F005: Importance of decreased intracellular phosphate and ATPase activities in SHR

• Published in: American journal of hypertension 2000-04, Vol.13 (S2), p.170A-170A
• Main Authors: Kisters, K., Krefting, E.R., Kohnert, K.D., Honig, A., Bettin, D.
• Format: Article
• Language: English
• Subjects: ATP; magnesium; Phosphate; SHR; smooth muscle cells
• ISSN: 0895-7061; 1941-7225; 1879-1905
• DOI: 10.1016/S0895-7061(00)01141-9

An alteration of phosphate concentrations and ATP metabolism seems to be involved in the pathogenesis of primary hypertension. Only sparse data exist concerning intracellular phosphate concentrations in hypertensive cells. Therefore, we studied the intracellular phosphate content in 10 SHR of the Münster strain as compared to 10 normotensive age-matched WKY rats. Measurements were performed in smooth muscle cells of the abdominal aorta (3 μm thick) by means of electron-probe X-ray microanalysis technique (Camscan CS 24 apparatus, Cambridge, UK). Additionally red blood cell ATP and the Na+/K+-ATPase activity was measured. The cellular phosphate content of smooth muscle cells was 15.81 ± 1.22 g/kg dry weight in SHR vs. 23.6 ± 0.79 g/kg dry weight in WKY (means ± SD, p < 0.01). In 7 animals each, erythrocytic ATP content was 180.2 ± 102 in SHR vs. 432 ± 72 μmol/l cells in WKY (p < 0.01). The Na+/K+-ATPase activity was significantly decreased in hypertensive animals as compared to controls (6.49 ± 2.3 vs. 12.64 ± 2.9 nmol/Pi/mg/protein/min (p < 0.01). Intracellular phosphate and ATP metabolism are disturbed in SHR as compared to controls. This might be due to a membrane defect or a magnesium deficiency in hypertensive cells.