X-ray microanalysis of uterine secretion in the mouse.

In an attempt to characterize ion transport mechanisms in the uterine epithelium the effect of diuretics on the elemental composition of the uterine secretion was investigated by X-ray microanalysis. Mice were treated with a variety of diuretics and Sephadex beads were incubated in situ in the uterus where they absorbed the uterine secretion. In animals treated with furosemide, bumetanide, or amiloride, the concentration of Na, K, and Cl in the uterine secretion was significantly decreased. After treatment with acetazolamide, only the K concentration was significantly decreased. Treatment with diuretics also decreased the concentration of P and S in the uterine secretion, indicating that less mucus was absorbed to the Sephadex beads. Transmission electron microscopy confirmed that treatment with amiloride and furosemide decreased the amount of mucus covering the epithelium. A possible explanation is that because of lack of water, the uterine mucus cannot leave the lumen of the uterine glands and reach the surface of the epithelium where the beads are. The data strongly suggest that Na+, K+, and Cl- transport in the uterine epithelium is dependent on a basolaterally situated Na(+)-(K+)-Cl(-)-cotransport mechanism. Disturbance of normal ion and water transport apparently affects the composition and consistency of the mucus, which may help explain abnormalities in cervical mucus in patients with cystic fibrosis.