Magnesium Regulation of Calcium in Essential Hypertension

<p>Essential hypertension is a complex disease which is treated by palliative methods, since the causal factors are as yet unknown. A variety of both genetic and environmental factors probably combine to produce chronic high blood pressure. A genetic model of essential hypertension, spontaneously hypertensive rats (SHR), and its control strain Wistar Kyoto (WKY) were used to investigate a possible environmental causal factor, cellular magnesium deficit, and its impact on the functional ability of the calcium ATPase. Rats were fed either a magnesium-deficient or a magnesium-sufficient diet for 10 weeks, after which the calcium ATPase activity was measured in intact red blood cells (RBC). Free intracellular calcium [Ca²⁺]i accumulation in response to a five minute 10 nM ionomycin challenge was estimated in blood mononuclear cells (MNC) loaded with the calcium indicator fura-2 AM. Plasma and RBC total magnesium were measured and found to be considerably lower in magnesium-deficient rats. Magnesium-deficient RBC of both SHR and WKY demonstrated lower Ca ATPase activity when stimulated either with 0.3 μΜ or 35 μΜ Ca²⁺than did magnesium-sufficient cells. Magnesium-deficient MNC of SHR accumulated more [Ca²⁺]i than magnesium sufficient cells when challenged with ionomycin. However there was considerable individual variation. Results in WKY were not statistically different. These experiments showed that dietary magnesium can have a significant effect on the calcium handling of model cells and perhaps on the vascular smooth muscle cells of essential hypertensive patients, leading to increased vascular resistance.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry and Biochemistry

Year dc:date.available

1992

Author dc:creator

• Gordon, Elaine Pringle

Contributors dc:contributor

• Frank Lattanzio
• Dieter Bartschat
• Barbara Hargrave
• Howard D. White

• Hypertension
• Magnesium
• Calcium regulation
• Cell Biology

Repository record dc:identifier

https://digitalcommons.odu.edu/biomedicalsciences_etds/102

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:biomedicalsciences_etds-1109