Obesity associated pathophysiological & histological changes in WNIN obese mutant rats.

Background & objectives: WNIN/Ob (obese and euglycaemic) and WNIN/GR-Ob (obesity with impaired glucose tolerance), were isolated and established from Wistar rat stock (WNIN). Both strains showed physical, physiological and biochemical indices related to obesity. We present here haematology, histology and pathophysiological changes between the phenotypes of these strains, lean (+/+), carrier (+/-) and obese (-/-). Methods: A total of 72 animals of equal gender consisting of three phenotypes were used for the study. Haematology, organ weights were measured and histopathology of the tissues studied using standard procedures. In 12 lean and obese rats (equal gender) of WNIN/GR-Ob group morphometry of pancreatic islets was done immunohistochemically (IHC). Results: Obese rats of both the strains showed normal haematology (except low platelet count), but exhibited changes in the organ weights and in histopathology in organs like liver, kidney, brain and testis/ovary. Hyperplasia of adipocytes was seen in obese rats as compared to lean and carrier. IHC of obese rat pancreas showed that both islet density and volume were significantly (P<0.05) increased compared to lean littermates. Interpretation & conclusions: The histological and pathophysiological changes seen in these mutants were in tune with obese phenotype exhibited by these animals.

Evaluation of the anti-ulcer activity of NR-ANX-C (a polyherbal formulation) in aspirin & pyloric ligature induced gastric ulcers in albino rats.

Background & objectives: The aetiology of gastric ulcers is not completely understood and continuous use of anti-ulcer agents leads to many side effects. In this study we evaluated the anti-ulcer efficacy of a polyherbal formulation with potent antioxidant activity in aspirin and pyloric ligature induced gastric ulcers in rats. Methods: The efficacy of the polyherbal formulation NR-ANX-C (composed of the extracts from Withania somnifera, Camellia sinensis, Ocimum sanctum, shilajith and triphala) was evaluated in terms of antioxidant potential as assessed in terms of protection from lipid peroxidation and the antiulcer activity as seen by the area of gastric lesions, gastric juice volume, gastric pH, total acidity and total adherent gastric mucus content. Results: In our study, NR-ANX-C (25 and 50 mg/kg) was more efficacious than ranitidine in reducing ulcer index in both the models. At the highest dose tested (50 mg/kg), NR-ANX-C was comparable to omeprazole in preventing ulcer formation in the pyloric ligature model. NR-ANX-C showed a dose- dependent decrease in gastric juice volume and total acidity in both the models. A dose-dependent increase in gastric pH and total adherent gastric mucus was also seen in NR-ANX-C treated groups. The extent of lipid peroxidation was also reduced in the test drug treated groups. Interpretation & conclusion: Based on our findings, we presume that the cytoprotective, anti-secretary and antioxidant properties of NR-ANX-C were responsible for its anti-ulcer activity. These findings suggest the potential for use of NR-ANX-C as an adjuvant in the treatment of gastric ulcer.

Estudo fisiofarmacológico de ratos mutantes portadores de hipotricose(ratos paraíba): aspectos da reproduçäo, morfologia e termoregulaçäo / Physiopharmacologic study of hypotrichotic strain of rats (Paraíba): aspects related to reproduction, morfology and temperature regulation

Através do protocolo de cruzamentos realizados entre animais heterozigotos obtivemos cerca de 23 por cento de animais pelados e no acasalamento entre machos pelados e fêmeas heterozigotas obtivemos cerca de 44 por cento de animais portadores da mutação. - Fêmeas peladas, apesar de férteis apresentam dificuldade na amamentação. Dos 28 filhotes nascidos de fêmeas com esse genótipo, nenhum sobreviveu. 3- No estabelecimento da colônia, o primeiro grupo de animais F1 produzido apresentou peso corporal significativamente menor que o dos animais do grupo Wistar. Nas fêmeas essa diferença chegou a 50g na fase adulta e nos machos 80g, correspondendo a 20 por cento e 30º/o respectivamente. 4- Após o segundo acasalamento, ocasião em que foi feita a classificação dos animais em homozigotos (pp), heterozigotos (Pp) e controle (PP), não foram mais observadas diferenças no peso das fêmeas dos diferentes genótipos. Entretanto, machos pelados continuaram a apresentar peso corporal 20 por cento menor e animais do grupo controle e 10 - 15 por cento menor que animais heterozigotos. Essas diferenças no peso corporal puderam ser observadas a partir de 42 dias de idade, acentuando-se na fase adulta. 5- Nos estudos em gaiola metabólica verificou-se que o consumo de ração foi aproximadamente o dobro em ratos pelados em comparação ao grupo controle. Fêmeas peladas consumiram cerca de 14g/100g de peso/dia enquanto que para o grupo controle esse valor foi de 7,3g1100g peso/dia. Nos machos, essa proporção se repetiu. Machos pelados consumiram 12,14g/100g peso/dia, enquanto que animais do grupo controle consumiram 6,63g1100g peso/dia. Fêmeas e machos heterozigotos apresentaram valores intermediários...(au)

Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat

Taiep is an autosomal recessive mutant rat that shows a highly hypomyelinated central nervous system (CNS). Oligodendrocytes accumulate microtubules (MTs) in association with endoplasmic reticulum (ER) membranes forming MT-ER complexes. The microtubular defect in oligodendrocytes, the abnormal formation of CNS myelin and the astrocytic reaction were characterized by immunocytochemical and ultrastructural methods during the first year of life. Optic nerves of both control and taiep rats were processed by the immunoperoxidase method using antibodies against tubulin, myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP). Taiep oligodendrocytes are strongly immunoreactive against tubulin, indicative of a significant accumulation of microtubules. Early differentiated oligodendrocytes observed with electron microscopy show that MT-ER complexes are mainly present in the cell body. This defect increases during the first year of life; oligodendrocytes show large MT-ER complexes projected within oligodendrocyte processes. Using anti-MBP, there was a progressive reduction of immunolabeling in the myelin sheaths as taiep rats grew older. Ultrastructural analysis revealed severely dysmyelinated axons with a frequently collapsed periaxonal collar. However, through age the myelin sheath became gradually infiltrated by MTs, suggesting their contribution to premature loss of myelin in the taiep rat. Axons of one-year-old taiep rats were severely demyelinated. Modifications in astrocytes revealed by the GFAP antibody showed a strong hypertrophy with increased immunostaining in their processes. As demyelination of axons progressed, taiep rats developed a strong astrogliosis. The present findings suggest that in taiep rats the early abnormal myelination of axons affects the adequate maintenance of myelin, leading to a progressive loss of myelin components and severe astrogliosis, features that should be considered in the pathogenesis of dysmyelinating diseases

A new mutant hairless mouse with limph node hyperplasia and late onset of autoimmune pathology

Adult BALB/c male mice were injected with a single dose of ethyl nitroso urea (ENU; 250 mg/Kg, ip) and mated to C57BL/6, DBA/2 AND A/J adult females 13 weeks later. F1 males were mated with BALB/c females and F2 females were then backcrossed to the F1 parents. One BALB/c male mouse thus teated gave origin to a mutant presenting hair and skin alterations similar to those of natural hairless mutants. The new mutation is located on chromosome 14 near the Es10 locus, and probably at the same locus for the hairless mutation. Similar to the hairless mouse, this new mutant has a normal phenotype at birth and after three weeks starts to loose hair which is never replaced. Additionally, the skin becomes thickened and wrinkled. One feature that distinguishes this mutant from other hairless mice is the peculiar enlargement of its axillary and cervical lymph nodes. The new mutant develops membranoproliferative glomerulonephritis similar to the rhino mouse, one of the hariless allele mutants already described in the literature, but with a much later onset

Secreción de amilasa y quimotripsinógeno en la rata diabética por estreptozotocina / Secretion of amylase and chymotrypsinogen in streptozotocin induced diabetic rats

Se ha estudiado el contenido de amilasa y quimotripsinógeno en la secreción pancreática basal y post-estimulación de la rata anestesiada, y en su respectivo homogenado pancreático. Estos valores se han comparado con los provenientes de un grupo de ratas con diabetes por estreptozotocina. La secreción basal de la rata anestesiada tiene una relación amilasa/quimotripsinógeno de 70,3 ñ 1,1, después de la estimulación con ceruleína (600ng/kg) este valor cae a 17,9 ñ 1,9, siendo de 20,3 ñ 1,2 las cifras halladas en el homogenado pancreático. Se confirma de esta manera que la secreción pancreática basal en la rata anestesiada proviene de un compartimiento minoritario, e inversamente la obtenida post-estimulación provendría de un reservorio mayoritario (proporciones enzimáticas similares a las del páncreas total). En los animales diabéticos se ha observado una relación amilasa/quimotripsinógeno de 40,6 ñ 0,6 durante la secreción basal, después de la estimulación con ceruleína esta cifra en el jugo pancreático desciende a 8,7 ñ 0,9, siendo el valor en sus respectivos homogenados pancreáticos de 9,7 ñ 0,9. La diabetes ha provocado una reducción proporcionalmente mayor para la amilasa que para el quimotripsinógeno, en la secreción basal, en la secreción post-estimulación y en el homogenado pancreático. En conclusión, la diabetes modifica el contenido de las enzimas estudiadas con similar intensidad en ambos compartimientos; la insulina no sería probablemente responsable directa de las diferentes proporciones enzimáticas presente en ambos compartimientos secretorios

Adverse effect of 1, 25-dihydroxycholecalciferol on erythrocyte precursors in the rats

La administración oral de 0.5 ugm/d/100 gm de peso a ratas normales produjo una significativa despoblación de la médula ósea, especialmente en la línea eritroide. El análisis de muestras de sangre periférica mostró ligera anemia con reticulocitopenia. La tasa de desaparición de eritrocitos marcados con 51-cr no fue afectada por el tratamiento, lo que sugiere que éste impide que la médula ósea reponga los eritrocitos a la tasa normal. El efecto adverso del tratamiento sobre la eritropoyesis parece relacionado con el grado de hipercalcemia que, a su vez, depende del contenido de la dieta