Md. Sauro et Jw. Hadden, CELL-FREE THYMIC EXTRACT FROM HYPERTENSIVE RATS INDUCES HYPERTENSION IN NORMOTENSIVE RATS, Immunopharmacology and immunotoxicology, 17(1), 1995, pp. 137-149
This study examined the role of the thymus in hypertension. Seven to e
ight week old, normotensive Wistar-Kyoto rats (WKYs) (systolic blood p
ressure 138 +/- 7 mm Hg) received a bolus injection of (1) WKY thymic
extract (control), (2) spontaneously hypertensive rat (SHR) thymic ext
ract, (3) SHR liver extract or (4) normotensive Sprague-Dawley rat (SD
) thymic extract. Blood pressures of WKYs receiving SHR thymic rose si
gnificantly (p < 0.01) over an eight week period (168 +/- 6 mm Hg), wh
ile WKYs injected with WKY thymic extract (143 +/- 10), SHR liver extr
act (144 +/- 5) or SD thymic extract (138 +/- 4) showed no change in b
lood pressure. Thymuses from WKYs injected with SHR extract were signi
ficantly (p < 0.01) smaller than thymuses from WKYs injected with WKY
extract. Aorta from WKYs administered SHR extract were significantly (
p < 0.01) hyperresponsive to contractile agents, suggesting that immun
e dysfunction may lead to vascular damage as seen in several hypertens
ive models. The results suggest that hypertension can be transferred v
ia an endogenous thymic factor, possibly a viral pathogen.