A link between polymorphonuclear leukocyte intracellular calcium, plasma insulin, and essential hypertension.

Abstract

BACKGROUND:

Intracellular ionized calcium ([Ca2+]i) is a key mediator in the activation and oxidant production by peripheral polymorphonuclear leukocytes (PMN). Primed PMN contribute to oxidative stress (OS) and inflammation in essential hypertension (EH). Elevated [Ca2+]i has been described in insulin-resistant states and in various cell types in EH but not in EH PMN. The aim of this study was to evaluate the levels of [Ca2+]i in peripheral EH PMN in relation to plasma insulin levels and blood pressure (BP).

METHODS:

The PMN were separated from blood of 20 nonsmoking, nonobese untreated EH patients, age range 20 to 60 years and from 20 age- and gender-matched healthy individuals (NC). Plasma glucose and insulin levels 2 h after a 75-g oral glucose load, reflected insulin resistance. PMN [Ca2+]i was measured by flow cytometry in isolated cells stained with Fluo-3.

RESULTS:

The EH PMNs showed significantly increased [Ca2+]i compared to NC PMN. Eighty percent of EH patients showed significantly higher plasma insulin levels after glucose load. Linear regression analysis showed significant correlation between 1) PMN [Ca2+]i and mean arterial pressure (MAP) (r = 0.5, P < .006); 2) PMN [Ca2+]i and fasting plasma insulin (r = 0.7, P < .005); and 3) fasting plasma insulin and MAP (r = 0.4, P < .04).

CONCLUSIONS:

This study adds PMN to previously described cells exhibiting elevated [Ca2+]i, contributing to OS and inflammation. The correlation of individual BP with both PMN [Ca2+]i and plasma insulin levels, together with the fact that elevated [Ca2+]i mediates PMN priming, suggest that elevated [Ca2+]i and insulin are involved in the pathogenesis of hypertension-induced vascular injury in EH.

• Authors: Shifra Sela, Revital Shurtz-Swirski, Raymond Farah, Rivka Levy, Galina Shapiro, Judith Chezar, Shaul M Shasha, Batya Kristal
• Journal: American journal of hypertension (Am J Hypertens) Vol. 15 Issue 4 Pt 1 Pg. 291-5 (Apr 2002) ISSN: 0895-7061 [Print] United States
• PMID: 11991212 (Publication Type: Journal Article)

Chemical References

• Insulin
• Calcium

Topics

• Adult
• Calcium (metabolism)
• Female
• Humans
• Hypertension (blood, etiology)
• Insulin (blood)
• Male
• Middle Aged
• Neutrophils (metabolism)
• Oxidative Stress