Biomedical subjects

C Sala

Publications and source records attributed to C Sala.

At least 55 records · Page 3Linked to original sources

PubMed1996

Expression of two neuronal nicotinic receptor subunits in innervated and denervated adult rat muscle.

The presence of transcripts coding for various alpha and beta subunits of neuronal acetylcholine receptors was investigated using polymerase chain reaction (PCR) on RNA extracted from innervated and denervated adult rat muscles. The results indicate that mRNAs coding for the neuronal alpha 4 and beta 2 subunits are expressed by adult muscles. Unlike avian embryonic muscle tissue, mRNA coding for alpha 7 and beta 4 subunit was undetectable. Denervation did not significantly modify the expression levels of the alpha 4 and beta 2 subunit-specific mRNAs. The results complement our previous immunohistochemical data and suggest that neuronal acetylcholine receptors are expressed by adult muscle tissue and may play a role in the control of muscle function.

Age Factors↗

PubMed1996

Excretory responses to renal nerve stimulation during inhibition of neutral metalloendopeptidase and angiotensin-converting enzyme in the rat.

To evaluate the interaction between renal nerves, the atrial natriuretic peptide (ANP), and the renin-angiotensin system (RAS), electrical stimulation of renal nerves was performed in spontaneously hypertensive rats (SHR) and in their normotensive controls, Wistar Kyoto rats (WKY), before and after pharmacologic treatment with (a) a neutral endopeptidase inhibitor (NEP-i) to enhance the intrarenal ANP activity; (b) an ACE inhibitor (ACE-i) to block RAS; (c) both NEP-i and ACE-i; and (d) the vehicle of the drugs. Renal nerve stimulation did not change arterial pressure (AP) but reduced renal blood flow (RBF), glomerular filtration rate (GFR), and urinary sodium excretion (UNa+V) in both WKY and SHR. NEP-i treatment in WKY and SHR had no systemic or renal hemodynamic effects but increased GFR and urinary cyclic guanosine monophosphate (GMP) excretion; UNa+V increased (+2.78 +/- 0.31 microEq/min) in WKY, whereas it did not change in SHR (+0.83 +/- 0.79 microEq/min). In both strains, ACE-i treatment reduced AP, increased RBF, and did not change GFR and UNa+V. The combined treatment with NEP-i and ACE-i did not modify the natriuretic effect observed in NEP-i treated WKY (+4.29 +/- 1.25 microEq/min), but it elicited a natriuretic effect in SHR (+3.98 +/- 1.29 microEq/min). Pharmacologic treatment did not change the hemodynamic and excretory responses to renal nerve stimulation in both WKY and SHR. In conclusion, NEP-i treatment increased UNa+V in normotensive rats without changing AP. In hypertensive rats, the natriuretic effect of NEP-i became evident only after block of RAS by ACE-i. Neither NEP-i nor ACE-i, even in combination, could modify the renal responses to sympathetic stimulation.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1996

FISH characterization of the Xq21 breakpoint in a translocation carrier with premature ovarian failure.

A panel of ordered YAC clones, isolated using STSs in the Xq13-Xq23 region, was used to characterize by Fluorescent In Situ Hybridization (FISH) the Xq21 breakpoint in a t(X;1)(q21;p34) translocation female with premature ovarian failure. The YAC 949E11 was found to span the breakpoint, but also to join the two non-overlapping YACs 36CB1 and 40AB3, proximal and distal, respectively, to the patient's Xq21 breakpoint.

Adolescent↗

PubMed1996

Humoral effects of selective adenosine agonists in spontaneously hypertensive rats.

OBJECTIVE: We studied the dose-response effects of acute administration of the selective A1 adenosine receptor agonist 2-chloro-N6-cyclopentyladenosine (CCPA), the selective A2A agonists 2-hexynyl-5'-N-ethylcarboxamidoadenosine (2HE-NECA) and 2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS 21680) and the non-selective agonist N-ethylcarboxamidoadenosine (NECA) on plasma renin activity, atrial natriuretic peptide, cyclic guanosine 3',5'-monophosphate (cGMP) and endothelin-1 in spontaneously hypertensive rats. METHODS: The drugs were administered intraperitoneally in four doses to conscious rats. Systolic blood pressure and heart rate were measured by the tail-cuff technique. Both humoral and hemodynamic parameters were determined 1 h after dosing in separate sets of animals. RESULTS: All the compounds induced a dose-dependent decrease in systolic blood pressure that was associated with different changes in heart rate. Heart rate was decreased by all doses of CCPA and by the higher doses of the non-selective compound (NECA) and increased by both A2A agonists. Plasma renin activity also changed in opposite directions, being decreased by CCPA but increased dose-dependently by 2HE-NECA and CGS 21680 and only moderately by NECA. Plasma atrial natriuretic peptide and cGMP levels increased dose-dependently after CCPA and NECA, but were unaffected by the A2A agonists. None of the compounds altered plasma endothelin-1 levels. CONCLUSIONS: These results indicate that the renin-suppressive effect of the A1 agonist, which is associated with a cardiodepressant action, may be attributed either to a direct inhibition of renin release or to the concomitant increments in plasma atrial natriuretic peptide and its second messenger, cGMP. In contrast, the renin-stimulating effect of the A2A agonists may result either from direct stimulation of renin secretion or from reflex sympathetic activation secondary to the fall in blood pressure.

Adenosine↗

PubMed1995

Sympathetic activation and loss of reflex sympathetic control in mild congestive heart failure.

BACKGROUND: Baroreflex control of sympathetic activity is impaired in severe congestive heart failure (CHF), probably causing the marked sympathetic activation typical of this condition. Little information exists, however, as to whether baroreflex impairment and related sympathetic activation also occur in mild CHF. METHODS AND RESULTS: We studied 19 patients (age, 57.5 +/- 2.2 years, mean +/- SEM) with CHF in New York Heart Association (NYHA) class III or IV and with a marked reduction in left ventricular ejection fraction (LVEF, 30.1 +/- 1.5% from echocardiography) and 17 age-matched patients with CHF in NYHA class I or II and with an only slightly reduced LVEF (44.9 +/- 3.3%) that never was < 40%. Seventeen age-matched healthy subjects served as control subjects. Primary measurements included beat-to-beat arterial blood pressure (with the Finapres technique), heart rate (from ECG), and postganglionic muscle sympathetic nerve activity (MSNA, from microneurography at the peroneal nerve). Measurements were performed at baseline and during baroreceptor stimulation (intravenous phenylephrine infusion), baroreceptor deactivation (intravenous nitroprusside infusion), and cold-pressor test. Baseline blood pressure was similar in the three groups, whereas heart rate was progressively greater from control subjects to patients with mild and severe CHF, MSNA (bursts per 100 heart beats) increased significantly and markedly from control subjects to patients with mild and severe CHF (47.1 +/- 2.9 versus 64.4 +/- 6.2 and 82.1 +/- 3.4, P < .05 and P < .01, respectively). Heart rate and MSNA were progressively reduced by phenylephrine infusion and progressively increased by nitroprusside infusion. Compared with control subjects, the responses were strikingly impaired in severe CHF patients, but a marked impairment also was seen in mild CHF patients. On average, baroreflex sensitivity in mild CHF patients was reduced by 59.1 +/- 5.5% (MSNA) and 64.8 +/- 4.8% (heart rate). In contrast, reflex responses to the cold-pressor test were similar in the three groups. CONCLUSIONS: These results demonstrate that in mild CHF patients the baroreceptor inhibitor influence on heart rate and MSNA is already markedly impaired. This impairment may be responsible for the early sympathetic activation that occurs in the course of CHF.

Adult↗

PubMed1995

Immunohistochemical localization of neuronal nicotinic receptor subtypes at the pre- and postjunctional sites in mouse diaphragm muscle.

The existence of neuronal nicotinic acetylcholine receptor (nAChR) subunits was investigated in the cryostat sections of mouse diaphragm muscles using the indirect immunofluorescence technique. The specific immunolabelings with monoclonal antibodies (mAbs) to beta 2 and to alpha 8 subunits of neuronal nAChR were observed at the endplate determined by labeling with a fluorescent dye (BODIPY)-conjugated alpha-bungarotoxin. The immunoreactivity of mAb to the alpha 3 subunit of neuronal nAChR was detected on the motor nerve fibers including the nerve terminals. These results provide evidence that the subtypes of postsynaptic nAChR, recognized by the anti-beta 2 and/or anti-alpha 8 mAbs, and the presynaptic nAChR recognized by the anti-alpha 3 mAb, are present at the neuromuscular junction, in addition to the classical muscle nAChR.

Animals↗

PubMed1995

Effects of exposure to high altitude on plasma endothelin-1 levels in normal subjects.

OBJECTIVE: To assess whether the hypoxia associated with exposure to high altitude affects plasma endothelin-1 levels, and whether changes in endothelin-1 are related to those in systemic and pulmonary blood pressure. DESIGN: Eight normal subjects ascended Mount Everest to an altitude of 5050 m within a period of 8 days (study 1) and 10 ascended Mount Rosa in the Italian Alps to an altitude of 4559 m within 2 days (study 2). In study 1 systemic blood pressure, heart rate, haematocrit, haemoglobin oxygen saturation (evaluated by percutaneous oximetry) and venous plasma endothelin-1 were measured several times during the ascent, and twice more during the time spent at high altitude. In study 2 the same parameters as well as systolic pulmonary pressure by echocardiography were evaluated on the second day of resting at 4559 m. In both studies, data obtained during the expeditions were compared with those collected from the same subjects at sea level. RESULTS: In study 1 plasma endothelin-1 increased progressively up to 4240 m (from 1.8 +/- 0.1 pg/ml at sea level to 2.7 +/- 0.2 pg/ml) and decreased slightly thereafter; these increments were directly related to the decrements in percutaneous oxygen saturation, which, at that altitude, fell from 98.6 +/- 0.2% at sea level to 80.8 +/- 0.4%. Blood pressure and haematocrit also rose in response to exposure to high altitude but these changes were not related to changes in endothelin-1. In study 2 the increments in plasma endothelin-1 were similar to those observed in study 1 and the changes again correlated with changes in oxygen saturation as well as with those in systolic pulmonary pressure. On average, systolic pulmonary pressure increased from 19 +/- 1 to 26 +/- 1.9 mmHg, whereas systemic blood pressure and haematocrit were unchanged. CONCLUSION: Exposure to high altitude is associated with consistent increases in plasma endothelin-1. This is probably the result of augmented secretion of the peptide in response to hypoxia and may contribute to the physiological adaptation of the pulmonary circulation to this condition.

Adult↗

PubMed1995

Assessment of cardiovascular risk factors in menopausal Argentinian women.

The cardiovascular risk factor profile was assessed in a population sample consisting of 60 nonmenopausal (control) and 100 menopausal women from different cities in Buenos Aires Province, Argentina. Each subject was individually interviewed and asked to complete a specially designed questionnaire aimed at identifying cardiovascular risk factors. A clinical general and gynecological examination including blood pressure and anthropometric measurements as well as a Papanicolaou smear were performed. The most prevalent risk factor in the menopausal group was low physical activity (87% of the subjects), followed by nervous complaints (67%), obesity (64%), familial antecedents of cardiovascular disease (CVD; 38%) and hypertension (33%). Other risk factors assessed showed a level of prevalence below 10%. In the control group, a tobacco smoking habit was the CVD risk factor with the highest prevalence (47%). Nervous complaints also showed a high prevalence (48%). Most menopausal patients (77%) had a cardiovascular risk index (RI) level between 1.5 and 4.0, whereas 17% of these subjects had an RI greater than 4.0 (high-risk patients). The present study reveals that, in the studied community, the menopause is associated with increased levels of both estrogen-dependent and psychosocial risk factors for CVD.

Adult↗

PubMed1995

Atrial natriuretic peptide and hemodynamic changes during normal human pregnancy.

We compared plasma atrial natriuretic peptide (ANP) and cGMP levels during normal pregnancy--a condition characterized by hypervolemia, high cardiac output, and decreased vascular resistance--with postpartum levels and assessed their relation to pregnancy-induced hemodynamic changes. Humoral and hemodynamic variables were measured in healthy women subjects in the supine and upright postures at each trimester of pregnancy and postpartum. Supine plasma ANP was increased throughout pregnancy (32 +/- 5, 21 +/- 3, and 19 +/- 2 versus 15 +/- 1 pmol.L-1, respectively, at each trimester versus postpartum), as was cGMP (8.6 +/- 1, 7.1 +/- 1, and 6.6 +/- 1 versus 5.6 +/- 1 nmol.L-1), and their increments were directly related (r = .68, P < .01). Both ANP and cGMP levels did not differ from postpartum levels after subjects stood. Supine stroke volume was initially increased but declined below postpartum levels in late pregnancy (69 +/- 4, 60 +/- 3, and 44 +/- 3 versus 58 +/- 4 mL.m-2), whereas after subjects stood it was always higher (56 +/- 3, 58 +/- 3, and 49 +/- 2 versus 44 +/- 2 mL.m-2); thus, stroke volume tended to increase in response to standing in late pregnancy. Supine cardiac index had a similar trend, which was opposite to that of total peripheral resistance (1213 +/- 62, 1265 +/- 79, and 1729 +/- 89 versus 1654 +/- 92 dyne.s-1.cm-5.m-2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Calcitonin gene-related peptide: possible role in formation and maintenance of neuromuscular junctions.

The expression and content of calcitonin gene-related peptide (CGRP) and secretogranin II (SgII) in adult rat motor neurons were examined by in situ hybridization, Northern blot analysis, and immunocytochemistry. Normal motor nerve terminals did not contain detectable CGRP or SgII. Ten to 15 days after a peripheral nerve crush about 80% of the motor nerve terminals reinnervating the soleus (SOL) muscle contained detectable CGRP but no SgII. Thereafter, the percentage of CGRP-positive terminals declined towards zero. In the spinal cord, CGRP expression was higher than normal 1 d after a sciatic nerve crush and increased during the next few days. No increase in SgII expression was observed. Nerve blocks by tetrodotoxin (TTX) and botulinum toxin (BoTX) increased CGRP content and expression in motor neurons but had no effect on SgII. After 10 d of BoTX treatment and 33 d of TTX treatment (the longest time points studied), more than 90% of the motor nerve terminals stained for CGRP. The density of large dense core vesicles (LDCVs) was also higher than normal in such terminals. Some increase in CGRP content and expression occurred in the nontreated side. In a group of rats, the peroneal nerve was stimulated electrically with brief, intermittent pulse trains at 100 Hz. The stimulation was applied below a TTX block that had started 7 or 19 d earlier. One minute of such stimulation was sufficient to remove CGRP from most of the terminals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Distribution of nicotinic receptors in the human hippocampus and thalamus.

Neuronal nicotinic acetylcholine receptors consist of different subunits, alpha and beta, with different subtype arrangement corresponding to distinct pharmacological and functional properties. The expression of alpha 3, alpha 7 and beta 2 mRNA in the human brain was studied by in situ hybridization and compared to [3H]nicotine, [3H]cytisine and [125I]alpha-bungarotoxin binding in contiguous sections. The beta 2 probe showed a strong hybridization signal in the granular layer of the dentate gyrus and in the CA2/CA3 region of the hippocampus and in the insular cortex, and a signal of lower intensity in the subicular complex and entorhinal cortex. The alpha 3 probe showed strong hybridization in the dorsomedial, lateral posterior, ventroposteromedial and reticular nuclei of the thalamus, and a weak signal in the hippocampal region and in the entorhinal, insular and cingular cortex. The amount of alpha 7 mRNA was high at the level of the dentate granular layer and the CA2/CA3 region of the hippocampus, in the caudate nucleus and in the pulvinar and ventroposterolateral nuclei of the thalamus. [3H]Nicotine and [3H]cytisine binding appeared to be identical in anatomical distribution and relative intensity. It was high in the thalamic nuclei, the putamen and in the hippocampal formation in the subicular complex and the stratum lacunosum moleculare. The level of [125I]alpha-bungarotoxin binding was particularly high in the hippocampus and in the pyramidal cells of the CA1 region, but was relatively low in the subicular complex. Our data indicate that in the human brain nicotinic receptor subtypes have discrete distributions, which are in part different from those of other species.

Adult↗

PubMed1994

Cobalt exposure in 'hard metal' and diamonds grinding tools manufacturing and in grinding processes.

Cobalt is considered to play a major role in the development of 'hard metal' interstitial lung disease, asthma and other adverse health effects. A survey of occupational exposure of workers is a fundamental step to obtain exposure-response information and for preventive action. Process related exposure assessment was performed before and after technical control in small and medium size factories in a large surveillance programme. Cobalt containing airborne dusts were sampled by performing multiple measurements at the workplace of each process in which the types of job and duration of exposure were similar. Samples were analyzed by atomic absorption spectroscopy. Very high exposure levels encountered before technical control were significantly lowered with efficient local exhaust ventilation plant in 'hard metal' and grinding processes, but sometimes the TLV of 0.05 mg/m3 were exceeded. In the manufacture of grinding tools, major steps in cobalt control by local ventilation was not able to keep exposure below the TLV; exposures from 0.12 to 0.75 mg/m3 were recurrent and these need control strategies.

Air Pollutants, Occupational↗

PubMed1994

Immunolocalisation of chromogranin B, secretogranin II, calcitonin gene-related peptide and substance P at developing and adult neuromuscular synapses.

The localisation of chromogranin B, secretogranin II, calcitonin gene-related peptide and substance P was characterised by the use of indirect immunofluorescence techniques at neuromuscular junctions in frog, mouse and rat muscles. We found that chromogranin B, secretogranin II and calcitonin gene-related peptide are co-expressed in the frog, 1 week old mouse and 1 week old rat endplates. Substance P immunoreactivity could only be detected in frog muscles.

Animals↗

PubMed1994

Distribution of neuronal nicotinic receptor subunits in human brain.

Neuronal nicotinic acetylcholine receptors (nAchRs) are multimeric proteins constituted of two different subunits, alpha and beta, with different subtypes arrangement and different pharmacological and functional properties. nAchRs mediate neurotransmission in many central and peripheral synapses and appear to be affected in human degenerative disorders. We have studied the distribution of nAchR in human brain, particularly in the hippocampus and thalamus, by binding of 3H-nicotine and 3H-cytisine and by in situ hybridization with human alpha 3 and beta 2 nAchR subunits of mRNA. An alpha 3 probe shows a strong hybridization signal in the thalamus, while a beta 2 probe has a good signal at the level of the enthorinal cortex, hippocampus and in caudate and putamen. The alpha 3 and beta 2 mRNA localization is different from that described in other species. 3H-nicotine and 3H-cytisine binding were very similar in terms of anatomical distribution and comparable to the binding described in other animal species. The binding of the two ligands was distributed over the areas labeled by the alpha 3 and beta 2 probes and did not completely overlap with either of the subunits.

Alkaloids↗

PubMed1994

Isolation of new genes in distal Xq28: transcriptional map and identification of a human homologue of the ARD1 N-acetyl transferase of Saccharomyces cerevisiae.

In this paper, we describe the physical and transcriptional organization of a region of 140 kb in Xq28, 5' to the L1CAM gene. By isolation and mapping of CpG islands to the physical map of the region, isolation of cDNAs, determination of partial nucleotide sequences and study of the pattern of expression and of the orientation of the transcripts identified we have established a transcriptional map of this region. In this map, previously identified genes (L1CAM, V2R, HCF1 and RnBP) have been positioned as well as 3 new genes. All genes in the region are rather small, ranging in size from 2 to 30 kb, and very close to one another. With the exception of the V2R gene, they are housekeeping, have a CpG island at their 5' end and the same orientation of transcription. This kind of organization is consistent with the one previously described for the more distal portion of Xq28, between the Color Vision (CV) and the G6PD genes and indicates that genes with housekeeping and tissue specific pattern of expression are interspersed in the genome but they are probably found in different 'transcriptional domains'. Among the new genes, TE2 demonstrated 40% identity with the protein N-acetyl transferase ARD1 of S. cerevisiae: TE2 may be the human homologue of the S. cerevisiae gene.

Acetyltransferases↗

PubMed1994

Hemodynamic and humoral effects of chronic treatment with the neutral endopeptidase inhibitor SCH 42495 in spontaneously hypertensive rats.

Blockade of atrial natriuretic factor (ANF) degradation by specific neutral endopeptidase (NEP) inhibitors may be useful in treatment of hypertension because of the potential diuretic, natriuretic, and arterial pressure (AP)-lowering effects. To test this possibility, we examined the effects of chronic oral treatment with the NEP inhibitor SCH 42495 on BP, diuresis, natriuresis, plasma ANF, cyclic GMP, and the renin-angiotensin system (RAS) in conscious unrestrained spontaneously hypertensive rats (SHR) and compared them with the effects induced by the angiotensin-converting enzyme (ACE) inhibitor spirapril (SPIR). Four groups of adult SHR were treated orally for 4 weeks with placebo, SCH 42495 3 mg/kg twice daily (b.i.d.), SCH 42495 30 mg/kg b.i.d., and spirapril 1 mg/kg b.i.d. Systolic BP (SBP) was measured weekly, and 24-h urine was collected every week for measurement of urinary volume, sodium, potassium, and cyclic GMP excretion. Plasma ANF, cyclic GMP, renin activity (PRA), and aldosterone (ALDO) were determined from blood collected when the rats were killed. After 4-week treatment with SCH 42495, circulating levels of ANF were similar in both SCH 42495- and placebo-treated SHR; plasma cyclic GMP was higher, however, in the treated rats than in controls and urinary cyclic GMP increased only with the higher dose of SCH 42495. PRA and plasma ALDO tended to be lower in both SCH 42495-treated groups than in controls, yet BP, diuresis, and natriuresis throughout the study were not different from controls. In contrast, spirapril decreased BP; this effect was associated with significant increments in renin and decrements in ALDO and ANF, without changes in plasma and urinary cyclic GMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1994

Effect of atrial natriuretic factor infusion on basal and CRH-stimulated ACTH, cortisol and aldosterone levels in patients with Cushing's or Addison's disease.

OBJECTIVE: While it has been shown that atrial natriuretic factor (ANF) is able to inhibit CRH-stimulated ACTH secretion in vitro, in normal men conflicting results on its effect on ACTH/cortisol responses to insulin and CRH have been reported. Since no data are available concerning the possible influence of ANF on the hypothalamic-pituitary-adrenal axis in states of ACTH hypersecretion, the effect of ANF on pituitary-adrenal function in basal conditions and after CRH stimulation has been investigated in patients with Cushing's (n = 4) and Addison's disease (n = 4). DESIGN: On two different days all patients underwent the following procedures: (a) alpha-human ANF was infused, after a priming dose of 100 ng i.v., at a rate of 0.01 microgram/kg/min over 5 hours. After 120 minutes of ANF infusion, oCRH (1 microgram/kg) was i.v. injected as a bolus; (b) vehicle infusion was given over 5 hours and at 120 minutes oCRH was injected. Plasma ANF, ACTH, cortisol, aldosterone, renin activity and K+ were measured; heart rate and blood pressure were monitored. RESULTS: In Cushing's disease plasma ANF rapidly increased within 30 minutes of the exogenous peptide infusion (from 27 +/- 5 to 73 +/- 14 pmol/l; mean +/- SE), whereas in the vehicle study its concentration was unchanged. During the first 2 hours of both tests no significant modifications in ACTH levels were observed. After CRH the plasma ACTH peak was unchanged. Serum cortisol levels progressively declined during the first 2 hours of ANF infusion (from 778 +/- 150 to 461 +/- 48 nmol/l; P < 0.05), whereas no changes were observed during vehicle. After CRH serum cortisol rose to similar peaks. Plasma aldosterone levels were significantly reduced during the first 2 hours of ANF infusion (from 81 +/- 20 to 35 +/- 7 pmol/l P < 0.05), whereas no changes were found during vehicle. A similar aldosterone rise was induced by CRH during either vehicle or ANF. Mean plasma renin activity slightly declined and the changes were similar on both occasions. In Addison's disease ANF levels rose within 30 minutes of the peptide infusion (from 12 +/- 1 to 49 +/- 8 pmol/l), while they were unchanged during vehicle. A slight decline in ACTH levels in the first 2 hours was observed during either vehicle or ANF infusion. After CRH the plasma ACTH peaks were similar. Mean plasma renin activity was unaffected by vehicle, while ANF caused a decline during the first 2 hours (from 13.4 +/- 0.8 to 7.7 +/- 0.3 ng/ml/h). In all patients, heart rate, blood pressure and K+ were only slightly affected on both occasions. CONCLUSIONS: (1) In patients with corticotrophin hypersecretion ANF does not influence basal and CRH-stimulated ACTH secretion; (2) in Cushing's disease ANF inhibits cortisol and aldosterone basal secretion; this effect is not mediated by ACTH and is over-ridden by CRH stimulation.

Addison Disease↗

PubMed1994

Corneal nerve damage and regeneration after excimer laser photokeratectomy in rabbit eyes.

PURPOSE: To investigate corneal nerve damage and its subsequent regeneration after excimer laser photokeratectomy in rabbit eyes. METHODS: Corneal photokeratectomy was performed on the right eyes of 34 pigmented rabbits, while the left eyes were used as a control. A Summit UV 200 excimer laser (Summit Technology, Waltham, MA) was used to produce a 100 microns depth phototherapeutic keratectomy (4.5 mm diameter). The rabbits were killed at 0, 1, 2, 3, 4, 5, 7, 8, 10, 15, and 20 days and 1, 2, 3, and 4 months after treatment. Corneal nerve regeneration was investigated using a monoclonal antibody directed against a 150 kD subunit of neurofilaments, in combination with acetylcholinesterase staining. RESULTS: At time 0, the subepithelial plexus had disappeared completely from the photoablated area. One day after treatment, some regenerating nerves sprouting within the treated area were visualized by a monoclonal antibody directed against a 150 kD subunit of neurofilaments. Acetylcholinesterase staining was detectable 7 days later. One month after surgery the subepithelial plexus had already reappeared, but was morphologically disorganized. Four months after treatment, the newly formed subepithelial plexus had considerably thickened in comparison with that of the control eye. CONCLUSIONS: This study shows that corneal nerve regeneration after excimer laser photoablation in rabbit eyes, although more intense, is similar to that produced after other surgical procedures involving the epithelium and the anterior stroma or one of the two.

Acetylcholinesterase↗