Ocular motility alterations in orbital fractures: pre-post evaluation in maxillofacial surgical treatment.

PURPOSE: The study aims to investigate the ability of maxillofacial surgery to reduce strabismus and improve ocular clinical symptomatology in patients with fracture of the medial or lateral floor of the orbit, or both, and to evaluate such abilities relative to the temporal distance between trauma and surgery. PATIENTS AND METHODS: 25 patients with traumatic diplopia were evaluated by CT, Goldman manual field of view, Hess-Lancaster test, eye examination and orthoptic examination, before and after surgery. RESULTS: We observed: a statistically significant reduction of the deviation angle, both from close and long distance (P = 0.0054 and P = 0.0051 respectively) with a 38% reduction of the deviation from short distance and 54% from afar; a regression of diplopia in 20% of the surgically treated cases (CL from 0 to 39%), significant at the Mc Nemar test; a negative correlation with the time elapsed between the onset of the fracture and maxillofacial surgery (R = -0.26), even if the analysis did not show a statistical significance of the data (P = 0.2). However, it is evident that the maximum improvement is observed only in cases operated within 5 months of the trauma, while the failures (worsening or persistence of diplopia) were observed only in the cases operated later. CONCLUSION: We can state that the intervention reduces strabismus and improves ocular symptomatology, as it statistically significantly reduces cases of diplopia; furthermore, it would seem preferable to intervene early, especially when damage to a muscular structure is suspected, even if the data do not allow definitive conclusions in this regard.

The economic burden of musculoskeletal disorders on the Italian social security pension system estimated by a Monte Carlo simulation.

The aim of the study is to estimate the pension costs incurred for patients with musculoskeletal disorders (MDs) and specifically with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) in Italy between 2009 and 2012. We analyzed the database of the Italian National Social Security Institute (Istituto Nazionale Previdenza Sociale i.e. INPS) to estimate the total costs of three types of social security benefits granted to patients with MDs, RA and AS: disability benefits (for people with reduced working ability), disability pensions (for people who cannot qualify as workers) and incapacity pensions (for people without working ability). We developed a probabilistic model with a Monte Carlo simulation to estimate the total costs for each type of benefit associated with MDs, RA and AS. We also estimated the productivity loss resulting from RA in 2013. From 2009 to 2012 about 393 thousand treatments were paid for a total of approximately €2.7 billion. The annual number of treatments was on average 98 thousand and cost in total €674 million per year. In particular, the total pension burden was about €99 million for RA and €26 million for AS. The productivity loss for AR in 2013 was equal to €707,425,191 due to 9,174,221 working days lost. Our study is the fi rst to estimate the burden of social security pensions for MDs based on data of both approved claims and benefits paid by the national security system. From 2009 to 2012, in Italy, the highest indirect costs were associated with disability pensions (54% of the total indirect cost), followed by disability benefits (44.1% of cost) and incapacity pensions (1.8% of cost). In conclusion, MDs are chronic and highly debilitating diseases with a strong female predominance and very significant economic and social costs that are set to increase due to the aging of the population.

Effectiveness of diagnosis and early treatment of ocular motility alterations in premature infants.

Objective: Prematurity often results in important developmental sequelae of brain structures, particularly those involved in processing visual information, such as the optic nerve, primary visual cortex and visuomotor integration areas. The aim of this study is to analyse the functionality of the sensory and motor pathways of the visual system by means of an orthoptic-ophthalmological assessment. Materials and methods: In this retrospective study, 151 records were examined, covering a period from 2000 to 2020, of preterm patients with gestational age < 32 weeks and birth weight ≤ 1,500 g up to an average age of about 8 years, referred to the Centre for Paediatric Ophthalmology and Strabology of the Ophthalmology Clinic of the Policlinico Umberto I, La Sapienza University of Rome, who underwent a complete ophthalmological and orthoptic assessment including the following tests measurement of ocular deviations according to the Hirschberg method, Lang I-II test, Titmus Stereotest, objective convergence assessment and ocular motility examination. Results: From the charts reviewed, 24.5% (37/151) of patients had Retinopathy of the Premature (ROP); while 38% of the whole sample (57/151) had strabismic amblyopia, of the latter only 31.5% (18/57) had ROP. In 8% of patients (12/151) the stereoscopic sense was absent, in 45% (8/151) stereopsis was gross (> 60 seconds of arc). In addition, 20.52 % (31/151) had a manifest eye deviation. 7.28% (11/151) had hypermetropia in the right eye (RE); 7.95% (12/151) hypermetropia in the left eye (OS); 3.31% of the patients (5/151) had myopia in the RE; 2% (3/151), myopia in the left eye (LE). In addition, the study of ocular motility revealed varying degrees of alteration poorly correlated with prematurity status. Conclusion: It was found that amblyopia, stereopsis and objective convergence are more affected by ROP than strabismus, refractive defects and ocular motility, indicating that premature children are particularly susceptible to ophthalmological and orthoptical alterations.

Clinical manifestations due to pharmacological interactions in pediatric ophthalmic surgery: topical drugs and general anaesthesia.

INTRODUCTION: The authors consider the type and the incidence of the adverse effects due to the interaction between ophthalmic drugs and general anaesthesia in pediatric ophthalmic surgery. PATIENTS AND METHODS: The experience included 176 general anaesthesia in 100 children aged between 9,2 months and 11,4 years (mean age 4,9 years). RESULTS: In the 100 patients we reported: 4 cases (2.7% general anaesthesias) of sinus tachycardia with heart rhythm varying between 170 and 180 beats per minute (3.6%); 5 cases of sinus bradycardia, varying between 60 and 70 beats per minute (3.3%); 3 cases of bronchospasm (2%); 2 cases of psychomotor agitation/disturbances in pre-convulsive state after anaesthesia (1.3%); 3 cases of arterial hypotension (60-70 mmHg) (2%); 7 cases of skin rush around neck and chest (4.6%); 1 case of prolonged apnoea (0.6%). CONCLUSIONS: The clinical manifestations, principally on the cardio-circulatory and nervous system are subjected to critical revision, to foresee the pharmacological interferences and therefore to prepare the necessary measure of medical treatment.

Ocular traumatology in children. A retrospective study.

UNLABELLED: OBIECTIVE: This study assesses the descriptive epidemiology of children with eye injuries presenting to the Emergency Department of a non exclusive Paediatric University Hospital - First Division of Ophthalmology of "Sapienza" University of Rome - over a period of 12 years. STUDY DESIGN: A retrospective long term study of 12 years. PARTICIPANTS: All paediatric patients (up to 14 years of age) presenting with ocular injuries and hospitalized. METHODS: It was analyzed the incidence of the ocular trauma among males and females. The situation in which the trauma occurred, type of trauma (contusive or perforating), the presence of endo-bulbar foreign bodies, visual acuity outcome. RESULTS: There were 203 patients who presented to the Emergency Department in the period examined. Contusive traumas were 130 (90 males, 40 females). The perforating trauma were 73 (63 males, 10 females). The presence of an endo-bulbar foreign body was registered in 10 patients. A detailed analysis of the causes of the trauma is therefore provided. We evidence that males were almost exclusively involved in sport traumas (60 males versus 2 females), and in second instance accidental trauma is almost equally divided between two genders. CONCLUSIONS: Our retrospective study presents the paediatric cases of a non exclusive Paediatric University Hospital where 3% of ocular traumas requiring hospitalization were in children. Therefore our data could be useful in order to bring about the necessary preventive measures to minimize paediatric eye injuries.

Anisometropia and isoametropia associated with microstrabismus: effectiveness of late anti-amblyopia treatment.

PURPOSE: Outcomes Research Study on patients suffering from anisometropia or isoametropia associated with amblyopia and microstrabismus to show the impact of late occlusion treatment on therapeutic prognosis. MATERIALS AND METHODS: Enrollment of all the eligible patients presenting to recruiting centers at the Department of Pediatric Ophthalmology and Strabismus - Ophthalmological Clinic - Policlinico Umberto I - Rome. At baseline, all patients will undergo an opthalmologic evaluation. Recruited patients will be followed for a 2-year period. Our test group was composed of 31 patients, 11 with bilateral and 20 with monolateral amblyopia, totalling 42 amblyopic eyes, and it was assessed - always by the same examiner - with the help of the following orthoptic examinations: Wirt test, Irvine-Jampolsky test (4 dioptre fixation task), Visuscope, Cover Test, Bagolini striated glasses, and Worth lights test. We assessed pre-post treatment variations observed in the overall group of amblyopic eyes, regardless of the differences between RE and LE. OUTCOMES: Of the 31 children, 58.1% were males and 41.9% female, average age between 6 and 14 years. Of the 42 amblyopic eyes, after daily occlusion of 8 hours ± 2.30 SD, we recorded an improvement of 71.4%, and visual acuity increased from an average of 0.4 LogMAR to 0.1 LogMAR. CONCLUSION: Late anti-amblyopic occlusion treatment proved effective in the long term for children 6 to 12 years, specifically regarding visual acuity, fixation, stereopsis, and binocular collaboration in patients suffering from anisometropia or isoametropia and microstrabismus.

Management della retinopatia diabetica e dell'edema maculare diabetico: linee guida "Euretina 2017".

Si prevede che la malattia diabetica con tutte le sue complicanze avrà un forte aumento di incidenza con un grosso impatto socioeconomico nei prossimi decenni in tutto il mondo. Pertanto ben si comprende l'importanza di individuare attraverso una fine diagnostica quanto più precocemente la comparsa dei sintomi diabetici, migliorare lo stile di vita ed impostare cure efficienti. Riportiamo la serie di raccomandazioni EURETINA 2017, dei maggiori esperti in Europa per la gestione della malattia diabetica e delle complicanze della retina. Per combattere questa "pestilenza" occorre un team medico preparato. Il trattamento laser è stato considerato sino a non molto tempo fa il Gold standard della retinopatia diabetica e dell'edema diabetico (RD e EMD). Recenti studi hanno dimostrato, invece, che si possono raggiungere risultati migliori mediante l'iniezione diretta di farmaci nella cavità vitreale. In particolare è emerso terapia di prima linea, molecole in grado di inibire il fattore di crescita endoteliale vascolare (anti VEGF) mentre non è più raccomandata la fotocoagulazione laser per il trattamento del DME. Nell'ambito delle molecole farmacologiche gli steroidi hanno mantenuto un ruolo nella gestione del DME cronicamente persistente.

Inferior Oblique Weakening and Abnormal Head Position: Controlled Myotomy versus Recession.

Purpose. Randomized controlled trial aimed at comparing surgical outcomes in a group of patients suffering from hyperfunction of the inferior oblique (IO) muscle with abnormal head position (AHP). The surgical techniques being compared are Recession and (thread) Controlled Myotomy. Materials and Methods. The group of 20 patients suffering from medium-high hyperfunction of the IO was assessed through an ophthalmological and orthoptic examination. 10 patients underwent traditional Recession (Group A) and 10 were treated with Controlled Myotomy (Group B). Results. The average age was 19 years ± 10.7 SD. After 1 year, 20% of Group A showed a small Vertical Deviation associated with a small AHP, while 80% had orthophoria and 40% of them had a small AHP. 80% of Group B showed a small Vertical Deviation associated with an equally small AHP, while 20% had orthophoria with a full resolution of AHP. Conclusion. Based on the results obtained and the fewer intrasurgical risks involved, thread Controlled Myotomy proved to be a valid alternative to Recession. Furthermore, in case of Recession, over the long period a small residual AHP remained in the patients who had orthophoria, unlike Myotomy which led to a total resolution.

Reduced diabetogenic effect of streptozotocin in rats previously adapted to a high-protein, carbohydrate-free diet.

The diabetogenic effects of streptozotocin (STZ) (40 or 60 mg/kg body wt, i.v.) were examined in rats that had been previously fed either a high-protein, carbohydrate-free (HP) diet (70% protein, 8% fat) or a control diet (66% carbohydrate, 16% protein, 8% fat), and maintained on the same diets after drug injection. Rats on the HP diet 15-21 days before STZ administration showed reduced mortality and decreased severity of diabetes as judged by rate of body-weight change, plasma glucose, urine volume and glycosuria, serum and pancreatic insulin, and morphology of islets of Langerhans. In rats on the control diet, values for serum and pancreatic insulin did not differ 2 and 14 days after 40 mg/kg of STZ. In contrast, in rats under the HP regimen, serum insulin levels doubled 14 days after STZ and pancreatic insulin content was almost 20 times higher than at day 2. Rats previously fed on the HP diet for 21 days, but transferred to the control diet 2 days after STZ injection, also showed reduced severity of diabetes, as indicated by rates of body-weight gain, urinary excretion of urea, and levels of serum and pancreatic insulin. However, in these animals the effects of the HP diet were not as marked as those observed in the rats that were maintained on the HP diet after STZ injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced lipogenesis in rats fed a high-protein carbohydrate-free diet.

Rates of fatty acid synthesis were assessed in carcass, liver, and adipose tissue from rats fed for 30 to 40 days a balanced diet (66% wt/wt carbohydrate, 17% casein, 8% fat) or a high-protein carbohydrate-free diet (70% casein, 8% fat). Despite similar body weight increases, carcass fatty acid content of rats on the high-protein (HP) diet was 13% less, and the weight of their epididymal fat pads was reduced by 29% in relation to the controls. In vivo incorporation of 3H2O into carcass fatty acids (FA) and into liver triacylglycerol (TAG) was significantly reduced in HP-fed rats. FA synthesis from 14C-acetate, glucose, or leucine and from 3H2O was also markedly decreased in liver slices from HP rats. The amount of 3H-TAG that accumulated in plasma of rats injected with triton WR 1339 to block peripheral utilization of lipoprotein corresponded in HP and control rats to only 4.1% and 5.0%, respectively, of 3H-FA recovered in carcasses from animals not treated with triton, indicating that almost all of the carcass 3H-TAG was synthesized in situ. However, on a long term basis, the reduced hepatic lipogenesis and the resulting decreased transport of TAG might affect lipid accumulation in HP rats. In vivo lipogenesis from 3H2O and in vitro FA synthesis from 3H2O and from 14C-precursors did not differ significantly in retroperitoneal and epididymal adipose tissue from HP and control rats. In both groups of animals, in vivo rates of lipogenesis were higher in retroperitoneal than in epididymal adipose tissue but still did not account for rates of FA synthesis by carcasses, suggesting the existence of other sites with higher lipogenic activity.

Lipolysis and the antilipolytic effect of insulin in adipocytes from rats adapted to a high-protein diet.

Free fatty acid (FFA) mobilization during fasting was investigated in rats fed a high-protein, carbohydrate-free (HP) diet (70% casein, 8% fat, wt/wt) or a balanced diet (66% carbohydrate, 17% casein, 8% fat) for 30 to 40 days. In vivo, rats on the HP diet showed reduced rates of plasma FFA increase during fasting. Their blood sugar remained unchanged and was higher than that of control rats 24 hours after removal of food. In the fed state, serum insulin levels were smaller in HP-fed rats but did not differ significantly in the two experimental groups during fasting. In vitro, the rates of glycerol and FFA release by epididymal fat pads obtained from fasted rats were similar in rats consuming the HP diet. Fat cells isolated from rats on the HP diet also had reduced rates of basal lipolysis. Furthermore, they showed a significant increase in responsiveness to the lipolytic action of noradrenaline and an increase in both sensitivity and responsiveness to the inhibitory effect of insulin on noradrenaline-stimulated lipolysis. Adipocytes from HP-fed and control rats had mean diameters of 51 and 60 mu, respectively, and estimated average volumes of 90 and 142 pL. On the basis of existing data on the correlation between size and lipolytic activity of fat cells, the smaller size of the adipocytes from HP-fed rats might account for the lower rate of basal lipolysis but not for the increased response to the hormones. The increased sensitivity of fat cells to the antilipolytic action of insulin may have been an important factor in the reduced lipomobilization during fasting in rats under the high-protein regimen.

Dietary sodium restriction exacerbates age-related changes in rat adipose tissue and liver lipogenesis.

To investigate the effects of prolonged dietary sodium restriction on lipid metabolism, male rats weighing 35 to 40 g (just weaned) were fed either a low-salt (LSD) or a normal salt diet (NSD) and used in metabolic experiments after 1, 2, or 3 months of diet consumption. After 2 and 3 months on the diet, LSD rats showed increased amounts of lipid in carcass and retroperitoneal tissue. In both LSD and NSD, extending the feeding period from 2 to 3 months resulted in a marked reduction in the in vivo rates of adipose tissue fatty acid synthesis that was accompanied by increases in liver lipogenesis and in the activity of adipose tissue lipoprotein lipase (LPL). However, these increases were more marked in LSD rats. Thus, in vivo rates of liver fatty synthesis and LPL activity in LSD rats, which were already higher (by about 35% and 20%, respectively) than in controls after 2 months, attained levels 50% higher than those in NSD animals after another month on the diet. Brown adipose tissue (BAT) thermogenic capacity, estimated after 2 and 3 months by the tissue temperature response to norepinephrine (NE) injection and by guanosine diphosphate (GDP) binding to BAT mitochondria, did not change in controls, but was significantly reduced in LSD rats. This raises the possibility that a decrease in overall energy expenditure, together with an LPL-induced increased uptake of preformed fatty acids from the circulation, may account for the excessive lipid accumulation in LSD rats. Taken together, the data indicate that prolonged dietary sodium restriction exacerbates normal, age-related changes in white and BAT metabolism.

Relative importance of sympathetic outflow and insulin in the reactivation of brown adipose tissue lipogenesis in rats adapted to a high-protein diet.

The effect of denervation or acute insulin deficiency on brown adipose tissue lipogenesis was investigated in rats adapted to a high-protein diet before and after diet reversion to a balanced diet. Denervation of rats fed the balanced diet induced a 50% reduction in in vivo rates of brown adipose tissue fatty acid synthesis, with decreased activities of acetyl-CoA carboxylase and adenosine triphosphate (ATP)-citrate lyase. The markedly (80%) reduced fatty acid synthesis and enzyme activities in brown adipose tissue from rats adapted to the high-protein diet were not affected by denervation. Replacement of the high-protein diet by the balanced diet for 24 hours restored fatty acid synthesis to normal levels, but recovery of enzyme activities was only partial. Lipogenesis restoration and partial recovery of enzyme activities were impaired in denervated tissue from high-protein diet-fed rats. In all experimental conditions, the activities of acetyl-CoA carboxylase and ATP-citrate lyase showed a better correlation with brown adipose tissue lipogenesis than the generators of H(+), glucose-6-P dehydrogenase, and malic enzyme. Anti-insulin serum administration during the 12- to 24-hour period after diet reversion completely blocked lipogenesis recovery in innervated and denervated tissues and drastically reduced brown adipose tissue lipogenesis of concomitantly injected rats fed the balanced diet. The data suggest that efficient and rapid adjustments of brown adipose tissue lipogenesis require sympathetic activation, and that this tissue can maintain significant, albeit reduced, rates of lipogenesis in the absence of sympathetic activation, but not in the absence of insulin.

Glucose uptake and glycolytic flux in adipose tissue from rats adapted to a high-protein, carbohydrate-free diet.

Rates of glucose uptake by epididymal and retroperitoneal adipose tissue in vivo, as well as rates of hexose uptake and glycolytic flux in isolated adipocytes, were determined in rats adapted to a high-protein, carbohydrate-free (HP) diet and in control rats fed a balanced (N) diet. Adaptation to the HP diet induced a significant reduction in rates of glucose uptake, estimated with 2-deoxy-[1-(3)H]-glucose, both by adipose tissue (epididymal and retroperitoneal) in vivo and by isolated adipocytes. Twelve hours after replacement of the HP diet with the balanced diet, rates of adipose tissue uptake in vivo in HP-adapted rats returned to levels that did not differ significantly from those in N-fed rats. The rate of flux in the glycolytic pathway, estimated with (3)H[5]-glucose, was also significantly reduced in adipocytes from HP-fed rats. In agreement with the above findings, the activities of hexokinase (HK), phosphofructo-1-kinase (PFK-1), and pyruvate kinase (PK) were markedly reduced in adipose tissue from HP-adapted rats. The activity of pyruvate kinase was partially reverted by diet replacement for 12 hours. The low-plasma insulin and high-glucagon levels in HP-fed rats may have played an important role in the reduction of adipose tissue glucose utilization in these animals.

Effect of cold acclimation on brown adipose tissue fatty acid synthesis in rats adapted to a high-protein, carbohydrate-free diet.

The effect of cold acclimation on brown adipose tissue (BAT) fatty acid synthesis was investigated in rats adapted to a high-protein, carbohydrate-free diet. At an ambient temperature (25 degrees C), rates of fatty acid synthesis in BAT from rats adapted to the high-protein diet were reduced to 27% of rats fed the balanced diet and increased markedly after cold acclimation (10 days at 4 degrees C), although the increase was smaller than in control rats. BAT weight increase induced by cold acclimation was smaller in rats fed the high-protein diet (30%) than in controls (100%). When expressed per whole tissue, maximal activities of BAT glucose-6-phosphate dehydrogenase, malic enzyme, adenosine triphosphate (ATP)-citrate lyase, and acetyl-coenzyme A carboxylase were markedly reduced in high-protein diet-adapted rats at 25 degrees C and increased after cold acclimation in BAT from the 2 groups. However, when expressed per milligram protein, only acetyl-coenzyme A carboxylase showed an increase in both controls and in rats fed the high-protein diet. G6P-dehydrogenase, malic enzyme, and ATP-citrate lyase increased (per milligram protein) only in rats adapted to the high-protein diet and actually decreased in BAT from cold-acclimated control rats. Initial (before activation) pyruvate dehydrogenase (PDH) complex activity was lower in BAT from rats fed the high-protein diet at 25 degrees C and increased in cold-acclimated rats from the 2 groups. Circulating levels of insulin decreased in the 2 groups after cold acclimation. The data suggest that the cold acclimation-induced increase in BAT lipogenesis in rats adapted to the high-protein diet was due to a restoration of sympathetic activity, which induced both BAT hyperplasia and activation of adipocyte free fatty acid (FFA) synthesis, with an important participation of acetyl-coenzyme A carboxylase and pyruvate dehydrogenase.

Glucose contribution to in vivo synthesis of glyceride-glycerol and fatty acids in rats adapted to a high-protein, carbohydrate-free diet.

Triacylglycerol (TAG) synthesis from all carbon sources and from glucose carbon was evaluated in rats fed a high-protein, carbohydrate-free (HP) diet or control diet by determining simultaneously in the same animal the rate of incorporation of 3H2O and of 14C-glucose into the two TAG moieties in the carcass, liver, and retroperitoneal and epididymal adipose tissue. Incorporation rates of 3H2O into TAG-fatty acids (FAs) in the two adipose tissues and in liver were reduced in HP rats to about 20% and 50%, respectively, of the rates in control rats. In the two experimental groups, glucose was a poor precursor for FA synthesis, contributing only 22.8% of whole-body (carcass plus liver) total FA synthesis in control rats and even less (14%) in HP rats. In contrast to the reduction in FA synthesis, incorporation of 3H2O into TAG-glycerol in HP rats did not differ significantly or was even higher (in epididymal tissue) versus the control level. In all tissues of both HP and control rats, the rate of 14C-glucose incorporation into TAG-glycerol was much higher than the rate of incorporation into FA. Glyceroneogenesis, estimated by subtracting TAG-glycerol synthesis from glucose from the rate obtained with 3H2O, was significantly increased in adipose tissue from HP rats, with almost all of the glycerol formed by this route being used to esterify preformed FAs. It is suggested that the increased adipose tissue glyceroneogenesis is important for esterification of diet-derived FA and preservation of body fat stores in rats adapted to the HP diet.

Glucose uptake, glucose transporter GLUT4, and glycolytic enzymes in brown adipose tissue from rats adapted to a high-protein diet.

In vivo rates of glucose uptake, insulin-responsive glucose transporter (GLUT4) content, and activities of glycolytic enzymes were determined in brown adipose tissue (BAT) from rats adapted to a high-protein, carbohydrate-free (HP) diet. Adaptation to the HP diet resulted in marked decreases in BAT glucose uptake and in GLUT4 content. Replacement of the HP diet by a balanced control diet for 24 hours restored BAT glucose uptake to levels above those in rats fed the control diet, with no changes in GLUT4 levels in 4 of 5 animals examined. BAT denervation of rats fed the control diet induced a 50% reduction in glucose uptake, but did not significantly affect the already markedly reduced BAT hexose uptake in HP diet-fed rats. It is suggested that the pronounced decrease in BAT glucose uptake in these animals is due to the combined effects of the HP diet-induced reductions in plasma insulin levels and in BAT sympathetic activity. Adaptation to the HP diet was accompanied by decreased activities of hexokinase, phosphofructo-1-kinase, and pyruvate kinase (PK). The activity of BAT PK in HP diet-fed rats was reduced to about 50% of controls, and approached normal levels 24 hours after diet reversion. BAT denervation induced a small (15%) decrease in BAT PK activity in control rats, but did not affect the activity of the enzyme in HP diet-adapted rats. Also, denervation did not interfere with the restoration of PK activity induced by diet substitution. Treatment with anti-insulin serum resulted in an almost 50% reduction in PK activity in both innervated and denervated BAT from rats fed the control diet, but caused a much smaller ( thick approximate 20%) decrease in BAT from HP diet-fed rats. Furthermore, anti-insulin serum administration completely suppressed the restoration of BAT PK activity induced by diet reversion. These data suggest that, differently from glucose uptake, BAT PK activity is predominantly controlled by hormonal/metabolic factors.

Gluconeogenesis activation after intravenous angiotensin II in freely moving rats.

Intravenous (IV) administration of angiotensin II (0.95 nmol/100 g body weight) produced a marked increase in plasma glucose of 20 h fasted rats. To investigate the possibility of a stimulation of gluconeogenesis, conscious unrestrained rats were continuously infused with [14C]bicarbonate, 60 microl/min (0.18 microCi/min), and label incorporation into circulating glucose was determined before and after angiotensin injection. The rate of 14C incorporation into blood glucose of fed rats increased significantly after angiotensin II administration, a 279% increase after 20 min (P < 0.01). In conclusion, the results of the present study show that the hyperglycemia induced by intravenous (IV) administration of angiotensin II is accompanied by an activation of gluconeogenesis, as evidenced by a rapid and marked increase in the rate of 14CO2 incorporation into circulating glucose.

Intra-ventromedial hypothalamic injection of cholinergic agents induces rapid hyperglycemia, hyperlactatemia and gluconeogenesis activation in fed, conscious rats.

Microinjections of carbachol (50 nmol) or neostigmine (25 nmol) in 0.5 ml saline into the ventromedial nucleus of the hypothalamus (VMH) (but not into the lateral hypothalamic area) of fed, conscious rats produced marked increases in plasma glucose and lactate, which were suppressed or markedly reduced by previous adrenodemedullation. The rate of incorporation of 14C from infused bicarbonate (0.60 microliter, 0.20 microCi/min), an index of gluconeogenic activity, increased significantly after VMH administration of neostigmine. The data suggest that cholinergic synapses in the VMH participate of a central glucoregulatory system that increases hepatic glucose production mainly through a stimulation of adrenal medulla epinephrine secretion.