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PubMed1984

Effects of adrenalectomy on energy balance, diet-induced thermogenesis and brown adipose tissue in adult cafeteria-fed rats.

Feeding adult male rats a palatable cafeteria diet stimulated energy intake and expenditure but also raised body weight and energy gains. Bilateral adrenalectomy (ADX) had little effect on stock-fed animals, but prevented the development of obesity in cafeteria-fed rats by depressing food intake and energetic efficiency. Adrenalectomy also markedly increased the thermogenic activity of brown adipose tissue, and depressed insulin levels, particularly in the cafeteria group.

Adipose Tissue, Brown↗
PubMed1981

Adrenalectomy decreases amino-acid transport in hepatocytes.

The effect of adrenalectomy on basal and hormone-stimulated amino-acid transport in liver was investigated by measuring the uptake of alpha-aminoisobutyric acid in freshly isolated rat hepatocytes. Adrenalectomy resulted in a 50% decrease in the transport capacity of hepatocytes; this change was accounted for by a diminution in the Vmax of a low affinity component of transport and specifically affected the A-transport system. Cortisone therapy fully restored the capacity of hepatocytes to transport amino acids. Sensitivity and responsiveness of hepatocytes from adrenalectomized animals to insulin, glucagon and dexamethasone, tested for the capacity of these hormones to stimulate AIB transport in vitro, were essentially identical with that of hepatocytes from control rats. The results support the concept of a positive (stimulatory) role of glucocorticoids in vivo, in the regulation of amino acid transport in the liver.

Adrenalectomy↗
PubMed1987

Modulation of beta-adrenergic receptors in the pituitary gland following adrenalectomy in rats.

The effects of adrenalectomy on beta-adrenergic receptors in the rat pituitary were examined using quantitative in vitro autoradiography with 125I-iodocyanopindolol (125ICYP). 125ICYP binding in the anterior, intermediate and posterior lobes of the pituitary gland was significantly increased in chronically adrenalectomized rats. The increase in 125ICYP binding sites in the rat pituitary following adrenalectomy was not reversed by glucocorticoid replacement with dexamethasone. These data indicate that catecholamines of adrenomedullary origin are capable of modulating beta-adrenergic receptors in the pituitary gland and suggest that peripheral epinephrine may be important in regulating pituitary hormone secretion.

Adrenalectomy↗
PubMed1994

Adrenalectomy decreases vasoactive intestinal peptide mRNA levels in the rat suprachiasmatic nucleus.

Vasoactive intestinal peptide (VIP) concentrations were shown to be regulated by adrenal steroids. Therefore, we investigated whether adrenal steroids affect VIP mRNA levels, which would suggest an effect on VIP mRNA expression. Adrenalectomy performed on adult male rats resulted in a significant decrease in VIP mRNA in the hypothalamus (from 10.6 +/- 0.3 to 3.5 +/- 0.2 arbitrary units). In situ hybridization experiments revealed that a major site of VIP mRNA expression in the hypothalamus is the suprachiasmatic nucleus. Indeed, adrenalectomy resulted in an approximate decrease by half in VIP transcripts in this nucleus. However, this decrease was not reversed by replacement treatment with corticosterone or the glucocorticoid agonist, RU28362. Thus, VIP mRNA may be regulated by indirect mechanisms, influenced by the adrenal gland.

Adrenalectomy↗
PubMed1982

Adrenalectomy increases sprouting in a peptidergic neurosecretory system.

The neurons of the paraventricular nucleus of the hypothalamus have a substantial vasopressin-containing projection to the zona externa of the median eminence. Several parameters of neuronal function are increased in these cells following adrenalectomy; these increases can be prevented by glucocorticoid treatment. We have now used this system to study the effect of adrenal removal on the sprouting of axons in response to a unilateral lesion of the paraventricular nucleus. Results obtained from both immunocytochemical and anterograde tracing experiments indicate that the capacity of the paraventricular nucleus axons to sprout is enhanced in adrenalectomized animals. Anterograde tracing experiments indicate that the projection from the paraventricular nucleus to the zona externa is predominately ipsilateral confirming the findings of Alonso & Assenmacher and that sprouting does not occur in intact animals with a unilateral paraventricular nucleus lesion. However, the zona externa of adrenalectomized animals with a unilateral paraventricular nucleus lesion is filled bilaterally with neurophysin terminals: the volume occupied by such fibers is the same as in non-lesioned, adrenalectomized animals. These findings are interpreted to indicate that sprouting can occur in this system if the animal is adrenalectomized. To estimate the time course of sprouting, animals were first adrenalectomized for 2 weeks and then a unilateral lesion placed in the paraventricular nucleus. Animals were killed 1-26 days following lesion placement and the brains processed for immunocytochemistry. Initial denervation in the zona externa due to the lesion can be detected by day 6 post-lesions while reinnervation (sprouting) is seen by day 26. The results suggest that the increase in metabolic activity induced by adrenalectomy in the vasopressin neurons under study may influence the ability of the axons of these cells to produce new terminals.

Adrenal Glands↗
PubMed1993

Adrenalectomy attenuates kainic acid-elicited increases of messenger RNAs for neurotrophins and their receptors in the rat brain.

Treatment with excitotoxin kainic acid is known to increase the level of messenger RNAs for nerve growth factor and brain-derived neurotrophic factor in the brain. In this study we have used quantitative in situ hybridization to analyse the effect of glucocorticoids on kainic acid-induced increase of nerve growth factor and brain-derived neurotrophic factor messenger RNA in the rat brain. In adrenalectomized animals, the kainic acid-mediated increase of brain-derived neurotrophic factor messenger RNA in the hippocampus and the cerebral cortex was reduced by 50% compared to sham-operated animals. The increase of nerve growth factor messenger RNA elicited by kainic acid in the dentate gyrus was almost completely abolished in adrenalectomized animals. No significant change was seen in c-fos messenger RNA in the hippocampus of adrenalectomized rat after kainic acid injection compared to sham-operated kainic acid-treated rats, while a three-fold reduction was seen in the cerebral cortex. Dexamethasone injection prior to kainic acid administration potentiated the kainic acid-induced increase of nerve growth factor messenger RNA in the dentate gyrus and the piriform cortex. In contrast, dexamethasone pretreatment did not potentiate the kainic acid-mediated increase of brain-derived neurotrophic factor messenger RNA. We also examined the effect of adrenalectomy and kainic acid injection on tropomyosin receptor kinase B and C messenger RNA, encoding essential components of high-affinity receptor for brain-derived neurotrophic factor/neurotrophin-4 and neurotrophin-3, respectively. Following adrenalectomy no change of tropomyosin receptor kinase B or C messenger RNA was detected in any of the brain regions studied compared to sham-operated animals. The injection of kainic acid caused four-fold and two-fold increases of tropomyosin receptor kinase B messenger RNA in the dentate gyrus and cerebral cortex, respectively, but no change in tropomyosin receptor kinase C messenger RNA in any of these regions. In adrenalectomized animals receiving kainic acid, the level of tropomyosin receptor kinase B messenger RNA was decreased both in the dentate gyrus and cerebral cortex as compared to sham animals treated with kainic acid. Taken together, the data suggest that excitotoxins and glucocorticoids both influence expression of brain-derived neurotrophic factor and nerve growth factor messenger RNA in the brain, but by two different mechanisms, where the effect of excitotoxin-evoked seizures is modulated by glucocorticoids.

Adrenalectomy↗
PubMed1995

Adrenalectomy alters the response of neurons in the bed nucleus of the stria terminalis to electrical stimulation of the medial amygdala.

This study was performed to characterize the effects of adrenalectomy (ADX) on electrical activity and synaptic responses of bed nucleus of the stria terminalis (BNST) and preoptic area (POA) neurons, which are involved in the control of limbic-hypothalamo-pituitary-adrenocortical (LHPA) activity. Adrenalectomy altered the response of BNST neurons to medial amygdala (AME) stimulation, increasing the proportion of excitatory responses and reducing the number of cells inhibited. No such effects were found for neurons within the POA. The basal activity of neurons recorded within the BNST and POA, as well as the latencies and duration of responses, was not affected. The specificity of the effects upon BNST, but not POA, neurons suggests that the response of BNST neurons to AME stimulation is corticosteroid dependent, whereas the response of preoptic neurons is not.

Adrenalectomy↗
PubMed1991

Modulation of carbon tetrachloride hepatotoxicity and xenobiotic-metabolizing enzymes by corticosterone pretreatment, adrenalectomy and sham surgery.

These investigations sought to determine the role of physiological concentrations of natural glucocorticoids in modulating chemical toxicity, and to ascertain if effects on toxicity may be due to alterations of chemical metabolizing enzymes by glucocorticoids. The hepatotoxic response to carbon tetrachloride (CCl4) in adrenalectomized or naive Long Evans rats treated with corticosterone was assessed. Alterations of hepatic cytochrome P-450 concentration, mono-oxygenase activities, NADPH-cytochrome (P-450)c reductase activity, and glutathione S-transferase activity were examined. Adrenalectomy and to a lesser extent sham surgery were protective, but corticosterone administration increased CCl4 hepatotoxicity. Corticosterone administration to adrenalectomized or sham-operated rats reduced the protective effect of these treatments. Correlating with the in vivo response, mono-oxygenase activities decreased after adrenalectomy and sham surgery, but increased with glucocorticoid administration. These studies suggest that basal, stress-associated, and pharmacological concentrations of a natural glucocorticoid can modify chemical toxicity and alter hepatic enzymes important to chemical metabolism.

Adrenalectomy↗
PubMed1995

Combined effects of adrenalectomy and noise exposure on compound action potentials, endocochlear potentials and endolymphatic potassium concentrations.

The effects of removal of endogenous corticosteroids via bilateral adrenalectomy in combination with noise exposure (30 min at 100 dB) were determined by recording compound action potential (CAP) and endocochlear potentials (EP), and by measuring potassium concentrations (K+e) within the endolymph. Thirty-eight Long-Evans rats were divided into groups according to experimental treatments: adrenalectomy (ADX) or non-ADX and noise exposure or non-noise exposure. CAP thresholds, EP and K+e values were subjected to repeated-measures analysis of variance with group and time as factors classifying the measurements. Noise exposure resulted in significant elevations of CAP thresholds in both the ADX and non-ADX animals, but had no effect on either EP or endolymphatic K+e. Recovery was noted during all post-exposure measurement periods and was significantly faster for ADX animals. EP and K+e did not change during or after noise exposure. ADX animals showed a non-significant reduction of EP and a statistically significant increase of K+e during all measurement periods as compared to non-ADX animals.

Acoustic Stimulation↗
PubMedDate not supplied

Taste reactivity to ethanol in rats: influence of adrenalectomy or ipsapirone.

The affective mimetic responses of male Wistar rats with prior access to 6% ethanol in their home cages were observed during intraoral infusions of an equivalent alcohol solution. Ethanol preference in the home cage appeared unrelated to measures of aversion and ingestion in the taste reactivity tests in normal rats. Adrenalectomy, which significantly reduced home cage ethanol preference, failed to influence the taste reactions elicited by ethanol or water. On the other hand, treatment of intact rats with the 5-HT1A receptor agonist ipsapirone (2.5 mg/kg), a drug that also decreases ethanol drinking in two-bottle intake tests, did increase the duration of aversive groomings, whereas measures of ingestion remained unaffected. These results suggest that ipsapirone, but not adrenalectomy, may alter the palatability of ethanol; this perceptual change may partly underlie the ability of ipsapirone to reduce home cage alcohol drinking in the rat.

Adrenalectomy↗
PubMed1995

Bilateral adrenalectomy induces early onset of summer fur growth in mink (Mustela vison).

The purpose of this study was to determine the effects of bilateral adrenalectomy on the time at which growth of the summer pelage begins in mink. Bilateral adrenalectomy of adult female mink between 2 and 11 March 1991, supplemented with deoxycorticosterone (DOC) as a mineralocorticoid, resulted in the onset of the summer fur growth approximately 5 weeks earlier than the controls (P < 0.01). Mink with their adrenal glands intact and treated with DOC, exhibited summer fur growth 2 weeks earlier than the controls (P < 0.01). The duration of time between the first observed hair growth and attainment of maximal guard hair length, was approximately 10 days longer in mink with their adrenal glands intact and supplemented with DOC than the controls (P < 0.05). Adrenalectomized mink treated with DOC exhibited guard hair growth for approximately 13 days longer than controls (P < 0.05). Although exogenous DOC initiated hair growth, the rate of growth appeared to be reduced. These data suggest that adrenal hormones, of undetermined identity, exert a tonic inhibitory effect on the initiation of summer fur growth in mink and may be part of the mechanism through which changes in photoperiod regulate the onset of hair growth cycles.

Adrenalectomy↗
PubMed1989

Effects of adrenalectomy on CRH regulation of ACTH release: adenylate cyclase activity, cyclic AMP-dependent protein kinase activity and ACTH release.

Corticotropin releasing hormone (CRH) stimulation of ACTH release and cyclic AMP-mediated events involved in the control of ACTH release were compared in sham-operated and adrenalectomized rats. CRH-stimulated adenylate cyclase activity was decreased in pituitary homogenates from adrenalectomized animals. CRH-stimulated cyclic AMP accumulation was essentially abolished and CRH-stimulated cyclic AMP-dependent protein kinase (A-kinase) activity was decreased in freshly prepared anterior pituitary cells from adrenalectomized animals. Basal and CRH-stimulated ACTH release was elevated in these cells. Since ACTH release is increased in adrenalectomized rats despite the down regulation of CRH-linked pituitary mechanisms, we speculate that the site of action of disinhibition by corticosterone of ACTH release (or synthesis) following adrenalectomy is distal to the generation of cyclic AMP and/or that non-CRH mediated mechanisms assume a greater role in ACTH regulation following adrenalectomy.

Adenylyl Cyclases↗
PubMed1992

Adrenalectomy, corticosteroid replacement and their importance for drug-induced memory-enhancement in mice.

Adrenalectomy blocks the memory-improving effect of piracetam-like compounds in mice. If this blockade is due to the removal of endogenous corticosteroids, replacement therapy with exogenous corticosteroids should reinstate the effects on memory. The present experiments were designed to determine the appropriate replacement dose (concentration in the drinking fluid) for corticosterone and aldosterone, the main corticosteroids in mice. Based on the effects of corticosterone on thymus weight, replacement with 3 micrograms/ml corticosterone given in the drinking fluid (0.9% NaCl) for one week was found to be appropriate. The appropriate replacement dose for aldosterone was found by giving aldosterone to adrenalectomized (ADX) mice in the drinking fluid in combination with 3 micrograms/ml corticosterone. The combination of 3 micrograms/ml corticosterone + 30 ng/ml aldosterone resulted in a plasma ratio of corticosterone/aldosterone which most closely approximated the ratio seen in sham-ADX control animals. The physiologic adequacy of the corticosteroid replacement doses resulting from this study were clearly demonstrated in subsequent behavioral experiments where blockade of the memory-enhancing effects of piracetam by adrenalectomy were overcome by replacement with either 3 micrograms/ml corticosterone or 30 ng/ml aldosterone given in the drinking fluid.

Adrenalectomy↗
PubMed1996

Effects of food deprivation and adrenalectomy on CYP3A induction by RU486 in female rats.

We have studied the effects of food deprivation and adrenalectomy on the induction by RU486 of female rat liver microsomal CYP3A apoprotein, erythromycin N-demethylase and diazepam C3-hydroxylase activities. RU486 was a potent inducer of CYP3A apoprotein in intact animals and food deprivation enhanced this response. Food deprivation alone caused only weak CYP3A apoprotein induction suggesting a synergistic interaction in the regulation of protein expression. These results were reflected in the measurements of diazepam C3-hydroxylase activity. This confirms diazepam C3-hydroxylase as a useful and easily measured index of CYP3A monooxygenase content in female rat liver microsomes. Erythromycin N-demethylase did not show concordance with this pattern; this monooxygenase was much more strongly induced by food deprivation alone than by RU486 administration and, in addition, adrenalectomy abolished the induction response to food deprivation. The lack of correspondence between the apoprotein and erythromycin N-demethylase results suggests that non-CYP3A or novel, hitherto uncharacterized CYP3A isoforms may contribute to erythromycin N-demethylation in female rats. The close agreement between the results for CYP3A apoprotein and diazepam C3-hydroxylase indicates that although RU486 possesses a terminal acetylenic moeity it does not, at the dosages used here, cause mechanism-based inactivation of the CYP3A monooxygenase protein it induces. Current studies are directed to characterizing the particular CYP3A isoform(s) whose production is stimulated by RU486.

Adrenalectomy↗
PubMed2004

[Laparoscopic adrenalectomy for large tumors].

AIM OF THE STUDY: To analyze indications and results of laparoscopic adrenalectomy for large tumors (> 6 cm). METHODS: It is a retrospective study including patients between January 1994 and December 2003 operated on for large adrenal lesions > or =6 cm. The size was given by the pathologist. All the patients had a flank transperitoneal approach. Analysed Parameters were: operative difficulties; operative time; conversion rate; postoperative morbidity, follow-up and histologic data. RESULTS: Fourteen patients (10 female and 4 male) were included. Mean age at the time of the diagnosis was 52 years (range: 17-79). Mean size of the lesions was 7 cm (range: 6-10 cm). Mean operative time was 132 mn (range: 120-240 mn). None of the patients experienced surgical complications. Two conversions were needed (for vena cava attachments in one case and because of a retrocava localization in the other case). Three patients had morbidity: one intraperitoneal hemorrhage occurring at the second postoperative day and needing laparotomy; one left pneumopathy; and one case of neuralgia due to a port insertion. Mean hospital stay was 4,5 days. Histologic data showed: five ganglioneuromas, three pheochromocytomas, three adenomas, two adrenocortical carcinomas, and one postpancreatitis cytosteatonecrosis. CONCLUSION: Laparoscopic adrenalectomy is feasible for large lesions > or =6 cm when no evidence of malignity is demonstrated neither by the preoperative imaging study nor by the surgical exploration.

Adolescent↗
PubMed2004

The effects of adrenalectomy in blood flow adjustments produced by sciatic nerve stimulation in rats.

Sciatic nerve stimulation (SNS) produces hypertension, tachycardia, vasodilatation in the stimulated limb and vasoconstriction in the limb contralateral to the stimulation site. These autonomic adjustments represent an equivalent of the cardiovascular responses described as features of defense-alerting reactions. However, while the muscle vasodilatation observed in rats during stimulation of hypothalamic sites involved in defense reactions has been referred to as a general, non-selective increase in blood flow, previous studies conducted on cats have demonstrated that high-intensity cutaneus stimulation produces vasodilatation in the stimulated limb and vasoconstriction in the other limbs. In anesthetized rats, the effects of SNS in the muscle vascular territory of the contralateral limb, as well as the participation of circulating catecholamines in these adjustments continued to be unknown. Therefore, in the present study we investigated the blood flow adjustments elicited by SNS in the stimulated and in the contralateral hind limbs before and after bilateral adrenalectomy. In urethane-anesthetized, paralyzed, and artificially ventilated rats, SNS (800-1000 microA, 1 ms, 100 Hz, 10 s) produced hypertension, tachycardia, vasodilatation in the stimulated hindlimb and vasoconstriction in the contralateral hindlimb. After bilateral adrenalectomy the pressor responses to SNS were abolished, the vasodilatation in the stimulated limb was greater and the vasoconstriction in the contralateral limb was replaced by vasodilatation. These results suggest that the vasodilatation in the stimulated limb does not depend on circulating catecholamines.

Adrenalectomy↗
PubMed2006

Laparoscopic adrenalectomy.

Laparoscopic adrenalectomy (LA) was first described in the literature in 1992, and has become the preferred method for the removal of benign functioning and non-functioning tumors of the adrenal gland <12 cm. The objectives of the present study are to review the experience of LA gained since it was first done in 1992 and to critically evaluate its effectiveness for the surgical management of endocrine hypertension; specifically pheochromocytoma, aldosteronoma and Cushing's syndrome and disease, as opposed to open adrenalectomy. The benefits of minimally invasive techniques for the removal of the adrenal gland include decreased requirements for analgesics, improved patient satisfaction, shorter hospital stay and recovery time when compared to open surgery. LA can be performed safely for bilateral disease and may become the standard of care for malignant tumors. Current limitations are operator-dependent and not a factor of limitations of minimally invasive techniques. A thorough pre-operative work-up is key for differentiating the various cases of hypertension and adequate pre-operative treatment is paramount when indicated.

Adenoma↗
PubMed2006

Combined lung resection and transdiaphragmatic adrenalectomy in patients with non-small cell lung cancer and homolateral solitary adrenal metastasis.

Surgery may offer a long-term survival benefit to a small proportion of patients with operable non-small cell lung cancer (NSCLC) and solitary adrenal metastasis. Several approaches to lung resection with a separate open or laparoscopic adrenalectomy have been advocated. We describe a technique that allows a single incision, single operation through a transdiaphragmatic approach to the ipsilateral adrenal gland following a standard lung resection through a postero-lateral thoracotomy. By using this approach, along with the harmonic scalpel to aid adrenal dissection, both lobectomy and adrenalectomy can be carried out safely and effectively with minimal perioperative and postoperative morbidity.

Adrenal Gland Neoplasms↗