ISSN:
0942-0940
Keywords:
Substance P
;
vasospasm
;
subarachnoid haemorrhage
;
isometric tension recording
;
cyclic GMP
;
rabbit
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The vasoactive effects of substance P (SP), as well as the content of cyclic guanine monophosphate (cGMP), were determined in the rabbit basilar artery after subarachnoid haemorrhage (SAH). Out of 47 rabbits, 24 were subjected to a SAH, induced by injecting 5ml of autologous arterial blood into the cisterna magna; 23 were used as controls. In 20 animals (10 SAH and 10 controls), isometric tension recording of isolated rings of the basilar artery — dissected 2 days after SAH — was employed to assess the dosedependent vasodilatation to SP (10−10 to 10−6M) after precontraction with serotonin (10−8 to 10−5M). In 15 animals (8 SAH and 7 controls), the basal cGMP content was measured in the basilar artery 2 days after SAH. In the other 12 animals (6 SAH and 6 controls), the increase in cGMP content was measured in the basilar artery after a 10-minute incubation with SP (10−6M). SP caused significantly less dilatation in animals subjected to SAH than in controls, especially for concentrations between 10−9 and 10−6M (p 〈 0.001). The cGMP content in the arteries 2 days after SAH was significantly lower than in control arteries (31.5 ± 7.3 against 57.3 ± 4.3 pmoles/g tissue). In the preparations incubated with SP, the increase of cGMP was 440 ± 115% in the control arteries, and only 97 ± 30% in the arteries after SAH. It is concluded that the vasodilator activity of SP is significantly impaired after SAH. Moreover, the changes in cGMP content after SAH suggest a link between impaired vasoactive response to SP and decreased production of cGMP after SAH.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01541798
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