Fig. 7
Involvement of proteinase-activated receptor type 1 (PAR1) in the serosal trypsin-induced I sc increase. a–c Attenuation of the ΔI sc induced by trypsin after pre-exposure to SFFLRN-NH 2 , a PAR1-activating peptide (AP). a The control ΔI sc induced by serosal trypsin (100 nM). Mean values are presented, n = 4. b ΔI sc induced by trypsin was obtained in the tissue that had been pretreated with serosal SFFLRN-NH2. Mean values are presented, n = 4. c Peak values for ΔI sc induced by serosal trypsin (100 nM) in the absence (control; shown in a) and presence (SFFLRN-NH 2 ; shown in b) of pre-exposure to PAR1-AP. Each data value is presented as the mean ± SE. *P < 0.05, paired t test. d–e Attenuation of ΔI sc induced by the serosal PAR1-AP (30 μM), after pre-exposure to serosal trypsin (100 nM). d The control ΔI sc induced by SFFLRN-NH2 was obtained in tissue that had been pretreated with trypsin, but only after the soybean trypsin inhibitor (0.59 mg/ml, serosal side) had been added. Mean values are presented, n = 4. e The soybean trypsin inhibitor was added after trypsin had worked for 20 min, and ΔI sc induced by SFFLRN-NH2 was finally obtained. Mean values are presented, n = 4. f The peak values for the increases in I sc (ΔI sc) induced by SFFLRN-NH2 after pre-exposure to trypsin (trypsin treated; shown in e) are expressed as a percentage of the control response (control; shown in d) obtained in the adjacent tissue. Each data value is presented as the mean ± SE. *P < 0.05, paired t test