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Biomedical subjects

S Cheung

Publications and source records attributed to S Cheung.

At least 19 recordsLinked to original sources
PubMed2004

Blockade of platelet-derived growth factor receptor-beta by CDP860, a humanized, PEGylated di-Fab', leads to fluid accumulation and is associated with increased tumor vascularized volume.

PURPOSE: CDP860 is an engineered Fab' fragment-polyethylene glycol conjugate, which binds to and blocks the activity of the beta-subunit of the platelet-derived growth factor receptor (PDGFR-beta). Studies in animals have suggested that PDGFR-beta inhibition reduces tumor interstitial fluid pressure, and thus increases the uptake of concomitantly administered drugs. The purpose of this study was to determine whether changes in tumor vascular parameters could be detected in humans, and to assess whether CDP860 would be likely to increase the uptake of a concurrently administered small molecule in future studies. PATIENTS AND METHODS: Patients with advanced ovarian or colorectal cancer and good performance status received intravenous infusions of CDP860 on days 0 and 28. Patients had serial dynamic contrast-enhanced magnetic resonance imaging studies to measure changes in tumor vascular parameters. RESULTS: Three of eight patients developed significant ascites, and seven of eight showed evidence of fluid retention. In some patients, the ratio of vascular volume to total tumor volume increased significantly (P < .001) within 24 hours following CDP860 administration, an effect suggestive of recruitment of previously non-functioning vessels. CONCLUSION: These observations suggest that inhibition of PDGFR-beta might improve delivery of a concurrently administered therapy. However, in cancer patients, further exploration of the dosing regimen of CDP860 is required to dissociate adverse effects from beneficial effects. The findings challenge the view that inhibition of PDGF alone is beneficial, and confirm that effects of PDGFR kinase inhibition mediate, to some extent, the fluid retention observed in patients treated with mixed tyrosine kinase inhibitors.

Adult↗
PubMed2002

Efficacy of contained metaphyseal and periarticular defects treated with two different demineralized bone matrix allografts.

The efficacies of two different allografts, Grafton (demineralized bone matrix [DBM] in a glycerol carrier) and Orthoblast (DBM in a reverse thermal poloxamer carrier) were examined from cases involving periarticular fractures. Demographic, perioperative, and outcome data for patients with periarticular fractures who underwent a prospectively designed protocol for bone grafting were compiled, with 15 cases using Orthoblast and 13 using Grafton. A successful graft was defined as healing on the first graft attempt without complications. Healing was determined by radiographic studies and clinical evaluation. The successful graft rates of Orthoblast and Grafton were 15/15 and 9/13, respectively.

Adult↗
PubMed2001

Effect of antibiotic-loaded hydrophilic stent in the prevention of bacterial adherence: a study of the charge, discharge, and recharge concept using ciprofloxacin.

BACKGROUND: Ciprofloxacin prophylaxis significantly prolonged stent patency in cats, but human studies produced conflicting results, possibly due to varying drug levels in bile. The uptake (charge) and release (discharge) of ciprofloxacin from a hydrophilic stent (HS) in an antibiotic solution and the effect of a ciprofloxacin-loaded stent (CHS) in inhibiting Escherichia coli adherence were tested. The adjuvant effect of ciprofloxacin perfusion (recharge) in the inhibition of E coli adherence was also tested. METHODS: Uptake: segments of HS were immersed in 5 mL of ciprofloxacin solutions for 24 hours. Ciprofloxacin remaining in solution was measured to determine the uptake by the HS. Release: CHS were placed in 5 mL water for 24 hours, and released ciprofloxacin was measured. CHS were placed on culture plates with E coli and incubated; diameters of inhibited zones were measured. CHS 0.5 cm in length were incubated in separate 5 mL E coli suspension (10(7) colony forming units [CFU]/mL) in 2% ox bile for 4 hours. E coli adhered on CHS were measured and compared with control HS. An E coli (10(6) CFU/mL) suspension was perfused through a modified Robbins device (MRD)-containing CHS. Stents were removed at regular intervals and processed to determine the adherence of E coli; non-loaded HS served as controls. The experiment was repeated by using CHS together with perfusion of ciprofloxacin solution (0.3 microg/mL) into the MRD for up to 7 days; normal saline solution was used as a control in a second MRD. Stents were removed daily to determine the adherence of E coli. RESULTS: Uptake and release of ciprofloxacin by HS and CHS, respectively, were related to concentration of ciprofloxacin. Between 50% to 90% of the drug was released in 24 hours. Zonal inhibition of E coli growth was proportional to the concentration of ciprofloxacin on the CHS. There was an initial 10-fold reduction in attached E coli on CHS compared with controls, but this effect diminished after 24 hours. With ciprofloxacin perfusion, there was a 100-fold reduction in adhered E coli on CHS, although there was no change in E coli concentration in bile. CONCLUSIONS: There was a free exchange (uptake and release) of ciprofloxacin along a concentration gradient between the antibiotic solution and HS. CHS reduced the number of adhered E coli, but the effect was short-lived. Perfusion of ciprofloxacin offers an adjuvant benefit by enhancing inhibition of E coli adherence on CHS.

Anti-Bacterial Agents↗
PubMed2001

Angiotensin II promotes glucose-induced activation of cardiac protein kinase C isozymes and phosphorylation of troponin I.

Activation of the protein kinase C (PKC) family is a potential signaling mechanism by which high ambient glucose concentration modulates the phenotype and physiological function of cells. Recently, the cardiac renin angiotensin system (RAS) has been reported to promote PKC translocation in the diabetic heart via the angiotensin (ANG) II type 1 receptor (AT-1R). To evaluate the molecular events coupled with high glucose-induced PKC translocation and to examine the role of endogenously released ANG II in myocyte PKC signaling, primary cultures of adult rat ventricular myocytes were exposed to normal (5 mmol/l) or high (25 mmol/l) glucose for 12-24 h. Western blot analysis indicated that adult rat ventricular myocytes coexpress six PKC isozymes (alpha, beta(1,) beta(2,) delta, epsilon, and zeta). Translocation of five PKC isozymes (beta(1), beta(2), delta, epsilon, and zeta) was detected in response to 25 mmol/l glucose. Inhibition of phospholipase C with tricyclodecan-9-yl-xanthogenate blocked glucose-induced translocation of PKC-beta(2), -delta, and -zeta. Inhibition of tyrosine kinase with genistein blocked glucose-induced translocation of PKC-beta(1) and -delta, whereas chelation of intracellular Ca(2+) with 1,2-bis(2-aminophenoxy)ethane N,N,N,'N'-tetraacetic acid blocked translocation of PKC-beta(1) and -beta(2). Enzyme-linked immunosorbent assay performed on culture media from myocytes maintained in 25 mmol/l glucose detected a twofold increase in ANG II. Addition of an AT-1R antagonist (losartan; 100 nmol/l) to myocyte cultures blocked translocation of PKC-beta(1), -beta(2), -delta, and -epsilon. Phosphorylation of troponin (Tn) I was increased in myocytes exposed to 25 mmol/l glucose. Losartan selectively inhibited Tn I serine phosphorylation but did not affect phosphorylation at threonine residues. We concluded that 1) 25 mmol/l glucose triggers the release of ANG II by myocytes, resulting in activation of the ANG II autocrine pathway; 2) differential translocation of myocyte PKC isozymes occurs in response to 25 mmol/l glucose and ANG II; and 3) AT-1R-dependent PKC isozymes (beta(1), beta(2), delta, and epsilon) target Tn I serine residues.

Angiotensin II↗
PubMed2001

Pushing the envelope. Case studies on how fast you can and cannot return the elite athlete to running.

When treating an elite athlete, a physician always must keep in mind the status of the athlete in training, upcoming sports events, and the athlete's financial status. If the treatment requires the athlete to withdraw from regular training or sports events, a modified training program should be considered. This modified training must be balanced with returning the athlete back to full form and keeping him or her physically fit.

Adolescent↗
PubMed2000

Healing of spontaneous coronary dissection in the context of glycoprotein IIB/IIIA inhibitor therapy: a case report.

Spontaneous coronary artery dissection is a rare cause of myocardial infarction. It is a condition with greater prevalence in young women, particularly in the peripartum or early postpartum period. It also has been described following intense physical exercise. The pathophysiologic characteristics remain unclear. Unlike atherosclerotic intimal dissection, the dissection plane lies within the media or between the media and adventitia. We describe a case of spontaneous coronary artery dissection in a 44-yr old menstruating woman with mitral valve prolapse, who experienced acute myocardial infarction after twisting and throwing a heavy piece of luggage. Coronary angiography showed coronary artery dissection in a left anterior descending coronary artery at the point of its emergence from its intramural course. An intimal plaque with 90-95% obstruction and reduced (TIMI I) flow was demonstrated. The patient was treated with continued glycoprotein IIb/IIIa inhibitor infusion. Angiographic resolution with return of prompt (TIMI III) flow was noted. Optimal management of spontaneous coronary artery dissection has not been established and may vary, depending upon the presence of intimal versus extramural compromise. Coronary artery bypass, stenting, and thrombolysis have been successful and also have failed, owing to extension of dissection. Our patient is the first reported patient to have received tirofiban therapy in the context of spontaneous coronary artery dissection. Medical therapy has been used most often, and angiographic resolution has been documented at 94 days, 7 mo, and 1 yr. We document the earliest case of spontaneous angiographic resolution-within 20 hr.

Adult↗
PubMed1999

Identification of clinical risk factors for nosocomial pneumococcal bacteremia.

Clinical risks for nosocomial pneumococcal bacteremia (NPB) have been analyzed previously in case series, a study design inadequate for this purpose. Therefore, we performed a case-control study of NPB, pairing each of 37 cases identified retrospectively at the Minneapolis Veterans Affairs Medical Center from the period of 1984-1994 with four or five hospitalized controls. Comorbidities identified at the time of admission that were significantly associated with NPB on univariate and multivariate analysis included respiratory or hematologic malignancy, anemia, chronic obstructive pulmonary disease, and coronary artery disease. All characteristic symptoms and signs of pneumococcal infection were significantly more common in cases than in controls. NPB was strongly associated with death within 7 days of the index blood culture date, and the mortality rate among cases was 40.5%, compared with 1.2% among nonbacteremic controls (P < .00001). We conclude that NPB is a highly lethal infection that is associated with distinct but identifiable clinical risks, symptoms, and signs.

Aged↗
PubMed1999

Neurofibromatosis bright objects in children with neurofibromatosis type 1: a proliferative potential?

OBJECTIVES: The purpose of this study was to investigate the natural history of the high signal intensities shown on long TR sequences-neurofibromatosis type 1 bright objects (NBO)-in children with neurofibromatosis type 1 (NF1). We have paid particular attention to the development of tumors in these areas of abnormality. METHODS: During a 12-month period in 1992 to 1993, 46 children with clinically proven NF1 had a magnetic resonance (MR) examination at our institution. These were reviewed along with any previous or subsequent MR examinations that had been performed. We recorded the number, volume, and distribution of the abnormal high signal intensities and their change with time when serial examinations were performed. RESULTS: NBO were found in 93% of 46 children with NF1 on the original cross-sectional study. The most common anatomic sites were the globus pallidus (30.4%), cerebellum (23.5%), and midbrain (16.2%). The number and volume of NBO varied significantly with age. NBO were uncommon in children younger than 4 years but were very common and extensive between 4 to 10 years. A significant reduction in the number and volume of NBO was demonstrated in children older than 10 years as shown on both the cross-sectional and longitudinal portions of the study. Eight brain tumors (nonoptic pathway) were demonstrated in the 46 children (17%) with 1 child having two tumors. Only 1 child had symptoms referable to the tumor at the time of diagnosis. Five tumors developed in NBO that were documented on serial MR examinations. All those cases developed in children aged 7 to 12 years, and all these children had higher than average numbers and volumes of NBO. CONCLUSIONS: NBO occur commonly in children with NF1 and are most prevalent between the ages of 4 and 10. We have shown a high frequency of brain tumors in our children with NF1, but the majority of these were asymptomatic. We have demonstrated proliferative change NBO in 11% of 46 children. Most NBO regress with age and seem to be benign, however, young children with a large number and volume of NBO should be followed closely with regular MR examinations because of an increased risk of proliferative change. neurofibromatosis type 1, magnetic resonance, tumor, astrocytoma, childhood.

Brain↗
PubMed1998

Contribution of dopamine neurons in the medial zona incerta to the innervation of the central nucleus of the amygdala, horizontal diagonal band of Broca and hypothalamic paraventricular nucleus.

Results of previous studies suggested that incertohypothalamic dopamine (IHDA) neurons located in the medial zona incerta (MZI) project to the central nucleus of the amygdala (cAMY), horizontal diagonal band of Broca (HDB), and paraventricular nucleus (PVN). The overall goal of the present study was to determine the relative contribution of IHDA neurons to the DA innervation of these brain regions. A combined fluorescent and in situ hybridization histochemical procedure was employed to localize the retrograde tracer fluoro-gold (FG) in cells expressing tyrosine hydroxylase (TH) mRNA in the MZI following its iontophoretic injection into either the cAMY, HDB or PVN. For comparison, the numbers of dual labeled FG/TH mRNA neurons in the midbrain were also determined. One week after unilateral injection of FG into the cAMY, cells containing FG+TH mRNA were found in the ipsilateral MZI, substantia nigra zona compacta (SNC) and ventral tegmental area (VTA). The total numbers of cells labeled with FG varied with the size of the injection site, but the ratio of dual labeling in the MZI to that of the SNC-VTA remained constant across animals at approximately 1:6. FG injections into the HDB resulted in a ratio of dual labeled cells in the ipsilateral MZI and VTA of approximately 1:2, but no dual labeled cells were found in the SNC. Dual labeled cells were only found in the ipsilateral MZI in animals receiving FG injections in the PVN. Thus, DA terminals in the PVN originate exclusively from IHDA neurons in the MZI, whereas these neurons provide only a portion of the DA innervation of the cAMY and HDB. The similar distribution of dual labeled cells in the MZI following FG injections into the cAMY, HDB and PVN suggests that perikarya of IHDA neurons projecting to these regions are not organized into distinct groups.

Amygdala↗
PubMed1998

Xenotransplantation of adult porcine islets in diabetic mice. A study of UVB irradiation, cryopreservation and immunosuppression on graft survival time.

The major obstacle for successful xenotransplantation of islets to large animals and human diabetics is the host rejection. To address the rejection problem, we studied the efficacy of UV-B irradiation, cryopreservation and immunosuppression on the in vivo functional time and immunogenicity of adult porcine islets (PI) in outbred CD1 mice. Exposure of PI to UV-B irradiation between 300-1800J/M2 did not affect the cellular viability as assessed by fluorescein diacetate or their daily insulin secretion in vitro. Fresh PI normalized the blood glucose (BG) of diabetic CD1 mice for 3.1+/-0.6 (n = 8, mean+/-SEM) days. Islets treated with 600J/M2 UV-B irradiation or cryopreservation had similar graft functional times to fresh islets upon transplantation in diabetic CD1 mice. Immunosuppression with cyclosporin A (CsA), antilymphocyte serum (ALS) and FK506 prolonged the functional time of fresh pig islets to 7.9+/-0.9 (n = 9), 6.2+/-1.3 (n = 5) and 24.2+/-10.4 (n = 12) days, respectively. However, additional pretransplant treatment with either UV-B irradiation or cryopreservation did not further increase the functional time of pig islets in mice immunosuppressed with CsA. Furthermore, there was no apparent difference in the frequency of appearance of cytotoxic antibodies and antibody titers in the recipients of UV-B irradiated or cryopreserved pig islet compared with non-treated islets. The UV-B irradiation and cryopreservation of PI before transplantation with the present protocols did not appear to have significant effect on the islet immunogenicity when assessed by in vivo survival duration and anti-donor antibody titer production.

Animals↗
PubMed1998

Pharmacological evidence that neurotensin mediates prolactin-induced activation of tuberoinfundibular dopamine neurons.

The purpose of this study was to investigate the role of neurotensin (NT) receptors in mediating the stimulatory effects of prolactin on the activity of tuberoinfundibular dopamine (TIDA) neurons in male and female rats. TIDA neuronal activity was estimated by measuring concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC) in terminals of these neurons in the median eminence (ME). Haloperidol activates TIDA neurons indirectly by blocking D2 receptors on pituitary lactotropes, thereby increasing secretion of prolactin. Twelve hours after administration of haloperidol (1 mg/kg, s.c.), DOPAC concentrations in the ME were increased. Blockade of NT receptors with the selective antagonist SR-48692 had no effect per se on basal DOPAC concentrations in the ME but produced a dose-related (10-1,000 microg/kg, i.p.; 1 h) reversal of haloperidol-induced increases in ME DOPAC concentrations. In contrast, SR-48692 had no effect on either basal or haloperidol-induced increases in plasma prolactin. SR-48692 also blocked the stimulatory effects of prolactin (10 microg/rat, i.c.v.; 12 h) on ME DOPAC concentrations. SR-48692 was equally effective in blocking the stimulatory effects of haloperidol and prolactin on TIDA neurons in male and female rats. These results suggest that NT mediates the induced stimulatory effect of hyperprolactinemia on the activity of TIDA neurons in both males and females, whereas the tonic regulation of these neurons by prolactin in females occurs via an NT-independent mechanism.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1997

Dopamine receptor-mediated regulation of expression of Fos and its related antigens (FRA) in somatostatin neurons in the hypothalamic periventricular nucleus.

Somatostatin (SS)-containing perikarya located within the hypothalamic periventricular nucleus (PeVN) comprise a heterogenous population of neurons with both local intrahypothalamic and distant extrahypothalamic axonal projection sites. The close proximity of SS perikarya and their dendrites to dopaminergic (DA) neuronal processes in the PeVN suggests that these peptidergic neurons may be regulated by DA receptor-mediated mechanisms. To test this, the effects of the D1 agonist SKF 38393 and D2/3 agonist quinelorane were examined on expression of the immediate early gene products Fos and its related antigens (FRA) in SS-immunoreactive (IR) neurons in the PeVN. SS-IR neurons were located in the most medial portion of the PeVN bordered medially by the third ventricle and laterally by tyrosine hydroxylase (TH)-IR neurons. In control rats, 10-15% of all SS-IR neurons contained FRA-IR. Activation of D1 receptors with SKF 38393 had no effect on either the total number of SS-IR neurons or the number of SS-IR neurons containing FRA-IR. In contrast, activation of D2/3 receptors with quinelorane decreased the number of SS-IR neurons containing FRA-IR, without affecting the total number of SS-IR neurons. The D2/3 antagonist raclopride had no effect per se, but prevented the quinelorane-induced decrease in the number of SS neurons expressing FRA-IR. These results reveal that activation of D2/3 (but not D1) receptors inhibits expression of the immediate early gene products FRA in SS-containing neurons in the PeVN, but expression of FRA in SS neurons is not tonically inhibited by dopamine acting on D2/3 receptors.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1997

Gonadal steroid hormone regulation of proopiomelanocortin gene expression in neurons that innervate the median eminence of the rat.

The effect of gonadal steroid hormones on the expression of proopiomelanocortin (POMC) in neurons that innervate the median eminence (ME) was investigated using combined retrograde neuronal labeling and in situ hybridization histochemistry. It was observed that gonadal hormone treatment significantly increased the expression of POMC mRNA. The results suggest that POMC neurons directly innervate the ME, where POMC-derived peptides could rapidly inhibit luteinizing hormone-releasing hormone release following the preovulatory hormone surge.

Animals↗
PubMed1997

Simultaneous gas chromatographic determination of methamphetamine, amphetamine and their p-hydroxylated metabolites in plasma and urine.

We report a method for the simultaneous determination of methamphetamine, amphetamine and their hydroxylated metabolites in plasma and urine samples using a GC-NPD system. The analytical procedures are: (1) adjust the sample to pH 11.5 with bicarbonate buffer, saturate with NaCl and extract with acetate; (2) back-extract the amines in the ethyl acetate fraction with 0.1 M HCl; (3) adjust the pH of the acid fraction to 11.5 and follow by extraction in ethyl acetate; (4) reduce the volume of ethyl acetate under nitrogen and derivatize the concentrate with trifluoroacetic anhydride or heptafluorobutyric anhydride before the GC analysis. The derivatives were separated on a GC-NPD system equipped with a HP-5 column of 25 m x 0.32 m I.D. and a 0.52 micron film of 5% phenylmethylsilicone. The detection limit (taking a signal-to-noise ratio of 2) of heptafluorobutyl derivatives of methamphetamine and its metabolites in plasma and the trifluoroacetyl derivatives in urine was 1 ng/ml (22 pg on column). The limit of quantitation of the heptafluorobutyl derivatives in the plasma was 1 ng/ml (22 pg on column), and that of the trifluoroacetyl derivatives in urine was 20 ng/ml (73 pg on column). The between-day variation was from 0.9 to 17.4% and within-day variation from 0.9 to 8.3%. This method was used successfully in the quantitative determination of methamphetamine and its p-hydroxylated metabolites in the plasma and urine of human subjects.

Amphetamine↗
PubMed1997

A primate model for studying focal dystonia and repetitive strain injury: effects on the primary somatosensory cortex.

BACKGROUND AND PURPOSE: Job-related repetitive strain injuries (RSIs) are increasing, and current treatment strategies often fail to return injured people to work. This study documented the neural consequences of using two different movement strategies for active, repetitive hand closing and opening. METHODS: Two owl monkeys were trained for 20 weeks to repetitively close a handpiece against an 80-g force (3-400 trials per day, training at 80%-90% accuracy). One monkey used a highly articulated hand-squeezing strategy, and the other monkey used a proximal arm-pulling strategy. Changes in motor performance were analyzed, and the electrophysiological maps of the hand representation on the trained primary sensory cortex (area 3b) were compared with those of untrained control animals and the untrained sides of the trained monkeys. RESULTS: The monkey using the articulated hand-squeezing strategy showed motor deterioration and dedifferentiation of the normally sharply segregated areas of the hand representation in area 3b. Mild degradation of the hand representation was measured in the monkey using the proximal arm-pulling strategy, but there was no motor dysfunction. CONCLUSION AND DISCUSSION: Attended, highly articulated, repetitive finger squeezing degrades the hand representation and interferes with motor control. A proximal, more variable repetitive strategy minimized the sensory degradation and preserved motor control. Restoring the hand representation may be a critical part of treatment for patients with chronic RSI and focal hand dystonia.

Animals↗
PubMed1997

Role of gonadal steroids in determining sexual differences in expression of Fos-related antigens in tyrosine hydroxylase-immunoreactive neurons in subdivisions of the hypothalamic arcuate nucleus.

Dual immunohistochemistry was employed to examine the role of gonadal steroids in determining sexual differences in the expression of Fos and its related antigens (FRA) in tuberoinfundibular dopaminergic (TIDA) neurons located in the dorsomedial (DM-) and ventrolateral (VL-) subdivisions of the arcuate nucleus (ARC). In the DM-ARC, there was no sexual difference in the number of tyrosine hydroxylase (TH)-immunoreactive (-IR) perikarya, but the number of these containing FRA-IR was greater in females than in males in all but the most caudal region. In the VL-ARC, there were more TH-IR perikarya in males than in females, but there was no sexual difference in the numbers of those containing FRA-IR throughout the entire rostrocaudal extent of this nucleus. Ovariectomy decreased the number of TH-IR perikarya containing FRA-IR in the DM-ARC, but not in the VL-ARC, whereas orchidectomy increased the number of TH-IR perikayra containing FRA-IR in both the DM-ARC and VL-ARC. These gonadectomy-induced effects were reversed by estrogen and testosterone, respectively. These results reveal gonadal steroid-dependent sexual differences in the regulation of immediate early gene expression in anatomically discrete subpopulations of TIDA neurons. In females, estrogen stimulates FRA expression in TIDA neurons in the DM-ARC, whereas in males, testosterone inhibits FRA expression in TIDA neurons in both the DM-ARC and the VL-ARC.

Animals↗
PubMed1996

Dopamine receptor-mediated regulation of corticotropin-releasing hormone neurons in the hypothalamic paraventricular nucleus.

The present study examined the effects of intraperitoneal administration of selective D1 (SKF 38393) and D2 (quinelorane) dopaminergic receptor agonists on Fos-like immunoreactivity (Fos-LI) and levels of corticotropin-releasing hormone (CRH) mRNA in the paraventricular nucleus of the hypothalamus (PVN) and in the central nucleus of the amygdala (cAMY). Ninety minutes after administration of the D1 agonist SKF 38393, Fos-LI was increased in both the PVN and cAMY. Administration of SCH 39166, a selective D1 antagonist, blocked and attenuated the SKF 38393-induced increase in Fos-LI in the PVN and cAMY, respectively. Similarly, 90 minutes after intraperitoneal injection of the D2 agonist quinelorane, Fos-LI was increased in both PVN and cAMY. Administration of the selective D2 antagonist raclopride prevented the ability of quinelorane to increase Fos-LI in the PVN and cAMY. Both SKF 38393 and quinelorane stimulated the expression of CRH and mRNA in the PVN, but failed to alter its expression in the cAMY. Taken together, these results indicate that stimulation of either D1 and D2 dopaminergic receptors activates CRH neurons in the PVN. Stimulation of either D1 or D2 receptors activates neurons in the cAMY, but these changes do not appear to be occurring in CRH neurons.

Amygdala↗