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A new, simple and fast method for directional pulsed doppler flow probe-construction
1301 experiments the vessels were denuded of endothelium. The vessels were cleaned and rings were prepared and gently suspended in a 20 mL, organ bath containing a physiological solution. The rings were subjected to an initial tension of 1 g, maintained at 37°C, gassed continuously with 95~; 02 and 5% CO2 and allowed to equilibrate for 2 hours. After the equilibration period the rings were contracted with bolus doses of NA (30 uM) and the absence of the endothelium was demonstrated by the lack of relaxatory activity of ACh (50 uM). In subsequent studies the rings with/without endothelium were initially contracted with ET-1 (5 pmoles) and when a sustained contraction was reached cumulative dose response curves were constructed to cicletanine (1 × 10 -5 to 2 x 10 -4 M) and atrial natriuretic peptide (ANP: 1 to 4 ug/mL). In a further study the rings (n = S) were incubated with indomethacin (5 uM) for 15 minutes and the effects of cicletanine on ET-1 induced contraction were reexamined. Cicletanine produced dose dependent inhibition of the ET-1 induced contraction in the presence and absence of endothelium. Data showed that the cicletanine was producing slightly greater inhibitory effects in denuded rings compared to non-denuded rings. This difference was non-significant. In this preparation ANP also produced inhibitory effects on ET-1 precontracted rings, but was not as effective as cicletanine. At the highest dose ANP failed to produce more than 50~; inhibition on the contracted rings. In the final study indomethacin blocked the relaxatory effects of cicletanine. The findings indicate that cicletanine elicits greater inhibitory activity in the denuded rings. Recent evidence has emerged suggesting that removal of the rat aortic endothelium enhances the in vitro release of PGI2 in response to numerous agents like noradrenaline and thromboxane A2 (U46619) analogue (Jeremy and Dandona, 1989). In this study ANP was able to inhibit the ET-1 induced contractions in the rings, however, cicietanine appears to be more effective than ANP. Further evidence from this study indicates that inhibition of cyclo-oxgenase activity with indomethacin blocks the relaxatory effects of cicletanine. In conclusion this supports the mour,;ing evidence that cicletanine produces its effects through releasing PGI2.
References Dorian et al., 1984, Biochem. Pharmacol. 33, 2265. Guinot, P and Frolich, J.C., 1985, Drug Res. 35, 1714. Jeremy, J.Y. and Dandona, P., 1989, Br. J. Pharmacol. 96, 243.
I P.we.150 I
A new, simple and fast method for directional pulsed doppler flow probe-construction Wouters, W., Cornelissen, J., Hoetmer, B. and Remie, R. Department of Pharmacology, Duphar B. V., P.O. Box 900, 1380 DA Weesp, The Netherlandv
The availability of an ultrasonic pulsed Doppler flowmeter system (545C-4, Bioengeneering, University of Iowa, USA) has enabled us to measure continuously multiple regional blood flows, using a small single piezoelectric crystal that functions as a transmitter-receiver. The cristal operates at a frequency of 20 MHz and is encapsulated in a silicon cuff. However, probe construction as described by Haywood et al. (1981) is a time-devouring affair and commerciai|y available probes are very expensive. We developed a simple and fast method to construct smali flow probes, which were used in freely moving rats as well as in anaesthetized animals. The signals of both types of probes were compared. 1. In a piece of Silastic Medical-Grade Tubing (Dow-Corning 0.76 nun I.D., 1.65 mm O.D., and 15 mm long) a hole was made under a 45 o angle to the lumen, using a sharpened blund 20G hypodermic needle (hole-puncturer). 2. The cristal together with insulated electrical leads was inserted into the lumen under a 45 ° angle and was kept in place with silicon glue. 3. Another piece of Silastic tubing of the desired diameter was glued against the tube containing the cristal. The insulated wires were covered with silicon glue at the point where they passed the Silastic tubing. 4. The tube was cut longitudinally and from the inside the wall of the silicon tubing was punctured under a 45 ° angle with a sharpened blund 17G needle.
1302 5. The tubing was cut to size and was ready for use. Probes were placed around the infra renal abdominal aorta, just caudal from the left spermatic artery and were secured with two 8-0 Ethilon (Ethicon) sutures. The wires together with a lniniature two-pole plug (made from an IC-foot) were run subcutaneously and emerged at the crown of the head where they were fixed to the skull with acrylic glue. In our hands probc-construction takes about 10 rain. The obtained signals did not differ in amplitude nor in signal to noise-ratio when compared to ,,he former method.
Reference Haywo¢~l, J.R., R.A. Shaffer,C. Fastenow, G.D. Fink and MJ. Brody (1981) Am. J. Physiol.241 (Heart Circ. Physiol.10): H273-H278.
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Pharmacological activity o| a natural flavono~d (IdB 1056) Conti, M., Cristoni, A. and Magistretti, M.J. lnverni della Beffa Research and Development Laboratories, Milan, Italy
Flavonoids, a family of compounds widely occurring in plant PAngdom, are reported to possess interesting pharmacological properties including vasoprotective, healing and antiinflammatory activities (Gabor, 1982; Anton, 1988).As a part of a sistematic research on bioflavonoids and in particular on anthocyanidins, we have synthesised 3,5,7-trihydroxy-2-(3,4,5-trihydroxyphenyl)-l-benzopyrilium chloride (IdB 1056), endowed with antioxidant and free radical scavenging activities (Gabetta et al., 1990). The effects of IdB 1056 on the peripheral circulation were tested in rats and rabbits using the Evans Blue leakage technique according to the method of Udaka and in guinea pigs fed on vitamin and deficient diet according to the method of Crampton. IdB 1056 dose dependently reduced the increase of capillary permeability induced by intradermal injection of different noxious agents. At intraperitoneal doses betweer~ 12.5 and 200 mg/kg and at oral doses of 100 and 200 mg/kg, IdB 1056 compared favourably with the reference drugs. IdB 1056 was also able to reduce the rabbit ciliary body microvascular permeabiligy increased by local application of histamine. The activity was already statistically significant after a single oral administration (100 or 200 mg/kg) and became more evident after repeated administrations. Vhen given by oral route at doses of 200 or 400 m g / k g to guinea pigs, IdB 1056 significantly enhanced the cap~,try resistance impaired by a vitamin and deficient diet. The vasoprotective activity together with the very good tolerability makes IdB 1056 a good candidate for a deeper pharmaco!o~cal evaluation.
References Gabor, M., in: Flavonoids and Bioflavonoids, 1981, Eds. Farkas L. et al., p. 3~3, F!sevier Scientific Publishing Company - N.Y., 1982. o Anton, R., Progress in Clinical and Biological Research, 280, p. 423, 1988. Gabetta, B., Morazzoni, P., Pifferi G, International Joint Symposium on Biology and Chemistry of Active Natural Substances, Bonn - July 17, 1990.
References Dorian et al., 1984, Biochem. Pharmacol. 33, 2265. Guinot, P and Frolich, J.C., 1985, Drug Res. 35, 1714. Jeremy, J.Y. and Dandona, P., 1989, Br. J. Pharmacol. 96, 243.
I P.we.150 I
A new, simple and fast method for directional pulsed doppler flow probe-construction Wouters, W., Cornelissen, J., Hoetmer, B. and Remie, R. Department of Pharmacology, Duphar B. V., P.O. Box 900, 1380 DA Weesp, The Netherlandv
The availability of an ultrasonic pulsed Doppler flowmeter system (545C-4, Bioengeneering, University of Iowa, USA) has enabled us to measure continuously multiple regional blood flows, using a small single piezoelectric crystal that functions as a transmitter-receiver. The cristal operates at a frequency of 20 MHz and is encapsulated in a silicon cuff. However, probe construction as described by Haywood et al. (1981) is a time-devouring affair and commerciai|y available probes are very expensive. We developed a simple and fast method to construct smali flow probes, which were used in freely moving rats as well as in anaesthetized animals. The signals of both types of probes were compared. 1. In a piece of Silastic Medical-Grade Tubing (Dow-Corning 0.76 nun I.D., 1.65 mm O.D., and 15 mm long) a hole was made under a 45 o angle to the lumen, using a sharpened blund 20G hypodermic needle (hole-puncturer). 2. The cristal together with insulated electrical leads was inserted into the lumen under a 45 ° angle and was kept in place with silicon glue. 3. Another piece of Silastic tubing of the desired diameter was glued against the tube containing the cristal. The insulated wires were covered with silicon glue at the point where they passed the Silastic tubing. 4. The tube was cut longitudinally and from the inside the wall of the silicon tubing was punctured under a 45 ° angle with a sharpened blund 17G needle.
1302 5. The tubing was cut to size and was ready for use. Probes were placed around the infra renal abdominal aorta, just caudal from the left spermatic artery and were secured with two 8-0 Ethilon (Ethicon) sutures. The wires together with a lniniature two-pole plug (made from an IC-foot) were run subcutaneously and emerged at the crown of the head where they were fixed to the skull with acrylic glue. In our hands probc-construction takes about 10 rain. The obtained signals did not differ in amplitude nor in signal to noise-ratio when compared to ,,he former method.
Reference Haywo¢~l, J.R., R.A. Shaffer,C. Fastenow, G.D. Fink and MJ. Brody (1981) Am. J. Physiol.241 (Heart Circ. Physiol.10): H273-H278.
P.we.151 [
Pharmacological activity o| a natural flavono~d (IdB 1056) Conti, M., Cristoni, A. and Magistretti, M.J. lnverni della Beffa Research and Development Laboratories, Milan, Italy
Flavonoids, a family of compounds widely occurring in plant PAngdom, are reported to possess interesting pharmacological properties including vasoprotective, healing and antiinflammatory activities (Gabor, 1982; Anton, 1988).As a part of a sistematic research on bioflavonoids and in particular on anthocyanidins, we have synthesised 3,5,7-trihydroxy-2-(3,4,5-trihydroxyphenyl)-l-benzopyrilium chloride (IdB 1056), endowed with antioxidant and free radical scavenging activities (Gabetta et al., 1990). The effects of IdB 1056 on the peripheral circulation were tested in rats and rabbits using the Evans Blue leakage technique according to the method of Udaka and in guinea pigs fed on vitamin and deficient diet according to the method of Crampton. IdB 1056 dose dependently reduced the increase of capillary permeability induced by intradermal injection of different noxious agents. At intraperitoneal doses betweer~ 12.5 and 200 mg/kg and at oral doses of 100 and 200 mg/kg, IdB 1056 compared favourably with the reference drugs. IdB 1056 was also able to reduce the rabbit ciliary body microvascular permeabiligy increased by local application of histamine. The activity was already statistically significant after a single oral administration (100 or 200 mg/kg) and became more evident after repeated administrations. Vhen given by oral route at doses of 200 or 400 m g / k g to guinea pigs, IdB 1056 significantly enhanced the cap~,try resistance impaired by a vitamin and deficient diet. The vasoprotective activity together with the very good tolerability makes IdB 1056 a good candidate for a deeper pharmaco!o~cal evaluation.
References Gabor, M., in: Flavonoids and Bioflavonoids, 1981, Eds. Farkas L. et al., p. 3~3, F!sevier Scientific Publishing Company - N.Y., 1982. o Anton, R., Progress in Clinical and Biological Research, 280, p. 423, 1988. Gabetta, B., Morazzoni, P., Pifferi G, International Joint Symposium on Biology and Chemistry of Active Natural Substances, Bonn - July 17, 1990.