Effect of sildenafil citrate on the structure of rat liver: a histological, histochemical and immunohistochemical study

Sildenafil citrate [SC] is an effective drug for treatment for erectile dysfunction, which is a common symptom in patients with liver disease. The effect of SC on liver structure is elusive and has not been thoroughly studied. The aim of this study was to investigate the effect of SC treatment for different periods and its withdrawal on the liver structure in adult male rats. Twenty-four adult male albino rats were classified into four groups: group I [control], group II [rats treated with SC orally at a dose of 10 mg/kg/day for 4 weeks], group III [rats treated with 10 mg/kg/day SC for 8 weeks] and group IV [recovery group; rats treated similarly as group III and then left for 4 weeks without SC treatment]. Liver specimens were processed for histological, histochemical and immunohistochemical study. In group II, the liver revealed significant enlargement of many hepatocytes with clumping of cell organelles in their cytoplasm. There were frequent Kupffer cells, activated hepatic stellate cells and increased deposition of collagen fibers. In group III, these changes were more marked, in addition to reduced glycogen staining in hepatocytes. Dilated bile ductules and cellular infiltration were noticed in many portal tract areas. In the recovery group, most changes were relatively reduced but not reversed completely. SC exerted deleterious structural effects on the hepatic tissue that were more pronounced with longer duration of SC administration. Some of these deleterious effects were reversible after discontinuation of the drug

Effect of shark liver oil on renal cortical structure in hypercholesterolemic rats

Numerous studies reported the association between hypercholesterolemia and renal damage. Elevated plasma cholesterol is involved in the onset and progression of renal diseases. Shark liver oil is reported to be an antioxidant and hypolipidemic. This study was conducted to investigate the possible effects of two different doses of shark liver oil in reducing renal cortical changes associated with high cholesterol diet feeding in correlation with serum lipids. Forty rats were divided into two groups: control group [group 1 = 1 0 rats] and high cholesterol diet-fed group [group 2 = 30 rats]. Group 2 was further subdivided into three subgroups: group 2a, nonsupplemented with shark liver oil; group 2b, supplemented with 1 0% shark liver oil; and group 2c supplemented with 20% shark liver oil. Kidney samples were processed for general histological, immunohistochemical, and ultrastructural study of the renal cortex. Blood samples were collected for assessment of serum lipids. High cholesterol diet-fed group showed prominent podocyte injury characterized by de novo desmin staining and flattening and fusion of foot processes. Some renal corpuscles exhibited thickening and distortion of the glomerular basement membrane. Renal tubular cells showed intracellular vacuoles and mitochondrial degeneration. These structural changes were associated with altered serum lipids. Shark liver oil dietary supplement noticeably ameliorated renal cortical damage and corrected the changes in serum lipids with better improvement in the 20% shark liver oil-supplemented group. This study reveals the beneficial effect of shark liver oil, as a health supplement, in ameliorating the structural renal cortical damage and hypercholesterolemia associated with high cholesterol diet feeding

Advances in tissue engineering: current status and future prospects

Recent developments in biomedical engineering as well as basic biology and medicine have enabled us to induce cell-based regeneration of body tissue aided by self-repairing tissues or substitute biological functions of damaged organs with cells. For successful tissue regeneration, it is important to provide cells with an environment suitable for the induction of cell-based tissue regeneration. Tissue engineering is a newly emerging biomedical technology providing the potential to create the environment for tissue regeneration with various biomaterials. This study presents an overview of recent researches and clinical data on tissue regeneration based on tissue engineering, briefly explaining the key technologies of tissue engineering

Postnatal development of the female rabbit vomerosensory epithelium: a light and electron microscopic study

The vomeronasal organ [VNO] is an essential organ with regard to its recognition as a receptor of nonvolatile substances known as pheromones and its link with mammalian reproduction. The postnatal development of the vomerosensory epithelium of the VNO of female white rabbits has been investigated in this study. Four age groups [newborn, 1 week, 2 weeks, and 1 month] were studied using light and electron microscopic techniques. Three basic cell types have been distinguished in the rabbit vomerosensory epithelium: supporting cells, sensory neuronal cells, and basal cells. The supporting cells showed signs of maturation as enlargement and branching of the microvilli and difficulty of identification of centrioles in the apical parts of the cells. The sensory cells showed different stages of maturity; some changes have been found in the morphology and development of the cell organelles. There was decrease in the number of ribosomes and increase in the number of arborizations of their microvilli. The basal cells were present more at birth and decreased as the rabbits grew. There was maturation of the histological structure of the sensory epithelium of the VNO of female rabbits, which indicated the presence of great signs of functional activity at birth that continued during the first month of age to acquire mature functional capability

Effect of low phosphate diet on the structure of the rat parathyroid and thyroid glands

Dietary phosphate restriction in patients with chronic renal insufficiency has been demonstrated to prevent the increase in serum parathyroid hormone [PTH] levels clinically. Besides, the effect of phosphate on serum PTH levels is reported to be independent of changes in the level of both serum calcium and vitamin D. To investigate the structure of the parathyroid and the thyroid glands in rats fed restricted phosphate diet. Three groups of adult Wistar rats were used in this study. Group I, served as control. They were fed with regular balanced diet containing normal [0.6%] phosphate, normal [0.6%] calcium diet. Groups II and Ill [the experimental groups], were fed low [0.02%] phosphate, normal [0.6%] calcium and low [0.02%] phosphate, low [0.02%] calcium diets respectively for 30 days. The morphology of the parathyroid and thyroid glands was studied, using light and electron microscopic techniques. The parathyroid glands of groups II and Ill were atrophied with connective tissue invasion and darkening of the chief cells. The chief cells revealed well developed Golgi and RER cisternae, and the cytoplasm contained numerous small granules containing particulate material. The thyroid follicles in group Ii animals appeared lighter in staining, whereas in group Ill, most of the follicular cells were darkened. However, the activation was focal in distribution. Active interaction between the thyroid follicular and the adjacent parafollicular cells was evident. Both the plasma and nuclear membranes of the follicular cells exhibited signs of interactions. The thyroid parafollicular cells in group H appeared dark and contained numerous secretory granules, whereas in group III they were pale and contained few granules. It can be concluded that phosphate restriction induces a direct atrophic effect on the parathyroid gland, independent of calcium level. On the other hand, phosphate restriction influences the thyroid parafollicular cells indirectly, most probably through modulating the blood calcium level. It can also be concluded that a mutual cooperation exists between the thyroid follicular and parafollicular cells

Histological study on the effect of low level perinatal lead exposure on the cerebellar cortex of adult male albino rat

Lead contaminating drinking water is most often a problem in houses. As the nervous system is the primary target for the low levels of lead exposure, more attention has been directed towards lead poisoning. To determine the toxic effect of chronic low level of lead acetate on the histological structure of the cerebellar cortex of adult male albino rats. A total number of 5 pregnant albino rats were used. Lead exposure was initiated on gestation day 6 with the addition of daily doses of 0.2% lead acetate to distilled deionized drinking water and lasted until weaning. Half of the weaned male offspring were maintained on lead treated water supply until the age of two months [treated]. The remaining half received distilled deionized water until the age of 2 months [withdrawal]. Control animals received distilled deionized water. Specimens from the cerebellar cortex were processed for examination by light and electron microscope. Lead level in blood, urine and cerebellar tissue was estimated by spectrophotometry. In lead exposed rats, Purkinje cells, oligodendrocytes and Golgi cells were affected. The number of Purkinje cells decreased. The myelinated axons showed vacuoles. Blood capillaries were affected. Lead level in blood and cerebellar tissue was high. In the withdrawal group, some Purkinje cells revealed partial recovery while others showed more progress in degeneration. Chronic low level perinatal lead exposure had toxic effect on the cerebellar cortex of adult male albino rat mild regression was revealed after lead cessation

Diabetogenic effect of clozapine

Clozapine is one of the commonly used atypical antipsychotics. Several pharmacoepidemiologic studies have supported the notion that atypical antipsychotics may raise the risk of diabetes. Precise risk estimates for hyperglycemia-related adverse events in patients treated with atypical antipsychotics are not available. This study aims to clarify the diabetogenic effect of clozapine on the blood glucose level and on the cellular level by histopathological and immunohistochemical examination of pancreas. Twenty adult albino male rats were divided into two groups; first one as a control group received distilled water orally for 90 days. The other group received 13 mg of clozapine orally daily for the same duration. The rats were sacrificed and blood samples for assessment of glucose level were obtained. The pancreas was processed for histopathological, histochemical and immunohistochemical examination. The results showed hyperglycaemia in the clozapine treated group. Hisopathological examination of the pancreas of treated animals showed many large sized islets of Langerhans, sprouting of new islets from a pre-existing one and many small scattered islets within pancreatic lobules denoting hyperplastic changes. Also, some islets showed apoptotic cells and others showed lymphocytic infiltration. Endocrine-like masses of cells could be observed in relation to many interlobular ducts. Interlobular and interacinar fibrosis was observed by using masson's trichrome stain. PAS reaction revealed increased thickness of the basement membrane of the islets capillaries. Immunohistochemical staining with anti-insulin antibody showed strong staining of the hyperplastic islets of treated animals. Hislopathological and immunohistochemical observations suggested that clozapine treatment has a diabetogenic effect on the pancreatic islets of Langerhans. The pathogenesis of clozapine-associated diabetes is very similar to type 2 diabetes mellitus