OBJECTIVETo study the influence of transcranial high-voltage electrical burn (HEB) on rheological changes of leukocytes in mesentery capillary in rats and the therapeutic effects of ulinastatin.

METHODSForty-five SD rats were divided into control (C), electrical burns (EB), and ulinastatin treatment (UT) groups according to the random number table, with 15 rats in each group. Model of HEB was reproduced in rats of EB and UT groups with voltage regulator and experimental transformer, and then rats in EB group was intraperitoneally injected with 2 mL isotonic saline while rats in UT group was intraperitoneally injected with 2 mL ulinastatin (2 x 10(4) U/kg). Rats in C group received sham burn with the same treatment as used in EB group but without electric current. Rheological changes of leukocytes in mesentery capillary were observed with Bradford microscope at 15 minutes before HEB and 5 minutes, 1, 2, 4, 8 hour (s) after HEB (PHM or PHH), including counting the number of rolling leukocytes, leukocytes rolling speed, the number of leukocytes adherent to mesentery capillary, total leukocyte-endothelium contact time (TLECT). Data were processed with t test.

RESULTS(1) The number of rolling leukocytes from PHM 5 to PHH 8 was increased in EB group and UT group as compared with that at 15 minutes before HEB, especially at PHM 5 [(51.4 +/- 3.2), (24.6 +/- 1.9) cells/min, respectively] which were higher than that in C group [( 1.1 +/- 0.7) cells/min, with t value respectively 59.28, 44.99, P values all below 0.05]. The number in UT group at each time point after burn was less than those in EB group, especially at PHM 5 (t = 27.97, P < 0.05). (2) Compared with that at 15 minutes before HEB, the rolling speed of leukocytes from PHM 5 to PHH 8 was slow in EB group and UT group, especially at PHM 5 [(90 +/- 9), (175 +/- 13) microm/s, respectively] which were slower than that in C group [(277 +/- 12) microm/s, with t value respectively 47.97, 21.59, P values all below 0.05]. The rolling speed in UT group from PHM 5 to PHH 8 was faster than that in EB group, especially at PHM 5 (t = 20.55, P < 0.05). (3) Compared with that at 15 minutes before HEB, the number of leukocytes per 100 micrometer capillary from PHM 5 to PHH 8 was increased in EB group and UT group, especially at PHM 5 (23.27 +/- 3.20, 5.80 +/- 1.61, respectively) which were higher than that in C group (0, with t value respectively 28.16, 13.95, P values all below 0.05). The number of adhered leukocytes in UT group at each time point after burn was less than that in EB group, especially at PHM 5 ( t = 18.89, P < 0.05). (4) Compared with that at 15 minutes before HEB, TLECT from PHM 5 to PHH 8 was increased in EB group and UT group, especially at PHM 5 [(14.45 +/- 1.99), (3.66 +/- 0.96) s/min, respectively] which were longer than that in C group (0 s/min, with t value respectively 28.12, 14.77, P values all below 0.05). TLECT in UT group from PHM 5 to PHH 8 was shorter than that in EB group, especially at PHM 5 (t = 18.91, P < 0.05). (5) No rolling leukocyte or wall-adherent leukocyte was found in blood flow of arterioles or capillaries of rats in three groups at each time point.

CONCLUSIONSTranscranial HEB can lead to abnormal rheological changes of leukocytes in mesentery capillary in rats, and the changes can be ameliorated by ulinastatin.