P1-15-01: Oral Fluoropyrimidine (UFT and S-1) May Augment the Efficacy of Aromatase Inhibitor Via the Down-Regulation of Estrogen Receptor in Estrogen-Responsive Breast Cancer Xenografts

Breast cancer patients has tended to be more personalized by biomarkers, such as estrogen receptor (ER), HER-2 and other risk factors. Adjuvant endocrine therapy is recommended for all ER-positive breast cancer patients, and the addition of adjuvant chemotherapy to endocrine therapy has been shown to further improve the prognosis of ER-positive breast cancer patients. Addition of an oral fluoropyrimidine, UFT was shown to improve the outcome of patients with luminal A cancer. Based on these studies, the present preclinical study was designed to evaluate a new combination therapy comprised of the aromatase inhibitor anastrozole (ANA) and the oral fluoropyrimidines, UFT and S-1 against luminal A human breast cancer cell line MCF-7/Arom 14, which was stably transfected with the cDNA of human aromatase. MCF-7/Arom 14 cells showed a high aromatase activity (111.6±69.6 fmole/mg protrin/hr) in vivo. Testosterone failed to induce cell growth of parent MCF-7. But, MCF-7/Arom 14 cells were potentiated by both testosterone and E2 in vitro, and ANA and 5-fluorouracil (5-FU) inhibited cell growth at concentrations of 0.005 to 10 and 0.2 to 5 μM, respectively. The combination of 5-FU and ANA additively inhibited cell growth. MCF-7/Arom 14 was implantable in vivo, but it failed to grow in he absence of E2 or testosterone releasing pellet (Tes-P). The growth of MCF-7/Arom 14 was significantly inhibited by ANA and S-1 or UFT alone vs Control (Tes-P alone) in vivo. The combination of ANA with S-1 or UFT administered using a 21-day consecutive, metronomic-like regimen. On day 22, relative tumor volume (RTV) treated by ANA and UFT or ANA and S-1 was significantly lower than either mono-therapy by Welch's t-test. Based on RTV change the period required for the RTV to reach 3 was estimated, and its differences between control was designated as growth delay period (GDP). GDP of combination-therapy was 2 to 4 times longer than either mono-therapy.

Expression and activity of Kdp under acidic conditions in Escherichia coli

Escherichia coli has three major K(+) uptake systems, Trk, Kup, and Kdp, which have been studied extensively at near neutral pH. However, the function of these transporters under acidic conditions is not well understood, although growth and survival under acidic conditions are important for bacterial pathogenesis. In this study, we examined the expression and activity of Kdp under acidic conditions and found that the transport activity of Kdp is decreased at low pH and that the expression of kdp is regulated by the internal K(+) concentration in a pH-independent manner. Consequently, the low activity of Kdp was compensated for by the induction of its elevated expression by low K(+) accumulation via Kdp at acidic pH.

Prevalence and impact of rhinitis in asthma. SACRA, a cross-sectional nation-wide study in Japan

BACKGROUND

Asthma and rhinitis are common co-morbidities everywhere in the world but nation-wide studies assessing rhinitis in asthmatics using questionnaires based on guidelines are not available.

OBJECTIVE

To assess the prevalence, classification, and severity of rhinitis using the Allergic Rhinitis and its Impact on Asthma (ARIA) criteria in Japanese patients with diagnosed and treated asthma.

METHODS

The study was performed from March to August 2009. Patients in physicians' waiting rooms, or physicians themselves, filled out questionnaires on rhinitis and asthma based on ARIA and Global Initiative for Asthma (GINA) diagnostic guides. The patients answered questions on the severity of the diseases and a Visual Analog Scale. Their physicians made the diagnosis of rhinitis.

RESULTS

In this study, 1910 physicians enrolled 29,518 asthmatics; 15,051 (51.0%) questionnaires were administered by physician, and 26,680 (90.4%) patients were evaluable. Self- and physician-administered questionnaires gave similar results. Rhinitis was diagnosed in 68.5% of patients with self-administered questionnaires and 66.2% with physician-administered questionnaires. In this study, 994 (7.6%) patients with self-administered and 561 (5.2%) patients with physician-administered questionnaires indicated rhinitis symptoms on the questionnaires without a physician's diagnosis of rhinitis. Most patients with the physician's diagnosis of rhinitis had moderate/severe rhinitis. Asthma control was significantly impaired in patients with a physician's diagnosis of rhinitis for all GINA clinical criteria except exacerbations. There were significantly more patients with uncontrolled asthma as defined by GINA in those with a physician's diagnosis of rhinitis (25.4% and 29.7%) by comparison with those without rhinitis (18.0% and 22.8%).

CONCLUSION

Rhinitis is common in asthma and impairs asthma control.

Study of PAH dissipation and phytoremediation in soils: comparing freshly spiked with weathered soil from a former coking works

A comparison was made between the dissipation of polycyclic aromatic hydrocarbons (PAHs) in soil freshly spiked with pure PAHs, soil spiked with a coal tar mixture and a contaminated soil from a former coking works where the PAHs had been present for more than a century. The potential of five selected plant species for phytoremediation was investigated. The levels of all 7 PAHs in chemically amended soil, both planted and unplanted, fell significantly (>80% reduction) over the 12 weeks of the growing trial. In the coal tar treated soils all PAHs were significantly reduced. In both the planted and unplanted soils the 2-3 ringed compounds demonstrated much greater loss (>77%) than the 4-6 ringed (16-39%). The 3-4 ringed compounds demonstrated strong evidence of phytoremediation but not the 5-6 ringed. The coking soil showed limited reduction (7-24%) of all 12 PAHs present. There was little difference in dissipation between the PAHs and little evidence of a phytoremediation effect in coking soil. The results demonstrated that the form in which PAHs were added to soil influenced their susceptibility to dissipation. Therefore, predictions of PAH dissipation from laboratory amended soil do not reflect the true situation in the field.

A randomized-controlled trial to investigate the effects of rivoglitazone, a novel PPAR gamma agonist on glucose-lipid control in type 2 diabetes

AIM

To examine the efficacy, safety and tolerability of rivoglitazone, a novel thiazolidinedione (TZD), and explore its effects on glucose and lipid control compared to placebo and pioglitazone in Chinese type 2 diabetic patients who are treatment naÏve or treated with a single oral blood glucose-lowering drug.

METHODS

This was a double-blind, randomized, placebo- and active-controlled study. A total of 287 Chinese type 2 diabetic patients with suboptimal glycaemic control (defined as HbA1c ≥6.5 to <10% and fasting plasma glucose ≥7 to ≤15 mmol/l) were enrolled. One hundred and seventy-four eligible patients were randomized into one of the five treatment arms for 12 weeks: placebo, pioglitazone 30 mg daily, rivoglitazone of dose 0.5, 1.0 or 1.5 mg daily. In a full set analysis, we used analysis of covariance to compare the primary endpoint defined as change in HbA1c from baseline to week 12/last observation carried forward in the rivoglitazone group at each dose level with the placebo group.

RESULTS

Changes in HbA1c were -0.11% in the 0.5-mg group; -0.22% in the 1-mg group and -0.17% in the 1.5-mg rivoglitazone group; -0.06% in the 30-mg pioglitazone group and 0.61% in the placebo group. Compared to placebo, changes were significant in all active treatment groups (all p < 0.05). Increase in high-density lipoprotein cholesterol and decrease in triglyceride were observed in the rivoglitazone 1 and 1.5 mg groups, respectively, compared to placebo from baseline to week 12 (p < 0.05). Drug-related oedema was reported in eight patients (7.7%) in all rivoglitazone groups compared to six patients (16.2%) in the pioglitazone group and one patient (3.0%) in the placebo group.

CONCLUSIONS

Rivoglitazone is an efficacious, safe and well-tolerated TZD which improved glycaemic control in Chinese type 2 diabetic patients up to 3 months.

Historical perspective and future direction of coagulation research

Over the past 100 years, remarkable advances have been made in our understanding of the mechanisms of blood coagulation. Starting with the early clinical observations of rare patients with hereditary clotting disorders, our knowledge has increased in keeping pace with the introduction of new technologies: from simple laboratory tests to protein chemistry, to DNA technology, and to gene targeting technology. Advances in basic research have been successfully translated into improved methods for the diagnosis of bleeding disorders as well as thrombosis, and the development of recombinant clotting factors for replacement therapy in patients with haemophilia. New promising anticoagulants have also been developed for the treatment of thrombotic disorders. Based on the unique nature of blood coagulation research the close interactions and collaborations between basic scientists and clinicians have played a major role in these developments. It is anticipated that blood coagulation research will continue to play a leading role in promoting better care of the patients with bleeding disorders or thromboembolism.

Measurement of glycated hemoglobin and glycated albumin in umbilical cord: evaluation of the glycemic control indicators in neonates

OBJECTIVE

As neonatal blood contains a high proportion of fetal hemoglobin (HbF), it is difficult to use high-performance liquid chromatography (HPLC) method, latex-immunoturbidimetry (LA) method and enzymatic methods, which determine hemoglobin A(1C) (HbA(1C)) in order to provide the glycemic control indicators of neonates. In this study, we evaluated glycated hemoglobin (GHb) and glycated albumin (GA) as appropriate indicators of the glycemic control in the neonatal period.

STUDY DESIGN

Umbilical cord blood samples collected during delivery were subjected to measurements of GHb (HPLC methods using two different instruments, LA method, enzymatic method and affinity method) and serum GA.

RESULT

HbA(1C) levels determined by the HPLC method, the LA method and the enzymatic method were as low as <3.0% in all the cases. Although GHb determined by the affinity method was 3.6 ± 0.2%, this method may not measure accurately the values of glycated HbF plus glycated HbA. Serum GA was 9.4 ± 1.1%.

CONCLUSION

We speculate that serum GA, but not GHb, could be used as glycemic control indicators in neonates.

Pharmacokinetic impact of SLCO1A2 polymorphisms on imatinib disposition in patients with chronic myeloid leukemia

The purpose of this study was to explore the role of the organic anion-transporting polypeptide (OATP) 1A2, which is encoded by SLCO1A2, in the cellular uptake of the Bcr-Abl tyrosine kinase inhibitor imatinib, and the relationship between SLCO1A2 polymorphisms and the pharmacokinetics of imatinib in patients with chronic myeloid leukemia (CML). Imatinib uptake was significantly enhanced in OATP1A2-transfected human embryonic kidney (HEK) 293 cells (P = 0.002). Naringin, an OATP1A2 inhibitor, decreased the transport of imatinib in OATP1A2-transfected HEK293 cells, the human intestinal cell line Caco-2, and K562 CML cells. Linkage disequilibrium was found between the SLCO1A2 -1105G>A and -1032G>A genotypes in 34 CML patients and 100 healthy subjects. Imatinib clearance in CML patients was influenced by the SLCO1A2 -1105G>A/-1032G>A genotype (P = 0.075) and the SLCO1A2 -361GG genotype (P = 0.005). These findings suggest that imatinib is transported into cells by OATP1A2, and that SLCO1A2 polymorphisms significantly affect imatinib pharmacokinetics.

A new method for typing bovine major histocompatibility complex class II DRB3 alleles by combining two established PCR sequence-based techniques

Recently, two polymerase chain reaction sequence-based typing (PCR-SBT) methods were reported for the genotyping of the bovine leukocyte antigen (BoLA)-DRB3. One technique is a single PCR-SBT (sPCR-SBT) method that generates heterozygous sequences that are subsequently analyzed by the haplofinder program, while the other technique is a nested PCR-SBT (nPCR-SBT) method that allows the analysis of heterozygous sequences using the assign 400ATF software. In this study, these techniques were compared and then integrated to produce an improved genotyping method. The primer set used for sPCR-SBT was more accurate than those used for nPCR-SBT. Combining sPCR-SBT with the assign 400ATF software previously reported for nPCR-SBT enables rapid and accurate genotyping of a large number of DNA samples.

The effect of testosterone upon the urate reabsorptive transport system in mouse kidney

It is hypothesized that hyperuricemia in males is caused by androgen-induced urate reabsorptive transport system in the kidney. The expression of urate transporter 1 (Urat1), sodium-coupled monocarboxylate transporter 1 (Smct1) and glucose transporter 9 (Glut9) were investigated in orchiectomized mice with or without testosterone replacement. Testosterone enhanced mRNA and protein levels of Smct1 while those of Glut9 were attenuated. Although the mRNA level of Urat1 was enhanced by testosterone, the corresponding levels of Urat1 protein remained unaffected. Thus, the induction of Smct1 by testosterone is a candidate mechanism underlying hyperuricemia in males.

Phase II study of nedaplatin and irinotecan with concurrent thoracic radiotherapy in patients with locally advanced non-small-cell lung cancer

Background:

Current international guidelines recommend the use of platinum-based chemotherapy with thoracic radiotherapy (TRT) for patients with locally advanced non-small-cell lung cancer (NSCLC).

Methods:

Patients with unresectable stage IIIA or IIIB NSCLC were treated with nedaplatin (NP) at 50 mg m⁻² and irinotecan (CPT) at 60 mg m⁻² on days 1 and 8 every 4 weeks for two to four cycles with concurrent TRT (2 Gy per day, total 60 Gy).

Results:

All 35 patients were able to receive a total of 60 Gy. Adverse effects and events in chemotherapy with TRT were grade 3 or 4 anaemia, neutropenia and thrombocytopenia, which occurred in 3.0%, 32.8% and 6.0% of patients, respectively. There was no grade 3 pneumonitis or oesophagitis. Adverse effects and events in chemotherapy alone were mild. There was no treatment-related death. An overall response rate was 94.3%. The median progression-free and overall survivals were 13.0 and 36.0 months, respectively. The 5-year disease-free and overall survival rates were 25.7% and 40.0%, respectively.

Conclusion:

NP and CPT treatment with concurrent TRT is effective and safe for patients with unresectable, locally advanced NSCLC.

Diurnal changes in the partial pressure of carbon dioxide in coral reef water

Coral reefs are considered to be a source of atmospheric carbon dioxide because of their high calcium carbonate production and low net primary production. This was tested by direct measurement of diurnal changes in the partial pressure of carbon dioxide (Pco(co2)) in reef waters during two 3-day periods, one in March 1993 and one in March 1994, on Shiraho reef of the Ryukyu Islands, Japan. Although the Pco(co2) values in reef waters exhibited large diurnal changes ranging from 160 to 520 microatmospheres, they indicate that the reef flat area is a net sink for atmospheric carbon dioxide. This suggests that the net organic production rate of the reef community exceeded its calcium carbonate production rate during the observation periods.

Fitzgerald Trait: Deficiency of a Hitherto Unrecognized Agent, Fitzgerald Factor, Participating in Surface-Mediated Reactions of Clotting, Fibrinolysis, Generation of Kinins, and the Property of Diluted Plasma Enhancing Vascular Permeability (PF/Dil)

The prolonged partial thromboplastin time observed in the plasma of a 71-yr-old asymptomatic man was related to the deficiency of a hitherto unrecognized agent. The patient's plasma also exhibited impaired surface-mediated fibrinolysis and esterolytic activity and impaired generation of kinins and of the property enhancing vascular permeability designated PF/Dil. The patient's plasma contained normal amounts of all known clotting factors except Fletcher factor (a plasma prekallikrein) which was present at a concentration of 10-15% of pooled normal plasma. Fletcher trait plasma, however, contained normal amounts of the agent missing from the patient's plasma and corrected the defects in clotting, fibrinolysis, and vascular permeability. Fletcher trait plasma was less effective in correcting generation of kinins and esterolytic activity, presumably because of the patient's partial deficiency of prekallikrein. The site of action of the factor deficient in the patient's plasma appeared to be subsequent to the activation of Hageman factor and plasma prekallikrein. A fraction of normal plasma, devoid of other clotting factors, corrected the defect in clotting in the patient's plasma; a similar fraction of the patient's plasma did not correct this abnormality. No evidence yet exists pointing to the familial nature of the patient's defect. Tentatively, the patient's disorder may be referred to by his surname as Fitzgerald trait, and the agent apparently deficient in his plasma as Fitzgerald factor.

Habitat and food partitioning of billfishes (Xiphioidei)

Species composition and food habits of four istiophorid billfishes were investigated and compared in three different tropical areas of the eastern North Pacific Ocean by longline operations from September to November 2004. Sailfish Istiophorus platypterus, shortbill spearfish Tetrapturus angustirostris and blue marlin Makaira nigricans had specific habitat preferences and mainly occurred in the near-continent area (13-16 degrees N; 103-107 degrees W), the open-ocean area (16-18 degrees N; 118-134 degrees W) and the near-equator area (5 degrees N; 104-120 degrees W). Small (<140 cm in lower jaw-fork length) striped marlin Kajikia audax mainly occurred in the near-continent area; however, large (>/=140 cm) individuals occurred throughout all three areas. Prey compositions of large K. audax in the three areas were different from one other reflecting the prey availability in each area. In the open-ocean area, molid fishes were dominant in mass for both large K. audax (49%) and T. angustirostris (73%), and large K. audax also fed on ostraciid (33%) and scombrid fishes (15%). In the near-continent area, tetraodontid fishes were dominant for large and small I. platypterus (54, 57%), and both large and small K. audax also fed on tetraodontid fishes (3, 12%). Large K. audax in this area fed mainly on scombrid fishes (86%). These results indicate that large K. audax show overlaps but little segregations of its prey with other billfishes. In the near-equator area, stomach contents of large K. audax and M. nigricans were few and billfish prey items were thought to be scarce.

Ammonium ion level in serum affects doxorubicin release from liposomes

In this study, we measured the release of drug from liposome-encapsulated doxorubicin (DXR) in human and mouse serum. While human serum did not induce DXR-release, mouse serum significantly induced DXR-release in a temperature- and time-dependent manner. Release of DXR was clearly observed in ultrafiltrated mouse serum, indicating that low-molecular substances affect DXR-release. Therefore, the level of Na+, Cl(-), NH4+, and urea nitrogen in each type of serum was measured. Only the concentration of NH4+ in mouse serum was significantly higher than that in human serum. Furthermore, addition of ammonium acetate to human serum induced DXR release at the same level observed in mouse serum. These results indicate that the NH4+ concentration in serum might greatly affect the release of DXR from liposomes.

Magnetization-dependent loss in an (Al,Ga)As optical waveguide with an embedded Fe micromagnet

The dependence of waveguiding loss on the magnetization of a Fe micromagnet embedded into the (Al,Ga)As optical waveguide was examined as a possible readout method for the spin-photon memory. The optical detection of the magnetization direction of a Fe micromagnet was demonstrated for the micromagnet sizes of 3 microm x 4 microm and 3 microm x 8 microm with signal-to-noise ratios of 4.8 and 6 dB, respectively. In the case of smaller sizes, the use of spin injection from the micromagnet into a semiconductor optical amplifier was proposed for the optical detection of the magnetization.

Small Cell Carcinoma of the Esophagus Treated with Esophagectomy and following Chemotherapy: Case Report with Review of the Literature

We report 2 cases of small cell carcinoma of the esophagus treated with esophagectomy as a primary treatment and following chemotherapy. One patient (pT1N1M0) achieved long-term survival, while the other patient (pT1N1M1-lym) died 18 months after surgery. We used reports on 47 Japanese patients receiving esophagectomy as a primary treatment to determine when esophagectomy for small cell carcinoma of the esophagus is indicated. We conclude that esophagectomy as a local treatment provides relatively good long-term survival only in patients without lymph node involvement.

Abstract C6: Phase 1 study of conatumumab (AMG 655), a proapoptotic death receptor-5 agonist antibody, in Japanese patients with advanced solid tumors

Background: Conatumumab is an investigational, fully human monoclonal agonist antibody that binds human death receptor-5 (DR5, TR-2), activates caspases, and induces apoptosis in sensitive tumor cells. The primary objectives of this phase 1 study were to assess the safety, tolerability, and pharmacokinetics (PK) of conatumumab in Japanese patients (pts) with advanced solid tumors.

Method: This is an open-label ascending dose study with a starting dose level of 3 mg/kg. Subsequent doses of 10 mg/kg and 20 mg/kg were planned. Six pts were enrolled into 1 of 3 dose cohorts (3, 10, or 20 mg/kg) of conatumumab administered intravenously once every 2 weeks as a single-agent. No conatumumab was administered on day 43 to allow assessment of terminal PK parameters. Conatumumab receptor occupancy on monocytes was assessed during the first treatment cycle. Pts remained on study until tumor progression or unacceptable toxicities occurred.

Results: Eighteen pts (6 in each dose cohorts) received at least 1 dose of conatumumab; 9 pts were men; median age was 58 years. Tumor types included: colorectal (5), non-small cell lung (4), gastric (2), soft tissue sarcoma (2) and one each of pancreatic cancer, thymoma, mesothelioma, rectal carcinoid and parotid cancer. The grade 3 adverse events included blood creatine phosphokinase increase, pain and increased lipase. One treatment emergent serious adverse event of pain was reported in cohort 2. This serious adverse event was not considered by the investigator to be related to conatumumab. There were no DLTs observed as defined in the protocol. No deaths occurred during treatment or the safety follow-up period. No subjects had an adverse event leading to conatumumab discontinuation. Conatumumab demonstrated dose-linear kinetics with a half-life of 12 to16 days. Pharmacokinetic profiles were similar to those in the Caucasian population. Tumor response data were available for all patients. A best response of stable disease (defined as a lack of progression at the first assessment at 8-weeks) was reported in 9 patients and progressive disease in 9 patients. Monocytes were found to express DR5, and showed a high degree of conatumumab receptor occupancy after treatment at all dose levels.

Conclusions: Conatumumab administered up to 20 mg/kg once every 2 weeks did not result in dose limiting toxicities in Japanese patients with advanced solid tumors. Adverse events and pharmacokinetics were similar to those in the first in human study conducted in the United States.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C6.

[Relationship between pleural indentation on computed tomography scans and pleural invasion in small peripheral lung cancer of 2 cm in size or less]

Eighty-six cases of small peripheral lung cancer without contact with the chest wall on computed tomography (CT) scans were studied on the presence of radiological pleural indentation and pathological pleural invasion. Twenty-three tumors in 44 cases with pleural indentation were found to reach the pleura histologically, but only one in 42 cases without pleural indentation. There is a high possibility of pleural invasion or contact with the pleura in small lung cancers with pleural indentation. There was no relationship between the presence of pleural indentation and the tumor/chest wall distance on CT scans. Pleural indentations were more frequently seen in small adenocarcinomas of low ground-glass opacity (GGO) ratio or Noguchi's type C. Small lung nodules with pleural indentation had better be removed as early as possible because of the possibility of pleural invasion and pleural dissemination.

The role of limbic-hypothalamic systems in metabolic responses of phenylalanine to repeated cold exposures in rabbits

In this study we examine the effects of lesions to limbic or hypothalamic structures on the metabolic responses of phenylalanine in liver slices prepared from rabbits exposed to cold stress (-20 degrees C) for 12 hours at a fixed time once a day. The results were as follows: 1. The 1st cold exposure (cold exposure on the 1st day) had marked and various effects on phenylalanine metabolism, and the metabolic responses of phenylalanine to cold exposure gradually decreased and then completely disappeared with repetitions of exposure in intact rabbits. 2. The metabolic patterns and responses of phenylalanine to the 1st cold exposure were altered by lesioning the periventricular arcuate nucleus (ARC), ventromedial hypothalamus (VMH), stria terminalis (ST) or dorsal fornix (FX). 3. The complete abolishment of the metabolic responses to cold exposure by its repetition was observed in rabbits with lesions in the ARC or VMH as well. 4. In contrast, metabolic responses of phenylalanine to cold exposure in rabbits with lesions in the ST or FX remained even after six exposures. These results suggest that the ARC, VMH, amygdala (AMYG)-ST system and dorsal hippocampus (HPC)-FX system played a role in the metabolic regulation of phenylalanine and in the metabolic responses of phenylalanine to the 1st cold exposure and that the AMYG-ST and HPC-FX systems, but not the ARC or VMH, participated in the process of the metabolic adaptation of phenylalanine to cold exposure.

Influence of electrical stimulation of the limbic structure on adrenocortical steroidogenesis in hypophysectomized rats

The effects of electrical stimulation of the medial amygdala (AMYG) and dorsal hippocampus (DHPC) on the rates of 14C transfer from 14C-1-acetate into adrenocortical steroids in adrenal slices of hypophysectomized rats were investigated. The 14C transfer rates into corticosterone were increased by stimulation of the AMYG and DHPC. The 14C transfer rates into cortisol were increased by the AMYG stimulation but were not altered by the DHPC stimulation. From these results, it might be suggested that these limbic structures were involved in the regulation of adrenocortical steroidogenesis without participation of the pituitary.

Influence of the electrical stimulation of the medial amygdala on adrenocortical sensitivity to adrenocorticotrophin in hypophysectomized rats

The effects of electrical stimulation of medial amygdala on the adrenocortical sensitivity to adrenocorticotrophin (ACTH) were investigated in hypophysectomized rats. The intravenous injection of ACTH increased the rates of 14C transfer from 14C-l-acetate into corticosterone and cortisol in the adrenal slices of hypophysectomized rats. The electrical stimulation of the medial amygdala produced a further increase in the rates of 14C transfer from 14C-l-acetate into corticosterone and cortisol. From these results, it might be suggested that the medial amygdala was capable of enhancing the adrenocortical steroidogenesis in response to ACTH.