Biomedical subjects

E Carmona-Calero

Publications and source records attributed to E Carmona-Calero.

12 recordsLinked to original sources

PubMed2000

Effect of hypertension on the angiotensin II fibres arriving at the posterior lobe of the hypophysis of the rat. An immunohistochemical study.

We studied immunohistochemically the posterior lobe of the hypophysis (PL) of 15-week-old spontaneously hypertensive rats (SHR) and of matched normotensive Wistar Kyoto rats (WKY), by using our own polyclonal antibody raised in mice against Angiotensin II (mouse-antiangiotensin II, MAAII). The blood pressure, water intake and volume of the PL were also recorded. The SHR rats were hypertensive, drank more water and showed a clear hypertrophy of their hypophysial PL. Also the PL of the SHR animals showed an increase in the immunoreactivity to the anti-angiotensin II antibody in the fibres arriving at the PL, with respect to the PL of WKY rats. This increase is compatible with the hyperactivity of the brain RAS, depletion of vasopressin content in the PL and increase in plasmatic levels of vasopressin described in SHR rats with respect to normotensive animals, as angiotensin II could locally stimulate vasopressin release to plasma from the neurohypophysis.

Angiotensin II↗

PubMed1999

Effect of hypertension and captopril treatment on the vasopressin in the rat median eminence and posterior lobe of the hypophysis. An immunohistochemical study.

The present study analyses the effects of hypertension and/or its oral treatment with captopril (angiotensine-converting enzyme inhibitor) on the rat median eminence (ME) and the posterior lobe of the hypophysis (PL). After an immunohistochemical reaction using an antibody against arginine-vasopressin, we compared by densitometry the amount of vasopressin immunoreactive material (vasopressin-ir) of these centers in 4 groups of animals: control Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR), WKY rats treated with captopril (WKY-T) and SHR rats also treated with the same drug (SHR-T). Captopril was administrated at a dosage of 0.1 mg/ml in the drinking water from the 8th to the 15th weeks. We have found that the rats showing the lowest level of vasopressin-ir, in both ME and PL, were those from the SHR group, the concentration increasing after oral captopril treatment (SHR-T), although without reaching the values of WKY rats. Then, ACE inhibition by captopril influences vasopressin content in brain areas where the hormone is concentrated before being released, which supports the hypothesis that suggests a central modulatory effect of ACE inhibitors, contributing to their therapeutic action on hypertension.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1998

Changes in the secretory activity of the subcommissural organ of spontaneously hypertensive rats.

The subcommissural organ (SCO) is a glandular circumventricular organ secreting glycoproteins into the cerebrospinal fluid. The SCO of 15-week-old spontaneously hypertensive rats (SHR) and of matched normotensive Wistar-Kyoto rats (WKY) was studied immunocytochemically by using an antibody against the glycoproteins secreted by the SCO. The blood pressure, water intake and volume of brain ventricles of SHR and WKY rats were also recorded. The SHR were hypertensive, drank more water and did not display dilatation of the brain ventricles. The SCO of the SHR rats showed a drastic decrease of the immunoreactive material stored in the rough endoplasmic reticulum whereas the amount of immunoreactive apical secretory granules did not vary with respect to the SCO of WKY rats. These changes are compatible with an increased secretory activity of the SCO of the SHR rats. It is suggested that the changes in the SCO of SHR rats, and their hypertensive state, are interrelated phenomena.

Animals↗

PubMed1998

The effects of chronic administration of captopril on the mouse median eminence.

The effects of Captopril (an angiotensin-converting enzyme inhibitor) on the median eminence (ME) of the male albino mouse have been examined using morphometric and immunohistochemical procedures. We measured the nuclear area of the ependymocytes of the ME and of the glial cells of the reticular external zone of the ME. We also determined the cell/neuropil coefficient (CNC), which expresses the relation between cellular area and neuropil of the ME, and the global volume of the ME in each animal. For the immunohistochemical study we used rabbit antiarginine-vasopressin, and compared the results in the different groups of mice. We detected an increased in the immunoreactive material (arginine-vasopressin, A-V) and an increase in the global volume of the organ and also an increase of the neuropil of the ME after the longest exposure to the drug. These alterations could be related to the inhibition of the brain angiotensin II by captopril and the accumulation of vasopressin in the fibrous tract that runs from the paraventricular nucleus (PVN) to the neurohypophysis.

Administration, Oral↗

PubMed1998

Effects of alcohol and aging on the cingular (area 24) and frontal (area 6) cortical areas of the mouse.

We have studied the morphometric changes of the neurons of the cingular area 24 and frontal area 6 of the mouse, produced by age and/or chronic alcohol intake. The parameters analyzed were nuclear area of these cortical neurons and cellular density (cell/neuropil coefficient). We detected a decrease in the number of neurons with age in practically all layers of the control animals. In the animals that chronically ingested the alcoholic solution, we also detected a decrease in the number of neurons with age, but only in layer V of the frontal cortex and in layer VI of the cingular area 24. The comparison between the control and the alcoholic group showed that alcohol intake caused an increase in the nuclear area of the neurons in layer II-III of the frontal cortex at 180 days, while in the cingular cortex the increase in nuclear area of its neurons was significative at 180 days in layer II-III and at 35 and 180 days in layers V and VI. We think that these changes are the expression of the neuronal plasticity in both cortical areas in response to the alcohol exposure.

Aging↗

PubMed1995

Effects of chronic alcohol intake on the vasopressin content in the hypothalamic paraventricular and supraoptic nuclei of the mouse. An immunohistochemical and morphometric study.

The present study analyses the response of the paraventricular (PVN) and supraoptic (SPO) nuclei of the hypothalamus of the male mouse to chronic alcohol intake by immunohistochemical and morphometric methods. We relate the intensity of the reaction to A-V with the vasopressin content of the nucleus, as all the slides, from the control and experimental groups, were processed at the same time and with the same solutions of the antibodies. We suggest that the accumulation of vasopressin, observed in the alcohol-treated animals, of both hypothalamic nuclei could be related to an inhibition of vasopressin release and/or transport from the SPO and PVN to the neurohypophysis and to an increase in vasopressin synthesis in the SPO as this nucleus shows an increase in its nuclear sizes, an index of the function of the neurons.

Alcoholism↗

PubMed1995

Alcohol effects on paraventricular hypothalamic nucleus morphometry.

The morphometric effects of postnatal exposure to alcohol on the neurons of the paraventricular hypothalamic nucleus (PVN) have been studied in four different topographic subdivisions of the nucleus: rostral, intermediate medial, intermediate lateral and caudal. Male mice were exposed to alcohol during lactation and after weaning by addition of 20% of ethanol to the drinking water that was first ingested by the mother and thereafter by the experimental animals themselves. Animals were sacrificed at the 25th, 35th, 45th, 55th and 100th postnatal day. Nuclear sizes of the PVN neurons (Perimeter, area and maximum diameter) were determined in both control and experimental alcohol-treated groups. The shape of these neuronal nuclei was also determined and compared. PVN responds globally to alcohol exposure, showing a decrease in the neuronal nuclear sizes in the four studied PVN subdivisions of the alcohol-treated mice at the 35th and 45th and 100th day. We suggest that these decreases could be related to changes in gonadal hormone levels induced by alcohol exposure and/or disturbances of brain neurotransmitter and neuropeptide metabolism caused by ethanol.

Animals↗

PubMed1995

Alcohol intake effects on the dorsal vagal complex of the rat: a cellular morphometric study.

We have analyzed the morphometric effects on the dorsal vagal complex (DVC) of the rat of alcohol exposure and/or hypoproteic diet intake during 8 weeks. In the area postrema (AP), alcohol treatment (combined with normal isoproteic or hypoproteic diet) caused a significant decrease in karyometric parameters. In the dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitari (NTS), the alcohol isoproteic intake (AI) produced an increase in neuron size (expressed by an increase in the neuronal nuclear area and the cell/neuropil coefficient). The hypoproteic diets produced a reduction in the global volume of each structure of the DVC which was accompanied by a decrease in global brain volume. These results indicate that after 8 weeks of treatment, alcohol is the main cause of the morphometric alteration found in the DVC, while variations in the amount of protein intake appear to produce global effects on the whole brain.

Animals↗

PubMed1994

Alterations of the subcommissural organ in the hydrocephalic human fetal brain.

We have studied the subcommissural organ of two hydrocephalic brains, of 20 and 21 gestational weeks and of two normal brains, aged 19 and 23 gestational weeks. Both hydrocephalic cases presented a size reduction of the subcommissural organ compared to the normal cases; only in one case, there were also alterations of the morphological components of the subcommissural organ, suggesting different pathogenic relationships between hydrocephalus and dysplasia of the subcommissural organ.

Abortion, Spontaneous↗

PubMed1993

The effects of chronic administration of captopril on the mouse subfornical organ and area postrema.

We have studied by morphometric procedures the chronic effect of captopril on the subfornical organ (SFO) and area postrema (AP) of the adult mouse. Oral administration of captopril does not produce any change in the size of individual nuclei of the ependymocytes and neurons in both centers. However, there are other quantitative effects of captopril on the global volume of the SFO and on the neuropil and vascular elements of both the SFO and AP which present a significant increase. It is suggested that this increase is due to metabolic processes at the level of both circumventricular organs.

Administration, Oral↗

PubMed1990

Development of the median eminence in the male mouse. Karyometric effect of neonatal and prepuberal castration.

We have studied the karyometric development of the ependymocytes of the median eminence and ependyma adjacent of the arcuate nucleus in a control group of male albino mice from the 5th to the 160th postnatal day, and in other two experimental groups of animals that were castrated at two different days: the first and the 20th day of life. We have found differences in the spontaneous development of both ependymocytes showing the median eminence ependyma a more closely relationship to changes of gonadal hormone levels around puberty. In both zones, the response of the ependymocytes to neonatal castration was clearly more significative than that obtained after prepuberal castration, with lower values in the castrated animals than in the control mice. We suggest that this could be related to nervous and hormonal mechanisms.

Animals↗

PubMedDate not supplied

Alcohol effects on the morphometric development of the subfornical organ and area postrema of the albino mouse.

We have studied the development of the nuclear sizes of ependymocytes and neurons of two circumventricular organs of the male alcoholic mouse: the Subfornical Organ (SFO) and the Area Postrema (AP), comparing the results with a control group. The global volume of both centers was also studied. The results show that the SFO, a structure related to the control of fluid balance, responds to alcoholism with an increase of the global volume. This increase could be related to the variations of salt-water balance and/or blood pressure in chronic alcoholism. However, the size of cell nuclei in the SFO is not affected. In contrast, the AP responds to chronic alcoholism like other nervous centres, with a decrease of the nuclear size of its cells. The global volume of AP does not change.

Alcoholism↗