Biomedical subjects

F Amenta

Publications and source records attributed to F Amenta.

At least 37 records · Page 2Linked to original sources

PubMed2000

Effect of calcium antagonists on glomerular arterioles in spontaneously hypertensive rats.

Through the use of microanatomic techniques, we investigated the effects of treatment with some dihydropyridine-type calcium antagonists (CAs) (ie, lercanidipine, manidipine, and nicardipine) and with the nondihydropyridine-type vasodilator hydralazine on hypertension-dependent glomerular injury and on the morphology of afferent and efferent arterioles in spontaneously hypertensive rats (SHR). Fourteen-week-old male SHR and age-matched normotensive Wistar-Kyoto rats were left untreated (control groups). Four additional groups of 14-week-old SHR were treated for 12 weeks with daily oral doses of 2.5 mg/kg lercanidipine, 5 mg/kg manidipine, 3 mg/kg nicardipine, or 10 mg/kg hydralazine. These treatments decreased systolic blood pressure values to a similar extent in SHR. Signs of glomerular injury, as characterized by glomerulosclerosis, hypertrophy, and an increased number of mesangial cells, were observed in control SHR. The treatment with CAs improved glomerular morphology and decreased the number of mesangial cells. Lercanidipine and manidipine were more effective than nicardipine in countering glomerular injury. In the SHR, both afferent and efferent arterioles revealed luminal narrowing, accompanied by increased wall thickness in efferent arterioles. The dihydropyridine-type derivatives that were tested decreased the luminal narrowing of afferent arterioles. Lercanidipine and manidipine countered the luminal narrowing of efferent arterioles. Hydralazine had no effect on hypertension-dependent glomerular injury or vascular changes. The present data indicate that lercanidipine and manidipine vasodilate afferent and efferent arterioles in SHR. A vasodilatory activity on efferent arteriole, which is not induced by the majority of CAs, may represent an useful property in the treatment of hypertension complicated by renal disease.

Albuminuria↗

PubMed2000

Neurotrophin and neurotrophin receptor expression in alveolar macrophages: an immunocytochemical study.

Alveolar macrophages play a crucial role in regulating lung immune responses and in maintaining the integrity of the respiratory tract. Neurotrophins (NTs), besides to their neurotrophic activities, exhibit physiological effects in the immune system. In this study, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), NT-3 and low- (p75) and high affinity (Trks) NT receptors were investigated by immunocytochemistry in cytospin centrifuged preparations of human alveolar macrophages. Approximately 2.5% alveolar macrophages were immunoreactive for NGF, whereas no macrophages displaying immunoreactivity for BDNF or NT-3 were observed. A 3.5% macrophages displayed immunoreactivity for TrkA-receptor protein, 10% for TrkB-receptor protein (full length isoform), and 2% for TrkC-receptor protein. No low-affinity p75 NT and TrkB[-] truncated isoform receptor immunoreactive macrophages were found. These findings support the hypothesis that NTs and the corresponding receptors may play a role in regulating immunological and functional activity of alveolar macrophages via paracrine/autocrine mechanisms.

Adult↗

PubMed2000

Nephroprotective effect of treatment with calcium channel blockers in spontaneously hypertensive rats.

The influence of hypertension and of treatment with some dihydropyridine-type Ca(2+) channel blockers and with the nondihydropyridine-type vasodilator hydralazine on the morphology of kidney was investigated in 26-week-old spontaneously hypertensive rats (SHR) and in age-matched Wistar-Kyoto rats. Fourteen-week-old SHR were treated for 12 weeks with a nonhypotensive dose of lercanidipine or with equihypotensive doses of lercanidipine, manidipine, nicardipine, and hydralazine. In control SHR, systolic pressure values were significantly higher in comparison with Wistar-Kyoto rats. Treatment with the low dose of lercanidipine did not reduce systolic blood pressure in SHR, whereas the higher dose of lercanidipine or other compounds tested significantly decreased systolic pressure values. Glomerular hypertrophy accompanied by signs of glomerulosclerosis, increase of mesangial cells, and convoluted tubules degeneration were observed in control SHR. Hypotensive doses of Ca(2+) antagonists countered glomerular injury, the increase of mesangial cells, the reduction of capsular space, and tubular degeneration. Hydralazine, in spite of its hypotensive activity, displayed a slight nephroprotective action. The nonhypotensive dose of lercanidipine countered in part glomerular injury, narrowing of capsular space, and tubular degeneration, and decreased mesangial cell augmentation in SHR. These results suggest that treatment with dihydropyridine-type Ca(+2) antagonists counters hypertensive glomerular and tubular changes occurring in SHR. The demonstration of nephroprotection by the nonhypotensive dose of lercanidipine suggests that the renal effects of the compound may be in part unrelated to its hemodynamic activity.

Animals↗

PubMed2000

The International Radio Medical Centre (C.I.R.M.): an organization providing free medical assistance to seafarers of any nationality world wide.

The International Radio Medical Centre (Centro Internazionale Radio Medico, C.I.R.M.) was founded in 1935 with the purpose of giving radio medical advice to ships on any nationality navigating on all seas of the world. The Centre has its headquarters in Rome, and its medical services are completely free of charge. They also include arrangements for the transfer, if necessary, of a patient to a ship with a doctor on board or if the distance allows it, to evacuate the patient for hospitalization. Requests for medical advice reaching C.I.R.M. are handled by doctors on continuos duty at the C.I.R.M. headquarters. These doctors advice on the appropriate treatment and keep in contact with every ship that has asked for assistance, following up the progress of the patient until his recovery or evacuation to the hospital on shore.

Global Health↗

PubMed1999

Radioligand binding assay of M1-M5 muscarinic cholinergic receptor subtypes in human peripheral blood lymphocytes.

Analysis of lymphocyte muscarinic cholinergic receptors using quantitative techniques such as radioligand binding assay is made difficult due to the low density of these sites and the lack of subtype-specific selectivity of most available muscarinic ligands. In this study, a combined kinetic and equilibrium labeling technique recently developed for brain tissue was used for labeling the five muscarinic cholinergic receptor subtypes in intact human peripheral blood lymphocytes. No specific muscarinic M1 receptor binding was detectable in human peripheral blood lymphocytes using [3H]-pirenzepine as a ligand. Labeling of M2-M5 muscarinic receptors using [3H]N-methyl-scopolamine (NMS) by occluding various receptor subtypes with muscarinic antagonist and mamba venom resulted in the labeling of M2-M5 receptors in brain as well as in human peripheral blood lymphocytes. The relative density of different receptor subtypes was M3 > M5 > M4 > M2. The development of a reproducible technique for assaying muscarinic cholinergic receptor subtypes expressed by human peripheral blood lymphocytes may contribute to clarify their role in lymphocyte function.

Adult↗

PubMed1999

Age-related changes of glial fibrillary acidic protein immunoreactive astrocytes in the rat cerebellar cortex.

Age-related changes of glial fibrillary acidic protein (GFAP) immunoreactivity were investigated in the cerebellar cortex of young (3 months), adult (12 months) and old (24 months) rats using immunohistochemical techniques associated with image analysis. In young rats, cell bodies of GFAP-immunoreactive astrocytes were found in the white matter and in the granular layer of cerebellar cortex. Radially-oriented branches of astrocytes which are sited in the granular layer were also observed in the molecular layer. The number of GFAP-immunoreactivity astrocytes of white matter was decreased in adult and old rats in comparison with young cohorts, whereas their size increased progressively from 3 to 24 months old. The number and the size of GFAP-immunoreactive astrocytes of the granular layer was similar in young and adult rats. An increased number and size of GFAP-immunoreactive astrocytes was noticeable in old rats in comparison with younger cohorts. The number of radially oriented branches of the molecular layer was the same in the three age groups investigated. The above results indicate that GFAP-immunoreactive astrocytes of rat cerebellar cortex undergo age-related changes. The not homogeneous sensitivity to aging of cerebellar astrocytes suggests that evaluation of changes of different cell populations of cerebellar cortex should represent an important step of research on aging cerebellum.

Aging↗

PubMed1999

Dopamine D1-like receptor subtypes in human peripheral blood lymphocytes.

Molecular biology studies have shown that human peripheral blood lymphocytes express a dopamine D5 receptor, whereas no information is available on dopamine D receptor, the other dopamine D1-like receptor subtype. Radioligand binding assay investigations with the nonsubtype selective dopamine D1-like receptor antagonist [3H]SCH 23390 as radioligand have suggested the presence of a dopamine D5 receptor in human peripheral blood lymphocytes. However, so far no evidence was provided as whether or not human peripheral blood lymphocytes express a dopamine D1 receptor. In this study, we have investigated dopamine D1 and D5 receptor mRNA and the influence of antibodies against dopamine D1 and D5 receptors on [3H]SCH 23390 binding to intact human peripheral blood lymphocytes. The two receptors were also analyzed by immunocytochemistry. Dopamine D5 receptor, but not D1 mRNA, was detected in human peripheral blood lymphocytes. Anti-dopamine D5 receptor antibodies, but not anti-dopamine D1 receptor antibodies, significantly decreased [3H]SCH 23390 binding to human peripheral blood lymphocytes. A dark-brown immunoreactivity was visualized in cytospin centrifuged human peripheral blood lymphocytes exposed to anti-dopamine D5, but not to anti-dopamine D1 receptor antibodies. These data collectively indicate that dopamine D5 receptor is the only dopamine D1-like receptor subtype expressed by human peripheral blood lymphocytes.

Adult↗

PubMed1999

Forebrain white matter in spontaneously hypertensive rats: a quantitative image analysis study.

The volume and the morphology of brain white matter as well as the number and the size of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes were investigated in 6-month-old spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) rats. The volume of frontal and occipital cortex and of hippocampus was decreased in SHR in comparison with normotensive rats, whereas the volume of neostriatum was unchanged. A remarkable decrease of the volume of internal capsule and striosomes, a moderate reduction of that of corpus callosum and no changes of the volume of external capsule and of white matter of hippocampus were also observed in SHR. In SHR the number of astrocytes was higher in the frontal and occipital cortex and in the white matter of the CA1 and CA3 subfields of the hippocampus, but not in the corpus callosum or in the grey matter of the CA1 and CA3 subfields. Staining for myelin did not reveal alterations in single fibre sheath morphology. These findings indicate the occurrence of changes of forebrain white matter in SHR, consisting in the reduction of it without qualitative modifications of myelinated fibres. The development of gliosis apparently not related with changes of volume of white matter was also found.

Animals↗

PubMed1999

NADPH-diaphorase histochemistry in the rat cerebral cortex and hippocampus: effect of electrolytic lesions of the nucleus basalis magnocellularis.

Unilateral or bilateral electrolytic lesions of the nucleus basalis magnocellularis (NBM) increased NADPH-diaphorase in the fronto-parietal cortex and in the CA1-CA3 fields of the hippocampus. NBM is the cholinergic basal forebrain nucleus supplying the fronto-parietal cortex but not the hippocampus. This increase was more remarkable at 4 weeks than at 2 weeks after lesioning. Monolateral or bilateral lesioning of the NBM increased to a similar extent NADPH-diaphorase. The number of neurons expressing NADPH-diaphorase was not statistically different between sham-operated and NBM-lesioned rats. These results indicate that similarly as reported in experimental damage of several brain areas, lesions of the NBM induce NADPH-diaphorase. The induction of this marker for nitric oxide synthase occurs both in the target of projections arising from the NBM such as the frontal cortex and in an area not directly supplied by NBM such as the hippocampus. Lesion-induced NADPH-diaphorase increase may contribute to neurodegenerative changes caused by damage of the NBM area.

Animals↗

PubMed1999

Increased expression of dopamine receptors on lymphocytes in Parkinson's disease.

Dopamine D1-like and D2-like receptors on peripheral blood lymphocytes (PBL) were assayed in 50 de novo patients with idiopathic Parkinson's disease (PD), in 36 neurologic control subjects (multiple-system atrophy, n = 16; essential tremor, n = 10; other neurodegenerative diseases, n = 10), and in 26 healthy control subjects by radioligand binding assay techniques using [3H]SCH 23390 and [3H]7OH-DPAT as ligands. Patients with PD revealed a higher density (Bmax) of dopamine D1-like (p <0.001) and D2-like (p <0.00001) receptors on PBL than either neurologic or healthy control subjects, whereas no differences in Bmax were observed among patients affected by other neurologic diseases and healthy control subjects. The affinity (Kd) of both radioligands was similar in the groups investigated. The pharmacologic profile of [3H]SCH 23390 and [3H]7OH-DPAT binding was consistent with the labeling of dopamine D5 and D3 receptor subtypes, respectively. Twenty-five of the 50 patients with PD were retested after 3 months of therapy with levodopa or bromocriptine. Both treatments reduced the density of D1-like (p <0.001) and D2-like (p <0.001) receptors on PBL to values comparable to those of control subjects. The increased density of D1-like and D2-like receptors on PBL in de novo PD patients may represent an upregulation mechanism resulting from the diffuse impairment of the dopaminergic system in PD.

Aged↗

PubMed1999

Ca2+ channels of the L-type in peripheral blood lymphocytes of essential hypertensives.

Ca2+ channels of the L-type were assayed in human peripheral blood lymphocytes of normotensive control subjects and of essential hypertensives using radioligand binding assay techniques. The dihydropyridine Ca2+ channel blocker [3H](+)-PN 200-110 [isopropyll-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methox ycarbonyl-2,6-dimethyl-3-pyridine carboxylate] was used as a ligand. [3H](+)-PN 200 110 was bound specifically to human peripheral blood lymphocytes in a manner consistent with the labeling of Ca2+ channels of the L-type. No significant differences in the dissociation constant (Kd), in the maximum density of binding sites (Bmax) or in the pharmacological profile of [3H](+)-PN 200 110 binding were found between normotensive subjects and different degree essential hypertensives. Analysis of the intralymphocytic free Ca2+ concentration did not reveal differences between normotensive subjects and essential hypertensives. Although hypertension is associated with altered membrane handling of Ca2+, no changes in the expression of peripheral blood lymphocyte Ca2+ channels of the L-type or in intralymphocytic Ca2+ concentrations were found in essential hypertensives. Human peripheral blood lymphocytes therefore cannot represent a peripheral marker of altered Ca2+ handling in hypertension.

Adult↗

PubMed1999

Evaluation of an agonist index: affinity ratio for compounds active on muscarinic cholinergic M2 receptors.

A protocol for predicting full agonist, partial agonist, and antagonist profiles of compounds with M2 muscarinic cholinergic receptor activity was developed using radioligand binding assay techniques with [3H]-N-methyl scopolamine (NMS) and [3H]-Oxotremorine-M (Oxo-M) as radioligands. Full muscarinic cholinergic receptor agonists such as muscarine and oxotremorine-M expressed a high agonist index (> 3000 for M1 muscarinic cholinergic receptors and > 900 for M2 muscarinic cholinergic receptor), whereas muscarinic receptor antagonists (selective or non-selective) for different receptor subtypes gave a low (0.5-10) agonist index. Functional studies performed on preparations of guinea-pig ileum and heart were consistent with radioligand binding assay experiments. The above results suggest that similarly as already established for the M1 muscarinic cholinergic receptor subtype, evaluation of the [3H]-NMS/[3H]-Oxo-M ratio may provide useful information on the profile of compounds acting at the M2 muscarinic cholinergic receptor subtype. The availability of simple and predictive techniques for the characterization of muscarinic M2 cholinergic receptor agonists, may help the identification of new compounds in therapeutic areas in which stimulation or inhibition of this receptor is desirable.

Animals↗

PubMed1999

Dopamine D2-like receptors on human peripheral blood lymphocytes: a radioligand binding assay and immunocytochemical study.

1. Peripheral blood lymphocytes express dopamine D1-like and D2-like receptors which were investigated using radioligand binding assay and molecular biology techniques. Analysis of dopamine D2-like receptors expressed by human peripheral blood lymphocytes with radioligand binding assay may offer a rapid technique for assessing receptor changes in disorders characterized by involvement of the dopaminergic system. However, the suitability of radioligand binding assay techniques to measure dopamine D2-like receptors is questioned. 2. In view of the discrepancy between data of dopamine D2-like receptor determination with molecular biology and radioligand binding assay techniques, we have assayed dopamine D2-like receptors expressed by human peripheral blood lymphocytes using as radioligands the dopamine receptor agonist 7-[3H]-hydroxy-N,N-di-n-propyl-2-aminotetraline ([3H]-7-OH-DPAT) and two antagonists ([3H]-spiperone and [3H]-nemonapride). 3. Analysis of saturation curves revealed a concentration-dependent binding of all compounds to human peripheral blood lymphocytes. Dissociation constant (Kd) values averaged between 0.15 and 0.40 nM for different radioligands. The maximum density of binding sites (Bmax) was low, ranging from 4.15 +/- 0.05 fmol/10(6) cells with [3H]-spiperone and 8.66 +/- 0.04 fmol/10(6) cells with [3H]-7-OH-DPAT. 4. Displacement curves of [3H]-7-OH-DPAT, [3H]-spiperone and [3H]-nemonapride binding to human peripheral blood lymphocytes revealed, using radioligand concentrations giving the highest specific:non-specific binding ratio, a pharmacological profile consistent with the labelling of dopamine D2-like receptors. The use of higher radioligand concentrations resulted in a poorly displaceable and characterizable binding. 5. Detection of dopamine D2, D3 and D4 receptor immunoreactivity in cytospin centrifuged peripheral blood lymphocytes revealed dopamine D3 and D4 but not D2 receptor immunostaining. 6. The above findings indicate in agreement with molecular biology studies, that dopamine D2-like receptors expressed by human peripheral blood lymphocytes belong to the D3 and D4 receptor subtypes. These receptors are detectable using either dopamine D2-like receptor agonists and antagonists as radioligands if controlled experimental conditions are followed. The standardisation of immunocytochemical techniques for detecting human peripheral blood lymphocyte dopamine receptors may contribute to clarify their role in lymphocyte function or as a peripheral marker of the status of the dopaminergic system.

Benzamides↗

PubMed1999

alpha1-adrenergic receptor subtypes in human peripheral blood lymphocytes.

We investigated the expression of alpha1-adrenergic receptor subtypes in intact human peripheral blood lymphocytes using reverse transcription-polymerase chain reaction (RT-PCR) and radioligand binding assay techniques combined with antibodies against the three subtypes of alpha1-adrenergic receptors (alpha1A, alpha1B, and alpha1D). RT-PCR amplified in peripheral blood lymphocytes a 348-bp alpha1A-adrenergic receptor fragment, a 689-bp alpha1B-adrenergic receptor fragment, and a 540-bp alpha1D-adrenergic receptor fragment. Radioligand binding assay with [3H]prazosin as radioligand revealed a high-affinity binding with a dissociation constant value of 0. 65+/-0.05 nmol/L and a maximum density of binding sites of 175. 3+/-20.5 fmol/10(6) cells. The pharmacological profile of [3H]prazosin binding to human peripheral blood lymphocytes was consistent with the labeling of alpha1-adrenergic receptors. Antibodies against alpha1A-, alpha1B-, and alpha1D-receptor subtypes decreased [3H]prazosin binding to a different extent. This indicates that human peripheral blood lymphocytes express the three alpha1-adrenergic receptor subtypes. Of the three different alpha1-adrenergic receptor subtypes, the alpha1B is the most represented and the alpha1D, the least. Future studies should clarify the functional relevance of alpha1-adrenergic receptors expressed by peripheral blood lymphocytes. The identification of these sites may represent a step for evaluating whether they represent a marker of alpha1-adrenergic receptors in cardiovascular disorders or for assessing responses to drug treatment on these receptors.

Adrenergic alpha-1 Receptor Antagonists↗

PubMed1999

Sulphatides in the brain of spontaneously hypertensive rats.

Sulphatides 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.

Animals↗

PubMed1998

Sensitivity to ageing of the limbic dopaminergic system: a review.

The limbic system includes the complex of brain centres, nuclei and connections that provide the anatomical substrate for emotions. Although the presence of small amounts of dopamine (DA) in several limbic structures has been recognized for a long time, for many years it was thought that limbic DA represented a precursor of noradrenaline in the biosynthetic pathway of catecholamines. More recent evidence has shown that limbic centres and nuclei are supplied with a dopaminergic innervation arising from the ventral tegmental area (field A10) and in smaller amounts from the mesencephalic A9 field. The dopaminergic limbic system is sensitive to ageing. Parameters of dopaminergic neurotransmission (DA levels, biosynthetic and catabolic markers and DA receptors) undergo age-related changes which depend on the structure and species investigated and are characterized mainly by a decline of different parameters examined. In this paper, the influence of ageing on DA biosynthesis, levels, metabolism and receptors are reviewed in laboratory rodents, monkeys and humans as well as in cases of Alzheimer's disease and Parkinson's disease. The possibility that changes of dopaminergic neurotransmission markers in the limbic system are associated with cognitive impairment and psychotic symptoms affecting the elderly is discussed. Better knowledge of dopaminergic neurotransmission mechanisms in the so-called physiological ageing and in senile dementia may provide new insights in the treatment of behavioural alterations frequently occurring in old age.

Aging↗

PubMed1998

Labeling of dopamine D3 and D4 receptor subtypes in human peripheral blood lymphocytes with [3H]7-OH-DPAT: a combined radioligand binding assay and immunochemical study.

Molecular biology studies have demonstrated that human peripheral blood lymphocytes express dopamine D2-like receptors belonging to the D3 and D4 receptor subtypes, whereas the characterization of these receptors using radioligand binding assay techniques provided conflicting results. The preferential dopamine D3 receptor agonist [3H]7-hydroxy-N, N-di-n-propyl-2-aminotetralin ([3H]7-OH-DPAT) was used recently for labeling lymphocyte dopamine D3 receptor. However, the selectivity of this compound for the D3 receptor was questioned. In this study we have investigated human peripheral blood lymphocyte dopamine receptor subtypes labeled by [3H]7-OH-DPAT using a conventional radioligand binding assay technique and antibodies against dopamine D2-like receptor subtypes. [3H]7-OH-DPAT was specifically bound to intact human peripheral blood lymphocytes with a dissociation constant (Kd) value of 0.32 + 0.03 nM and a maximum density of binding sites (Bmax) of 18.2 + 0.8 fmol/2 x 10(6) cells. [3H]7-OH-DPAT binding was unaffected by antibodies against dopamine D2 and D2S receptors. Anti-dopamine D3 and D4 receptor antibodies reduced [3H]7-OH-DPAT binding by about 53% and 32% respectively. Combination of anti D3 and D4 receptor antibodies reduced remarkably [3H]7-OH-DPAT binding. The above results suggest that the dopamine receptor agonist [3H]7-OH-DPAT labels dopamine D3 and D4 receptor subtypes in human peripheral blood lymphocytes. The use of antibodies raised against dopamine receptor subtypes in combination with radioligand binding assay may contribute to define receptor subtypes expressed by human peripheral blood lymphocytes in health and disease.

Adult↗

PubMed1998

Astrocyte changes in aging cerebral cortex and hippocampus: a quantitative immunohistochemical study.

Glial cells are sensitive to aging, but the real extent of age-related quantitative and qualitative changes of these brain cellular elements has not yet been clarified. Brain volume undergoes age-related changes, but several studies on the number of glial cells have not taken this important variable into account. In this study we quantitatively evaluated the number and morphology of glial fibrillary acidic protein (GFAP)-immunoreactive astroglia in the frontal cortex and in the CA1 subfield of the hippocampus of male Sprague-Dawley rats of aged 12 and 24 months, considered adult and aged, respectively. The volume of frontal cortex was unchanged in the two age groups investigated, whereas the volume of hippocampus was higher in aged rats. An increase in the number and size of GFAP-immunoreactive astrocytes was observed in the frontal cortex and in the CA1 subfield of the hippocampus of aged rats. The numeric increase in astrocytes was more pronounced in the hippocampus than in the frontal cortex, whereas age-related hypertrophy of astroglia was more accentuated in the frontal cortex. The possible significance of hyperplasia and hypertrophy of GFAP-immunoreactive astrocytes in the frontal cortex and in the CA1 subfield of the hippocampus of aged rats is discussed.

Age Factors↗