摘要:

SUMMARY1. The limited therapeutic role of pulmonary vasodilation reflects lack of their selectivity for the pulmonary vasculature, and many drugs have been evaluated for effectiveness; however, none has gained widespread clinical use.2. Milrinone (MIL) is a newly synthetized phosphodiesterase inhibitor, which has potent positive inotropic and vasodilatory effects.3. The present study shows the effects of MIL on the pulmonary circulation in dogs with pulmonary hypertension due to autologous muscle‐induced pulmonary embolism, and also demonstrates a comparison with those of dopamine and dobutamine.4. As MIL showed potent vasodilatory effects on the pulmonary vasculature, it had a potential clinical role in the treatment of pulmonary hypertensio

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01267.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. The effects of porcine endothelin‐1 (10‐12‐5 × 10‐10mol/kg) on arterial blood pressure (BP) and the renal, mesenteric and carotid blood flow (BF), and the effects of endothelin‐1 antibody were studied in rabbits.2. Endothelin‐1 caused a sustained increase in BP. The renal, mesenteric and carotid BF were decreased dose‐dependently by endothelin‐1. The approximate half‐maximal effective values (ED50) were 5.5 × 10‐11, 8.6 × 10‐11and 2.0 × 10‐10mol/kg for renal, mesenteric and carotid BF respectively. Compared with carotid BF, the renal and mesenteric BF responses were significantly more sensitive to endothelin‐1.3. Combined administration of endothelin‐1 and its antibody showed a significant inhibition of the BP and renal BF responses. However, endothelin‐1 antibody alone did not change either BP, renal BF, mesenteric BF or carotid BFin vivo.4. The present results demonstrate that endothelin is a potent vasoconstrictorin vivo.However, circulating endothelin may not contribute to the control of BF and BP. The role of endothelin as a local modulator of the vascula

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01268.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. To investigate the effect of lignocaine upon coronary blood flow, myocardial systolic wall function and high energy phosphate stores, lignocaine was administered as a rapid intravenous injection to 14 open chest anaesthetized swine.2. Before and after injection, measurements were made of coronary blood flow by electromagnetic flow probe, per cent wall thickening by ultrasonic crystals, adenosine triphosphate (ATP) and creatine phosphate (CP) content by myocardial biopsy, and arterial pressure by central aortic catheter. The animals were divided into two groups based on whether or not they received a continuous low‐dose infusion of lignocaine prior to the study. Group I received the continuous low‐dose infusion of lignocaine and group II did not.3. With a 2 mg/kg lignocaine injection, peak diastolic coronary flow rose significantly in groups I and II by 27±7 and 29±7% respectively. This was followed by a significant decline in per cent wall thickening in groups I and II of ‐11±2 and ‐19±6% respectively. In group I myocardial CP content decreased after lignocaine injection by 58±6% and ATP tended to rise even though systolic and diastolic pressure did not change significantly. In group II neither CP nor ATP changed significantly, but systolic and diastolic blood pressure decreased significantly.4. Repeat lignocaine injections were given over a wider dosage range (0.5–4.0 mg/kg) to determine dose–response for lignocaine versus coronary blood flow. Coronary blood flow increased and per cent wall thickening decreased as doses of lignocaine were increased.5. It was concluded that rapid intravenous lignocaine injection appeared to cause a dose‐dependent coronary dilatation and systolic dysfunction. Pre‐treatment with low‐dose continuous infusion of lignocaine appeared to result in a decrease in CP and a rise in ATP when compared with no pre‐treatment—despite a similar effect on myocardial functi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01269.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. In our study we followed the growth rate and the haematologic changes occurring in albino rats of Wistar strain when living in a hypoxic environment. Two generations of hypoxic rats were observed for changes in their erythrocytes (RBC), haematocrit (Hct) and haemoglobin (Hb): the first generation (H1) and the second generation (H2). A few hours after birth, the H1 rats were placed and raised in a normobaric hypoxic environment (10% O2in N2). The H2 rats were born and raised in the environment previously described. The control group had a normoxic environment. The H1 and H2 rats had inferior growth rates in respect to their controls, but H2 were found to have a larger growth rate than the H1 group. The RBC, Hct and Hb had values significantly greater for both H1 and H2 when compared with their controls. However, we did find that the values of H2 were significantly lower than H1. We believe that these results are in relation to the degree of development of the adaptive processes to the hypoxic environment of the H2 rats.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01270.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. The effects of prolonged administration of testosterone oenanthate (TE) on sympathetic neurotransmission to the rat isolated seminal vesicle were examined.2. TE was administered at either 1.2 or 2.4 mg/kg subcutaneously (s.c.) thrice weekly for 8 weeks. A separate group of rats was administered the vehicle, sesame oil, 0.5 mL/kg, s.c. at the same regime and used as controls. TE administration increased plasma testosterone and dihydrotestosterone levels and seminal vesicle weights. TE 2.4 mg/kg suppressed fertility in male rats.3. The mean ‐log EC50values of adrenalin and noradrenaline in seminal vesicles from the control group were 5.30 (95% confidence limits: 5.14, 5.58; d.f. = 14) and 4.92 (95% confidence limits: 4.56, 5.49; d.f. = 14) respectively. Neither of these estimates were modified by TE administration.4. The mean noradrenaline content (μg/tissue) in seminal vesicles from control rats was 0.88±0.09 μg/tissue. This did not change with TE treatment. Tissue noradrenaline concentration (μg/g tissue), on the other hand, decreased by more than 50% in preparations from rats treated with TE. This was paralleled by a decrease in the density of catecholamine fluorescence.5. Mean responses to field stimulation (20 pulses, 60 V dial setting, 2 ms, 1–70 Hz) appeared to decrease in preparations from TE treated groups; this decrease was, however, not statistically significant (P>0.05; d.f. = 15).6. It is concluded that prolonged administration of testosterone oenanthate to rats, at doses sufficient to suppress fertility, decreases the density of sympathetic innervation to the seminal vesicle by increasing smooth muscle mass. Treatment does not, however, modify the responses of this preparation to exogenously added catecho

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01271.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Intravenous infusions of UK14304 (0.3–10 μg/kg per min) in pithed rat produced dose‐dependent pressor responses which were not affected by prazosin (10 μg/kg) but were reduced by yohimbine (0.3 mg/kg).2. Pressor responses to noradrenaline (0.1 μg/kg), phenylephrine (1 μg/kg) and vasopressin (10 mU/kg) were enhanced during infusions of UK14304 (0.03–1 μg/kg per min). Likewise, pressor responses to spinal sympathetic stimulation were enhanced during infusions of low concentrations of UK14304 (0.03–0.3 μg/kg per min) but were reduced during infusion of a higher concentration of UK14304 (10 μg/kg per min).3. After administration of yohimbine (0.3 mg/kg) or the calcium channel blocking drug diltiazem (infused at 50 μg/kg per min), pressor responses to noradrenaline and UK14304 were reduced, and responses to noradrenaline during infusion of UK14304 were not enhanced.4. Prazosin (10 μg/kg) revealed a secondary depressor component in the response to sympathetic stimulation which is due to β‐adrenoceptor activation, since it was abolished by ICI 118551 (0.3 mg/kg). In the presence of ICI 118551 plus prazosin, pressor responses to sympathetic stimulation were enhanced during infusions of UK14304.5. The depressor response to nitroprusside and the depressor component of responses to sympathetic stimulation after prazosin were enhanced during infusions of UK14304 at concentrations that increased the blood pressure.6. The findings show that α2‐adrenoceptor activation enhanced the pressor responses to sympathetic nerve stimulation, noradrenaline, phenylephrine and vasopressin in the pithed rat and α‐adrenoceptor activation produced depressor responses which increased with

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01272.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. Rabbits were treated with the antiparasitic drug ivermectin at subcutaneous doses of 0.2, 1 and 2.5 mg/kg and blood collected weekly for 4 weeks thereafter for measuring some blood parameters. At a dose of 0.2 or 1 mg/kg the drug had no significant effect on any of the parameters measured. At a dose of 2.5 mg/kg, the drug reduced significantly the erythrocyte counts, haemoglobin concentration, haematocrit, mean corpuscular haemoglobin concentration and mean corpuscular haemoglobin on weeks 1, 2, 3 and 4. Platelet counts were not significantly affected.2. In another trial, ivermectin was injected subcutaneously at a dose of 2.5 mg/kg, after pre‐treatment with either saline or vitamin K (30 μg/kg for 30 days), and prothrombin time, bleeding time and platelet counts measured at weekly intervals for 4 weeks. Bleeding time and thrombin time were significantly increased 1 week after treatment, and remained higher than the control for 4 wee

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01273.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARY1. One millilitre of 5% glucose (vehicle,n= 10) or 1 mL solution of lithium chloride (LiCl) (0.5 or 2.0 mmol/kg per day,n= 10 for each) was injected intraperitoneally in Wistar rats at 10:00 or 22:00 h for 6 days. Blood samples for ionized and total calcium were taken on day 7.2. Mild elevations in ionized, but not non‐ionized (total‐ionized) calcium were observed following LiCl treatment in both administration times.3. The increment in ionized calcium was greater when LiCl was injected at 22:00 h than when it was given at 10:00 h.4. These data indicate that: (1) the influence of lithium on calcium metabolism varies with its administration time; and (2) mild hypercalcaemia induced by the agent mainly depends on the elevation in the ionized fraction of calc

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01274.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Report on AIDS: Policies and Programs for the Workplace.By Kathleen C. Brown and Joan G. Turner.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1990.tb01275.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY