[Effect of the thymus on the development of genetic hypertension in the Lyons-strain rat (LH)].
The aim of this work was to determine the part played by the thymus in the development genetic hypertension. This study was conducted in the genetically hypertensive rats (LH) of the lyon strain and their two simultaneously selected controls: the normotensive (LN) and low blood pressure (LL) rats. Systolic blood pressure (SBP) and immunological characteristics were investigated in sham-operated and neonatally thymectomized rats of the 3 strains. At 5 weeks of age, sham-operated LH rats exhibited a higher SBP (122 +/- 4 mmHg) than LN (111 +/- 2 mmHg) and LL (100 +/- 2 mmHg) controls. White blood cell numbers and percentage of circulating lymphocytes, thymus histology as well as T cells and T subsets percentages in that organ did not significantly differ within the 3 strains. On the contrary, in the animals of the 3 strains, a positive relationship could be established between the SBP and the proliferative response of the splenocytes to Pokeweed-Mitogen (r = 0.93; N = 30; p less than 0.001) or to Concanavalin A (r = 0.42; n = 30; p less than 0.05). After neonatal thymectomy the SBP of LH rats was more markedly decrease than that of LN and LL rats and established as follows: 103 +/- 2 mmHg; 102 +/- 2 mmHg; 97 +/- 2 mmHg for LH, LN and LL respectively. 21 weeks after thymectomy the SBP remained significantly decrease in LH rats only 160 +/- 5 mmHg vs 177 +/- 6 mmHg in sham-operated rats.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002452:Cell Count; D006973:Hypertension / Q000235:genetics / Q000276:immunology / Q000503:physiopathology*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D051381:Rats; D013154:Spleen / Q000276:immunology*; D013601:T-Lymphocytes; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology / Q000503:physiopathology*
Influence du thymus dans le développement de l'hypertension génétique chez le rat de souche lyonnaise (LH).