Morphine and kisspeptin influences on 5-α reductase and aromatase gene expression in adult male rats

Document Type : Original Article


1 Department of Animal Science and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran

2 Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran


Objective(s): Kisspeptin and opioids are important factors for controlling GnRH/LH secretion. In present study, influences of kisspeptin or morphine were investigated on 5α- reductase or aromatase (CYP19) genes expression in the hypothalamus, testis and liver. It aimed to investigate whether kisspeptin pathway may control morphine effects on plasma concentration of testosterone.
Materials and Methods: Twenty adult male rats in four groups received saline/saline, kisspeptin (1 nmol)/saline, morphine (5 mg/kg)/saline or kisspeptin/morphine respectively. Mean relative 5α-reductase and aromatase mRNA levels were determined by RT-PCR.
Results: Morphine/saline injection increased significantly mean relative mRNA levels of hypothalamic 5α-reductase or aromatase compared to saline/saline. While morphine/saline did not alter mRNA levels of them compared to saline/saline group in the testis and liver. Kisspeptin/saline did not significantly decrease mean relative 5α-reductase or aromatase genes expression compared to saline/saline group in the hypothalamus, testis and liver. Injections of kisspeptin/morphine did not significantly decrease mean relative 5α-reductase or aromatase genes expression compared to morphine/saline group.
Conclusion: Up-regulation of hypothalamic 5α-reductase or aromatase mRNA levels may partly induce the inhibitory effects of morphine on GnRH/LH release. Different effects of morphine on aromatase or 5α- reductase genes expression levels in the liver and testis compared to brain may be partly due to different sensitivity or functions of them to morphine used dose.


1. Schulster M, Bernie AM, Ramasamy R. The role of estradiol in male reproductive function. Andrology 2016; 18:435–440.
2. Cailleux-Bounacer A, Rohmer V, Lahlou N, Lefebvre H, Roger M, Kuhn JM. Impact level of dihydrotestosterone on the hypothalamic-pituitary-leydig cell axis in men. Int J Androl 2009; 32:57-65.
3. Shen M, Shi H.. Sex hormones and their receptors regulate liver energy homeostasis. Int J Endocrinol 2015; 2015:1-12.
4. Poletti A, Coscarella A, Negri-Cesi P, Colciago A, Celotti F, Martini L. 5 alpha-reductase isozymes in the central nervous system. Steroids 1998; 63:246-251.
5. Turgeon JL, Waring DW. Androgen modulation of luteinizing hormone secretion by female rat gonadotropes. Endocrinology 1999; 140:1767-1774.
6. Vuong C, Van Uum SH, O'Dell LE, Lutfy K, Friedman TC. The effects of opioids and opioid analogs on animal and human endocrine systems. Endocr Rev 2010; 31:98-132.
7. Aloisi AM, Ceccarelli I, Fiorenzani P, Maddalena M, Rossi A, Tomei V, et al. Aromatase and 5-alpha reductase gene expression: modulation by pain and morphine treatment in male rats. Mol Pain 2010; 6:1-9.
8. Amini H, Ahmadiani A. In vivo evidence for an increase in 5alpha-reductase activity in the rat central nervous system following morphine exposure. Int J Dev neurosci 2005; 23:621-626.
9. Meczekalski B, Katulski K, Podfigurna-Stopa A, Czyzyk A, Genazzani AD. Spontaneous endogenous pulsatile release of kisspeptin is temporally coupled with luteinizing hormone in healthy women. Fertil Steril 2016; 105:1345-1350.
10. Lippincott MF, Chan YM, Delaney A, Rivera-Morales D, Butler JP, Seminara SB. Kisspeptin responsiveness signals emergence of reproductive endocrine activity: implications for human puberty. J Clin Endocrinol Metab 2016; 101:3061-3069.
11. Roseweir AK, Kauffman AS, Smith JT, Guerriero KA, Morgan K, Pielecka-Fortuna J, et al. Discovery of potent kisspeptin antagonists delineates physiological mechanisms of gonadotropin regulation. J Neurosci 2009; 29:3920–3929.
12. Khazali H, Mahmoudi F, Janahmadi M. Hypothalamic Kiss1/ GPR54 genes expression and plasma LH secretion in morphine treated male rats. Int J fertil steril 2018; 12:223-228.
13. Mansour A, Khachaturian H, Lewis ME, Akil H, Watson S J. Anatomy of CNS opioid receptors. Trends Neurosci 1998; 11:308-314.
14. Clarke H, Dhillo WS, Jayasena CN. Comprehensive review on kisspeptin and its role in reproductive disorders. Endocrinol Metab 2015; 30:124-141.
15. Bois C, Delalande C, Nurmio M, Parvinen M, Zanatta L, Toppari J, et al. Age- and cell-related gene expression of aromatase and estrogen receptors in the rat testis. J Mol Endocrinol 2010; 45:147-159.
16. Mahmoudi F, Khazali H, Janahmadi M. Morphine attenuates testosterone response to central injection of kisspeptin in rats. Int J fertil steril 2014; 8:215-220.
17. Mellon SH, Griffin LD. Neurosteroids: biochemistry and clinical significance. Trends Endocrinol Metab 2002; 13:35-43.
18. Killian J, Pratis K, Clifton RJ, Stanton PG, Robertson DM, O'Donnell L. 5alpha-reductase isoenzymes 1 and 2 in the rat testis during postnatal development. Biol Reprod 2003; 68:1711-1718.
19.          Torres JM, Ruiz E, Ortega E. Development of a quantitative RT-PCR method to study 5alpha-reductase mRNA isozymes in rat prostate in different androgen status. Prostate 2003; 56:74-79.
20. Torres JM, Ortega E. Precise quantitation of 5alpha-reductase type 1 mRNA by RT-PCR in rat liver and its positive regulation by testosterone and dihydrotestosterone. Biochem Biophys Res Commun 2003; 308:469-473.
21. Torres JM, Ruiz E, Ortega E. Differential regulation of steroid 5alpha-reductase isozymes expression by androgens in the adult rat brain. FASEB J 2003; 17:1428-1433.
22. Hussain MA, Song WJ, Wolfe A. There is kisspeptin - and then there is kisspeptin. Trends Endocrinol Metab 2015; 26:564-572.
23. Szymanski L, Bakker J. Aromatase knockout mice show normal steroid-induced activation of gonadotrophin-releasing hormone neurons and luteinizing hormone surges with a reduced population of kisspeptin neurones in the rostral hypothalamus. J Neuroendocrinol 2012; 24:1222-1233.
24. Ross LA, Polotsky AJ, Kucherov A, Bradford AP, Lesh J, Chosich J, et al. Profound reduction of ovarian estrogen by aromatase inhibition in obese women. Obesity 2014; 22:1464-1469.
25. Mittelman-Smith MA, Wong AM, Kathiresan AS, Micevych PE. Classical and membrane-initiated estrogen signaling in an in vitro model of anterior hypothalamic kisspeptin neurons. Endocrinology 2015; 156:2162–2173.
26. Iwasa T, Matsuzaki T, Yano K, Mayila Y, Irahara M. Effects of dihydrotestosterone administration on the expression of reproductive and body weight regulatory factors in ovariectomized and estradiol-treated female rats. Gynecol Endocrinol 2018; 34:73-77.
27. Iwata K, Kunimura Y, Matsumoto K, Ozawa H. Effect of androgen on Kiss1 expression and luteinizing hormone release in female rats. J Endocrinol 2017; 233:281-292.