Hormonal regulation of leptin secretion from isolated adipose tissue of male rats

Leptin, the product of ob gene expression mainly by the white adipose tissue cells, is a plasma protein hormone appears to act as a key signaling factor for regulating body weight participating in regulation of energy homeostasis. The escalating interest in leptin study is due to its intimate relation to the worldwide prevalent problem of obesity which reached epidemic proportion.Now it's confirmed that one of the main mechanisms of obesity is decreased leptin action. Leptin seems to play dual role in human physiology being subjected to dual control [Caro et al, 1996] under chronic conditions of steady state energy balance, leptin is a static index of the amount of fat stored in the adipocytes, while under non steady state of energy balance situations leptin may be actively regulated by hormonal or nutritional changes

Assessment of heart rate variability as an index of cardiac autonomic modulation in control and depressed persons

Under steady state conditions, heart rate displays spontaneous beat-to-beat fluctuation. This fluctuation results from the continuous interaction between the neural or humoral control of cardiovascular function. The fluctuation of heart rate around its mean is called heart rate variability [HRV]. The mechanisms underlying the relationship between depression and cardiac events remain unclear. A disturbance of cardiac Sympathovagal balance is one of the most plausible candidates in depressed patients. To evaluate cardiac Sympathovagal activity in depressed, non cardiac patients. A 24-hour Holter electrocardiogram [ECG] was recorded in 15 newly diagnosed depressed patients and 15 healthy age and sex matched control subjects. Sympathovagal balance was evaluated through time domain parameters of Heart rate variability [HRV]. 15[th] patients with depression disorders were found to have elevated resting heart rate [HR], low heart rate variability [HRV]; decreased Mean NNI, SDNN, rMSSD and pNN50. There is considerable evidence of cardiac autonomic dysregalation. In depressed patients, measured by HRV parameters and these abnormalities may explain the increased cardiac morbidity and mortality rates in these patients

Trace elements and flapping tremors in patients with liver cirrhosis. Is there a relationship?

To investigate the possible correlation between hepatic flapping tremors and serum manganese Mn, iron Fe, zinc Zn, and copper Cu. This case control study was carried out in Assiut University Hospital, Assiut, Egypt from June 2006 to June 2007. It included 100 patients with liver cirrhosis, 78 had flapping tremor, and 22 had not, and 60 healthy controls. All patients were subjected to assessment of serum Mn, total Fe, total iron binding capacity TIBC, Zn, and Cu. Assessment of hepatic encephalopathy was carried out using a battery of cognitive function tests. All patients had electroencephalography and MRI of the brain.Compared to healthy controls, patients showed increase in Mn p<0.0001, Cu p<0.05 and decrease in TIBC p<0.000, Zn p<0.05. Eighty-two percent of patients had minimal hepatic encephalopathy mHE. In 85%, MRI-brain showed bilateral hyperintense substantia nigra and globus pallidus on T1-weighted images. A significant positive correlation was present between tremors and severity of liver dysfunction, mHE and serum Cu, and negative correlation with total Fe, TIBC, and Zn. Altered homeostasis of Mn and other minerals could be responsible for the pathophysiology of cognitive deficits associated with liver cirrhosis, but not with flapping tremors. The exact pathogenic role and possibilities for therapeutic implications need further study

Effect of acute and chronic pain on reproductive functions in female rats

In this work, 30 adult female rats were used to study the effect of acute and chronic pain on the reproductive functions. Rats were divided into three equal groups, i.e. control group, acute pain group [exposed to pain once for one hour] and chronic pain group [exposed to pain one hour daily for two weeks]. In each group, gonadotropines and sex hormones were measured .The uterus and ovaries of each group were examined microscopically for histopathological changes. The results showed that acute pain led to an increase in gonadotropines and sex hormones levels as well as histological changes in the uterus [some dilatation in the uterine lumen, decreased uterine vascularity and increased polymorph-nuclear leucocytes [PNL] infiltration and stromal cellularity] and the ovaries [increased number and viability of corpora lutea] The chronic pain led to an increase in FSH, and decrease in LH and sex hormones with, histological changes in the uterus [dilated uterine lumen with increased vascularity, PNL infiltration and stromal cellularity] and the ovary [viable corpora lutea disappeared and only regressive ones were found]. The results of this study showed that pain as a physiological stressor has negative effects on reproductive functions as it causes disturbances in the harmony of gonadotropines and sex hormones and their effects on target tissues

Ghrelin, leptin, insulin and insulin resistance in newly diagnosed type 2 diabetic patients

Objectives: To evaluate the hormonal changes ghrelin, leptin, insulin and insulin resistance in newly diagnosed type 2 diabetic patients and their relation to metabolic state

Methods: The present study was carried out on twenty newly diagnosed type 2 diabetic patients and fifteen apparently healthy persons as a control. Fasting plasma insulin, leptin, and ghrelin were measured by ELISA. Homeostasis Model Assessment [HOMA] is an arithmetic way of deriving indices of pancreatic endocrine function [beta cell function, HOMA-B] and peripheral tissue insulin sensitivity [HOMA-S] were calculated from fasting plasma samples

Results: In diabetic group BMI and waist circumference were significantly increase [p<0.0001and p=0.026]. Insulin and leptin were significantly increase [p<0.0001] while, ghrelin was significantly decrease [p<0.0001]. HOMA-S, significantly decrease [p=0.0110] while, HOMA-B non significantly increase. There was a negative correlation between plasma ghrelin and BMI [p=0.0149], waist circumference [p=0.0002], SBP and DBP [p<0.0001] while leptin showed significantly positive correlated with BMI and waist circumference [p<0.0001]. There was a negative correlation between plasma ghrelin and FBS [p=0.0005], PPBS [p<0.0001], and HOMA-B [p=0.0336] with positive correlation with HOMA-S [p<0.0001], while leptin showed significant positive correlation with HOMA-B [p=0.0023] and significant negative correlation with HOMA-S [p<0.0001]. There was a significant negative correlation between plasma ghrelin and serum triglyceride [p<0.001] and LDL cholesterol [p<0.0001] with a positive correlation with HDL cholesterol [p<0.0001] while leptin showed significant positive correlation with serum triglyceride [p=0.0020] and LDL cholesterol [p<0.0001] and significant negative correlation with HDL cholesterol [p<0.0001]. There was a negative correlation between plasma ghrelin and insulin and leptin [p<0.0001] with a positive correlation between insulin and leptin [p< 0.0001]

Conclusion: It is suggested that there is interaction between insulin and leptin hormones. Insulin has stimulatory trophic effect on leptin secretion, but the effect of leptin on insulin is controversial as leptin lowers insulin secretion and in the same time modulates insulin action and participates in the development of insulin resistance. It is speculated also that both insulin and leptin have inhibitory role on ghrelin level. Decreased plasma levels of ghrelin are significantly associated with abdominal adiposity, hyperinsulinemia and insulin resistance in type 2 diabetic patients. These hormonal changes are associated with clusters of metabolic abnormalities which are major CHD risk factors