Exhaustive exercise training enhances aerobic capacity in American alligator (Alligator mississippiensis)

The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, ventricular and skeletal muscle masses and haematocrit. Compared to sedentary control animals, alligators regularly trained for 15 months on a treadmill (run group) or in a flume (swim group) exhibited peak oxygen consumption rates higher by 27 and 16%, respectively. Run and swim exercise training significantly increased ventricular mass (~11%) and haematocrit (~11%), but not the mass of skeletal muscles. However, exercise training did not alter CS or LDH activities of skeletal muscles. Similar to mammals, alligators respond to exercise training by increasing convective oxygen transport mechanisms, specifically heart size (potentially greater stroke volume) and haematocrit (increased oxygen carrying-capacity of the blood). Unlike mammals, but similar to squamate reptiles, alligators do not also increase citrate synthase activity of the skeletal muscles in response to exercise

HEMORHEOLOGICAL CHANGES IN CONGESTIVE CARDIAC-FAILURE

The primary cardiac defect in Congestive Cardiac Failure(CCF) is decrease in intrinsic contractility of myocardium, usually brought on by prolonged pressure and/or volume overload. A wide range of factors may precipitate or aggravate or worsen blood flow conditions leading to the cardiac failure, and hemorheological factors could be one of them. This investigation aimed to study the possible role and association between change in hemorheological parameters and congestive cardiac failure. Parameters studied in this study on 88 patients of congestive cardiac faliure were - whole blood viscosity, plasma viscosity, red cell rigidity, hematocrit, erythrocyte sedimentation rate, fibrinogen, cholesterol, triglycerides and albumin. The patients were categorized in to 2 subgroups on the basis of their clinical history and diagnosis. The first group was, congestive cardiac failure with coronary heart disease and second group congestive cardiac failure with hypertension. There were significant changes in the hemorheological parameters in both the groups. In cases of congestive cardiac failure with coronary heart disease rise in blood viscosity at low shear rate(p<0.0001) was more significant as compared to high shear rate(p<0.01). Increases in plasma viscosity, red cell rigidity, fibrinogen and erythrocyte sedimentation rate were very significant. Among biochemical parameters increase in plasma triglycerides was statistically significant(p<0.01). In the second group, congestive cardiac failure with hypertension, showed marked increase in whole blood viscosity at low and high shear rates. In this group increase in red cell rigidity was most significant as(p<0.0001) compared to other parameters. Increase in plasma viscosity, fibrinogen and plasma cholesterol and triglycerides were also significant. It was found that the regular smokers had higher values of blood viscosity, red cell rigidity(p<0.05), hematocrit(p<0.005) and plasma viscosity(p<0.05) as compared to non-smoker patients in both the groups. There was no significant change in albumin and hematocrit in both the groups as compared to normal controls. The present study highlights the possible role of hemorheological factors along with other physiological factors in congestive cardiac failure

Evaluation of haemorheological, biochemical and microcirculatory parameters in young smokers

We studied 44 young smokers and 40 controls, all male, for haemorheological, biochemical, physiological and microcirculatory parameters. This study was conducted between January 1994 and December 1994. All the smokers have been smoking 13-18 cigarettes per day for the last three years, None of them were taking any medicine nor did they have any major health problem which could affect the results of our study. The results of our study clearly indicate that smokers have disturbed haemodynamic profile as compared to normal controls. This could result in worsening of blood flow condition, leading to development of various disorders

3D-QSAR and Molecular Docking Studies of 4-Anilinoquinazoline Derivatives: a Rational Approach to Anticancer Drug Design

The present article is an attempt to formulate the three-dimensional quantitative structure–activity relationship (3D-QSAR) modeling of 4-anilinoquinazoline derivatives having promising anticancer activities inhibiting epidermal growth factor (EGFR) kinase. Molecular field analysis was applied for the generation of steric and electrostatic descriptors based on aligned structures. Partial least-squares (PLS) methodwas applied for QSAR model development considering training and test set approaches. The PLSmodels showed some interesting results in terms of internal and external predictability against EGFR kinase inhibition for such type of anilinoquinazoline derivatives. Steric and electrostatic field effects are discussed in the light of contribution plot generated. Finally, molecular docking analysis was carried out to better understand of the interactions between EGFR target and inhibitors in this series. Hydrophobic and hydrogenbond interactions lead to identification of active binding sites of EGFR protein in the docked complex