摘要:

SUMMARYEffects of 2‐phenylaminoadenosine on SA nodal pacemaker activity and atrial contractility were studied, using eleven isolated, blood‐perfused dog atrial preparations. The compounds were administered via the cannulated sinus node artery of the isolated atrium.2‐Phenylaminoadenosine induced negative chronotropic and inotropic effects and was 100 times less potent than adenosine in this action.The interaction between adenosine and 2‐phenylaminoadenosine was studied. 2‐Phenylaminoadenosine potentiated the effect of adenosine on atrial muscle, but not that of acet

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00164.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00165.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYDespite widespread use of the writhing response to phenylbenzoquinone or acetic acid injection in mice as a screen for analgesic activity, possible mediators of this response remain unidentified.In the present experiments bothin vivoandin vitrotechniques have been used in an attempt to identify these mediators.Acetic acid‐induced writhing was unaffected by pretreatment with mepyramine, methysergide, disodium cromoglycate or cimetidine.Phenylbenzoquinone‐induced writhing was partially blocked by pretreatment with mepyramine or other antihistamines.Using guinea‐pig isolated ileum and rat fundus preparations asin vitroassay systems, no significant differences were detected in histamine, serotonin, or prostaglandin content of peritoneal fluid from writhing and control mice.Acetylcholine levels were at the limit of detection in these samples, and there was no evidence of kinin release.Thus the mediators involved in the writhing response remain unde

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00166.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARY1.Right ventricular hypertrophy was produced in dogs by banding of the pulmonary artery for 28 days (n= 7) and results were compared with those in sham‐operated dogs (n= 5).2. Myocardial noradrenaline and adrenaline levels were depressed in both the hypertrophied right ventricle and the non‐hypertrophied left ventricle and plasma levels were increased compared to the control dogs.3. Myocardial β‐adrenoceptors were assessed in membrane preparations of both ventricles by3H‐dihydroalprenolol binding. No change in binding site concentration (pmol/mg membrane protein) or in binding affinity was found in either the hypertrophied right ventricle or in the left ventricle.4. Divergent results of studies on β‐adrenoceptors in ventricular hypertrophy are difficult t

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00167.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARY1. Stroke‐prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar Kyoto rats (WKY) were ‘chemically sympathectomized’ immediately after birth with 6‐hydroxydopamine (6‐OHDA, 100 mg/kg s.c. daily) for the first 10 days of life.2. Body weight gain was diminished in both groups as compared with sham‐treated controls. Blood pressure was reduced in ‘sympathectomized’ SHRSP, and also WKY rats had a slightly lower blood pressure than control rats.3. Plasma concentration of angotensin II and renin content of the kidney were not influenced by 6‐OHDA.4. ‘Sympathectomized’ SHRSP retained similar amounts of sodium than sham‐treated SHRSP when sodium retention is expressed per body weight gained. Plasma and blood volumes were increased in both SHRSP and WKY rats, whereas packed cell volume was significantly decreased.5. These results demonstrate the significance of an intact sympathetic nervous system for the development of hypertension in SHRSP. The expanded plasma and blood volume in ‘sympathectomized’ rats indicate an important role of the sympathetic nervous system and/or the arterial blood pressure for the regulat

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00168.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARY1. Cyclic AMP and cyclic GMP levels were determined in bovine splenic nerve segments in the absence and presence of (±) ‐ isoprenaline, (‐)‐phenylephrine, clonidine and ICI 63 197 (a phosphodiesterase inhibitor). The chosen concentrations of adrenoceptor agonists were those which are known to affect stimulation‐induced overflow of noradrenaline from nerve terminals.2. The mean levels of cyclic AMP ranged from 229 to 555 pmol/g of microwave irradiated tissue. Mean cyclic GMP levels ranged from 27.9 to 42.2 pmol/g.3.Isoprenaline enhanced cyclic AMP levels but did not affect cyclic GMP levels. The effect was blocked with (±)‐propranolol. ICI 63 197 increased cyclic AMP levels but did not change cyclic GMP. Phenylephrine and clonidine caused no consistent changes in cyclic AMP or cyclic GMP levels or in the concentration ratio between these two nucleotides.4.The results support the involvement of cyclic AMP in the enhancing effect of β‐adrenoceptor agonists and phosphodiesterase inhibitors on stimulation‐induced release of noradrenaline from sy

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00169.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYAntinociceptive activity of hen egg white lysozyme (Fleming's lysozyme) was determined against abdominal contractions provoked by irritants injected in‐traperitoneally into mice. Carrageenan (2 mg) (CA) injected with arachidonic acid (15 μg) (AA) or prostaglandins PGE1or PGF2α(0.04 ng), brewer's yeast (10 mg), caolin (10 mg), mepartricin (80 U) and phenylquinone (50 μg) were used as irritants.2 Lysozyme was active at 400‐800 mg/kg i.v. against CA + AA, CA + PG, brewer's yeast and caolin nociceptive stimulation. The compound was more effective against CA + AA than against CA + PG. Acetylsalicylic acid at 50‐100‐200 mg/kg p.o. was equally active against CA + AA and CA + PG.3 Lysozyme was inactive in the tail pinch and hot plate tests that mainly detect central analgesics.4 The results are discussed in relation to the claim advanced years ago that lysozyme is an effective analgesic agent in humans. The compound was found active against herpes zoster or cancer pain but did not find use despite the favourable reports presented.5 The experimental results obtained on laboratory animals do not contradict the conclusions drawn after the clinical use of th

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00170.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARY1. Phentolamine was infused at low increasing doses (0.2, 0.3, 0.4 and 0.5 mg/min) in five patients with unilateral renal artery stenosis measuring active and inactive (cryoactivable) renin in the renal veins from the stenosed and nonstenosed kidney and in a peripheral vein.2. PRA values from the stenosed kidney (11.59, s.e.m. = 5.79 pmol ang I/ml per h) were higher than those in the peripheral vein (5.19, s.e.m. =2.64) while these latter were similar to those from the contralateral kidney (5.09, s.e.m. =2.93). Phentolamine significantly increased PRA from the stenosed kidney and in the peripheral vein in a dose‐related manner. PRA changes were unrelated both to blood pressure decrements and to heart rate increments induced by the drug.3. Before phentolamine, inactive renin from the stenosed kidney (5.19, s.e.m. = 2.84 pmol ang I/ml per h) did not differ significantly from that on the contralateral side (3.15, s.e.m. = 1.96) and in the peripheral vein (4.40, s.e.m. = 1.96). Phentolamine induced significant (P<0.005) increments of inactive renin only from the stenosed kidney at the doses of 0.3, 0.4 and 0.5 mg/min. Inactive renin from the contralateral kidney was unchanged and it tended to increase, but not to a significant extent, in the peripheral vein. A highly significant relationship was found between active and inactive renin from the stenosed kidney (r = 0.79,P<0.001,n= 25) and in peripheral blood (r = 0.71,P<0.001,n= 25) but not from the stenosed kidney (r = 0.29,n= 25).4. These results suggest that phentolamine, infused at low increasing doses causes an increase of PRA only in the stenosed kidney, an action which does not seem to be wholly explained by either sympathetic nervous system activation or decrease of renal perfusion pressure, and which suggests an action on intrarenal a‐adrenoreceptors. Furthermore, phentolamine stimulated inactive renin release only from the stenosed kidney without evidence of intrarenal conversion of the inactive into the active f

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00171.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYTotal fluid and saline intakes were greater in spontaneously hypertensive rats (SHR) than in normotensive rats (NTR).Total fluid and saline intake were significantly elevated in prehypertensive SHR, 5 weeks old, compared with age‐matched NTR, and the intakes fell with age in both strains but remained considerably greater in SHR.In SHR, in which the blood pressure was maintained at normotensive levels by treatment with hydralazine, the saline and fluid intakes remained elevated above those of NTR.SHR and NTR fed low sodium diet with water alone to drink have similar excretion rates of sodium, suggesting that their ability to conserve sodium was normal.Measurement of sodium excretion after three different levels of sodium loading, on normal or low sodium diets, also failed to demonstrate an abnormality of renal function in SHR.These results demonstrate that the fluid and saline intakes of SHR are elevated compared with NTR and this difference is independent of the hypertension in SHR and is not secondary to enhanced renal sodium los

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00172.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

SUMMARYThe effects of daily administration of propranolol on the distribution of cardiac output were studied in the late pregnant guinea‐pig.The animals were given either saline, 5 or 50 mg/kg per day ofl‐propranolol for 15 days during the last trimester of gestation.Blood flow responses were assessed by injecting 15 μm microspheres into the conscious animal one to two days prior to parturition.The fraction of cardiac output reaching the placentas was significantly reduced in both groups (P<0.5 andP<0.001, respectively), while flow to all other organs studied remained unaltered.It is suggested that propranolol exerts a selective effect on the placental vascular bed in the guinea

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1983.tb00173.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY