Effects on Leydig cells
Human studies
Ihentuge C, Csoka A. Epigenetic effects of finasteride on human Leydig cells. FASEB J. Supplement: Experimental Biology 2020 Meeting Abstracts. 2020;S1. doi:10.1096/fasebj.2020.34.s1.03823
Ihentuge C, Csoka A. Finasteride induces epigenetic modulation of LSP1: a gene implicated in neutrophil actin dysfunction disease. FASEB J. 2022 May;36 Suppl 1. doi:10.1096/fasebj.2022.36.S1.R4708
Iranmanesh A, Veldhuis JD. Combined inhibition of types I and II 5 alpha-reductase selectively augments the basal (nonpulsatile) mode of testosterone secretion in young men. J Clin Endocrinol Metab. 2005 Jul;90(7):4232-7. doi:10.1210/jc.2004-2262 | PubMed
Animal studies & reviews
Clegg ED, Cook JC, Chapin RE, Foster PMD, Daston GP. Leydig cell hyperplasia and adenoma formation: Mechanisms and relevance to humans. Reprod Toxicol. 1997;11(1):107-121. doi:10.1016/S0890-6238(96)00203-1 | PubMed
Freeman DA, Gocze PM, Porpaczy Z. Finasteride blocks progesterone synthesis in MA-10 Leydig tumor cells. Endocrinology. 1993 Oct;133(4):1915-7. doi:10.1210/endo.133.4.8404636 | PubMed
Murono EP, Washburn AL, Goforth DP. Enhanced stimulation of 5 alpha-reductase activity in cultured Leydig cell precursors by human chorionic gonadotropin. J Steroid Biochem Mol Biol. 1994 Mar;48(4):377-84. doi:10.1016/0960-0760(94)90078-7 | PubMed
Prahalada S, Majka JA, Soper KA, et al. Leydig cell hyperplasia and adenomas in mice treated with finasteride, a 5 alpha-reductase inhibitor: a possible mechanism. Fundam Appl Toxicol. 1994;22(2):211-219. doi:10.1006/faat.1994.1025 | PubMed
Prentice DE, Meikle AW. A review of drug-induced Leydig cell hyperplasia and neoplasia in the rat and some comparisons with man. Hum Exp Toxicol. 1995;14(7):562-572. doi:10.1177/096032719501400703 | PubMed
Raeside JI, Renaud RL, Marshall DE. Effect of a 5 alpha-reductase inhibitor on the metabolism of 19-norandrogens by porcine Leydig cells. Biochem Biophys Res Commun. 1992 Mar 31;183(3):1254-9. doi:10.1016/s0006-291x(05)80325-0 | PubMed
Case reports
Berthold D, Lhermitte B, Uffer M, Doerfler A. Finasteride-related Leydig cell tumour: report of a case and literature review. Andrologia. 2012;44 Suppl 1:836-837. doi:10.1111/j.1439-0272.2011.01214.x | PubMed
Schwartz M, Imperato-McGinley J, Peterson RE, et al. Male pseudohermaphroditism secondary to an abnormality in Leydig cell differentiation. J Clin Endocrinol Metab. 1981 Jul;53(1):123-7. doi:10.1210/jcem-53-1-123 | PubMed [Note: This case report predates finasteride.]
Related study
Murono EP, Washburn AL. Regulation of 5 alpha-reductase activity in cultured immature Leydig cells by human chorionic gonadotropin. J Steroid Biochem. 1990 May;35(6):715-21. doi:10.1016/0022-4731(90)90313-h | PubMed
General background
Aladamat N, Tadi P. Histology, Leydig Cells. In: StatPearls. StatPearls Publishing; 2022. http://www.ncbi.nlm.nih.gov/books/NBK556007/
Zirkin BR, Papadopoulos V. Leydig cells: formation, function, and regulation. Biol Reprod. 2018;99(1):101-111. doi:10.1093/biolre/ioy059 | PubMed
See also other special topics and research by system & function.