A pharmacological pilot study: application of an intermittent schedule of oral uracil and ftorafur (UFT) for hepatocellular carcinoma patients

Patients with hepatocellular carcinoma (HCC) are highly compromised by failing liver function. To retain good compliance in the administration of uracil and ftorafur (UFT) in such patients, an intermittent schedule for oral administration of UFT was expected to have the same effect as daily continuous use without affecting liver function. A pharmacological pilot study was carried out to confirm the efficacy of this schedule. Sixteen patients with HCC who underwent hepatectomy were given UFT 200 mg b.i.d. for five consecutive days. Blood samples were drawn before the last administration of UFT and at the operation (2 days after the last administration of UFT), and the tumor and adjacent liver tissue were collected. The concentration of ftorafur (FT), 5-fluorouracil (FUra) and uracil (Ura) in serum and liver tissue were measured. Oral administration of UFT 200 mg b.i.d. resulted in a trough level of FT, FUra and Ura in serum of 9.4 micrograms/ml, 13.3 ng/ml and 64.2 ng/ml, respectively. At the operation, FT and FUra in serum had decreased significantly. However, FUra in tissue was still higher than that in serum, in contrast to the results for FT and Ura. There was no difference in the concentration of FUra between the tumors and adjacent liver tissues. No side effect was noted in any of the patients. These results indicated that an intermittent schedule for the administration of oral UFT is not only tolerable but also effective because a sufficient concentration of FUra in the liver tissue is reached and maintained.

[The effects of preoperative transcatheter arterial chemoembolization (TAE) for the recurrence of hepatocellular carcinoma (HCC) from the viewpoint of consecutive tumor necrosis effect]

From 1990 to 1994, seventy-seven patients with HCC below 10 cm in tumor diameter underwent hepatic resections after TAE. They were divided into two groups: group C, complete necrosis (over 90% histologically at the maximum cutting surface of the specimen): group I, incomplete necrosis (under 90%). There were no significant differences in clinical background of patients, histopathological features and total disease-free survival rate (DFR) between the two groups. Nevertheless, DFR of patients in group C was significantly better than that of patients in group I, limiting the patients for curative resection. It was suggested that the recurrence of HCC after resection might be inhibited by curative operation following preoperative TAE with complete necrosis of tumor.

[Role of reservoirs in intraarterial chemotherapy for recurrent hepatocellular carcinoma after hepatectomy]

We conducted a retrospective study on the role of reservoirs in intraarterial chemotherapy for recurrent hepatocellular carcinoma (HCC) after hepatectomy. Ninety-two out of 170 patients with HCC who underwent hepatectomy from 1987 to 1992 in our institute were enrolled in this study. HCC recurred in 55 patients. A rate of good patency of the catheter of the reservoir at the time of recurrence was found in 72.7% of the patients. Transcatheter arterial embolization (TAE) for recurrent tumor was not feasible in 3 patients, because of occlusion of the hepatic artery (3.3% of patients with reservoir, 5.5% of patients with recurrence). Eleven patients were treated by intraarterial chemotherapy using the reservoir and TAE or TAE and PEIT (group R), and 11 patients were treated only with TAE and/or PEIT (group NR). Although there were no significant differences between the two groups in the number of recurrent lesions and operative procedures, tumor-free interval was shorter in group R. Cumulative survival rates after recurrence were not significant. The frequency of TAEs was lower in group R, which shortened the hospitalization for postrecurrence therapy. Thus, intraarterial chemotherapy using reservoir contributed to improvement of the quality of life of patients with recurrent HCC.

[Relationship between severity of farmer's lung and the level of soluble interleukin 2 receptors in serum]

A 54-year-old woman was admitted to Nayoro City Hospital because of a suspicion of farmer's lung (FL). She had been working on her farm for the previous 16 years. Every April she experienced fever, coughing, and dyspnea. Fine crackles were audible over both lung fields. On admission, arterial blood gas analysis showed hypoxemia, and pulmonary-function testing revealed restrictive lung disease and a low diffusing capacity. A chest X-ray film revealed radio-opacity throughout the lower lung fields. A 67Ga scintigram showed abnormal uptake in the lungs. Examination of bronchoalveolar lavage fluid revealed an abnormally high number of lymphocytes and a high CD4/CD8 ratio in the lymphocytes. Histological examination of a specimen obtained by transbronchial lung biopsy revealed interstitial pneumonitis. A precipitation test was positive for anti-Micropolyspora faeni antibody. After admission, symptoms resolved with no treatment. FL was diagnosed from anamnesis and the results of examinations. On admission, the level of soluble interleukin 2 receptor in serum was twice the upper limit of the normal value, and it decreased over time, a long with the severity of the disease. Serial measurements of levels of this receptor are clinically important for detecting the progression of adult T cell leukemia. This case suggests that they can also be useful for evaluating the severity of FL.

Renin-angiotensin system in stretch-induced hypertrophy of cultured neonatal rat heart cells

Although it is well known that mechanical load to cardiac muscles causes cardiac hypertrophy, little is known about how mechanical load is transduced into the activation of intracellular signals which are linked to cell growth. We investigated whether the cardiac renin-angiotensin system was involved in stretch-induced hypertrophy of cultured neonatal rat heart myocytes. Myocytes were cultured with serum-free medium in a deformable silicon dish. Stretch of cardiac myocytes significantly increased the protein/DNA ratio at culture days 6 and 7, and the RNA/DNA ratio at culture days 4 and 5. Stretch significantly accelerated rates of protein synthesis by 15%. c-fos mRNA expression was significantly increased after stretch. The stimulatory effects of cell stretch on these parameters were significantly inhibited by the angiotensin converting enzyme inhibitor, captopril, or the type 1 angiotensin II receptor antagonist, losartan. The concentrations of angiotensin I and angiotensin II in culture media were significantly increased by stretch. Stretch did not change the angiotensin converting enzyme activity. These studies demonstrate that mechanical stretch activates the cardiac renin-angiotensin system in a autocrine and paracrine system which acts as an initial mediator of the stretch-induced hypertrophic growth.

Significance of the right ventricular free wall in dogs with and without pulmonary constriction

To evaluate the role of the right ventricular (RV) free wall in cardiac function, RV and left ventricular (LV) wall segment lengths were measured by ultrasonic crystals in 10 open chest dogs with the pericardium preserved. Right coronary artery (RCA) was perfused separately by own blood and the flow was reduced stepwise until active shortening (delta L) of the RV segment disappeared or RCA flow became zero (Ischemia). The experiment was repeated with and without pulmonary stenosis (PS). At Ischemia, RV and LV systolic pressures decreased. RV end-diastolic length increased and RV delta L decreased. LV end-diastolic length and LV delta L were reduced. LV stroke volume concurrently fell. These changes became more prominent with PS. The critical level of RCA flow, at which RV delta L began to change, was higher with PS (5.27 +/- 2.85 ml/min, mean +/- S.D.) than without PS (1.44 +/- 1.16, p < 0.01). Based on the relationships between RV delta L and percent changes in RV developed pressure and stroke volume, the degree of the decreases in RV developed pressure and stroke volume at RV delta L of zero were estimated to be about 20%. These results indicate that the RV free wall partly contributes to maintaining the RV function, especially during RV pressure overload.

Malignant tumors of the nasal cavity: review of a 60-case series

Sixty cases of primary malignant tumor of the nasal cavity treated in our hospital between 1962 and 1993 were reviewed. Males were affected 2.8 times more frequently than females. The age at the first consultation ranged from 11 to 92 years, with a mean of 55.1 years. The peak distribution was seen in the 6th decade. Twenty-six cases were epithelial malignancies (squamous cell carcinoma 15; adenocarcinoma 3; adenoid cystic carcinoma 3; undifferentiated carcinoma 3; mucoepidermoid carcinoma 1; malignant mixed tumor 1), while 34 cases were non-epithelial malignancies (malignant melanoma 14; malignant lymphoma 14; plasmacytoma 3; olfactory neuroblastoma 2; rhabdomyosarcoma 1). The most common symptom on presentation was nasal obstruction (66.7%), followed by epistaxis (55.0%). The first recurrence was local in 19 patients, whereas cervical lymph node metastasis occurred in three patients, bone metastasis in two, intraperitoneal metastasis in two, and brain metastasis in one. The overall five-year cumulative survival rate was 48.0%. The five-year survival rates for squamous cell carcinoma, malignant melanoma, and malignant lymphoma were 57.0%, 31.0%, and 40.0%, respectively.

[Two hepatocellular carcinoma patients with biloma after transarterial embolization with lipiodol (Lip-TAE) leading to occlusion of portal vein]

We presented two patients with post-Lip-TAE biloma resulting in portal occlusion, and reviewed 20 previous studies including our cases to investigate their clinical characteristics. Case 1. A 31-year-old woman suffered from an HCC located at the S8 segment, and had a superselective embolization of feeding arteries using 3 ml of Lip, 300 mg of CBDCA, and 40 mg of Epi-Adriamycin (Epi-ADM). Eleven weeks later, CT showed multiple cystic lesions, and the percutaneous transhepatic drainages of the lesions were established. At 21 weeks after Lip-TAE, we found occlusion of the right branch of portal vein on CT, but she recovered from this condition, and was discharged 1 year later. Case 2. A 62-year-old man was diagnosed as HCC located at S7-6 segments, and was infused with 3 ml of Lip, 150 mg of CBDCA, and 30 mg of Epi-ADM through a right hepatic artery. Ten weeks later, CT showed a cystic lesion in the S7-8 segments, occlusion of the right anterior segmental branch of the portal vein, and the same drainage was also established. Unfortunately, he died of liver failure 18 weeks later. In the literature, biloma after Lip-TAE occurred at 71.2 mean days, ranging from 7 to 180 days, a with remarkable increase in biliary tree-associated enzymes. Seven (35%) of 20 patients died of liver failure or sepsis during 3 weeks and 1 year, and 3 (60%) of 5 patients accompanied by occlusion of a certain portal branch frequently died. We consider that these patients need intensive care and should be under long follow-up.

[Advantages and disadvantages of the intraarterial chemotherapy using a reservoir as postoperative adjuvant therapy for hepatocellular carcinoma]

We conducted a retrospective study on the efficacy and disadvantages of intraarterial chemotherapy using a reservoir (ICUR), as postoperative adjuvant therapy for hepatocellular carcinoma (HCC). One hundred and seventy HCC patients who underwent hepatectomy since 1987 to 1992 in our institute were enrolled in this study. Ninety-two patients were postoperatively treated with ICUR (group R), and seventy-eight patients without it (group N). There were no significant differences between the two groups in the preoperative evaluations of the characteristics of patients, tumors, and operative procedures. Although statistical significances were not found, disease-free rates within 1 year and cumulative survival rates appeared to be higher in group R than in group N. Patency of the catheter of reservoirs at one and two years were maintained in 80.3 and 44.1% of the patients, respectively. HCC recurred after an occlusion of the reservoir in 18 patients. In four out of these 18 patients, transcatheter arterial embolization (TAE) for recurrent tumors was not feasible, because of occlusion of the hepatic artery. TAEs for recurrent lesions would have been impossible in about 10% of all patients treated with ICUR. Thus, both the advantages and disadvantages should be taken into consideration on the indication of ICUR, and the maintainance of the catheter is important for successful ICUR.

Efficacy of long-term treatment with nipradilol, a nitroester-containing beta-blocker, in patients with mild-to-moderate essential hypertension

The effects of long-term treatment with nipradilol, a nitroester-containing beta-blocker, on casual and 24-hour blood pressures were studied in 70 patients with mild-to-moderate essential hypertension. Antihypertensive effects of nipradilol on casual blood pressure were observed in 68% of patients. Nipradilol reduced pulse rates, but no bradycardia was observed. The usefulness of nipradilol in the present study was 65%. The results of ambulatory blood pressure monitoring indicated that nipradilol reduced systolic blood pressure more than diastolic blood pressure, and reduced blood pressure during waking more than during sleep. These results suggest that nipradilol is a safe and useful long-term antihypertensive drug in both young and older patients with mild-to-moderate essential hypertension. When administered twice daily, nipradilol is effective throughout a 24-hour period.

The role of renal dopamine in the reduction of high blood pressure by beta 1-selective beta-blocker with intrinsic sympathomimetic activity in spontaneously hypertensive rats

The present experiments were undertaken to clarify the difference of renal dopamine production from beta 1-selective beta-blocker with and without intrinsic sympathomimetic activity (ISA). Either beta-blocker with ISA, celiprolol (100 or 300 mg/kg/day; CEL-100 or CEL-300) or beta-blocker without ISA, atenolol (50 mg/kg/day; ATE-50) was administered to the SHR from 19 to 26 weeks. Degrees of lowering blood pressure in CEL-300 SHR and in ATE-50 SHR were similar, but decrease in heart rate was significantly less in CEL-300 SHR than in ATE-50 SHR. Urine output, which was significantly less in control SHR than in control WKY, was significantly greater in CEL-100 SHR and CEL-300 SHR, but not in ATE-50 SHR. Urinary excretions of noradrenaline (u-NA) and dopamine (u-DA) were significantly higher in control SHR than in control WKY and a comparable u-DA/u-NA ratio was found in these two groups. U-DA and the ratio of u-DA/u-NA were significantly elevated in CEL-100 SHR and CEL-300 SHR, but not in ATE-50 SHR. There was a significant positive correlation between u-DA/u-NA ratio and urine output and a significant negative correlation between the ratio of u-DA/u-NA and change of blood pressure in control SHR, CEL-100 SHR and CEL-300 SHR. These results suggest that an enhancement of renal dopamine production by ISA (beta 2 stimulation) of beta 1-selective beta-blocker may contribute, at least in part, to the antihypertensive effect of this drug.

[Fourteen cases of malignant melanoma of the nasal cavity]

Fourteen cases of malignant melanoma of the nasal cavity were treated in our department during 31 years from 1962 to 1993. Ten were males and 4 were females. The ages ranged from 48 to 92 years old, with an average of 64.6 years. The chief complaints were epistaxis in 10 cases, nasal obstruction in 7, nasal cavity tumor in 1, and dull headache in 1. Histologically, 3 cases were amelanotic type, 3 oligomelanotic and 8 melanotic. The cellular types were classified as follows: 5 spindle and 9 large epitheloid cell types. Palliative treatment was performed in 1 patient, and 13 patients were treated radically. Local recurrences were seen in 8 patients, 9 regions; 3 near the posterior margin, 1 near the upper margin, 1 cheek, 2 ethmoid sinus, 1 maxillary sinus, and 1 uncertain. The cumulative survival rate among the 14 patients was 54.2% after 2 years and 31.0% after 5 years. One patient had local recurrence 13 years after surgical treatment.

Differential effects of amiloride on the basal rate and the pressure overload-induced increase in protein synthesis in perfused rat heart

The purpose of the present study were to determine the contribution of Na+/H+ exchange to pressure overload-induced cardiac hypertrophy and to examine its potential interaction with cAMP-dependent signaling pathway. Isolated rat hearts were perfused as Langendorff preparations with aortic pressure of 60 mmHg. In pressure overload group, aortic pressure was increased to 120 mmHg. cAMP contents in the heart perfused at 2 min were examined by RIA. Rates of protein synthesis were examined by 14C-phenylalanine incorporation into myocardial protein during the second hour of perfusion. Expression of c-fos mRNA in the heart perfused at 1 hour was analyzed by Northern blotting. Elevation of aortic pressure from 60 mmHg to 120 mmHg in perfused rat hearts increased cAMP contents from 4.89 +/- 0.09 to 6.30 +/- 0.28 pmol/mg protein and accelerated rates of protein synthesis from 644 +/- 13 to 860 +/- 49 mmol Phe/g dry heart/hr. Expression of c-fos mRNA was induced by elevated aortic pressure. Amiloride, an inhibitor of Na+/H+ exchange, decreased rates of protein synthesis in a concentration-dependent manner (12.5, 25, 50, 100 microM) but did not change cAMP content (5.25 +/- 0.11 pmol/mg protein) or expression of c-fos mRNA. Furthermore, amiloride did not prevent the increases in cAMP (6.99 +/- 0.34 pmol/mg protein), protein synthesis rates (476 +/- 18 to 689 +/- 31 nmolPhe/g dry heart/hr) and expressions of c-fos mRNA that were induced by elevation of aortic pressure. These results indicate that amiloride, an inhibitor of Na+/H+ exchange system, while influencing rates of protein synthesis, does not play an important role in pressure overload-induced cardiac hypertrophy. The mechanism by which amiloride influences cardiac protein synthesis is independent of the cAMP-dependent mechanism by which pressure overload induces cardiac hypertrophy.

Hypertrophic growth of cultured neonatal rat heart cells mediated by type 1 angiotensin II receptor

Primary cultures of neonatal cardiac myocytes were used to determine the identity of second messengers that are involved in angiotensin II (ANG II) receptor-mediated effects on cardiac hypertrophy and the type of ANG II receptor that is involved in ANG II-induced cell growth. Treatment of myocytes with ANG II significantly increased the protein-to-DNA and the RNA-to-DNA ratios. ANG II accelerated rates of protein synthesis by 24.9%. Intracellular free calcium was transiently increased after ANG II exposure. The activity of protein kinase C in particulate fractions was transiently increased after exposure to ANG II but returned to control level. The activity of protein kinase C in the cytosol was significantly decreased at all times after exposure to ANG II. After ANG II treatment, the content of c-Fos mRNA was increased. The stimulatory effects of ANG II on these parameters were inhibited by the type 1 angiotensin II receptor (AT1) antagonist, losartan. These studies demonstrate that ANG II-induced hypertrophic growth is, at least in part, mediated through AT1 receptors.

Novel 6,5-fused ring heterocyclic antifolates: biochemical and biological characterization

Six novel antifolates with 2,4-diaminopyrimidine-fused five-membered rings containing either pyrrole or cyclopentene rings were characterized at the cellular and biochemical level. Five of these antifolates were more growth inhibitory to the CCRF-CEM human leukemia cell line than methotrexate [MTX; drug concentration effective at inhibiting cell growth by 50% relative to untreated control (EC50), 12 nM], the antifolate used in the clinic, and two were more potent than 10-ethyl-10-deazaaminopterin (EC50, 2.7 nM); similar patterns of response were obtained in the FaDu and A253 squamous carcinoma cell lines. In addition, the growth inhibitory potency of these antifolates was generally less dependent on exposure time than was MTX. Growth inhibitory effects could be reversed by leucovorin, indicating an antifolate mechanism. These antifolates targeted dihydrofolate reductase (DHFR) based on direct human DHFR inhibition assays [drug concentration inhibiting enzyme activity by 50% (IC50), 0.6-28 nM; MTX IC50, 0.8 nM] and the cross-resistance of MTX-resistant CCRF-CEM cells containing elevated DHFR. Inhibition of human thymidylate synthase was generally weak. These 6,5-fused ring heterocyclic antifolates utilized the reduced folate/MTX transporter for uptake, based on the cross-resistance of MTX uptake-impaired CCRF-CEM cells, and were efficient substrates for this uptake system, based on inhibition of [3H]MTX uptake (IC50, 0.3-5.8 microM; aminopterin IC50, 2.6 microM). These analogues were substrates for CCRF-CEM folylpolyglutamate synthetase, with several being among the most active substrates now known (highest Vrel/Km 0.73; MTX and 10-ethyl-10-deazaaminopterin, 0.013 and 0.24, respectively). Substrate activity for murine intestinal folylpolyglutamate synthetase was also assayed, and a different specificity pattern was observed. These new antifolates are apparently not substrates for aldehyde oxidase. Analogues containing the fused cyclopentene ring are preferred to those containing the fused pyrrole ring based on growth inhibitory potency, effectiveness against decreased uptake mutants and apparent affinity for transport, and inhibition of DHFR. In addition, fused cyclopentene-containing analogues are efficiently polyglutamylated. The data indicate that antifolates with 2,4-diaminopyrimidine-fused five-membered rings, especially those containing the fused cyclopentene ring, are an important new class of antifolates which warrant further exploration at the synthetic and preclinical levels.

A case report of isolated levocardia without intracardiac anomalies associated with sick sinus syndrome

A 42-year-old female with cardiomegaly showed bradycardia without syncope. Clinical data showed that she had an isolated levocardia with interruption of the inferior vena cava. Isolated levocardia was defined as a normally placed heart associated with situs ambiguus of other viscera. She did not have intracardiac anomalies. Isolated levocardia without intracardiac anomalies, as in this case, has only been reported in 13 other cases. Isolated levocardia is often accompanied by severe complex intracardiac anomalies and, therefore, most of the patients have a short life span. Situs ambiguus, especially left isomerism, is frequently associated with deteriorated sinus node function, and an interruption of the inferior vena cava may also be an indication of this phenomenon. Therefore, the patient's sinus node function was examined using an electrophysiological study and a 24-hour ambulatory electrocardiogram. Sick sinus syndrome was finally confirmed.

Effect of regression of cardiac hypertrophy on ischemic myocardial damage in spontaneously hypertensive rats

Effects of reduction of blood pressure and regression of left ventricular hypertrophy following hydralazine and captopril therapy on ischemic cardiac function and myocardial metabolism were studied in spontaneously hypertensive rats (SHR). Hydralazine (1.5 or 3 mg/kg/day) and captopril (50 or 100 mg/kg/day) were administered to SHR from 19 to 26 weeks of age. Both hydralazine and captopril significantly decreased arterial blood pressure in SHR, but only captopril significantly reduced left ventricular weight. The percentage of V3 myosin isozyme significantly decreased in captopril-treated SHR compared to hydralazine-treated SHR. At the end of long-term treatment, hearts were removed and perfused for 15 min by the working heart technique, and then global ischemia was induced for 30 min. The ischemic heart was reperfused for 30 min. In hydralazine-treated SHR and captopril-treated SHR, the pressure-rate product and extent of recovery of the coronary flow during reperfusion following 30 min of ischemia were higher than those in control SHR, but this difference was significant only in captopril-treated SHR. Hydralazine and captopril treatment improved the restoration of the levels of ATP, creatine phosphate, total adenine nucleotide and energy charge potential in SHR after reperfusion following 30 min of ischemia, but only captopril had a significant effect. In conclusion, regression of left ventricular hypertrophy is more important than lowering of blood pressure in order to improve the ischemic myocardial damage.

Site of hypoxic pulmonary vasoconstriction in pulsatile perfused canine lung lobes

To elucidate the site of hypoxic pulmonary vasoconstriction (HPV) in the dynamic lung, we studied the effect of alveolar hypoxia (0 approximately 4% O2) on excised canine lung lobes with pulsatile perfusion from artery to vein (antegrade perfusion: AP) or vein to artery (retrograde perfusion: RP), and compared responses to hypoxia with those to serotonin and histamine. In our preparation, increases in the pulmonary vascular resistance (R) resulted in a wide range of decreases in the flow wave amplitude at the lobar inflow site (FA). These decreases in FA reflected reductions in the compliance of the vasculature proximal to the main site of resistance. The FA/R ratios of serotonin were 2.29 in AP and 0.24 in RP indicating the predominant arterial constriction, those of histamine were 0.07 in AP and 1.24 in RP indicating the selective venous constriction. In contrast, the responses to hypoxia were 0.38 in AP and 0.42 in RP. These results suggest that HPV occurs not only on the arterial side but on the venous side in the dynamic lung, and the main site of HPV is located in the peripheral pulmonary vasculature, between muscular arteries and veins which are constricted by serotonin and histamine.

Effect of bunazosin, a selective alpha 1-adrenoceptor blocker, on ischemic myocardium in perfused rat heart

The effects of bunazosin on the ischemic myocardium were investigated in isolated, perfused working rat hearts. Ischemia decreased the pressure-rate product and tissue adenosine triphosphate and creatine phosphate levels. Reperfusion did not restore the pressure-rate product nor the adenosine triphosphate levels completely. Bunazosin (5 x 10(-7) and 5 x 10(-6) mol/L) preserved the levels of adenosine triphosphate and creatine phosphate after 20 minutes of ischemia and increased the extent of recovery of the pressure-rate product during reperfusion. The results suggest that bunazosin protects the myocardium against ischemic damage.

Effects of regression of left ventricular hypertrophy following atenolol or bunazosin therapy on ischemic cardiac function and myocardial metabolism in spontaneously hypertensive rats

The effects of regression of left ventricular hypertrophy following atenolol and bunazosin therapy on ischemic cardiac function and myocardial metabolism in spontaneously hypertensive rats (SHR) were studied. Atenolol (50 mg/kg/day) and bunazosin (5 mg/kg/day) were administered to SHR from 19 to 26 weeks of age, whereas tap water was given to control SHR and normotensive Wistar-Kyoto rats (WKY). Both atenolol and bunazosin significantly decreased arterial blood pressure and significantly decelerated the increase in left ventricular weight in SHR. At the end of the long-term treatment, hearts were removed and perfused by the working heart technique for 15 min, and then global ischemia was induced for either 10 or 30 min. The ischemic heart was reperfused for 30 min. The pressure-rate product and the extent of recovery of the coronary flow after reperfusion following 30 min of ischemia in the bunazosin-treated SHR were significantly higher than those in the control SHR and the atenolol-treated SHR. The levels of adenosine triphosphate (ATP), creatine phosphate (CrP), and energy charge potential in the SHR heart reperfused after 30 min of ischemia were significantly lower than those in the reperfused WKY. Both atenolol and bunazosin improved the restoration of ATP and CrP in SHR after reperfusion following 30 min of ischemia. In conclusion, antihypertensive therapy with either atenolol or bunazosin was effective in preventing cardiac hypertrophy and ischemic damage caused by different mechanisms. Factors resulting from stimulation of the cardiac alpha 1 adrenoceptor may play an important role in the development of hypertensive cardiac hypertrophy, just as factors resulting from stimulation of the beta 1-adrenoceptor do.

Effect of pericardium on regional myocardial systolic function in acute ischemia

To know whether or not the pericardium affects regional myocardial systolic function in acute ischemia, we measured ischemic and non-ischemic segment lengths of the left ventricle using ultrasonic crystals in 10 open-chest dogs with the pericardium preserved. When the left ventricular pressure and segment lengths were stable after left circumflex coronary occlusion, we opened the pericardium widely. After coronary occlusion, end-diastolic length (EDL) in ischemic and non-ischemic segments increased, and the ischemic segment showed paradoxical systolic expansion while the non-ischemic segment increased its active shortening. After pericardiectomy, heart rate, left ventricular systolic pressure, and peak positive and negative dP/dt did not change. EDL in ischemic and non-ischemic segments further increased from 12.02 +/- 0.18 to 12.50 +/- 0.16 mm (mean +/- S.E., p less than 0.01) and from 11.12 +/- 0.20 to 11.45 +/- 0.18 mm (p less than 0.05), respectively, despite the concomitant fall in left ventricular end-diastolic pressure (LVEDP) from 12.4 +/- 0.6 to 10.6 +/- 0.8 mmHg (p less than 0.01). End-systolic length in ischemic and non-ischemic segments also increased from 12.37 +/- 0.25 to 12.70 +/- 0.20 mm (p less than 0.05) and from 8.50 +/- 0.13 to 8.74 +/- 0.13 mm (p less than 0.01), respectively, although the left ventricular end-systolic pressure did not change. Maximum expanded systolic length of the ischemic segment also increased from 12.99 +/- 0.20 to 13.42 +/- 0.16 mm (p less than 0.01). These results indicate that, in acute ischemia, the pericardium inhibits paradoxical systolic expansion of the ischemic region and increase in end-systolic length of non-ischemic segment. Thus, it is concluded that the pericardium modifies the regional myocardial systolic function in acute ischemia, perhaps through the mechanical restraint of the pericardium.

Responses of atrium and ventricle to sustained sympathetic nerve stimulation

To determine whether chronotropic and atrial inotropic responses to sympathetic nerve stimulation are maintained longer than ventricular inotropic response, the present study was performed with control and acute reserpinized dogs. We stimulated the right stellate ganglion of both groups supramaximally for 60 min and compared right atrial responses (chronotropism and inotropism) with left ventricular (LV) dP/dtmax. In the control group, heart rate (HR) immediately increased and was only slightly attenuated with 60 min of stimulation, and right atrial (RA) inotropic response was less attenuated than was LV response (7% in HR, 33% in RA dP/dtmax, 50% in LV dP/dtmax, P less than 0.01, from the peak value of each response). RA and LV norepinephrine (NE) content was decreased by the stimulation but remained higher than the LV control value. In the reserpinized group, NE content in the RA was low before the stimulation and was further decreased by the stimulation. In this group, HR response was attenuated (27% in HR, P less than 0.01) as was LV dP/dtmax, and the difference in contractile responsiveness between atrium and ventricle disappeared (58% in RA dP/dtmax vs. 61% in LV dP/dtmax, NS). The results indicate that the chronotropic response was only slightly attenuated and that the atrial contractile response was attenuated less than the ventricular response, with sustained sympathetic nerve stimulation in the normal heart. This can be ascribed to the much higher NE content in the RA than that in the LV.

Influence of reduced presynaptic myocardial norepinephrine stores on left ventricular contractility

Many investigators have reported that myocardial norepinephrine content is decreased in congestive heart failure. However there have been no studies of how decrease in myocardial norepinephrine might influence myocardial contraction. To clarify whether decreased myocardial norepinephrine per se affects myocardial contraction, we observed the change in left ventricular contractility during 30 min of left stellate ganglion stimulation in control and acutely reserpinized dogs. We obtained left ventricular max dp/dt and left ventricular end-systolic pressure-segment length relationships as indicators of left ventricular contractility. Both parameters decreased after left stellate ganglion stimulation in reserpinized dogs (left ventricular max dp/dt: 2064 +/- 200 to 1608 +/- 168 mmHg/s, left ventricular end-systolic pressure-segment length slope 117 +/- 22 to 79 +/- 14 mmHg/mm, n = 8, P less than 0.05), while they did not change in controls. In reserpinized dogs, left ventricular norepinephrine content decreased to one-third that of controls before the stimulation, and further decreased after stimulation. These data indicate that lowered myocardial norepinephrine itself may be responsible for the negative effect on left ventricular contractility in congestive heart failure.