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Sulphatides in the brain of spontaneously hypertensive rats.
No full textSulphatides were assayed in preparations of frontal cortex, neostriatum and hippocampus of 6-month-old male spontaneously hypertensive rats (SHR, systolic pressure 215 +/- 6 mmHg) and age-matched normotensive Wistar-Kyoto (WKY) rats (systolic pressure 143 +/- 6 mmHg) by thin layer chromatography associated with spectrophotometry and histochemistry. The volume of gray and white matter of the above areas was also measured by microanatomical techniques associated with image analysis. Sulphatide levels were unchanged in the frontal cortex and neostriatum and decreased in the hippocampus of SHR in comparison with WKY rats. No changes of metachromatic sulphatide staining were found in the different brain areas investigated of SHR, whereas a decrease of positive metachromatic areas was noticeable in the frontal cortex and neostriatum, but not in the hippocampus of SHR. A reduction of volume of frontal cortex gray and white matter as well as of striosomes and of gray matter of hippocampus was found in SHR. No changes in the total volume of neostriatum and in the volume of white matter of hippocampus were observed between SHR and normotensive WKY rats. These findings, which are consistent with recent evidence of the occurrence of atrophic changes in the brain of SHR, showed that sulphatide levels were decreased in the hippocampus of SHR. In this area no reduction of white matter was observed. Sulphatide concentrations are thought to reflect the status of brain myelinated fibers. The not parallel decrease of sulphatide levels and white matter volume in the majority of brain areas investigated suggests the occurrence in SHR of sulphatide changes not corresponding simply to a reduction of myelinated pathways
Autoradiographic localization of muscarinic cholinergic receptor subtypes in human placenta.
No full textThe localisation of M1-M4 muscarinic cholinergic receptor subtypes was investigated in sections of normal human term placenta by light microscope autoradiography. Muscarinic cholinergic receptor subtypes were found almost exclusively in syncytiotrophoblast. Neither other cellular components of placenta, nor blood vessels were labelled. Quantitative analysis of the density of silver grains developed in sections incubated with the different protocols for labelling M1-M4 receptor subtypes, revealed that syncytiotrophoblast expresses all subtypes of muscarinic cholinergic receptor investigated. A higher density of binding sites was found in the apical than in the basal portion of syncytiotrophoblast. The demonstration of muscarinic cholinergic receptors in syncytiotrophoblast suggests that a cholinergic system may have a role in regulating transport of compounds from maternal to foetal interface
Morphological and conduction changes in the sciatic nerve of spontaneously hypertensive rats.
No full textThe morphology and function of sciatic nerve were investigated in spontaneously hypertensive rats (SHR), either control or hydralazine-treated, and in normotensive Wistar Kyoto rats of 6 months of age. In control SHR decreased percentages of class I fibers (20-15 microm in diameter), of axonal NFP-H 200 kDa neurofilament protein immunoreactivity and of nerve conduction velocity were found. The percentages of class III (10-5 microm in diameter) and IV (<5 microm in diameter) and of S100beta-immunoreactive Schwann cell profiles were increased. Treatment with the hypotensive drug hydralazine countered sciatic nerve changes. The shift of nerve composition vs. smaller fibers is probably the cause of reduced nerve conduction velocity found in SHR and is consistent with the occurrence of a sympathetic hyper innervation in this animal model of hypertension. Our findings support the hypothesis that arterial hypertension may represent a risk factor of neuropathy
Microanatomical changes of intracerebral arteries in spontaneously hypertensive rats: a model of cerebrovascular disease of the elderly
No full textThe hippocampus in spontaneously hypertensive rats: a quantitative microanatomical study
No full textThe cerebral cortex of spontaneously hypertensive rats: a quantitative microanatomical study.
No full textThe morphology of cerebral cortex was investigated in male spontaneously hypertensive rats (SHR) aged 2, 4 and 6 months (pre-hypertensive, developing hypertension and established hypertension respectively) and in age-matched normotensive Wistar-Kyoto (WKY) rats using quantitative microanatomical techniques. Analysis included frontal and occipital cortex as a paradigm of motor and sensory cerebrocortical areas respectively. Values of systolic pressure were slightly higher in 2-month-old SHR compared to age-matched WKY rats and augmented progressively with increasing age in SHR. In frontal cortex of SHR a decrease of nerve cell number and of cortical volume was observed in layers V and VI of 4- and 6- month-old SHR, and in layers I-IV of 6- month-old SHR. In occipital cortex a decrease of the number of nerve cells and of cortical volume was observed in layers V and VI of 2-, 4-, 6- month-old SHR, and in layers I-IV of 6-month-old SHR. Numerical decrease of neurons in SHR affected to a greater extent occipital cortex than frontal cortex. An increase in the number of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes (hyperplasia) as well as in the mean immune reaction area (hypertrophy) was found in the two cerebrocortical areas investigated of 6-month-old SHR. The occurrence of apoptosis and/or necrosis identified using the terminal deoxyribo-nucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) technique was also observed in frontal and occipital cortex of 6-month-old SHR, but not of younger cohorts. These findings indicate the development of microanatomical changes in the cerebral cortex of SHR, the extent of which increases parallel with the progression of hypertension. The occurrence of cerebrocortical apoptosis and/or necrosis as well as the obvious astrogliosis occurring in established hypertension may account for the increased risk of vascular dementia that represents a specific trait of complicated hypertension
Nephroprotective effect of treatment with calcium channel blockers in spontaneously hypertensive rats
No full textThe cerebral cortex of spontaneously hypertensive rats: a quantitative microanatomical study
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