Purpose: To evaluate the effects of colforsin daropate, a water-soluble derivate known to improve contractility in fatigued canine diaphragm, at two different doses (low-dose and high-dose) on contractility of the non-fatigued diaphragm of dogs.
Methods: Twenty-four pentobarbitone-anesthetized dogs were divided into three groups of eight each: Group I received no study drug; Group II received low-dose (0.2 microg x kg-1 x min-1) colforsin daropate; Group III received high-dose (0.5 microg x kg-1 x min-1) colforsin daropate. Diaphragmatic contractility was assessed by transdiaphragmatic pressure (Pdi).
Results: In Group III, with an infusion of high-dose colforsin daropate, Pdi at low-frequency (20 Hz) and high-frequency (100 Hz) stimulation increased from baseline values (P < 0.05). Compared with Group I, Pdi at both stimuli increased during colforsin daropate administration in Group III (P < 0.05). In Group II, with an infusion of low- dose colforsin daropate, Pdi to each stimulus did not change.
Conclusion: Colforsin daropate, only when administered at high-dose, increases contractility of non-fatigued diaphragm in dogs.