Effects of angiotensin converting enzyme inhibitors MK 421, SA 446 and captopril on renal prostaglandin E and kinins in conscious normotensive rats

Angiotensin converting enzyme inhibition by MK 421, SA 446 or captopril (6 mg/kg/day ip) for up to 6 days induced significant fall in systolic blood pressure and plasma angiotensin II concentration. The hypotensive effect was greater in sodium depleted rats than in sodium repleted rats. The hypotensive effect was also accompanied by increased excretion of urinary prostaglandin E2, however the levels of urinary prostaglandin E2 in sodium repleted rats were not different from those in sodium depleted rats. Urinary kinin excretion was increased during infusion of MK 421, SA 446 or captopril in sodium depleted rats, whereas no significant change was found in sodium repleted rats. Thus the present results suggest that renal prostaglandin E system may not be essential for the hypotensive effect of these inhibitors. In addition, the greater hypotensive effect of these inhibitors in sodium depleted rats may be in part due to stimulated renal kinin system.

Antihypertensive effect of synthetic atrial natriuretic factor in vasopressin-infused rats

To assess the pathophysiological role of atrial natriuretic factors in the regulation of blood pressure, we studied the effect of chronic infusion of a synthetic atrial natriuretic factor of 25 amino-acid residues on blood pressure and sodium-water excretion. Experimental subjects were rats with hypertension made by chronic infusion of vasopressin on regular intakes of sodium or on sodium loading with 1% NaCl as drinking water. When a subdepressor dose (150 micrograms/kg/day) of synthetic atrial natriuretic factor was delivered via an osmotic minipump into the jugular vein simultaneously with 7.2 U/kg/day of vasopressin infused intraperitoneally by another osmotic minipump, the expected elevation of systolic blood pressure was completely inhibited. This was not accompanied by any changes in urine volume and urinary sodium excretion. The antihypertensive effect was sustained throughout the experimental period lasting 3 days in rats on regular sodium intake (p less than 0.01) or on sodium loading with 1% NaCl as drinking water (p less than 0.01). These results indicate that a subdepressor dose of synthetic atrial natriuretic factor can modulate the vasopressor effect of vasopressin. Therefore it is suggested that an atrial natriuretic factor may be involved in the regulation of blood pressure via its antagonizing effect to vasopressin.

Effects of ouabain on blood pressure regulation in rats

In order to test the hypothesis that a circulating inhibitor of the sodium-potassium ATPase pump may cause a concomitant rise in blood pressure and increased sodium excretion, we studied chronic effects of continuous infusion of ouabain, an inhibitor of sodium-potassium ATPase, for up to 6 days on systolic blood pressure and urinary sodium excretion in conscious rats. We also evaluated the effect of this substance in rats with hypertension induced by chronic infusion of norepinephrine. Continuous infusion of ouabain (1.2 mg/kg per day) into the jugular vein by an osmotic minipump did not induce any changes in systolic blood pressure and urinary sodium excretion in intact rats on regular diets. Furthermore it did not cause a change in systolic blood pressure in rats drinking 1% NaCl, and in unilaterally nephrectomized rats drinking 1% NaCl, when compared with vehicle-infused animals. When the same dose of ouabain was administered simultaneously with 1.8 mg/kg per day norepinephrine infused intraperitoneally by another osmotic minipump in conscious rats, systolic blood pressure rose on day 1 to only 129.3 +/- 2.8 mmHg compared with the rist to 145.0 +/- 2.0 mmHg when norepinephrine alone was infused (P less than 0.01). The antihypertensive effect of ouabain was sustained for the entire experimental period lasting for 6 days and was not associated with any changes in urinary sodium excretion. The administration of ouabain to rats made hypertensive by a 3-day infusion of norepinephrine, returned the blood pressure to control levels, and the antihypertensive effect was sustained throughout the experimental period lasting a further 3 days and was not associated with any changes in urinary sodium excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic effect of a synthetic atrial natriuretic factor on the development of hypertension in young spontaneously hypertensive rats

The chronic effect of a synthetic atrial natriuretic factor (ANF) of 25 amino acid residues on the development of hypertension in the 6-week-old spontaneously hypertensive rat (SHR) was assessed. The SHR, on regular diets or given 1% NaCl solution for drinking, were continuously infused with ANF (150 micrograms/kg per day) or vehicle (physiological saline) as controls for up to 14 days. The ANF attenuated transiently the development of hypertension in the sodium-loaded SHR, but the blood pressure returned to control levels by day 5. In SHR on regular diets ANF did not affect the development of hypertension. In addition, ANF did not induce any significant changes in urine volume, fluid intake, urinary sodium and potassium excretion, heart rate, heart weight or haematocrit in young SHR on either normal or increased sodium intake when compared with those in vehicle-infused SHR. These results suggest that ANF may exert some role via a vascular effect at the early stage of development of hypertension in young sodium-loaded SHR.

Effect of atrial natriuretic factor on angiotensin II-induced hypertension in rats

To assess the physiological role of atrial natriuretic factors in blood pressure regulation, we studied the effect of chronic infusion of a synthetic atrial natriuretic factor of 25 amino acid residues (Arg 102-Tyr 126) in rats with angiotensin II-induced hypertension. Rats were studied while on a normal sodium diet or during sodium loading with 1% NaCl solution used as drinking water. Systolic blood pressure decreased slightly during combined infusion of synthetic atrial natriuretic factor, 150 micrograms/kg/day, and angiotensin II, 900 micrograms/kg/day. This effect was sustained for 3 days in rats receiving a regular sodium intake (p less than 0.01) and during sodium loading (p less than 0.01). Administration of synthetic atrial natriuretic factor to rats made hypertensive by a 3-day infusion of angiotensin II reduced blood pressure slightly, but not to control levels, and this effect was sustained for the remaining 3 days of the experiment in both dietary groups. These results indicate that a nonhypotensive dose of synthetic atrial natriuretic factor can modulate the vasopressor effect of angiotensin II. Thus, the attenuating effect may be involved in blood pressure regulation independently of sodium metabolism, although its actual physiological importance remains undetermined.

Atrial natriuretic factor and cyclic guanosine 3',5'-monophosphate in vascular smooth muscle

To elucidate the molecular mechanism of the vascular action of atrial natriuretic factor (ANF), we investigated the effects of synthetic ANF and sodium nitroprusside on the levels of intracellular cyclic nucleotides and prostacyclin (measured as its stable metabolite 6-keto-prostaglandin F1 alpha) in cultured vascular smooth muscle cells from rat mesenteric artery and, in some experiments, from rat renal artery. Both ANF and sodium nitroprusside increased intracellular cyclic guanosine 3',5'-monophosphate (cGMP) levels in a dose-dependent manner but did not affect cyclic adenosine 3',5'-monophosphate levels or 6-keto-prostaglandin F1 alpha synthesis. The stimulatory effect of ANF and sodium nitroprusside on cGMP levels were additive. Neither the deprivation of extracellular Ca2+ nor calcium entry blockers affected ANF-stimulated cGMP levels. Preincubation of ANF or sodium nitroprusside with kallikrein attenuated only the effect of ANF on cGMP levels. The effect of kallikrein was abolished by serine protease inhibitors. In contrast, the oxidant methylene blue inhibited the effect of sodium nitroprusside on cGMP levels, but not that of ANF. The stimulatory effect of ANF on cGMP levels was greater in cells from renal artery than in those from mesenteric artery. These results in cultured vascular smooth muscle cells further support the hypothesis that cGMP mediates the vasorelaxant action of ANF.

Clinical evaluation of palliative therapy for unresectable primary liver cancer

Ninety-nine patients with unresectable primary liver cancer were treated with ligation of the hepatic artery (LHA), intra-arterial infusion chemotherapy (IAIC) or transcatheter arterial embolization (TAE) between 1960 and 1983. A statistical study was made of therapeutic effects and prognosis. The results are as follows: The mean survival time of 14 patients treated with LHA was about 5 months. The survival time of the LHA + IAIC with mitomycin C group was not prolonged as compared with that of the LHA group, but LHA + IAIC with Adriamycin (doxorubicin) group showed a significant prolongation of survival time over the LHA group. In the LHA + IAIC with Adriamycin group, the mean survival time was 12.8 months and the 1-year survival rate was 37.5%. Factors including age, presence of liver cirrhosis, number of involved segments, and degree of anaplasia graded on Edmondson's criteria did not influence survival time.

Isolation and characterization of monoclonal antibodies against calcium-activated neutral protease with low calcium sensitivity

Fifteen hybridomas secreting antibodies against calcium-activated neutral protease (CANP), especially those for rabbit muscle mCANP with low calcium sensitivity, have been produced by the cell fusion technique. Eight of the monoclonal antibodies belong to the class IgG1, one to the class IgG2a, and six to the class IgG2b. The antibodies from these clones were characterized with regard to their relative binding affinities to the large subunits (80K) and the small subunits (30K) of mCANP as well as mu CANP, which is another type of CANP with high calcium sensitivity. Fourteen antibodies bound only to the 80K subunit of mCANP and one antibody bound to the 80K subunit of both mCANP and mu CANP. These antibodies recognized rat mCANP but not chicken CANP, with the exception of one antibody. Examination of the effects of these antibodies on the enzyme activity of mCANP showed that six antibodies partially inhibited the enzyme activity and the others were noninhibitory. These monoclonal antibodies should be useful for analyzing the fine structure of CANPs and the mechanism of the activation of mCANP, and also for determining the intracellular localization of mCANP.

Mechanism of antihypertensive effect of atenolol in patients with borderline hypertension during short-term treatment. A comprehensive study

Short-term treatment with 1-(p-carbamoyl-methylphenoxy)-3-isopropylamino)-2-propanol (atenolol, Tenormin) (100 mg/d for 5 days) was conducted in 12 patients with labile essential hypertension. Before and at the end of the treatment, cardiohemodynamics, renal hemodynamic and excretory function, and renal pressor (renin-angiotensin-aldosterone) and depressor (renal kallikrein-kinin and prostaglandin) systems were examined. Atenolol decreased cardiac output (CO) without affecting total peripheral resistance. Atenolol also decreased plasma renin activity, plasma aldosterone concentration, urinary excretion of kallikrein-kinin, and urinary excretion of potassium whereas it increased plasma potassium concentration. Urinary excretion of prostaglandin E and sodium was not affected by atenolol. Glomerular filtration rate decreased, but renal plasma flow remained unchanged during the treatment by atenolol. A significant positive correlation was found between the changes in CO and in systolic blood pressure (SBP) while negative correlation was observed between the changes in total peripheral resistance and in SBP. A significant positive correlation was also noted between urinary kallikrein excretion and renal plasma flow. The change in urinary kinin excretion was conversely correlated to that in SBP. This study demonstrates that the hypotensive mechanism of atenolol is very complex. Decrease in CO and inhibition of renin-angiotensin-aldosterone system may mainly be responsible for hypotension. It is likely that potassium retaining action of atenolol partly contributes to its hypotensive action. It is also hypothetized that renal kallikrein-kinin system may play a role in modulating the hypotensive action of atenolol.

[Phase II study of (2''R)-4'-O-tetrahydropyranyladriamycin (THP) in patients with solid tumors. Multi-Institutional Cooperative Study]

A Phase II Study of (2''R)-4'-O-tetrahydropyranyladriamycin (THP) in patients with various solid tumors was carried out by 44 cooperative study institutions. Seven hundred fifty-six patients administered the drug intravenously were entered into this study. Of these, 499 patients were evaluated for objective responses. THP was given mainly at a dose of 40 to 60 mg/body every 3 to 4 weeks or 20 to 30 mg/body once a week. Response rates were 18.8% for head and neck cancer, 13.1% for stomach cancer, 21.4% for breast cancer, 22.2% for bladder cancer, 30% for renal pelvic and urinary tract tumor, 26.8% for ovarian cancer and 24.2% for uterine cancer. Overall response rate was 15.4% including 10 complete responses and 67 partial responses. Adverse reactions were similar to those previously reported in the phase I study, including gastrointestinal toxicities and myelosuppression. Alopecia and stomatitis, which are major side effects of other anthracyclines, were rather mild. Incidence of ECG changes was 2.8% and no congestive heart failure was observed.

[Phase II study of THP (2''R)-4'-0-tetrahydropyranyladriamycin) in breast cancer]

In a phase II study of THP, fifty-six patients with advanced or recurrent breast cancer were evaluated, and a response rate of 23.2% including 1.8% with complete response and 21.4% with partial response, was obtained. Response rates of THP varied according to the location of metastasis and the highest rate was shown to be 38.5% in patients with soft tissue metastasis. The median dose for inducing response was 100 mg with a range from 60 mg to 160 mg. Toxicities such as leukopenia and gastrointestinal disorders were observed during THP treatment. The favorable response to THP was close to that of adriamycin, but it was noteworthy that a lower frequency of alopecia occurred.

Effects of sodium and angiotensin II on urinary active and inactive kallikrein in rats

To assess possible relationships between sodium balance, angiotensin II (ANG II), and renal active and inactive kallikrein, we studied the effects of sodium loading with 1% NaCl and chronic ANG II infusion (900 micrograms/kg per day) on the urinary excretion of total and active kallikrein for 6 days in conscious rats. We determined urinary total, active and inactive kallikrein by measuring kallikrein activity using a kininogenase assay before and after treatment with trypsin (200 micrograms/ml). Sodium loading produced a sustained increase in urinary total, active and inactive kallikrein excretion. Chronic infusion of ANG II induced a sustained increase in urinary total, active and inactive kallikrein excretion in rats on a regular diet. In rats loaded with sodium, however, ANG II did not induce any further changes in urinary kallikrein excretion. Thus, the present study suggests that both sodium loading and ANG II infusion might stimulate the synthesis of renal kallikrein. In addition, it is suggested that ANG II infusion might stimulate the synthesis of kallikrein, at least partly, via the same mechanism as sodium loading does.

Atrial natriuretic factor inhibits the hypertension induced by chronic infusion of norepinephrine in conscious rats

To assess the physiological role of atrial natriuretic factors in the regulation of blood pressure and sodium-water excretion, we studied the chronic effects of continuous infusion of a synthetic atrial natriuretic factor of 25 amino acids for up to 3 days on systolic blood pressure, urine volume, and urinary excretion of sodium, prostaglandin E2 and kallikrein in conscious rats, and also evaluated the antihypertensive effect of this substance in rats with hypertension caused by chronic infusion of norepinephrine. Continuous infusion of atrial natriuretic factor (150 micrograms/kg per day) into the jugular vein via osmotic minipumps did not induce any changes in systolic blood pressure, urine volume, and urinary excretion of sodium, prostaglandin E2, and kallikrein for up to 3 days, compared with those in vehicle-infused rats. When the same dose of atrial natriuretic factor was administered simultaneously with 1.8 mg/kg per day of norepinephrine infused intraperitoneally by osmotic minipumps, the systolic blood pressure of conscious rats rose on day 1 to only 127.3 +/- 6.3 mm Hg compared with the rise to 146.3 +/- 1.6 mm Hg when norepinephrine alone was infused (P less than 0.05). The antihypertensive effect of atrial natriuretic factor was sustained for 3 days in rats infused with norepinephrine. The administration of atrial natriuretic factor to rats made hypertensive by 3 days of infusion with norepinephrine alone returned the blood pressure to control levels, and the antihypertensive effect was sustained throughout the experimental period lasting for 3 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Revision of porto-enterostomy in congenital biliary atresia

For the patients with insufficient bile flow following porto-enterostomy for congenital biliary atresia, removal or resection of granulation or scar tissue at the porta hepatis has been performed. Of 11 reoperations, constant bile excretion was obtained in four. Sufficient resection of scar tissue at the porta hepatis was most important for revision of porto-enterostomy. For resection of scar tissue, a special scissors devised by us was used.

[Cefminox concentration in tissues and clinical efficacy of cefminox in acute peritonitis]

Cefminox sodium (CMNX, MT-141), a new semisynthetic cephamycin, having marked resistance to beta-lactamase, and a broad spectrum of antibacterial activity against various bacterial species, including Haemophilus influenzae, Serratia marcescens and Citrobacter freundii, CMNX has higher activity in vivo than in vitro. For therapeutic purpose, CMNX was given in a daily dose of 0.5 g (0.5 g X 1) to 2 g (1 X 2) by intravenous drip infusion for 4 to 8 days to 24 cases with acute peritonitis (17 cases with acute appendicitis, 1 with localized peritonitis after gastrectomy, 1 with diffuse peritonitis due to perforative duodenal ulcer and 5 with panperitonitis due to intestinal obstruction). The clinical response was rated excellent in 9 cases, good in 14 cases and fair in 1 case and poor in none. No adverse effect was observed. There were 29 strains isolated organisms included 12 Escherichia coli, some Enterococcus faecalis and Pseudomonas aeruginosa. These isolated organisms were eradicated after CMNX treatment, except a strain of E. faecalis was decreased. In 19 cases of them, 16 cases with acute peritonitis due to acute appendicitis and 3 cases with acute panperitonitis due to intestinal obstruction, CMNX was administered intravenously in a dose of 1 g (1 case was 0.5 g) before or during the operation, and tissue specimens and body fluids samples were taken during the operation. CMNX concentration was determined to a bioassay with Escherichia coli NIHJ or Vibrio vercolans ATCC 8461 as the test organisms. CMNX concentrations in purulent ascites were 47.2 +/- 38.5 micrograms/ml (n = 23), those in infected appendix wall were 32.2 +/- 21.7 micrograms/g (n = 16), that in pus in appendix were 22.1 +/- 24.3 micrograms/ml (n = 8) and that in other non infected tissues were 24.3 +/- 22.0 micrograms/g (n = 8). CMNX concentrations in infected tissues were higher than the non infected tissues. In the 3 cases with empyemic appendicitis, CMNX levels in pus in appendix were more higher than that in appendix wall itself. Therefore, CMNX sodium appears to be a very useful drug when used for chemotherapy on acute peritonitis.

Decreased urinary active and inactive kallikrein by chronic infusion of vasopressin in conscious rats

To assess possible interactions of circulating vasopressin with the synthesis or activation of renal kallikrein, we studied the effect of chronic infusion of vasopressin (7.2 U/kg/day i.p.) for 6 days on the urinary excretion of total and active kallikrein in conscious rats. We determined urinary total, active and inactive kallikrein by measuring kallikrein activity using a kininogenase assay before and after the treatment with trypsin (200 micrograms/ml). Chronic infusion of vasopressin induced sustained decreases in urinary total, active and inactive kallikrein excretion, but did not affect the ratio of active to total kallikrein. The infusion of vasopressin induced significant increases in circulating levels of vasopressin (248.1 +/- 35.2 pg/ml in vasopressin-infused rats (n = 7) compared to 95.5 +/- 14.6 pg/ml in vehicle-infused rats (n = 7), p less than 0.001) and in weight gain (39.6 +/- 1.3 g in vasopressin-infused rats (n = 7) compared to 29.1 +/- 3.3 g in vehicle-infused rats (n = 7), p less than 0.05), and also sustained decreases in water intake and urine volume, but it did not induce any change in urinary sodium excretion. Circulating levels of angiotensin II was decreased by chronic infusion of vasopressin. Thus, the present study suggests that the elevation of circulating vasopressin levels induces a decrease in the synthesis of renal kallikrein.

Renal prostaglandin E in the hypotensive mechanism of MK-421 in conscious rats

To assess the role of renal prostaglandin E in the hypotensive mechanism of MK-421, we evaluated the effects of chronic infusion of MK-421 (6 mg/kg/day i.p.) on systolic blood pressure and urinary prostaglandin E excretion in conscious rats in states of sodium repletion or depletion and also during chronic infusion of norepinephrine (1.8 mg/kg/day i.p.) or vasopressin (7.2 U/kg/day i.p.). The hypotensive effect of MK-421 was greater in sodium depleted than in sodium repleted rats. The hypertensive effect of norepinephrine or vasopressin was inhibited by the simultaneous administration of MK-421. MK-421 induced an increase in the excretion of urinary prostaglandin E, in both sodium repleted and depleted rats. However, simultaneous administration of MK-421 had no influence on the increase in urinary prostaglandin E excretion induced by norepinephrine or vasopressin. In addition, the combined administration of MK-421 with indomethacin (10 mg/kg/day s.c.) still abolished the hypertensive effect of norepinephrine or vasopressin. The disparate effect of MK-421 on urinary prostaglandin E excretion suggests that the renal prostaglandin system is not essential for the mechanism of the hypotensive effect of MK-421.

Effect of anti-alpha-fetoprotein serum on human hepatoblastoma

There is no definitive treatment of hepatoblastoma. Except for radical resection, the prognosis of unresectable cases remains pessimistic. Therefore, the development of new anticancer drugs for this tumor is urgently needed. Using the human hepatoblastoma cell line (c-HB-3) we demonstrated that horse anti-alpha-fetoprotein containing serum suppressed proliferation of the hepatoblastoma cells. This effect was dependent on the duration of exposure and the concentration of anti-alpha-fetoprotein serum.

[Evaluation of cefotaxime for postoperative infection in surgery]

Cefotaxime (CTX) was microbiologically and clinically studied in surgery. CTX shows excellent antibacterial activity in vitro against Gram-negative bacilli including E. coli. Klebsiella spp., and Proteus spp. in comparison with cefmetazole (CMZ) and cefazolin (CEZ). Antibacterial activity of CTX is found to be superior to that of CEZ and equal to that of CMZ against Gram-positive bacteria (S. aureus and S. epidermidis). The antibacterial activity of CTX against anaerobic bacteria exceeds that of CEZ and almost equal to that of CMZ. It also showed minimum inhibitory concentration values which, clinically speaking, offer great expectation. CTX is also superior to CMZ and CEZ in its antibacterial activity against P. aeruginosa. Clinical studies were carried out in the group A for which CTX was administered a drug of first choice for postoperative infections in surgery, and in the group B for which CTX was administered as a drug of second choice since the antibiotic of first choice had been ineffective for these cases. As a result, high effective rates were obtained in both groups (80.3% for the group A, and 77.1% for the group B). With reference to the group B, an effectiveness rate of 100% was obtained for the cases in which CEZ had been ineffective and 55.6% was obtained for 10 cases in which mainly combination of CMZ had been ineffective. Side effects appeared in 3 cases (1 case each of tinnitus and malaise, vomiting and nausea, and fever) with an incidence rate of 1.46%. Abnormal clinical laboratory findings appeared in 4 cases (1 case each of leukopenia and increase in GOT and GPT; eosinophilia; increases in platelet and monocyte; and increases in GOT, GPT and A1-P) with an incidence rate of 1.95%.