Effects of low-level lead exposure on blood pressure and function of the rat isolated heart

Abstract

Objective:Exposure to low levels of lead acetate can induce hypertension in both humans and experimental animals. The exact mechanisms of lead-induced hypertension are not well understood, but its pathogenesis could be explained by the changes in heart rate and contractility.Materials and Methods:In the present study, the effects of exposure to 100 ppm of lead in drinking water (for periods of 4, 8, and 12 weeks) on blood pressure and some physiologic parameters (eg, electrocardiography [ECG], heart rate [HR], cardiac contractility, and coronary flow) of isolated beating rat heart was investigated using the Langendorff isolated heart apparatus. The isolated hearts were perfused with Krebs-Henseleit solution (37°C; pH 7.4; gassed with 95% O2 + 5% CO2). All data were digitized by a software program for further analysis.Results:The blood pressure in the 8- and 12-week lead-exposed groups was significantly increased as compared to the control group. The ECG showed arrhythmias and conduction abnormalities only in the late phases of exposure (12 weeks). The HR and contractility were significantly higher in the 8- and 12-week lead-treated rats but not in the 4-week group. No significant changes were observed in coronary flow.Conclusion:These results indicate that: 1) low levels of lead exposure do not significantly affect the ECG in the early phase, 2) low levels of lead exposure causes ECG changes in the late phases of exposure, and 3) this level of lead exposure can increase HR and cardiac contractility but has no effect on coronary flow.

Microfluidic heart on a chip for higher throughput pharmacological studies

“…We were able to create 19 replicates from the same fluidic chip and generate a pD2 value of 5.75 from our drug dose response data. Both the responses and pD2 value are similar to the responses reported in literature for rat heart 33, 34 and from in vitro experiments 35 . Figure 4c and 4d plot the contractile endpoints from the same chip in the control experiment (no drug exposure) and at 10 -4 M exposure to isoproterenol, respectively.…”

Hematobiochemical changes of lead Poisoning and amelioration with Coconut (<i>Cocos nucifera</i> L.) Water in wistar albino rats

“…Low levels Exposure of lead has been linked with functional and structural impairments in both human and experimental animals (Reza et al 2008). The hematopoietic, nervous and renal tissues are the main targets of lead.…”

BP-ANN for Fitting the Temperature-Germination Model and Its Application in Predicting Sowing Time and Region for Bermudagrass

“…This grass is adapted to extremely variable environments, such as fertile fields, arid land, saline land, wet irrigation canals and even contaminated wastelands with high levels of Pb, Cd, Zn and Cu [6]–[10]. In addition, the extracts from bermudagrass are well known for various medicinal properties including antimicrobial [11], [12], anti-inflammatory [13], [14], immunomodulatory [15], [16] and anti-diarrhea activities [17]. It has been therefore used to treat traumatic wounding, kidney calculi [18], hypoglycemia [19], depression [20] and cancer [21]–[23].…”