Effects of continuous subcutaneous insulin infusion on renal morphology in experimental diabetes. I. Blood glucose levels, body size, kidney weight and glomerulotubular morphometry

Observations have been made over a period of 16 weeks on three groups of rats: controls, untreated streptozotocin-diabetics and diabetics treated with continuous subcutaneous insulin infusion. Good control of circadian and diurnal blood glucose levels was achieved in the insulin-treated diabetics. Body weights and tibial lengths were reduced in untreated diabetics and improved, but not normalized, by insulin therapy. Kidney weights were similar in all groups. Glomerular size and number, tubule volume, glomerular basement membrane volume and surface area were essentially the same in all groups. However, the untreated diabetics possessed tubules of larger diameter and shorter length than those in controls. Both variables were preserved at normal values by insulin infusion therapy. These results illustrate the value of early blood glucose control for preventing at least some of the structural alterations associated with experimental diabetic nephropathy.     

Lipectomy, body weight, and body weight set point in rats.

Adult, Wistar male rats were lipectomized or sham lipectomized. The food-hoarding behavior was measured repeatedly and plotted against the animals' body weights. Body weight set point was estimated as the intercept of regression line of hoarding with the X axis. Body fat content was measured with a TOBEC body composition analyzer. Body weight set point, fat content, and girth were obtained initially, after surgery, and after recovery. The hoarding threshold was lowered for 2 weeks after surgery, from 561 +/- 20 to 512 +/- 19 g (lipectomized), and from 582 +/- 15 to 558 +/- 14 g (sham lipectomized). After a 4-week recovery, all rats reached their prelipectomy body weight set point and regained their initial body fat. Five weeks after surgery, no significant difference was found between the body weight set points of lipectomized and sham-lipectomized rats. This indicates that the body weight set point was not mainly modulated by fat depots. The transient lowering of the set point is thought to be due to surgical stress.     

Effects of single macronutrients on serum cortisol concentrations in normal weight men

A previous study reported that a high carbohydrate meal, in contrast to a high protein/fat meal, significantly increased cortisol concentrations in visceral obese subjects. The objective of this study was to identify effects of single macronutrients on plasma cortisol concentrations. Ten male subjects (age 27.3 ± 7.4 y, BMI 22.1 ± 1.7 kg/m²) were studied in a randomized crossover design on four days around lunchtime after consuming breakfast matched for daily energy requirements (DER 20%). For lunch they consumed one liter of a shake (DER 18%) containing either fat, protein or carbohydrate, with a raspberry taste and similar hedonic value (59 ±2 mm on a 100 mm VAS), using water as control. Serum cortisol concentrations were measured before lunch and during three hours following lunch. Baseline cortisol concentrations did not differ among treatments. The protein as well as the fat lunch caused a significant decrease in cortisol concentrations when compared to the carbohydrate lunch, and showed no difference from the control condition (p < 0.05). The cortisol response in the protein condition (AUC = 37,024 ± 3518 nmol/L min) and in the fat condition (AUC = 35,977 ± 3562 nmol/L min) were significantly smaller when compared with the cortisol response in the carbohydrate condition (AUC = 47,310 ± 3667 nmol/L min) (p < 0.03), but did not differ from the control condition (AUC = 32,784 ± 1683 nmol/L min) (Fig. 1). The cortisol response in the carbohydrate condition was significantly higher when compared with the response in the control condition (p < 0.004). We conclude that cortisol concentrations decreased after protein or fat intake, which was not different from control; this decrease was prevented by carbohydrate intake.     

Effects of black cohosh extract on body weight gain, intra-abdominal fat accumulation, plasma lipids and glucose tolerance in ovariectomized Sprague-Dawley rats

Extracts of the black cohosh (Actaea/Cimicifuga racemosa (CR)) have long been used to treat estrogen deficiency symptoms in women after menopause. Recent data from randomized controlled studies have shown that CR consumption alleviates “hot flushes” and due to the lack of uterotropic effects can be a safe alternative to estrogen replacement therapy. Objective: To evaluate the effects of dietary CR extract consumption on body weight (BW) gain, intra-abdominal fat (IAF) accumulation, plasma leptin, lipids and glucose tolerance in ovariectomized rats and to compare them with the effects of 17β-estradiol. Design: Twenty-seven female Sprague–Dawley rats were ovariectomized and fed soy-free chow with the addition of estradiol-3 benzoate (E2B) (10 mg/kg, n = 10) or CR BNO 1055 extract (6.67 g/kg, n = 9). The control group (n = 8) received soy-free chow only. Weight and food intake were recorded once a week. After 6 weeks, intra-abdominal fat was measured using computer tomography and the intraperitoneal glucose tolerance test was performed. In the seventh week of the experiment animals were sacrificed, blood was collected for plasma and uteri were removed. Results: Dietary CR BNO 1055 extract had no effects on uterine mass but significantly reduced serum lutenizing hormone (LH) levels (P < 0.05). Although, the average weekly food consumption throughout the experiment (calculated in g/kg of BW) did not differ between our studied groups, E2B or CR BNO 1055 treated animals gained less weight and had significantly less IAF accumulation compared to control animals (P < 0.05). E2B treatment also decreased plasma total (T-,) high-density lipoprotein (HDL-) and low-density lipoprotein (LDL)-cholesterol (P < 0.05). Plasma T-Ch levels in CR BNO 1055 treated animals did not differ from the controls whereas LDL-Ch levels were significantly higher and plasma triglycerides (TG) significantly lower (P < 0.05). In the glucose tolerance test, the area under the curve (AUC) was significantly smaller in the E2B treated animals compared to controls (P < 0.05). AUC in CR BNO 1055 treated animals did not differ significantly from the controls (P > 0.05). Nevertheless, fasting plasma insulin (FPI) levels were significantly lower in E2B and CR BNO 1055 treated animals (P < 0.05). Conclusions: In OVX rats, CR BNO 1055 extract consumption decreases enhanced pituitary LH secretion, attenuates body weight gain and IAF accumulation, lowers FPI and has no effects on uterine mass. The effects on plasma lipids seem to be more complex and are characterized by an increase of LDL-Ch and decrease of TG levels which is in contrast to the effects of estrogen.     

Effects of caffeine extract from kola nut on body weight, hematology, sperm reserve and serum enzyme activities in albino rats

This study investigated the effects of caffeine extract from kola nut on body weight, hematological indices, serum enzyme activities, and testicular morphology and function in male albino rats. Ten rats from a total of 58 rats used for this study were used for the assessment of baseline body weight, hematological indices, serum enzyme, and sperm reserve values. Later, three groups of 12 rats (groups A, B, and C) received 10, 20, and 30 mg/kg body weight dose levels of caffeine extract daily, respectively, via the intraperitoneal route for 30 days. The group D rats (n = 12) served as the control and received no caffeine extract treatment. Administration of caffeine extract from kola nut in rats led to significant (P < 0.05) reduction in mean body weight, packed cell volume, erythrocyte count, mean corpuscular hemoglobin concentration, and hemoglobin concentration. Mean total leukocyte count did not differ significantly (P > 0.05) in the three treatment groups relative to the control. Increasing the dose levels of the caffeine extract (10, 20, and 30 mg/kg body weight) significantly (P < 0.05) elevated the mean aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase values. Exposing rats to graded dose levels of caffeine extract led to a significant (P < 0.05) reduction in both gonadal and extra-gonadal sperm reserves. Liver sections of rats that received 30 mg/kg body weight of caffeine extract revealed enlarged portal ducts with cellular proliferation around the portal duct. The results of this study have not only shown the adverse effects of caffeine extract from kola nut in rats but have also provided additional knowledge and information to the existing pathophysiological implication of caffeine intake.     

Effects of stress and ovariectomy on the plasma cholesterol, serum triglyceride, and aortic cholesterol levels of female rats

Female Sprague-Dawley rats were either ovariectomized or sham-operated prior to puberty. As adults, they were maintained on a cholesterol-supplemented diet and subjected to either predictable, controllable shock; unpredictable, uncontrollable shock; or no shock for 30 days (51-min daily sessions). Sham-operated rats had higher plasma cholesterol levels than ovariectomized rats, but neither group showed an effect of stress treatments. For both groups, serum triglyceride and aortic cholesterol levels were lower in stressed than nonstressed rats. Additionally, the ovariectomized rats had higher levels of serum triglycerides than sham-operated controls.     

Effects of body weight loss and taste on VMH-LH electrical activity of rats.

Electrical responses of ventromedial (VMH) and lateral (LH) hypothalamus to graded decrease in body weight and to taste were recorded from a conscious rat with chronically implanted macroelectrodes. Graded reduction in body weight was correlated with gradual increase in LH activity and reciprocal decrease in VMH activity, both of which were stable and specific to each gradation in body weight. On gustation of any test solution, basal activity was temporarily altered, if any. On sweet taste of calorically rich sucrose, VMH activity was enhanced and LH showed decrease. But on sweet taste of calorically inert saccharin, VMH activity was increased, though a reciprocal decrease in LH was not shown. Contrastingly, both bitter taste and salt taste caused increased LH activity but no change in VMH activity. Enhanced VMH activity correlated with sweet taste may be due to activation of VMH glucoreceptors. LH activation correlated with bitter and salt taste is a likely response of two distinct groups of LH units; one responding to salt taste and the other to bitter aversive taste.     

FMH-induced decrease in central histamine levels produces increased feeding and body weight in rats.

The present study tested the long-term effects of the histamine (H) synthesis inhibitor alpha-fluoromethylhistidine (FMH) on feeding and body weight in rats. FMH (administered via 2-week osmotic minipumps) increased feeding significantly throughout the test period. Body weights were also significantly increased toward the end of the test period. Hypothalamic H assays, performed at the end of the study, confirmed that FMH-treated rats had significantly lower H levels than controls. In general, the results suggest that H activity and feeding are inversely related.     

Effect of pancragen on blood glucose level,capillary permeability and adhesion in rats with experimental diabetes mellitus

The effects of tetrapeptide pancragen (Lys-Glu-Asp-Trp-NH₂) on blood glucose level and permeability and adhesion of mesenteric capillaries were studied in Wistar rats with experimental streptozotocin-induced diabetes mellitus. Oral pancragen produced a pronounced hypoglycemic effect during treatment. Intramuscular pancragen normalized the adhesion of mesenteric capillary endothelium, but did not modify capillary permeability. The results indicate homeostatic and endothelioprotective effects of pancragen during the early period of diabetes mellitus. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 10, pp. 441–444, October, 2007     

Comparison of screening methods for diabetes mellitus, based on fasting glucose, HbA1C and fructosamine levels

Screening methods for diabetes mellitus, based on fasting glucose (FPG), HbA1C and fructosamine (FRA) levels were compared with regard to their screening power. The subjects studied were 699 health examinees. A significant elevation of the mean level of each screening index was observed in diabetic subjects, but not in borderline cases compared with that of normal subjects. The FPG, HbA1C and FRA levels in diabetic subjects distributed over a wide range overlapping largely with the distributions of non-diabetic subjects. No appreciable difference in the screening power was observed between FPG and HbA1C but specificity was low in FRG for the comparable sensitivity level. In the screening methods based on the combination of two or more indices, elevation of the sensitivity was noted, but the specificity declined, resulting in an increase of re-examination rate. Among them, the combination of FPG and HbA1C indicated the highest sensitivity.     

The relationship between serum cortisol,adrenaline, blood glucose and lipid profile of undergraduate students under examination stress

BackgroundStress is an extremely adaptive phenomenon in human beings and cortisol is a known stress hormone. Examination has been described as a naturalistic stressor capable of affecting human health.ObjectivesTo estimate the relationship between serum cortisol, adrenaline, fasting blood glucose (FBG) and lipid profile during examination stress.MethodsTwo hundred and eight (208) apparently-healthy undergraduate students (aged, 24 ± 6 years) were involved in the study. Exactly 5 mls of venous blood was collected from each subject 1–3 hours before a major examination. A second assessment was done on the same students 3–4 weeks before any examination (control samples). Cortisol and adrenaline were assayed using ELISA techniques, FBG was assayed using enzymatic method while lipid parameters were assayed using standard enzymatic-spectrophotometric methods.ResultsThere was statistically significant increase in serum cortisol, adrenaline, Total cholesterol, HDL-cholesterol and LDL-cholesterol levels in students under examination stress compared to the non examination period (p=0.001, 0.013, 0.0001, 0.0001 and 0.0001, respectively). FBG showed no significant increase. There was also significant positive correlation (r=0.297, p=0.032) between serum cortisol and TC/HDL ratio (cardiac risk factor) before examination stress but not during the stress period.ConclusionsSignificant positive correlation was observed between cortisol and TC/HDL ratio before examination stress.