The enzyme heme oxygenase (HO), which exists in inducible (HO-1) and constitutive (HO-2) isoforms, degrades heme to biliverdin and CO. CO depresses cardiac contraction via cGMP. We aimed to clarify a possible role for the HO-CO pathway in the pathogenesis of cirrhotic cardiomyopathy in bile duct-ligated rats. Four weeks after bile duct ligation or sham operation, rat ventricles were examined fo...

Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, is an integral membrane protein of the smooth endoplasmic reticulum. However, we detected an HO-1 immunoreactive signal in the nucleus of cultured cells after exposure to hypoxia and heme or heme/hemopexin. Under these conditions, a faster migrating HO-1 immunoreactive band was enriched in nuclear extracts, suggesting that H...

OBJECTIVE Obese leptin deficient (ob/ob) mice are a model of adiposity that displays increased levels of fat, glucose, and liver lipids. Our hypothesis is that HO-1 overexpression ameliorates fatty liver development. METHODS Obese mice were administered cobalt protoporphyrin (CoPP) and stannic mesoporphyrin (SnMP) for 6 weeks. Heme, HO-1, HO activity, PGC1α, FGF21, glycogen content, and lipog...

Heme oxygenase-1 (HO-1) induction by hemin or Panhematin protects against experimental pancreatitis. As a preclinical first step toward determining whether HO-1 upregulation is a viable target in acute pancreatitis (AP) patients, we tested the hypothesis that HO-1 expression in peripheral blood mononuclear cell (PBMC) subsets of hospitalized patients with mild AP is upregulated then normalizes ...

In anesthetized normotensive rats, activation of brainstem hemeoxygenase (HO) elicits sympathoinhibition and hypotension. Accordingly, we tested the hypothesis that attenuated basal or induced HO activity in the rostral ventrolateral medulla (RVLM) contributes to hypertension in the spontaneously hypertensive rat (SHR). We measured basal RVLM HO expression and catalytic activity and investigate...

BACKGROUND Pregnancy is characterized by an inflammatory-like process and this may be exacerbated in preeclampsia. The heme oxygenase (HO) enzymes generate carbon monoxide (CO) that induces blood vessel relaxation and biliverdin that acts as an endogenous antioxidant. MATERIALS AND METHODS We examined the expression and localization of HO-1 and HO-2 in normal and preeclamptic placenta using r...

Diabetic retinopathy is a leading cause of visual loss and blindness, characterized by microvascular dysfunction. Hyperglycemia is considered the major pathogenic factor for the development of diabetic retinopathy and is associated with increased oxidative/nitrosative stress in the retina. Since heme oxygenase-1 (HO-1) is an enzyme with antioxidant and protective properties, we investigated the...

Hemin, an oxidized form of heme, is an essential regulator of gene expression and cell cycle progression. Our laboratory previously reported (34) that chronic hemin treatment of spontaneously hypertensive rats reversed the eutrophic inward remodeling of small peripheral arteries. Whether long-term treatment of cultured vascular smooth muscle cells (VSMCs) with hemin alters the proliferation sta...

Heme oxygenase-1 (HO-1) plays a key role in protecting tissue from oxidative stress. Although some studies implicate HO-1 in modulating thrombosis after vascular injury, the impact of HO-1 on the rate of clot formation in vivo is poorly defined. This study examined the potential function of HO-1 in regulating platelet-dependent arterial thrombosis. Platelet-rich thrombi were induced in C57BL/6J...

The seminal discovery of nitric oxide (NO) in the 1980s unraveled the novel concept that an endogenous production of a gaseous substance such as NO can impart diverse and critical functional effects on a wide spectrum of biological and pathological processes. Intense investigations in the chemistry and biology of NO have led to numerous fruitful discoveries, enhancing our understanding of many ...