[Parathyroidectomy and calcium exchange in cardiovascular tissue in the SHR rat]

Previous work has shown that parathyroidectomy lessens hypertension if performed on young SHR (5-6 weeks of age). In this work, ionic changes (Na+, K+, Ca2+, Mg2+) were studied in heart and aorta during a chronic experimentation. In the heart, atria and ventricle, Ca2+ content was significantly diminished, 15 days after parathyroidectomy. Nevertheless after 8 months, this difference did not remain. A correlation between Ca2+ content and heart rate (lessened immediately after parathyroidectomy) is suggested. In the aorta, parathyroidectomy did not change Na+, K+, Ca2+ and Mg2+ content after 15 days. At the opposite Mg2+ content was significantly lessened after 8 months (-33 p. 100, p less than 0,001). Calcium content in the Lanthanum Resistant Fraction was also depressed significantly at this time. Variations in heart and aorta ionic contents are discussed in relation with hypertensive development.