Effect of genistein on the pancreas of streptozotocin-induced diabetic male rats: light and electron microscopic study

Diabetes mellitus is a worldwide serious health problem. The critical need for novel therapeutic approaches to treat diabetes mellitus is clear. Genistein, a natural soy isoflavone, have numerous health benefits attributed to multiple biological functions. To investigate the effect of genistein on the structure of pancreatic beta cells and acinar cells in streptozotocin-induced diabetic rats. Thirty adult male albino rats were classified into: group I [control], group II in which diabetes was induced by a single intraperitoneal injection of streptozotocin [STZ] [80 mg/kg] and group 111 in which the diabetic rats were injected subcutaneously with genistein [0.25 mg/kg/day] Alter 3 months, blood glucose concentrations were assessed and pancreas specimens were processed lor light and electron microscopic study. Immunohistochemical insulin reactivity and morphometric analysis of the islet diameter were also studied. STZ, in group II rats, caused shrinkage of the pancreatic islet and induced beta cell damage in addition to weak insulin immunoreactivity and elevated blood glucose level. Many Icinar cells of this group showed accumulated zymogen granules, pleomorphic mitochondria and small lipid droplets. Genistein, in group III rats, preserved beta cell mass as evidenced by the large islets with strong insulin immunoreactivity and the significant reduction in blood glucose level. Ultrastructurally, beta cells of group III rats had numerous secretory granules and well developed Golgi bodies. Iknvever, the acinar cells of genistein treated rats exhibited more structural changes than group II with loss of the normal polarity and marked damage of mitochondria. Zymogen granules exhibited low electron density with frequent docking to the lateral plasma membrane and granule-granule fusion. Genistein protected the beta cells against STZ-induced damage. However its deleterious effect on the pancreatic acinar cells might limit its benefit as a promising therapy for diabetes mellitus

Effect of nicotine on the structure of cochlea of guinea pigs / 대한해부학회지

Smoking has been positively associated with hearing loss in human. However, its effect on the cochlea has not been previously evaluated. Aim of work is to investigate the effect of nicotine, which is the primary pharmacological component of tobacco, on the structure of the cochlea of adult male guinea pigs. Fifteen male guinea pigs were classified into two groups: group I (control) and group II (nicotine treated group). Group II was further subdivided into two subgroups; IIA and IIB according to the dose of nicotine (3 mg/kg and 6 mg/kg, respectively). The cochlea was harvested and processed for light microscopy, transmission electron microscopy and scanning electron microscopy. Nicotine administration induced damage of outer hair cells which were distorted in shape with vacuolated cytoplasm and heterochromatic nuclei. Topography revealed damage of the stereocilia which included disorganization, bent and limp or complete loss and expansion of the surrounding supporting cells. These changes were more pronounced in the basal turn of the cochlea and mainly involved the outer hair cells. High dose induced more damage and resulted in protrusion of the apical poles of hair cells (blebing), particularly the outer two rows. Nicotine is proved to be harmful to the cells of the cochlea, particularly the outer hair cells of the basal turn. High doses induce blebing of hair cells.

Effect of selenium in ameliorating the effect of induced perinatal hypothyroidism on postnatal rat cerebellar cortex development: a histological and immunohistochemical study

Background: Thyroid hormone plays a key role in the development of the cerebellar cortex. Selenium is a nutritional element with antioxidant and neuroprotective properties

Aim: The aim of this study was to investigate the effect of selenium on the structural impairment of postnatal rat cerebellar cortex development induced by perinatal experimental hypothyroidism

Materials and methods: Pups from 20 pregnant rats were divided into four equal groups: group I: negative control group, group II: methimazole-induced hypothyroid group, group III: selenium-supplemented hypothyroid group, and group IV: selenium-supplemented group [positive control]. Treatment continued from gestational day 14 to postnatal day [P] 14. At P7, P14, and P28, blood samples were collected for assessment of serum thyroid hormone and right cerebellar hemisphere specimens were processed for histological, immunohistochemical, and morphometric procedures

Results: Pups of hypothyroid group showed a retarded postnatal cerebellar cortex development, more apparent at P7 and P14, evidenced by increased thickness of the external granular layer and delayed alignment and differentiation of Purkinje cells in addition to reduced proliferating cell nuclear antigen and increased caspase 3-immunoreactivity. At P28, dark cell degeneration of most Purkinje cells was observed. A significant decrease in the thickness of the molecular and internal granular layers and of the number and surface area of Purkinje cells was observed in all postnatal ages studied. Glial fibrillary acidic protein immunostaining showed increased positive astrocytes with twisting and thickening of their glial fibers. Selenium caused a marked amelioration of most of these structural alterations

Conclusion: Perinatal hypothyroidism impaired postnatal cerebellar cortex development. Selenium should be used as a dietary supplement during pregnancy, particularly in hypothyroid conditions

Effect of all-trans-retinoic acid on the structure of thyroid gland and pituitary tyrotrophs in streptozotocin-diabetic male rats

Background: Diabetes mellitus, a chronic disease with increasing prevalence worldwide, is known to be associated with thyroid disorders. Retinoic acid, a metabolite of vitamin A, is currently used for the treatment of diabetes and obesity

Aim of the work: The present study aimed to evaluate the possibility of using all-trans-retinoic acid [atRA] in reducing the structural changes of the thyroid gland and pituitary thyrotrophs in streptozotocin-induced diabetic rats

Materials and methods: Thirty adult male albino rats were divided into three equal groups: group I, control; group II, which included rats in which diabetes was induced by a single intraperitoneal injection of streptozotocin [100 mg/kg]; and group III, which included rats in which diabetes was induced as in group II, followed by an intraperitoneal injection of atRA [2.5 mg/kg/day] from the third day. After 4 weeks, thyroid and pituitary specimens were processed for light and electron microscopic study

Results: Most thyroid follicles of diabetic rats were distended with colloid and lined with flattened thyrocytes with hyperchromatic nuclei and vacuolated cytoplasm that contained dilated rough endoplasmic reticulum, few colloid droplets, and few lysosomes. Some exfoliated cells were observed in the lumen. C cells had rarefied cytoplasm containing a few secretory granules. The number of mast cells showed a nonsignificant change. Thyrotrophs showed dilated rough endoplasmic reticulum, destroyed mitochondria, and decreased secretory granules. The atRA-treated diabetic group showed almost the same structural alterations in the thyroid gland, with even more changes in thyrotrophs

Conclusion: Despite its current use as a novel therapy for diabetes, atRA exerted no ameliorating effect on diabetes-induced histological changes in the thyroid gland and, moreover, exacerbated the changes of pituitary thyrotrophs

Sex differences in dopaminergic neurons of substantia nigra pars compacta of adult and aged rats: a histological and immunohistochemical study

Substantia nigra pars compacta [SNC] is the main source of dopaminergic [DA] input to the striatum. Parkinson's disease is a neurodegenerative disease affecting DA neurons in SNC, with a higher incidence in men. To study the effect of sex on the structure of DA neurons in adult and aged rat SNC. The brains of 22 adult [11 males and 11 females] and 22 aged [11 males and 11 females] albino rats were processed for histological and immunohistochemical examination of DA neurons in the right SNC. Golgi-Cox staining of adult male SNC neurons showed more varicosities and less extension of their dendrites than adult female SNC. Adult male SNC showed a nonsignificant increase in tyrosine hydroxylase-positive neurons than adult female SNC. Aging-related changes were more marked in aged male rats. Aged SNC showed decreased packing density of neurons, some of which appeared irregular and deeply stained. A reduction in Nissl staining was observed. Golgi-Cox staining showed a marked decrease in extension and branching of the dendrites with loss of spines. Ultrastructurally, accumulation of lipofuscin pigment, membranous whorls, dilated Golgi bodies, decreased rough endoplasmic reticulum, and destroyed cristae of mitochondria were observed. A significant reduction in tyrosine hydroxylase-positive neurons was evident in aged SNC. Sex differences in DA neurons of SNC were more apparent in aged rats, with more degenerative changes in the aged male group, which may underlie the predisposition of males to Parkinson's disease

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 Nigella sativa oil on paracetamol-induced renal cortical damage in rats: light and electron microscopic study

Paracetamol or acetaminophen [IV-acetyl-p-aminophenol; APAP] is a widely used analgesic and antipyretic drug. Unfortunately, it is now reported as the most common cause of toxic ingestion in the world. Nigella sativa oil [NSO] is an extract of N. sativa having antioxidant properties. This study aimed to assess the possible role of NSO in ameliorating the toxic effect of APAP overdose on the rat renal cortical structure. Thirty male albino rats were divided into three equal groups. Group I was the control group. Group II comprised rats treated with APAP [750 mg/kg/day] orally for 7 days. Group III received NSO [2 ml/kg/day orally] 30 min before oral administration of APAP at the same dose as that of group II for 7 days. Kidney specimens were processed for light and electron microscopic study of the renal cortex. Plasma renin activity and arterial blood pressure were estimated. APAP-treated rats showed marked structural changes in the proximal convoluted tubules with dense nuclear staining, cytoplasmic vacuolization, increased peroxisomes, and partial loss of apical brush border and basal striations. Renal corpuscles revealed focal fusion of podocyte foot processes and irregular thickening of glomerular basement membranes. Juxtaglomerular cells contained few renin granules, reflecting an increase in renin exocytosis that coincided with increased plasma renin activity and increased arterial blood pressure. Concomitant administration of NSO with APAP revealed a noticeable amelioration of these histological and physiological changes. NSO exerted a protective effect against APAP-induced renal cortical damage

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

light and electron microscopic study of the effect of dehydroepiandrosterone sulfate on myocardium and adrenal zona reticularis of aged male albino rats

Aging is associated with a progressive decline of plasma levels of dehydroepiandrosterone [DHEA] and dehydroepiandrosterone sulfate [DHEAS]. The present work studied the effect of DHEAS administration on the age related histological changes in the myocardium of the heart [being implicated in increased death rate from cardiovascular diseases in the elderly] and in the adrenal zona reticularis [being the major source of DHEA and DHEAS secretion]. Thirty male albino rats were divided into three groups; ten animals each. Group I was the control adult group [6-months age], group II was the control aged group [24-months age], and group III was the treated aged group [24-months age] that received DHEAS orally in a dose of 0.05 mg/rat/day for one month. Specimens from the left ventricle of the heart and from the suprarenal gland were taken from all groups and prepared for light and electron microscopic examination. In control aged group, the myocardium exhibited disorganization of cardiac myocytes and an increase in collagen fibers. Many cardiac myocytes had deeply stained nuclei with increased heterochromatin. Their sarcoplasm showed variable staining intensity, ill defined cross striations, marked degeneration of the mitochondria and increased intermyofibrillar spaces. Other cardiac myocytes appeared relatively with more or less normal light and electron microscopic structure. The cells of adrenal zona reticularis of control aged animals showed irregularity and deeply stained nuclei, in addition to decreased frequency of mitochondria and accumulation of lipid droplets in their cytoplasm. After DHEAS administration, there was a marked reduction in the age related histological changes of both the myocardium and adrenal zona reticularis. The myocardium of DHEAS treated aged animals showed regular arrangement of cardiac myocytes with comparative decrease in appearance of collagen fibers compared to the control aged group. Many cardiac myocytes had relatively normal appearance of their nuclei and sarcoplasm with prominent cross striations, regular organization of myofibrils and less degenerative changes in the mitochondria compared to those of the control aged group. Most zona reticularis cells of DHEAS treated animals had rounded nuclei and relatively normal appearance of their cytoplasm with increased frequency of mitochondria and decreased content of lipid compared to those of the control aged group. The mechanism of action of DHEAS as an antiaging steroid has been discussed. The preventive effect of DHEAS against age related structural changes [although incomplete prevention] is promising of its use as replacement therapy in elderly people to prevent, delay or attenuate the cardiac disorders which accompany aging and to improve the enzymatic activities and endocrine function of adrenal zona reticularis, thus, promote improvement of health with aging

effect of medroxyprogesterone acetate on the structure of adrenal cortex [zona fasciculata] of adult female albino rat. Light and electron microscopic studies

The injectable contraceptive medroxyprogesterone acetate [MPA] is an internationally established option of birth control. To evaluate the possible effects of MPA on the structure of zona fasciculata cells, the adrenals of forty adult female albino rats were used. The experimental animals were divided into four groups treated as follows: group I was kept as control, groups II and III were injected intramusculary with MPA for 2 and 4 months respectively. Animals of group IV were injected for 4 months and sacrificed one month after the last injection. Specimens from the adrenal gland were taken and processed for light and electron microscopic examination. It has been found that MPA caused an increase in the thickness of zona fasciculate and activation of the cells when administered for 2 months. The cells showed numerous lipid droplets, large number of mitochondria and prominent smooth endoplasmic reticulum. However, MPA administration for 4 months resulted in reduction in the thickness of zona fasciculata with degenerative changes in its cells. The cells appeared small and separated from each other and exhibited many lysosomes and intracellular vacuolar spaces. After withdrawal, most of the cells appeared more or less normal and few cells showed some structural changes. These findings indicated that MPA at first caused activation of fasciculata cells and increased steroidogenesis, but prolonged use of MPA induced inactivation and degenerative changes in these cells. However some of these changes were reversible on withdrawal of the drug. Therefore precaution and follow up must be considered with prescribing this drug for prolonged periods