Demonstration and Characterisation of a Testicular Receptor for 1,25‐Dihydroxycholecalciferol in the Rat

Abstract

Defective luteinizing-hormone-mediated cAMP generation in rat testis was previously demonstrated by us in acute and chronic uremia. This defect was abolished by administration of 1,25-dihydroxycholecalciferol (1,25-dihydroxycalciol). In the present study, we furnish evidence for a cytosolic 1,25-dihydroxycalciol receptor in the rat testis.Testes of non-rachitic, rachitic or acutely uremic male Sprague-Dawley rats were homogenized in 0. [I91 and uterus [20].In previous studies, we could show diminished luteinizinghormone-mediated cAMP generation in Leydig cells [21] and ovaries [22] of rats with acute and chronic uremia. This defect was completely restored by administration of 1,25-dihydroxycalciol. This finding prompted us to examine whether testis possesses a receptor for 1,25-dihydroxycalciol. MATERIALS A N D METHODS AnimalsNon-rachitic Sprague-Dawley rats (Fa. Ivanovas, Kisslegg/ Allgiiu) were raised on normal diet [Fa. Altromin, Lage/Lippe: Altromin C 1000: 500 IU calciol/kg; 0.95 calcium, 0.65 7; phosphorus (w/w)] for 3 weeks. In a separate experiment, animals were either bilaterally nephrectomized or shamoperated 24 h before sacrifice. In a third series, rats were weaned from vitamin-D-deficient mothers and raised on commercial vitamin-D-deficient diet (Altromin 101 7 : no calciol; 1.3 % calcium; no phosphorus). The animals were kept in the dark and handled with gloves. (68 Ci/mmol) were obtained from Amersham/Buchler Co (Braunschweig) with a radiochemical purity by high-performance liquid chromatography between 93 -98 and essentially free of other metabolites. Specific radioactive reduction was achieved by addition of the appropriate concentration of non-radioactive sterol. Radioinert chromatographically pure 1,25-dihydroxycalciol, 25-hydroxycalciol, 24(R),25-dihydroxycalciol and 1 a-hydroxycalciol were a kind gift of Dr Schmidt-Gayk (Heidelberg). The following I4C-labeled materials were purchased

Effect of Vitamin D Repletion on Testicular Function in Vitamin D-Def icient Rats

“…However, there are certain reports [1][2][3][4][5] indicating the importance of vitamin D on the male repro ductive capacity and receptor sites for 1,25-dihydroxy vitamin D on both seminiferous tubules and interstitial tissues of adult rats and humans. A previous study [6] from this Values arc mean ± SE (n = 6 in each group).…”

The vitamin D receptor localization and mRNA expression in ram testis and epididymis

“…A prerequisite for being a vitamin D target organ is the expression of VDR. Intratesticular expression of VDR was first reported in 1983 (Merke et al, 1983). To date, many studies suggest that VDR exists in testis and/or male reproductive tract of human (Blomberg Jensen et al, 2010), rat (Merke et al, 1983;Johnson et al, 1996), mouse (Schleicher et al, 1989;Mahmoudi et al, 2013) and rooster (Oliveira et al, 2008).…”

Vitamin D sites and mechanisms of action: A histochemical perspective. Reflections on the utility of autoradiography and cytopharmacology for drug targeting

“…Despite advancement to further regions of the elephant's body, it has not been generally recognized yet that vitamin D is also a hormone of reproduction (Stumpf and Denny 1989), even though information in this direction has accumulated, with receptors and related functions discovered in placenta, uterus, oviduct, ovary, mammary gland, testis, epididymis, and prostate (Waiters 1981;Merke et al 1983;Schleicher et al 1989;Stumpf and Denny 1989;Majumdar et al 1994). To be able to arrive at such vision, another mental jump was needed and again a new paradigm, albeit quite heretical, had to be accepted.…”