The role of calcium in genetic hypertension.

Lau, Kai; Eby, B.

doi:10.1161/01.hyp.7.5.657

Cited by 63 publications

(18 citation statements)

References 112 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…PTH is known to increase intracellular calcium concentration and might thereby directly affect vascular smooth muscle tension. 2 We previously observed that the decrease in diastolic blood pressure to calcium supplementation in offspring with relatively high blood pressure was most clear in subjects with a relatively high plasma PTH or low serum calcium. 32 In one other study, hypertensive subjects with a relatively large urinary calcium excretion showed more pronounced decreases in blood pressure to calcium supplementation compared with those with normal urinary calcium excretion.…”

Section: Discussionmentioning

confidence: 97%

Alterations in calcium metabolism in young people at risk for primary hypertension. The Dutch Hypertension and Offspring Study.

Hooft¹,

Grobbee²,

Frölich³

et al. 1993

Hypertension

View full text Add to dashboard Cite

Several disturbances in calcium metabolism have been reported in primary hypertensive subjects. It is, however, not clear whether these alterations predate the development of hypertension or occur as a consequence of high blood pressure. We studied indexes of calcium metabolism in three groups of normotensive children with different familial predispositions for hypertension, based on parental blood pressure levels, with two, one, or no hypertensive parents. Plasma intact parathyroid hormone pressure regulation. In some hypertensive subjects, urinary excretion of magnesium may be decreased and show an inverse relation with blood pressure.16 Serum phosphate concentration is reported to be lower in hypertension and negatively related to blood pressure. 17Besides changes in serum and urinary electrolytes, raised circulating parathyroid hormone (PTH) levels have been demonstrated in hypertensive individuals. 1318 We reported previously that plasma intact PTH is raised in young hypertensive subjects compared with normotensive subjects of similar age, suggesting that alterations in calcium metabolism may be important in the early phase of primary hypertension. 1920Discussion remains as to whether changes in calcium metabolism are causally related to the development of high blood pressure. 21 In genetically hypertensive rats, calcium supplementation during the developmental phase of hypertension diminished the blood pressure increase. 22 In another study, however, genetically hypertensive rats fed a calcium-deficient diet did not show an increased blood pressure rise compared with rats fed a normal diet. 23 Parathyroidectomy in young genetically hypertensive rats, while keeping a normal serum calcium level, delayed the rise in systolic blood pressure for 42 weeks. 24 In humans, information on the part played by changes in calcium metabolism in the development of high blood pressure may be gained from comparison of

show abstract

Section: Discussionmentioning

confidence: 97%

Alterations in calcium metabolism in young people at risk for primary hypertension. The Dutch Hypertension and Offspring Study.

Hooft¹,

Grobbee²,

Frölich³

et al. 1993

Hypertension

View full text Add to dashboard Cite

show abstract

“…Young spontaneously hypertensive rats and Dahl salt-sensitive rats have higher 1,25-(OH)2D3 levels than Wistar Kyoto rats and Dahl salt-resistant rats, respectively (16,17). In humans, it has been reported that serum 1,2540H)2D3 is significantly increased in patients with low renin hypertension (18,19).…”

mentioning

confidence: 99%

“…It was also recently reported that 1,25-(OH)2D3 is synthesized in vascular endothelial cells (27) Cell culture. Neonatal rat vascular smooth muscle cells (strain R22D) were obtained from PeterJones (University ofSouthern California) (28) and were used for the present studies at passages [16][17][18][19][20][21][22][23][24][25][26][27][28]. The cells were maintained in Eagle's MEM with 10% FBS, 2% tryptose phosphate broth, penicillin (50 U/ml), and streptomycin (50 U/ml) in a humidified atmosphere of 5% CO2, 95% air at 370C (29).…”

mentioning

confidence: 99%

1,25-dihydroxyvitamin D3 modulates growth of vascular smooth muscle cells.

Mitsuhashi¹,

Morris²,

Ives³

1991

J. Clin. Invest.

167

View full text Add to dashboard Cite

We examined the effects of 1,25-dihydroxyvitamin D3(1,25-(OH)2D3) on the proliferation of vascular smooth muscle (VSM) cells. Receptors for 1,250-H)2D3 were demonstrated in fresh rabbit aortic tissue and in cultured rat VSM using binding of 13H1-1,25-0H)2D3 in sucrose density gradients of the tissue or cell homogenates. The receptor sedimented at 3.6 S, the sedimentation velocity of 1,2501H)2D3 receptors from other sources. 1,2540H)2D3 dramatically altered the growth of VSM, but this effect depended importantly on the basal conditions in which the cells were grown. In quiescent VSM deprived of serum for 72 h, 1,2540H)2D3 (0.1-10 nM), but not 25-(OH)D3 (up to 100 nM) increased thymidine incorporation up to 12-fold and cell number up to 2.6-fold compared with controls. The maximal effect of 1,25-(0H)D3 on thymidine incorporation was similar to the maximal effect of the growth factors a-thrombin or PDGF. Furthermore, the effects of 1,25-(OH)2D3 and thrombin on thymidine incorporation in quiescent cells were markedly synergistic, yielding a 78-fold increase in thymidine incorporation when both agents were added simultaneously. In "nonquiescent cells" which were exposed to serumfree medium for only 24 h, 1,2540H)2D3 (10 nM) also increased DNA synthesis 10-fold compared with controls. However, in striking contrast to what was observed in quiescent cells, 1,25-(OH)2D3 diminished the mitogenic response to thrombin by as much as 50% in nonquiescent cells. 1,25-(OHh)D3 also modulated the transcription of c-myc in response to thrombin. In quiescent cells, transcription was enhanced by 1,25-(OH)2D3, whereas in nonquiescent cells, thrombin-induced c-myc transcription was blunted. Thus, 1,25-(0H)2D3 is a potent modulator of the growth of cultured VSM. The direction of this modulation depends strongly on the conditions under which the cells are cultured. (J. Clin. Invest. 1991.

show abstract

“…Although the elevated serum 1,25(OH)2D3 concentrations could provide an adequate explanation for the enhanced intestinal Ca transport, additional studies are however necessary to critically evaluate a possible cause-and-effect relationship between these physiologic and chemical alterations. Similarly, although the presence of these changes in the prehypertensive stage of the SHR raises the possibility that they could play a role in the hypertension, more compelling evidence than those summarized (71) depends on future studies specifically evaluating the blood pressure response to correcting these abnormalities in very young SHR.…”

Section: Discussionmentioning

confidence: 99%

Increased calcium absorption in prehypertensive spontaneously hypertensive rat. Role of serum 1,25-dihydroxyvitamin D3 levels and intestinal brush border membrane fluidity.

Lau¹,

Langman²,

Gafter³

et al. 1986

J. Clin. Invest.

Self Cite

View full text Add to dashboard Cite

Changes in Ca absorption have been described in the spontaneously hypertensive rat (SHR) compared with Wistar-Kyoto (WKy) rats. In 3.5-wk-old SHR and age-matched WKy controls, we measured direct arterial blood pressure, Ca absorption, and serum 1,25-dihydroxyvitamin D3 11,25(OH)2D31 levels and small intestine brush border membrane (BBM) fluidity and lipid composition. The two objectives were (a) to define the nature of the absorptive changes before detectable hypertension and (b) to evaluate the potential mechanism(s). We found that even at this normotensive stage (106±4 vs. 107±2 torr for the female and 109±3 vs. 104±3 torr for the male), the SHR (a) absorbed more Ca (1.46±0.06 vs. 1.14±0.08 mmol/d and 1.53±0.06 vs. 1.28±0.06 mmol/d, respectively) and retained more Ca, (b) had higher serum 1,25(OH)D3 levels (340±36 vs. 160±18 pg/ml and 230±25 vs. 150±16 pg/ml, respectively), and (c) possessed BBM with increased fluidity and with reduced fatty acyl saturation index owing to decreased stearic (32.2±2.6% vs. 38.2±0.9%) but increased linoleic acids (12.2±2.0% vs. 7.6±1.6%). These results demonstrate increased Ca absorption in prehypertensive SHR associated with increased serum 1,25(OH)2D3 levels, increased intestinal BBM fluidity, and reduced saturation index, which singly or in combination could produce the changes in intestinal Ca transport.

show abstract

The role of calcium in genetic hypertension.

Cited by 63 publications

References 112 publications

Alterations in calcium metabolism in young people at risk for primary hypertension. The Dutch Hypertension and Offspring Study.

Alterations in calcium metabolism in young people at risk for primary hypertension. The Dutch Hypertension and Offspring Study.

1,25-dihydroxyvitamin D3 modulates growth of vascular smooth muscle cells.

Increased calcium absorption in prehypertensive spontaneously hypertensive rat. Role of serum 1,25-dihydroxyvitamin D3 levels and intestinal brush border membrane fluidity.

Contact Info

Product

Resources

About