Male reproductive health is declining worldwide. Infertility affects 7-26% of all couples, and in at least 1/3 of all cases, a male factor is responsible primarily due to poor semen quality. The incidence of testicular germ cell tumors (TGCTs) also increases worldwide. Several bone and mineral homeostasis factors are expressed in the normal testis and TGCTs. This Ph.D. thesis adds to the emerging evidence of a link between the gonads and bone and aims to study this cross-link in health and disease stages. 

In the first study, we show that family members with a heterozygous Q459R loss-of-function mutation in the calcium-sensing receptor gene (CASR) had the typical phenotype of familial hypocalciuric hypercalcemia 1 (FHH1) with disturbances in their calcium homeostasis. 

In the second study, we present the expression of factors involved in calcium homeostasis in mice and human testis and epididymis. 

In the third study, we found that spermatozoa from FHH1 patients showed a diminished response to sperm-activating factors such as calcium, bicarbonate, and progesterone, and were less likely to undergo the acrosome reaction compared with spermatozoa from healthy men. 

The fourth study demonstrated that biomineralization programs typical of the skeleton are ectopically elaborated in the testis in malignancy and non-malignant testicular disease stages.

Anders Juul

Martin Blomberg Jensen

Beate Lanske