Biomedical subjects

C Cavallotti

Publications and source records attributed to C Cavallotti.

At least 19 recordsLinked to original sources

PubMed1994

Age-dependent changes in gp75LNGFR (low-affinity nerve growth factor receptor) immunoreactivity in the rat cerebellar cortex.

The expression of gp75LNGFR (low-affinity receptor of the nerve growth factor (NGF) family of neurotrophins) immunoreactivity was studied in the cerebellar cortex of male Wistar rats of 3 months (young), 12 months (adult) and 24 months of age using immunohistochemical techniques and a monoclonal antibody against rat-gp75LNGFR. The percentage of Purkinje neurons displaying gp75LNGFR immunoreactivity (IR), and the intensity of gp75LNGFR IR in the cytoplasm of Purkinje and granule neurons, and in the neuropil of molecular layer of the cerebellar cortex were determined by quantitative image analysis and microdensitometry. The number of Purkinje neurons displaying gp75LNGFR IR and the intensity of gp75LNGFRIR in the cytoplasm of Purkinje neurons was significantly higher in rats of 12 months of age in comparison with 24- and 3-month-old rats. No significant changes were observed in the intensity of gp75LNGFRIR in the granule neuron layer of young, adult and old rats. In the molecular layer, the highest gp75LNGFRIR was found in young animals. It was reduced as a function of age. The present results show that changes in gp75LNGFRIR observed as a function of age affect to a different extent the three layers of the rat cerebellar cortex.

Aging↗

PubMed1994

Dopamine D1 and D2 receptors in the human ureter and urinary bladder: a radioligand binding and autoradiographic study.

OBJECTIVE: To analyse the pharmacological profile and the anatomical localization of the dopamine D1 and D2 receptors in sections of the pelvic part of the ureter and of the fundus of the urinary bladder. PATIENTS, MATERIALS AND METHODS: Samples of the pelvic part of the ureter and of the fundus of the urinary bladder were taken in men (age range 61 +/- 4 years) who were undergoing lower urinary tract surgery. Biochemical characterization and autoradiographical techniques were used on frozen sections of the ureter or the urinary bladder. [3H]-SCH 23390 was used as a ligand of dopamine D1 receptors and [3H]-spiroperidol as a ligand of dopamine D2 receptors. RESULTS: [3H]-SCH 23390 and [3H]-spiroperidol were bound by specific sections of the ureter and of the urinary bladder. The pharmacological profile of the binding was consistent with the labelling of D1 and D2 receptors respectively. Light microscope analysis of the localization of D1 and D2 receptors revealed the accumulation of the two radioligands in the tunica muscularis of the ureter or of the urinary bladder. CONCLUSION: A possible role of the dopaminergic system in the control of urine flow and of some dysfunctions of the lower urinary tract is suggested.

Aged↗

PubMed1994

Loss of dopamine D1-like receptors in the umbilical artery of pre-eclamptic subjects.

1. The influence of pre-eclampsia on the density and pattern of dopamine D1-like receptors was studied in frozen samples of the placental end of the umbilical artery by using radioligand binding and autoradiographic techniques in combination. 2. Analysis was performed on normotensive (n = 10) and pre-eclamptic subjects (n = 9) undergoing caesarean delivery, using [3H]-SCH 23390 as a ligand. Pre-eclamptic patients received a low salt diet and were treated with magnesium sulphate and hydralazine. The possibility that this treatment may cause changes in the density of dopamine D1-like receptors was evaluated by treating male Wistar rats in the same way and by determining [3H]-SCH 23390 binding in sections of the kidney which represents an organ containing dopamine D1-like receptors. 3. The density of dopamine D1-like receptors of the umbilical artery, which are probably vasodilatory, was decreased in pre-eclamptic compared with normotensive subjects. In contrast, the affinity of the radioligand for dopamine D1-like receptors was not statistically different between normotensive and pre-eclamptic subjects. Low salt diet, magnesium sulphate and hydralazine treatment did not affect [3H]-SCH 23390 binding to sections of rat kidney. This suggests that changes in the density of dopamine D1-like receptors in pre-eclamptic patients are a specific phenomenon not dependent upon antihypertensive measures. 4. Analysis of the pharmacological profile of [3H]-SCH 23390 binding to sections of the umbilical artery both in normotensive and pre-eclamptic subjects indicates the labelling of dopamine D5 receptors. 5. These findings collectively suggest that the dopaminergic vasodilatory tone in the umbilical artery is impaired in pre-eclampsia. The possible significance of these data should be clarified in future studies.

Adult↗

PubMed1993

Pharmacological characterization and autoradiographic localization of dopamine D1 receptors in the human umbilical artery.

Combined in vitro radioreceptor binding and autoradiographic techniques with [3H]SCH 23390 as a ligand were used to analyze the pharmacological profile and anatomical localization of dopamine D1 receptor sites in sections of human umbilical artery. The ligand was bound to sections of the artery in a manner consistent with the labelling of D1 receptors. These receptors, which show a fetal-to-maternal gradient with the highest concentration near the placenta, are located within the smooth muscle layer of the umbilical artery. The above findings suggest that endogenous dopamine may be involved in the control of the tone of the umbilical artery through the interaction with D1 receptors.

Adult↗

PubMed1993

Nerve growth factor receptor immunoreactivity in the cerebellar cortex of aged rats: effect of choline alfoscerate treatment.

The rat cerebellar cortex represents an interesting animal model for the analysis of age-dependent changes in brain microanatomy and function. Moreover, the cerebellar cortex contains detectable amounts of nerve growth factor (NGF) and express NGF receptors, which are sensitive to aging. Previous studies of our group have shown that treatment with choline alfoscerate (alpha-glyceryl-phosphorylcholine) countered the loss of nerve cells and fibers occurring with age in the cerebellar cortex. The present study was designed to assess whether treatment for 6 months with a daily dose of 100 mg/kg of choline alfoscerate has any effect on the expression of NGF receptor immunoreactivity in male Wistar rats of 24 months of age. Twelve-month-old rats were used as an adult reference group. NGF receptor immunoreactivity which was developed in the 3 layers of the cerebellar cortex in adult rats was decreased in the neuropil of the molecular layer and in the cytoplasm of Purkinje neurons of rats of 24 months. The number of NGF receptor immunoreactive Purkinje neurons was also lower in the oldest age group, whereas the NGF receptor immunoreactivity in the cytoplasm of granule neurons was unchanged. Treatment with choline alfoscerate increased NGF receptor immunoreactivity in the molecular layer and in the cytoplasm of Purkinje neurons as well as the number of immunoreactive Purkinje neurons but was without effect on NGF receptor immunoreactivity in the granule neurons. These results suggest that choline alfoscerate treatment may increase the expression of NGF receptors in the rat cerebellar cortex.

Aging↗

PubMed1993

Dopexamine hydrochloride in the human kidney: localization, receptor binding and effect on 3'-5'-cyclic adenosine monophosphate generation.

Dopexamine hydrochloride is a synthetic dopamine analogue recently developed to improve myocardial and renal performance in patients suffering from low cardiac output states. The present study was designed to assess the pharmacological profile and the anatomical localization of [3H]-dopexamine binding sites within the human nephron. The effects of dopexamine on the 3'-5'-cyclic adenosine monophosphate (cAMP)-generating system in membrane particles of the human kidney were also investigated. It was found that [3H]-dopexamine was specifically bound by sections of the human kidney. The binding was partly inhibited by the DA-1 receptor antagonist SCH 23390, by the beta 2-adrenoceptor antagonist ICI 118,551 and by the DA-2 receptor antagonist domperidone. The 3 antagonists in combination reduced [3H]-dopexamine binding to nonspecific values. Light microscope autoradiography revealed the accumulation of silver grains, corresponding to [3H]-dopexamine binding sites, within the different portions of the human nephron. The incubation of sections of the human kidney with [3H]-dopexamine plus SCH 23390 caused a remarkable reduction in the density of silver grains within the proximal tubule and the macula densa and a moderate decrease in the density of silver grains within the ascending and descending limbs of the loop of Henle as well as within the distal tubule. The incubation of sections of human kidney with [3H]-dopexamine plus ICI 118,551 caused a pronounced reduction in the density of silver grains within the glomerulus, the limbs of the loop of Henle, the distal tubule and the medullary collecting tubules and a moderate decrease in the density of silver grains within the macula densa and the proximal collecting tubule.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

PubMed1992

Changes in glutathione content and localization in rat heart as a function of age.

The influence of aging on glutathione levels and distribution in the heart was studied in male Sprague-Dawley rats of 3 (young), 12 (adult) and 24 (old) months of age using biochemical and histofluorescence techniques, respectively. Biochemical assays of reduced glutathione (GSH) in the right and left ventricles and in the septum showed a significant decrease in GSH levels in adult in comparison with young animals. No further changes were noticeable between adult and old rats. GSH histofluorescence revealed a rather homogeneous distribution of the product of histochemical reaction within both right and left atria in 3-month-old rats. In 12-month-old rats a reduction of GSH histofluorescence in comparison with younger animals was noticeable. The loss is more consistent in the epicardial portion of the right atrium and in the endocardial region of the left atrium. In the atria of 24-month-old rats GSH reactivity was homogeneously distributed throughout the atrial wall and was significantly lower than in young or adult rats. In 3-month-old rats GSH histofluorescence was slightly lower in the epicardial than in the endocardial portions of both ventricles. In adult rats a significant decrease of GSH histofluorescence was noticeable in comparison with 3-month-old rats. The loss is particularly pronounced within the endocardial region of the left ventricle. In 24-month-old rats GSH histofluorescence showed no significant differences between adult rats. However, GSH was more homogeneously distributed throughout the ventricular wall than in adult animals. The significance of these data is discussed in relation to the role that GSH plays in protecting the myocytes against free radical damage.

Aging↗

PubMed1992

Autoradiographic localization of the gamma-aminobutyric acid type A receptor agonist 3H-muscimol in the rat superior cervical ganglion.

The anatomical localization of gamma-aminobutyric acid type A (GABA-A) receptor sites in the rat superior cervical ganglion was studied using combined radioreceptor binding and autoradiographic techniques. 3H-Muscimol was used as a ligand of GABA-A receptor sites. The binding was consistent with the labelling of GABA-A sites. The dissociation constant value was 6.4 nmol/l, and the maximum density of binding sites was 146 +/- 7.8 fmol/mg tissue. Light microscope autoradiography revealed the accumulation of 3H-muscimol mainly in superior portions of the ganglion. Binding sites are located primarily in the neuropil rather than within ganglionic neurons. It is probable that the sites revealed by autoradiography are involved in the inhibition of acetylcholine release from ganglionic neurons.

Animals↗

PubMed1992

Venous wall ultrastructure in generalized venomegaly.

The ultrastructure of the v. colica sinistra in a case of generalized vasomegaly in man was examined. Elastic material was found in three forms: as a lightly osmiophil amorphous material bordering on myocytes, as a highly osmiophil elastic membrane, and as highly osmiophil slim elastic fibres of different orientation in the tunica media and adventitia. The slightly osmiophil elastic material is assumed to be newly formed by pinocytotic activity of the myocytes. The highly osmiophil elastic material indicates its impairment. No typical atherosclerotic changes were found in the examined vein. Based on a comparison with previous findings in the case of vasomegaly of the a. mesenterica inferior, the authors conclude that the venomegaly phenomenon is connected with degenerative changes in the elastic material of the vessel wall.

Aged↗

PubMed1992

A contribution to the morphology of tortuosity of arteries, aneurysms and arteriomegaly.

Using the electron microscope, the authors examined the structure of the wall in a case of arteriomegaly of the inferior mesenteric artery in man. Structural changes concerned the elastic material showing signs of degeneration. Based on a comparison with literary findings, the authors conclude that tortuosity of the arteries, aneurysms and arteriomegaly are caused by congenital, age-dependent and pathological changes in the elastic material in the vessel wall. There exist basic structural differences in the arterial wall in arteriomegaly and in atherosclerosis.

Aged↗

PubMed1991

Autoradiographic localization of muscarinic acetylcholine receptors in the rat pulmonary vascular tree.

The pharmacological characteristics and the anatomical localization of muscarinic receptors in the pulmonary vascular tree were investigated in lung sections of Wister-Kyoto (WKY) and spontaneously hypertensive rats (SHR). [3H]Quinuclidinyl benzylate [( 3H]QNB) was bound by sections of rat lung in a manner consistent with the labeling of muscarinic acetylcholine receptors, with a dissociation constant value (Kd) of 0.41 +/- 0.3 nM in WKY rats and of 0.37 +/- 0.2 nM in SHR. The density of muscarinic acetylcholine receptors was higher in sections of lung of WKY rats than of SHR. In the pulmonary vasculature these sites were associated with the smooth muscle of the medial layer of different size branches of the pulmonary artery and vein. No [3H]QNB binding sites were found within the endothelium in the blood vessels of either WKY rats or SHR. The density of [3H]QNB binding sites was significantly lower in the smooth muscle of pulmonary vein and its branches in SHR. There were no significant hypertension-dependent changes in the density and pattern of muscarinic receptors of pulmonary artery smooth muscle.

Animals↗

PubMed1991

Autoradiographic localization of the GABA-A-receptor agonist (3H)-muscimol in the rat intestinal musculature.

Radioreceptor-binding assay and autoradiography were used to study the pharmacological profile and the anatomical localization of GABA-A-receptor sites in sections of rat duodenum, jejunum and ileum. (3H)-Muscimol, used as a ligand, was bound by sections of the intestinal portions investigated in a manner consistent with the labeling of GABA-A-receptor sites. The dissociation constant (Kd) was about 12.5 nmol/l in the three different intestinal portions. The maximum density of binding sites (Bmax) was highest in the duodenum (118.9 +/- 7.4 fmol/mg tissue followed, in descending order, by the jejunum (105.8 +/- 6.3 fmol/mg tissue) and the ileum (67.8 +/- 5.9 fmol/mg tissue). Light microscope autoradiography revealed a dense accumulation of specific silver grains within intestinal smooth muscle. In the duodenum (3H)-muscimol-binding sites were rather homogeneously distributed both in circular and longitudinal smooth muscle. In the jejunum the density of silver grains was similar to that seen in the duodenum in the circular musculature and lower in the longitudinal musculature. The ileum displayed the lowest accumulation of (3H)-muscimol-binding sites, with no significant differences in the density of silver grains between the two muscular layers. The possible significance of the GABA-A-receptor sites observed in the intestinal musculature is discussed.

Animals↗

PubMed1990

The noradrenergic innervation of the ovary in old rats.

The influence of ageing on the noradrenergic innervation of the ovary was studied in female Wistar rats using high pressure liquid chromatography (HPLC) with electrochemical detection and catecholamine histofluorescence techniques. Old age was accompanied by a significant decrease in ovarian noradrenaline levels. In young animals (3-month-old) noradrenergic nerve fibres were distributed primarily to blood vessels and in lesser amounts to the interstitial glands. In aged animals (24-month-old) perivascular noradrenergic fibres were reduced by more than 40%; interstitial gland nerve fibres were reduced by approximately 20%. The possibility that impaired noradrenergic ovarian innervation occurring in old age may be in some way related with age-dependent failure in reproductive activity is discussed.

Aging↗

PubMed1990

Age-related changes of dopamine sensitive cyclic AMP generation in the rat frontal cortex.

The dopamine (DA) D-1 and D-2 receptors coupled to 3',5'-cyclic adenosine monophosphate (cAMP) generation were studied in membrane particles of the frontal cortex in young (3-month-old), adult (12-month-old) and aged (24-month-old) male Sprague-Dawley rats. Activation of D-1 receptors with DA, apomorphine or fenoldopam enhanced accumulation of cAMP in the frontal cortex of young rats. The stimulatory effect elicited by DA on cAMP generation declined by about 20% in adult rats. No further decline in cAMP accumulation was noticeable in aged animals. The response to dopaminergic agonists was blocked by the D-1 receptor antagonist SCH 29390 in the three age groups examined. The presence of D-2 receptors, negatively coupled to cAMP generation, was demonstrated by incubating frontal cortex membrane particles with SCH 23390 and then with DA. This inhibitory response, was also elicited with D-2 receptor agonists quinpirole or bromocriptine in the absence of SCH 23390 in which these compounds produced a decrease in cAMP. The decrease in cAMP caused following D-2 receptor stimulation was shown to be enhanced with age. No difference was observed between the three age groups of animals in the activation of cAMP production by forskolin. The present data suggest a selective decrease in the coupling between the D-1 receptor and cAMP generation in the frontal cortex of adult and aged rats and of an age-dependent increase in the coupling between the D-2 receptor and cAMP inhibition. The functional consequences of these biochemical changes may have important implications in the aging of the rat frontal cortex.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1990

Predominant epithelial localization of type A gamma-aminobutyric acid receptor sites within rat seminal vesicles and prostate glands.

In order to understand the role of the gamma-aminobutyric acid (GABA)-ergic system in the reproductive organs of the male, the biochemical characteristics and the autoradiographic localization of GABA type A (GABAA) receptor sites were studied in sections of the rat epididymis, seminal vesicles and prostate gland (lateral lobe) using 3H-muscimol as a ligand. No specific 3H-muscimol binding occurred in the epididymis. 3H-muscimol was bound to sections of seminal vesicles and prostate glands in a manner consistent with the labeling of specific GABAA receptors. Binding was saturable, reversible, with Kd values of 27.5 +/- 2.0 and 26.0 +/- 1.9 nmol/l and Bmax values of 230 +/- 21 and 160 +/- 13 fmol/mg protein for seminal vesicles and prostate glands, respectively. The rank order of potency of GABAergic drugs in inhibiting 3H-muscimol binding to sections of seminal vesicles and prostate glands was also consistent with the labeling of GABAA receptors. Autoradiography demonstrated the predominant accumulation of silver grains in the epithelium of seminal vesicles and prostatic glandular tissue. These findings further support the suggestion of a possible role of GABA in the male reproductive function. The predominant epithelial localization of GABAA receptors in the seminal vesicles and in the prostate gland allows us to hypothesize that GABA may be involved in the secretory activities of these glands.

Animals↗

PubMed1989

Autoradiographic localization of muscarinic receptors within the rat kidney.

We used a combination of radioreceptor binding and autoradiographic techniques to study the pharmacological characteristics and anatomical localization of [3H]quinuclidinyl benzylate (QNB) in kidney sections of Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). [3H]QNB was bound by sections of rat kidney in a manner consistent with the labeling of muscarinic acetylcholine receptors. Anatomically, these receptor sites were located primarily within the smooth muscle of the renal vascular tree and to a lesser extent within cortical and medullary tubules. The density of renal muscarinic acetylcholine receptors (both vascular and tubular) was decreased in hypertension but the affinity of the ligand for muscarinic receptors was unchanged. A possible role of muscarinic acetylcholine receptors in renal function is suggested.

Animals↗

PubMed1989

Autoradiographic localization of vasoactive intestinal polypeptide receptors in the rat mesenteric vascular tree.

By the use of combined in vitro radioreceptor binding and autoradiographic techniques, we analyzed the pharmacological properties and the anatomical localization of the vasoactive intestinal polypeptide (VIP) receptor in rat superior mesenteric artery and in medium and small mesenteric artery branches. 125I-VIP was bound by sections of rat superior mesenteric artery in a manner consistent with the labeling of specific VIP receptors, with Kd and Bmax values of 0.23 nM and 0.71 pmol/mg protein respectively. Inhibition of 125I-VIP binding with VIP and related peptides gives the following rank order of potency: VIP greater than peptide histidine methionine greater than secretin. Light microscope autoradiography reveals specific VIP binding sites within the medial layer of superior mesenteric artery and its branches. Medium and small sized vessels are richer in 125I-VIP binding sites than the larger ones.

Animals↗

PubMed1989

Effect of acetyl-L-carnitine treatment on the density of muscarinic receptors in the brain of methylazoxymethanol-microencephalic rats.

The effect of methylazoxymethanol (MAM), administered on the 15th gestational day, on the density and pattern of muscarinic cholinergic receptors in some brain areas was assessed using combined radioreceptor binding and autoradiographic techniques. The effect of 15 days' treatment with acetyl-L-carnitine on the same parameter was also assessed. The density of muscarinic cholinergic receptors was found to be increased in the brain of MAM-microencephalic rats. Acetyl-L-carnitine administration caused a significant reduction in the density of receptors under study. A possible role of acetyl-L-carnitine in restoring central cholinergic neurotransmission is discussed.

Acetylcarnitine↗