EFFECTS OF NICOTINE ON THE UTERINE EPITHELIUM STUDIED BY X-RAY-MICROANALYSIS

The composition of the uterine fluid is of importance for the developm ent of the embryo. The ionic composition of the uterine fluid is deter mined by transport processes in the uterine epithelium. The aim of the present study was to investigate whether nicotine can affect the ion transport processes and ultrastructure of the uterine epithelium in mo use and rat. The effects of nicotine on the uterine epithelium were co mpared with those on kidney and liver. Nicotine was administered to mi ce as an intraperitoneal injection of a 1 mu g/l nicotine solution twi ce daily for 8 days, or in the drinking water (108 mu M nicotine) for 15 days, whereas rats received nicotine in their drinking water for 10 days (54 or 108 mu M nicotine). In addition, primary cultures of endo metrial cells were exposed to nicotine in vitro. Changes in morphology were examined by transmission electron microscopy and changes in elem ental content by X-ray microanalysis. Nicotine caused a significant de crease in the concentrations of Na, K, and Cl in the uterine fluid and in the endometrial cells in situ. Similar changes in elemental concen trations were observed in endometrial cells in vitro. Ultrastructural changes in endometrial cells included swollen and damaged mitochondria . In liver and kidney much smaller effects of nicotine on the elementa l composition of the cells were observed. However, marked ultrastructu ral effects were seen in the kidney: a reduction in mitochondrial size and an increase in lysosomal volume. It is concluded that nicotine di rectly interferes with fluid transport across the uterine epithelium.