Comparison of contractile properties between slow and fast skeletal muscles of female diabetic Sprague-dawley rats

Objective: To compare isometric contraction, force-frequency relationship and muscle fatigue between slow and fast muscles of female type 2 diabetes mellitus Sprague-Dawley rats

Study Design: Experimental study

Place and Duration of Study: Physiology Department, Army Medical College, Rawalpindi and National Institute of Health, Islamabad from Jan to Dec 2015

Material and Methods: Twenty healthy female Sprague Dawley rats were divided into 2 groups with 10 rats in each group. Group-I [control] was fed with normal diet and group-II [diabetic] was given high fat diet. Group-II was given intraperitoneal streptozotocin [STZ] [35mg/kg body weight] on 15th day. Body weight, blood glucose and TG: HDL ratio were estimated on 21st day to confirm type II diabetes mellitus [T2DM] induction. Soleus and extensor digitorum longus [EDL] muscles were removed intact and fixed in organ bath system containing Krebs Ringer buffer solution and connected to data acquisition unit [iWorx] to study their contractile parameters

Results: Isometric twitch tensions of slow [soleus] and fast [EDL] muscles were similar in diabetic and control rats. Contraction and half relaxation times were slower in diabetic soleus muscles in comparison to control muscles. Diabetic soleus and EDL muscles displayed significantly [p<0.05] increased fatigability

Conclusion: In STZ induced type II diabetic slow muscles, the tetanic tension remains unaffected while contraction and half relaxation times were longer. In fast muscles, tetanic tension and the speed related properties remain unaffected. There was reduction in resistance to and recovery from fatigue in both slow and fast skeletal muscles

Effect of pomegranate peel alone and in combination with rosiglitazone on hyperglycemia and dyslipidemia in type 2 diabetes mellitus

Objective: To evaluate the effect of pomegranate peel extract with or without rosiglitazone on plasma glucose and lipid profile in insulin resistant diabetic rats

Study Design: Randomized controlled trial

Place and Duration of Study: Department of Physiology, Army Medical College, Rawalpindi, in collaboration with National Institute of Health [N.I.H], Islamabad from 1[st] January 2011 to 28[th] May 2011

Material and Methods: Type 2 diabetes mellitus was induced in sixty healthy rats. The diabetic rats were divided into four groups, namely diabetic control group which received intraperitoneal injection of normal saline daily, pomegranate group which was treated similar to control group and also received pomegranate peel extract [200mg/kg body weight] orally once daily, rosiglitazone group which received intraperitoneal injection of rosiglitazone [5mg/kg body weight] daily and the combined group received both pomegranate extract [100 mg/kg body weight, orally] and intraperitoneal injection of rosiglitazone [2.5 mg/kg body weight] daily for 28 days. After four weeks of treatment, terminal intracardiac sampling was done to measure plasma glucose and lipid profile

Results: The plasma glucose and mean serum levels of cholesterol, triglyceride, low density lipoproteins and very low density lipoproteins was significantly reduced [p<0.001] in pomegranate, rosiglitazone and combined groups respectively as compared to the diabetic control. The mean serum levels of high density lipoproteins were significantly [p<0.001] elevated in above mentioned groups as compared to the diabetic control

Conclusion: Pomegranate peel extract is hypoglycemic and hypolipidemic agent in low doses when used alone or in combination with rosiglitazone in type 2 diabetic rats

Adrenocortical response to 17-beta estradiol replacement in oophorectomized female Sprague Dawley rats

To determine the effect of estradiol treatment on serum corticosterone levels in Oophorectomized [OVX] female Sprague Dawley rats exposed to chronic restraint stress. Experimental study. Department of Physiology, Army Medical College, Rawalpindi and National Institute of health, Islamabad, from January to December 2008. A total of 90 female Sprague Dawley rats [age: 90 +/- 10 days], were divided into three groups, each having 30 rats. Group-I comprised of healthy control female rats whereas group-II and III were experimental female rats exposed to chronic restraint stress after bilateral Oophorectomy and called estradiol treated and vehicle treated groups. Estradiol treatment of Oophorectomized rats was done once daily for 2 weeks. At the end of experiment, the rats were sacrificed and intracardiac blood sampling was done to measure serum corticosterone levels by enzyme linked immunosorbent assay [ELISA] kit. The restraint stress to estradiol treated rats for 2 weeks revealed that serum corticosterone levels were significantly increased [31.32 +/- 5.46 ng/ml, p < 0.05] as compared to the healthy controls [17.48 +/- 4.14 ng/ml]. Chronic restraint stress results increases the serum corticosterone levels in Oophorectomized Sprague Dawley rats. Estradiol treatment increases the responsiveness of adrenal cortex of Oophorectomized female rats

Evaluation of oxidative stress, liver functions and anemia in lead intoxicated Sprague Dawley rats

To evaluate quantitative effect of lead exposure on the oxidative stress, liver functions and hematological profile. Seventy male healthy Sprague Dawley rats were randomly divided into two groups with thirty five rats in each group. Rats of lead intoxicated group were given weekly intraperitoneal injection of lead acetate 10 mg/kg body weight. After 6 weeks, intracardiac sampling was done and blood was used to determine hemoglobin concentration, erythrocyte count, red cell indices, serum MDA, serum ALT and AST levels. Lead intoxication of rats for 6 weeks revealed that serum MDA levels were increased to 7.8 +/- 0.48 micro mol/l [control = 3.2 +/- 0.27micro mol/l], ALT levels to 76.26 +/- 5.88 IU/l [control = 44.7 +/- 2.96] and AST levels to 258.06 +/- 13.30 IU/l [control = 156.8 +/- 5.04]. Hematological parameters of lead intoxicated group reveals lowered levels of hemoglobin, RBC count, MCHC and MCH while MCV remained statistically unchanged; manifesting hypochromic normocytic anemia. Lead intoxication for 6 weeks induces oxidative stress, hepatotoxicity and hypochromic normocytic anemia

Correlation of inflammatory markers with type 2 diabetes mellitus in Pakistani patients

To study the levels of inflammatory markers in Type 2 Diabetes Mellitus Pakistani patients and determine their correlation with the disease. This cross sectional study was conducted at Military Hospital, Rawalpindi, and Centre for Research in Experimental and Applied Medicine [CREAM], Army Medical College, Rawalpindi, Pakistan from June 2011-June 2012. We determined the levels of Erythrocyte Sedimentation Rate [ESR], Total Leukocyte Count [TLC], Interleukin 6 [IL-6] and Tumor Necrosis Factor- alpha [TNF- alpha] in 72 patients with Type 2 Diabetes Mellitus [T2DM] and 40 healthy controls. The levels were correlated with age, duration of the disease, Body Mass Index [BMI], lipid profile and insulin resistance. ESR, TLC, IL-6 and TNF- alpha were found to be significantly higher in T2DM patients. There was also statistically significant difference in BMI, fasting blood sugar, insulin resistance and dyslipidemia [except LDL] between diabetic and control group. All inflammatory markers except TNF- alpha were positively correlated with insulin resistance. Only TNF- alpha was found to be correlated to duration of the disease. Both TLC and Serum insulin were positively correlated to BMI. Inflammatory markers were not correlated to dyslipidemia. This is the first study reporting levels of cytokines in Pakistani diabetic patients and healthy controls. There is augmented inflammation in T2DM in Pakistani patients which plays role in higher insulin resistance in these patients. TNF- alpha levels increases with longer duration of the disease. Levels of inflammatory markers are not correlated to BMI, dyslipidemia or increasing age

Serum levo-carnitine levels and skeletal muscle functions in type 2 diabetes mellitus in rodents

To study serum levo-carnitine [l-carnitine] levels and isometric contraction, force frequency relationship and fatigue of rodent skeletal muscles in type 2 diabetes mellitus. Randomized controlled trial. Physiology Department, Army Medical College, Rawalpindi, from January 2009 to January 2010. Sixty Sprague-Dawley rats were randomly divided into two groups; group I [control], fed on normal diet adlibitum and Group II [diabetic], fed on high fat diet and administered streptozocin to induce type 2 diabetes mellitus [T2DM]. At 21[st] day, plasma glucose and TG/HDL ratio were measured to confirm the development of T2DM in group II. At 28[th] day, blood was drawn by intracardiac puncture to estimate serum levo-carnitine levels. Contractile functions of skeletal muscles were assessed by using iWorx AHK/214 physiological data acquisition unit. Simple muscle twitches, maximum isometric twitch tension [MITT], time-to-peak twitch tension [TPTT] and time-to-relax to 50% of the peak twitch tension [1/2RT] of extensor digitorum muscles were recorded. Muscles were stimulated at higher frequencies to determine maximum fused tetanic tension [MFTT], maximum fused tetanic tension after fatigue protocol [TTFP] and recovery from fatigue [RF]. Serum levocarnitine level decreased significantly in the diabetic group. Both groups had similar MITT, TPTT and 1/2RT but decline in MFTT, TTFP and RF was significant in the diabetic rats. T2DM adversely affected serum levocarnitine levels and the contractile functions of rodent skeletal muscle at high frequency stimulation

Effect of antioxidant supplementation on lipid peroxidation and antioxidant enzyme activity on exposure to acute restraint stress in sprague dawley rats

To determine the effects of ascorbic acid [AA] and alpha tocopherol [AT] supplementation on stress induced changes in serum malondialdehyde and serum superoxide dismutase levels in male Sprague Dawley rats. Quasi experimental study. Department of Physiology, Army Medical College Rawalpindi in collaboration with National Institute of Health, Islamabad during March 2009 to September 2009. Eighty male Sprague Dawley rats were divided into five groups with sixteen rats in each group. Group I served as control without stress and group II exposed to restraint stress for 06 hours, group III given ascorbic acid, group IV alpha tocopherol and group V was supplemented with both vitamins along with standard diet for one month. All antioxidant supplemented groups were exposed to restraint stress for six hours. Immediately after stress, the blood samples were analyzed colorimetrically to estimate serum malondialdehyde and superoxide dismutase by commercially available kits. There was no significant fall in serum malondialdehyde in rats supplemented with ascorbic acid alone, however rats supplemented with alpha tocopherol or combination of ascorbic acid and alpha tocopherol revealed significant fall in serum malondialdehyde and increment in superoxide dismutase activity. Alpha tocopherol alone and in combination with ascorbic acid is effective to prevent reactive oxygen species induced increase in lipid peroxidation and fall in super oxide dismutase activity thereby conferring protection against oxidative stress

Levo-carnitine normalizes blood glucose and lipid profile in insulin resistant type II diabetic rats

This study was planned to determine the effect of levo-carnitine on blood glucose and lipid profile in high fat diet fed, streptozotocin induced insulin resistant type II diabetic rats. Randomized controlled trial [RCT] Department of Physiology, Army Medical College, Rawalpindi from 20th to 15 Jan 2009. Ninety Sprague-Dawley rats were divided into three groups; each having 30 rats. Group I [control] was fed on normal diet while in Group II [Diabetic] diabetes was induced by feeding high fat diet and giving the injection of streptozotocin. Group III [Carnitine] was treated like group II to induce diabetes mellitus and later Levo-carnitine 200 mg/kg body weight/day was administered intraperitoneally for 6 days. The blood glucose and lipid profile were significantly deranged in the diabetic and carnitine groups as compared to the control. After levo-carnitine treatment the blood glucose level decreased significantly [p <0.001] in carnitine group [6.2 mmol/1] as compared to the diabetic group [22.7 mmol/1]. The levels of triglycerides, cholesterol and LDL were significantly decreased [P<0.001] in carnitine group 0.5 mmol/1, 1.3 mmol/1 and 0.2 mmol/1 as compared to the diabetic group 1.9 mmol/1, 4.4 mmol/1 and 3.1 mmol/1 respectively. HDL level was significantly raised [p<0.001] in the carnitine group [0.9 mmol/1] as compared to the diabetic group [0.4 mmol/1]. It is concluded that Levo-carnitine administration tends to normalize glycemic control and lipid profile in type II diabetes mellitus. However, human trial is recommended to ascertain its efficacy as an antidiabetic and antidyslipidemic agent for therapeutic use

Correlation of serum alanine aminotransferase and aspartate aminotransferase levels of liver histology in chronic hepatitis C

To assess the correlation of serum alanine aminostransferase and aspartate aminotransferase levels to severity of disease on liver biopsy in patients of chronic hepatitis C. Descriptive study. Department of Gastroenterology of Military Hospital, Rawalpindi, from January 2006 to February 2007. One hundred and seven diagnosed non-cirrhotic chronic hepatitis C adult patients were included. Serum alanine aminotransferase and aspartate aminotransferase levels were determined. Knodell histopathological Index was determined on liver biopsy. The correlation and regression value between serum alanine aminotransferase levels and liver histology and serum aspartate aminotransferase and liver histology in chronic hepatitis C patients was determined using Pearson correlation analysis. Patients of chronic hepatitis C had raised serum alanine aminostransferase and levels with the mean baseline level of 93 International units per liter [IU/L] with a range of 13-383 IU/L. Serum aspirate aminotransferase levels were also elevated with mean baseline level of 59.65 IU/L ranging from 18-370 IU/L. On liver biopsy based on Knobell histopathologicalIndex, 47.7% of patients had mild, 39.9% IU/L had moderate and 13.1% had severe disease. There was significant association between serum alanine aminostransferase levels severity of the disese on liver biopsy [p<0.03] with weak positive correlation between the two [r=0.217]. There was also significant association between serum aspartate aminotransferase levels and severity of the disease on liver biopsy [p<0.001] with weak positive correlation between the two [r=0.32]. The serum alanine aminostransferase and serum aspartate aminotransferase levels do not indicate the severity of the disease on liver biopsy in chronic hepatitis C patients

Effects of ascorbic acid and selenium supplementation on basal testosterone cortisol ratio in male sprague dawley rats

To determine the effects of ascorbic acid and selenium supplementation on basal testosterone cortisol ratio in male Sprague Dawley rats. Quasi experimental study. The study was carried out in the department of Physiology, Army Medical College Rawalpindi in collaboration with National Institute of Health, Islamabad during October 2006 to September 2007. Forty male Sprague Dawley rats were divided into four groups with ten rats in each group and above mentioned antioxidants supplementation were given along with standard diet for one month. After this, blood samples were taken and analyzed for serum testosterone and cortisol by ELISA and malondialdehyde levels colorimetrically. Results were analyzed on SPSS version 13 and p value less than 0.05 was considered significant. There was no significant rise in testosterone cortisol ratio in rats supplemented with single antioxidant, however rats supplemented with combination of ascorbic acid and selenium revealed significant rise in testosterone cortisol ratio with a fall in malondialdehyde levels. Synergistic effects of ascorbic acid and selenium may have resulted in a decline in reactive oxygen species induced lipid peroxidation and rise of testosterone cortisol ratio

Comparison of two methods for recording frog's myocardiogram

Frog's myocardiogram gives the medical students a clear understanding of the normal sequence of atrial and ventricular contraction and the effect of temperature, sympathetic stimulation and parasympathetic stimulation on frog's heart. The purpose of this study was to compare two methods used for recording of frogs myocardiogram, namely kymographic method and iWorx data acquisition unit Method, keeping in view the difference between the recordings obtained by two methods and the convenience for the medical students in recording the myocardiogram by the two methods. Frog was dissected and myocardiogram recorded first with the kymograph and than with the iWorx data acquisition unit. Frog's saline was pored at regular intervals and both kymographic and iWorx readings were taken thrice at an interval of 5 min. In the myocardiogram height of the recording on the y-axis indicates the strength of contraction by the frog heart. The height of myocardiogram recorded on the kymographic recording at intervals of 5 min each was compared with the height of the myocardiogram recorded on iWorx data acquisition unit at the same time. Comparison of the results at the same time interval show that iWorx data acquisition unit system reflects the mechanical activity of heart better than the conventional kymographic method. Even when the kymograph show no record of myocardial contractility the iWorx data acquisition unit still show the activity of the myocardium. This study shows that iWorx system reflects the mechanical activity in myocardium even when the kymograph cannot record it

Frequency of ventricular late potentials in healthy population

Ventricular late potentials are low amplitude signals detected on Signal averaged ECG. These potentials have been associated with the development of ventricular tachyarrhythmias. Few studies are available relating frequency of ventricular late potentials in healthy individuals but no such data is available for our population. We planned the study to determine frequency of ventricular late potentials in healthy subjects of our population. Thirty-seven healthy subjects with mean age 26 +/- 5 were included. All the subjects underwent ECG, Echocardiography, Exercise tolerance test, blood sugar profile and coronary angiogram to rule out all the possible confounders. Signal averaged ECG was performed on all the subjects to determine ventricular late potentials. Three parameters of SAECG, i.e., fQRS, LAS 40 and RMS 40 were measured using 1200 EPX arrhythmia research technology. Only 1 subject out of total 37 had ventricular late potentials [2.7%]. The frequency of ventricular late potentials in healthy subjects [2.7%] indicates the magnitude of development of ventricular tachyarrhythmias that may lead to vulnerability of sudden cardiac death. However study on larger scale is needed to confirm the frequency of ventricular late potentials in our population

Efficacy of combined interferon alpha and ribavirin therapy in patients of chronic hepatitis C

This study was carried out to determine the efficacy of combined interferon alpha and ribavirin therapy in patients of chronic hepatitis C. This study was conducted at Military Hospital Rawalpindi and Army Medical College, Rawalpindi from January 2006 to Feb 2007. One hundred and sixty seven non cirrhotic chronic hepatitis C patients were studied. The patients were grouped into study group [n=107] and control group [n=60]. The patients had persistently raised serum aminotransferase [ALT], positive HCV antibodies by 3[rd] generation ELISA, positive HCV RNA by polymerase chain reaction. Study group patients had positive histopathological findings on liver biopsy on basis of Knodell histopathological index [HPI]. At weeks 0, 12 and 24, blood samples were taken for the assay of serum alanine transferase [ALT] and serum, aspartate transferase [AST] levels in both the groups. Study group patients underwent 24 weeks Interferon and Ribavirin combination therapy and subsequently followed up for the response to treatment by the assay of HCV RNA by polymerase chain reaction at weeks 24. Control group included the patients without treatment plan but they also underwent screening for the same liver function tests. Patients of chronic hepatitis C [80 males and 27 females] had age range 18-48 years. After 24 weeks of INF and ribavirin therapy, 86% patients showed favourable response to treatment manifested by negative HCV RNA polymerase chain reaction. Treatment with Interferon and ribavirin combination therapy for 24 weeks produces significant virological response in patients of chronic hepatitis C at the end of treatment

Electrocardiographs diagnosis of left ventricular hypertrophy: comparison with echocardiography

The present study was conducted to determine the sensitivity and specificity of electrocardiographic criteria for the assessment of left ventricular hypertrophy by comparing it with the gold standard of echocardiography. Fifty clinically diagnosed patients of LVH were included in this collaborative study of Dept. of Physiology, Army Medical College, Rawalpindi and Department of Cardiology, Armed Forces Institute of Cardiology, Rawalpindi. ECG of the patients were recorded and Romhilt-Estes point score calculated. This was followed by echocardiography and left ventricular mass and left ventricular mass index was calculated. It was found that Romhilt-Estes point score system of ECG had a sensitivity of 35% and specificity 90%. It is concluded that the sensitivity of ECG is low in detecting LVH, however, sensitivity can be increased by combining Sokolow Lyons voltage criteria and Cornell voltage criteria with Romhilt-Estes point score. ECG is however still recommended as a routine investigation because of its cost effectiveness and easy availability

High resolution electrocardiography

High Resolution Electrocardiography is a very specialized type of surface ECG which involves computerized analysis of small segments of a standard ECG in order to detect abnormalities, termed Ventricular Late Potentials [VLP] that would be otherwise obscured by skeletal muscle and electrical noise. There are various types of these low amplitude signals which can be detected by High Resolution Electrocardiography but the most important are Ventricular Late Potentials and the main clinical use of High Resolution Electrocardiography is to detect these VLPs. Ventricular Late Potentials are present in terminal part of QRS complex and these may extend into ST segment as well; hence the name "late potentials" because they arise late in ventricular activation process