.
Kaplan, L. M., Gabriel, S. M., Koenig, J. I., Sunday, M. E., Spindel, E. R., Martin, J. B., and Chin, W. W. (1988). Proc. Natl. Acad. Sci. USA 85, 7408–7412.
O'Halloran, D. J., Jones, P. M., Ghatei, M. A., and Bloom, S. R. (1991). J. Endocrinol. 131, 411–419.
Cai, A., Bowers, R. C., Moore, J. P., and Hyde, J. F. (1998). Endocrinology 139, 2452–2458.
Wynick, D., Hammond, P. J., Akinsanya, K. O., and Bloom, S. R. (1993). Nature 364, 529–532.
Wynick, D., Smith, D. M., Ghatei, M., Akinsanya, K., Bhogal, R., Purkiss, P., Byfield, P., Yanaihara, N., and Bloom, S. R. (1993). Proc. Natl. Acad. Sci. USA 90, 4231–4235.
Vrontakis, M. E., Schroedter, I. C., Cosby, H., and Friesen, H. G. (1992). Endocrinology 130, 458–464.
Morishige, W. K., Pepe, G. J., and Rothchild, I. (1973). Endocrinology 92, 1527–1530.
Fang, X., Wong, S., and Mitchell, B. F. (1996). Endocrinology 137, 3213–3219.
Yoshinaga, K., Hawkins, R. A., and Stocker, J. F. (1969). Endocrinology 85, 103–112.
Escalada, J., Cacicedo, L., Ortego, J., Melian, E. and Sanchez-Franco, F. (1996). Endocrinology 137, 631–637.
Smith, M. S., and Neill, J. D. (1977). Biol. Reprod. 17, 255–261.
Taya, K., and Greenwald, G. S. (1982). Biol. Reprod. 27, 1090–1101.
Wang, H. J., Hoffman, G. E., and Smith, M. S. (1993). Endocrinology 133, 1657–1663.
Rondeel, J. M., de Greef, W. J., Visser, T. J., and Voogt, J. L. (1988). Neuroendocrinology 48, 93–96.
Moyer, J. A., O'Donohue, T. L., Herrenkohl, L. R., Gala, R. R., and Jacobowitz, D. M. (1979). Brain Res. 176, 125–133.
Hyde, J. F., and Keller, B. K. (1991). Endocrinology 128, 917–922.
Ahlbom, E., Grandison, L., Zhitvotovsky, B., and Ceccatelli, S. (1998). Endocrinology, 139, 2465–2471.
Hooi, S. C., Koenig, J. I., Gabriel, S. M., Maiter, D., and Martin, J. B. (1990). Neuroendocrinology 51, 351–356.
Hooi, S. C., Koenig, J. I., Abraczinskas, D. R., and Kaplan, L. M. (1997). Brain, Res. Mol. Brain Res. 51, 15–22.
Emanuel, R. L., Girard, D. M., Thull, D. L., and Majzoub, J. A. (1990). Endocrinology 126, 3016–3021.
Plotsky, P. M. and Meaney, M. J. (1993). Brain Res. Mol. Brain Res. 18, 195–200
Patel, B. K., Koenig, J. I., Kaplan, L. M., and Hooi, S. C. (1998). Metabolism 47, 603–607.
Grosvenor, C. E. and Mena, F. (1980). Endocrinology 107, 863–868.
de Greef W. J., and Visser, T. J. (1981). J. Endocrinol. 91, 213–223.
Plotsky, P. M. and Neill, J. D. (1982). Endocrinology 111, 168–173.
Grottoli, S., Arvat, E., Gianotti, L., Ramunni, J., Di Vito, L., Maccagno, B., Ciccarelli, E., Cananni, F., and Ghigo, E. (1996). J. Endocrinol. Invest. 19, 739–744.
Tan, J. T. T., Patel, B. K., Kaplan, L. M., Koenig, J. I., and Hooi, S. C. (1998). Endocrine 8, 85–92.
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Ren, J., Koenig, J.I. & Hooi, S.C. Stimulation of anterior pituitary galanin and prolactin gene expression in suckling rats. Endocr 11, 251–256 (1999). https://doi.org/10.1385/ENDO:11:3:251
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DOI: https://doi.org/10.1385/ENDO:11:3:251