Cadmium-induced decrement of the LH receptor expression and cAMP levels in the testis of rats.
Cadmium (Cd) is a widespread environmental pollutant, characterized by its ability to affect various organs. Adverse effect of Cd on the testis including decreased testosterone production are well-known phenomena, but the cellular events explaining these effects have not yet been established. In the present study the initial steps of gonadotropin mediated testosterone biosynthesis were examined in vivo in rats, in relation to Cd dose and time after injection. In the dose-response experiment Male Sprague-Dawley rats received a single subcutaneous (s.c.) injection of CdCl(2) (1, 5 or 10 micromol/kg body weight) and were sacrificed 48 h after injection. A statistically significant decrease in luteinizing hormone (LH) receptor mRNA level in the testicular tissue was demonstrated at the highest dose (10 micromol/kg). In the temporal-response experiment rats were given 10 micromol/kg of CdCl(2) s.c. and sacrificed 0.48, 4.8, 48 or 144 h after injection. LH receptor mRNA levels as well as cyclic adenosine monophosphate (cAMP) levels were found to be significantly lowered at 48 and 144 h. These observations of the mechanisms whereby Cd exerts its effect on the initial steps of testosterone biosynthesis are the first from in vivo experiments.
Gunnarsson
David
D
Department of Public Health and Clinical Medicine, Unit of Environmental Medicine, Umeå University, 901 87 Umeå, Sweden.
Nordberg
Gunnar
G
Lundgren
Per
P
Selstam
Gunnar
G
D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D000242:Cyclic AMP / Q000096:biosynthesis*; D004785:Environmental Pollutants / Q000009:adverse effects*; D007700:Kinetics; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011974:Receptors, LH / Q000096:biosynthesis*; D013733:Testicular Diseases / Q000139:chemically induced* / Q000378:metabolism; D013737:Testis / Q000187:drug effects / Q000378:metabolism
D004785:Environmental Pollutants; D012333:RNA, Messenger; D011974:Receptors, LH; D002104:Cadmium; D000242:Cyclic AMP