RNA and protein synthesis in different organs of rat offspring after chronic cadmium exposure during pregnancy.
Despite binding by placental metallothionein, cadmium (Cd) relatively easily enters fetal circulation and may be harmful to tissues and organs of offspring. Although Cd toxicology is relatively well described in the literature there are only few studies on Cd toxicity exerted during fetal life. We examined the influence of cadmium exposure during pregnancy on RNA and protein synthesis in different organs of the rat offspring. Their dams were fed diet containing cadmium chloride-treated drinking water during the whole pregnancy period at 50 ppm dose level. The offspring, 6-weeks-old male Wistars rats, weighing 105 + 10 g were subjected to examination. Synthesis of RNA and proteins was quantitated by scintillation technique, which measured incorporation of tritiated uridine and alanine, respectively. A set of 17 organs and tissues was examined. RNA synthesis increased significantly in buccal mucosa, tongue, parotid gland, cardiac muscle, brain and bone marrow. A strong induction of RNA synthesis in all four studied brain regions attracts special attention. The activation of RNA metabolism may be partly explained by the increased expression of genes involved in detoxication and adaptation (e.g., metallothionein, stress response proteins, etc.). A profile of protein synthesis was much more heterogenous with elevated H3-alanine uptake in 12 organs of experimental animals, however without any statistical significance. Since the study of protein synthesis did not demonstrate any significant changes in Cd-treated animals, the profile of RNA synthesis cannot be simply extrapolated on protein synthesis, probably because of complex post-transcriptional and post-translational genetic modifications.
Konecki
Janusz
J
Department of Histology and Embryology, Medical University of Silesia, Zabrze, Poland. wolynka@polbox.com
Słowiński
Jerzy
J
Harabin-Słowińska
Marzena
M
Helewski
Krzysztof
K
Głowacka
Maria
M
Wyrobiec
Grzegorz
G
D000818:Animals; D002104:Cadmium / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D005260:Female; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D002104:Cadmium; D012313:RNA