Objective: To observe mainfestations of syndrome and biochemical indices of hypertensive model rats with excessive accumulation of phlegm-dampness syndrome (EAPDS), and to explore its possible pathological mechanism.
Methods: EAPDS rat model was prepared in 50 Wistar rats by feeding with high fat forage. Meanwhile, a normal control group consisting of 10 Wistar rats was set up by feeding with normal forage. After 25-week continuous feeding, 22 rats with body weight (BW) and blood pressure (BP) exceeding 25% those of the control group were selected as a model group. BW, BP, blood lipids, and related serological indicators were detected in all rats. Morphological changes of target organs were observed. mRNA expression levels of leptin receptor (LepR), Janus kinase2 (Jak2), signal transducer and activator of transcription 3 (Stat3), suppressor of cytokine signaling-3 (Socs3), angiotensin II receptor type 1 (AT1), angiotensin II receptor type 2 (AT2), phosphatidylinositol 3 kinase (P13K), serine threonine kinase (Akt), nuclear factor of kappa B (NF-κBp65), inhibitor of nuclear factor kappa-B kinase α (IKKα), NF-kappa-B inhibitor β (lKKβ), NF-kappa-B inhibitor α (IKBα), and AMP-activated protein kinase (AMPK) were detected by quantitative real-time PCR (qPCR). Expression levels of AT1 and LepR in aorta were detected by immunohistochemical assay and Western blot respectively.
Results: Compared with the control group, BW, BP, and blood lipids increased; serum levels of leptin (Lep) , Ang II, Hcy, ET-1, TNF-α, IL-6, and p2-MG increased, but NO decreased in the model group (P < 0.05, P < 0.01). Aortal endothelial injury and smooth muscle cell proliferation occurred in the model group, accompanied with heart and renal injury. Compared with the control group, mRNA expression levels of LepR, Jak2, Stat3, Socs3, AT1 , PI3K, Akt, NF-κB p65, IKKβ, IKBα, and AMPK in aorta were up-regulated significantly (P < 0.05), while the expression of IKKa decreased (P < 0.05). Immunohistochem- ical staining showed, brownish yellow deposit of AT1 and LepR was obviously increased, with more extensively positive distribution. Western blot results showed, as compared with the control group, protein expression levels of AT1 and LepR obviously increased in the model group (P < 0.05).
Conclusions: Model rats exhibited typical syndromes of EAPDS. They put up weight with fat abdomen, gloomy hair, poor appetite, hypersomnia, lowered activities , reduced food intake, loose stool, dark red tongue, white tongue with white, thick, greasy fur. Lep could be taken as one of objective indicators for evaluating hypertension rat model with EAPDS.