In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 μg/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman’s space and tubula...

To test the hypothesis that cardiac norepinephrine depletion related to heart failure alters contractile responses to beta-adrenergic agonists with a component of "indirect" action (acting by release of neuronal norepinephrine), we examined the inotropic potential of several pharmacologically distinct beta-agonists. Contractile responses to the nonselective beta-agonist isoproterenol, the beta ...

Leptin regulates cardiovascular function. Leptin levels are elevated in obesity and hypertension and may play a role in cardiovascular dysfunctions in these comorbidities. This study was designed to determine the influence of hypertension on the cardiac contractile response of leptin. Mechanical and intracellular Ca(2+) properties were evaluated using an IonOptix system in ventricular myocytes ...

OBJECTIVES Recent studies have demonstrated that perivascular adipose tissue (PVAT) releases vascular relaxation factor(s). In this study, we examined if PVAT releases other vasoactive factors in response to perivascular nerve activation by electrical field stimulation (EFS). METHODS AND RESULTS In Wistar-Kyoto rats, rings of superior mesenteric artery (MA) with intact PVAT (PVAT (+)) showed ...

OBJECTIVES Physical activity has been well known to benefit heart function. The improved autonomic nervous activity is considered to be mainly responsible for this beneficial effect. However, the precise mechanism behind the intrinsic myocardial responsiveness to exercise is still unclear. This study was designed to examine the effect of swim training on myocardial response to insulin with a sp...

In helically cut strips of dog cerebral, coronary, mesenteric and femoral arteries, the contractile response to prostaglandin (PG) F2alpha, and E2, relative to contractions induced by 30 mM K+, did not appreciably differ, whereas relaxations induced by PGE1 relative to those induced by 10(-4) M papaverine were significantly different; the least in cerebral arteries and the greatest in mesenteri...

The heart responds to diverse forms of stress by hypertrophic growth accompanied by fibrosis and eventual diminution of contractility, which results from down-regulation of alpha-myosin heavy chain (alphaMHC) and up-regulation of betaMHC, the primary contractile proteins of the heart. We found that a cardiac-specific microRNA (miR-208) encoded by an intron of the alphaMHC gene is required for c...

Ginger root (Zingiber officinale) is an herbal supplement used to control severe nausea and vomiting during pregnancy. It is also prepared as a tincture to revitalize the uterus during labor. The purpose of this study was to determine if revitalizing the uterus involved changes in uterine contractile activity. Volumes of ginger root juice (20-1000 μL) were applied directly to isolated mouse ute...

The physiologic role of smooth muscle structure in defining arterial function is poorly understood. We aimed to elucidate the relationship between vascular smooth muscle architecture and functional contractile output. Using microcontact printing and muscular thin film technology, we engineered in vitro vascular tissues with strictly defined geometries and tested their contractile function. In a...

Skeletal muscle tissue engineering holds great promise for pharmacological studies. Herein, we demonstrated an in vitro drug testing system using tissue-engineered skeletal muscle constructs. In response to epigenetic drugs, myotube differentiation of C2C12 myoblast cells was promoted in two-dimensional cell cultures, but the levels of contractile force generation of tissue-engineered skeletal ...