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Updated: Jul 16, 2026

Frequent Tail-tip Blood Sampling in Mice for the Assessment of Pulsatile Luteinizing Hormone Secretion
Published on: July 4, 2018
Luteinizing hormone in testicular descent
Jorma Toppari1, Marko Kaleva, Helena E Virtanen
1Department of Physiology, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland. jorma.toppari@utu.fi
Abstract:
A proper hypothalamus-pituitary-testis axis with normal androgen synthesis and action is a prerequisite for normal testicular descent. Various defects in this axis may result in cryptorchidism but endocrine abnormalities are rarely detected. Androgens regulate testicular descent but androgen action alone is not sufficient for normal testicular descent. The regulation of androgen production is influenced both by placental human chorionic gonadotropin (hCG) and pituitary luteinizing hormone (LH). There is evidence that the longer pregnancy continues, the more important role pituitary LH may have. Insulin-like hormone-3 (INSL3) is suggested to be the main regulator of gubernacular development and therefore an apparent regulator of testicular descent. INSL3 production is also related to LH, and reduced INSL3 action is a possible cause for cryptorchidism. Cryptorchid boys have normal testosterone levels with slightly but significantly elevated LH levels as compared to healthy boys. This high gonadotropin drive may compensate for mild Leydig cell dysfunction in cryptorchidism.
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