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F Aguado

Publications and source records attributed to F Aguado.

45 records · Page 3Linked to original sources
PubMed1993

Distribution of insulin-like growth factor-I receptor mRNA in rat brain. Regulation in the hypothalamo-neurohypophysial system.

The distribution and regulation of mRNA for the IGF-I receptor (IGF-I-R) in the adult rat brain were studied by in-situ hybridization with a 35S-labelled cRNA probe. The pituitary gland showed a strong hybridization signal in the pars tuberalis (the surface of the median eminence), pars distalis and pars intermedia. Within the brain, a strong hybridization signal was found in the circumventricular organs, olfactory bulb, hippocampus, cerebellum and hypothalamus. IGF-I-R mRNA was consistently found in cell bodies of the hypothalamo-neurohypophysial system. Six days of intermittent salt-loading resulted in an increase in IGF-I-R gene expression in the supraoptic nucleus. The increase in IGF-I-R mRNA was accompanied by a high expression of c-Fos immunoreactivity in the same cells. The presence and regulation of IGF-I-R mRNA in the hypothalamus suggest that IGF-I may affect the local plasticity or modulation of activated magnocellular neurones by an autocrine or paracrine action through specific receptors in the hypothalamo-neurohypophysial system.

Animals↗
PubMed1992

Subcellular localization of insulin-like growth factor I (IGF-I) in Purkinje cells of the adult rat: an immunocytochemical study.

Insulin-like growth factor I (IFG-I) was localized by light and electron microscopic immunocytochemistry in the adult rat cerebellum. Neurons showing the same cytological characteristics and pattern of synaptic input as Purkinje cells were IGF-I immunoreactive. In these neurons, intense electron-dense reaction product was consistently located in the rough endoplasmic reticulum and, occasionally, in multivesicular bodies and associated with the nuclear envelope. Thus, the results of this study suggest synthesis IGF-I in Purkinje cells and furthermore provide anatomical support for IGF-I participation in paracrine or autocrine regulatory systems in the brain.

Animals↗
PubMed1992

Role of locally produced growth hormone-releasing factor in somatostatin regulation by fetal rat brain cells in culture.

To determine the possible physiological role of endogenous growth hormone-releasing factor (GRF) in the neuronal content and release of cerebral somatostatin (SS), we studied the effect of endogenous GRF blockade on the immunoreactive SS (IR-SS) content of cells and media in fetal rat cerebral cortical and hypothalamic cells in culture. Cells were cultured in minimum essential medium (MEM) with 10% fetal calf serum and 10% horse serum. After 7-10 days in vitro, media were replaced with MEM without sera containing anti-GRF immunoglobulins G (IgG) for 1, 5 or 24 h. Controls were incubated with equal amounts of IgG from normal rabbit serum (NRS). In another group of experiments, cells were incubated with GRF (10(-11) to 10(-7) M) for 1 or 24 h. Long-term exposure (24 h) to anti-GRF IgG resulted in decreased media and intracellular IR-SS content, in both cerebral cortical and hypothalamic cells. 24 h treatment with GRF caused a dose-dependent increase in the IR-SS content of cells and media, the stimulatory action being abolished by the addition of anti-GRF to plates containing 10(-7) M GRF. On the contrary, when cells were exposed to anti-GRF IgG for 1 h, IR-SS increased in the media as compared to the control group. Short-term incubation (1 h) with GRF (10(-9) to 10(-7) M) resulted in a dose-dependent inhibition of IR-SS content in the cells and media. This inhibitory action was partially prevented by the addition of anti-GRF to plates containing 10(-7) M GRF.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Immunocytochemical localization of insulin-like growth factor I in the hypothalamo-hypophyseal system of the adult rat.

Insulin-like growth factor I (IGF-I) is shown to be involved in the regulation of pituitary hormones. High IGF-I concentrations were detected in hypothalamus and pituitary during adulthood. This study was undertaken to analyze the cellular distribution of IGF-I in the hypothalamo-hypophyseal system of the adult rat using immunocytochemical procedures. IGF-I was found to be widely distributed throughout the hypothalamus; it was present in the magnocellular neurons of the supraoptic, paraventricular, and accessory nuclei. Moreover, nerve fibres and puncta containing immunoreactive IGF-I were localized in the median eminence and the posterior lobe of the pituitary. These results support possible IGF-I neuromodulatory or neurohormonal action in the hypothalamus on pituitary hormone regulation.

Animals↗
PubMed1991

Lasting loss in substance P following administration of substance P antiserum to newborn rats. An immunohistochemical study.

Substance P (SP) antiserum (500 micrograms protein) was administered to rats on the second day of life and the animals were sacrificed 3 months later. This treatment produced a loss in SP immunoreactive fibers in the dorsal horn of the spinal cord, in the substantia nigra and in the periaqueductal gray matter, when compared to control animals receiving a neonatal treatment of non-specific immunoglobulins. In the dorsal horn, the observed depletion was greater in the superficial layers, lamina I and lamina IIo. Immunoreactivity for Met-enkephalin was apparently unchanged by SP antiserum. Results of this study provide cytochemical evidence for a specific and lasting deleterious effect of SP antiserum on different SP-containing neuronal systems.

Animals↗
PubMed1991

Subcellular localization of nerve growth factor receptors in identified cells of the rat nucleus basalis magnocellularis: an immunocytochemical study.

The subcellular location of nerve growth factor receptor in the ventromedial portion of rat globus pallidus was investigated with affinity-purified monoclonal 192-IgG following the unlabelled antibody peroxidase-antiperoxidase immunocytochemical procedure. At the light microscopic level, punctate immunoreaction product was observed in the perinuclear region and in the plasma membrane of large, probably cholinergic neurons. Examination in the electron microscope of these neurons confirmed that nerve growth factor receptor-stained cells were basal forebrain cholinergic neurons. Within these cells, immunostaining occurred in the Golgi apparatus, in multivesicular bodies and, occasionally, in rough endoplasmic reticulum cisternae and the nuclear envelope. Moreover, patches of immunoreactivity were observed associated with the outer surface of the plasma membrane of the soma and their proximal dendrites and also with the plasma membrane of distal dendrites showing scarcity of synaptic input. Positive immunostaining was never observed in synaptic clefts, but filled the space between the plasma membranes of immunoreactive neurons and those of thin glial processes in their vicinity. The location of membrane nerve growth factor receptor in close apposition to membranes of neighbouring astrocytes rather than near synaptic complexes, suggests that glial cells may be a physiological source of nerve growth factor.

Animals↗
PubMed1989

[Modifications in the composition of plasma HDLs in non-insulin-dependent diabetics].

The levels of plasmatic lipids and the lipo and apoprotein composition of lipoprotein of high density were analysed in 18 patients, diagnosed as having non-insulin dependent diabetes, and compared to a control group of 18 healthy patients. 10 patients showed a moderate hypertriglyceridemia, this sub-group having the main HDL alteration. In this lipoprotein fraction an increase of triglycerides was observed, and a decrease in cholesterol and apoprotein III, probably as result of a lower activity of lipoprotein lipase in plasma.

Aged↗
PubMed1989

[Efficacy of various antihypertensive agents according to age and initial arterial pressure].

210 patients with mild-moderate high blood pressure have been studied. These patients were followed up for 4-6 weeks. Fifty patients were treated with 50 mg hydrochlorothiazide + 5 mg amiloride daily; 40 with 160 mg oxprenolol daily; 22 with 30-40 mg nifedipine daily; 38 with 240 mg verapamil daily and 60 with 50-100 mg captopril daily. We have observed: 1. All treatments have similar antihypertensive effectiveness. 2. Decrement in blood pressure was correlated with initial blood pressure in all treatments, directly. 3. This effectiveness was correlated positively with age in treatment with both diuretics and calcium-antagonists, and an inverse correlation with both beta-blockers and captopril. 4. It had no correlation between age and initial blood pressure in diuretic or beta-blocker treated groups. So diuretics shall be suggested in elderly patients and beta-blockers in younger patients. 5. The greater effectiveness of calcium-antagonists in the elderly should be explained because these patients have a higher initial blood pressure. 6. In this work there is an inverse correlation between age and initial blood pressure in the captopril-treated group; it should explain the greater effectiveness in younger persons. 7. Nothing opposes the use of calcium-antagonists or angiotensin converting enzyme inhibitor in all age groups.

Adult↗