Renal mass was surgically reduced in 78 dogs by uninephrectomy or by combined renal infarction and uninephrectomy. Renal clearance of inulin and renal clearance of exogenous creatinine were determined simultaneously, and the creatinine to inulin clearance (C/I) ratio was calculated. Clearance procedures were performed 2 to 3 months after reduction of renal mass, and were repeated at intervals thereafter. Overall, the C/I ratio was 1.008 +/- 0.007 for 192 determinations, with a highly significant correlation (R2 = 0.994, P < 0.0001) between creatinine clearance and inulin clearance. There was no significant effect of gender of dogs, time after partial renal ablation, or dietary protein intake on C/I ratios. Degree of renal ablation did not affect C/I ratios. The results indicated that exogenous creatinine clearance is a valid measure of glomerular filtration rate in both male and female dogs with reduced renal mass.

Pharmacokinetic variables of skeletal muscle creatine kinase (CK) activity after IV administration of a muscle extract; CK bioavailability after IM administration of the muscle extract; and effect of IM administration of saline solution, to appreciate the possible release of CK consecutive to muscle puncture, were determined in 6 cows. A general equation for the quantitative estimation of skeletal muscle damage also was derived. Administration of saline solution IM had no effect on plasma CK activity (ANOVA, P > 0.05) in any of the cows. After IV administration of the muscle extract (150 U/kg of body weight), mean volume of the central compartment, plasma half-life, and plasma clearance of CK were 0.027 +/- 0.007 L/kg, 520 +/- 109 minutes, and 6.43 +/- 2.29 ml/kg/h, respectively. After IM administration (150 U/kg), mean bioavailability of CK was 51 +/- 17% and maximal plasma CK activity (500 +/- 97 U/L) was observed at 454 +/- 131 minutes. The rate of CK activity entry into plasma was determined by use of deconvolution analysis. Two peaks were observed; the first appeared before the 30th minute after IM administration, and the second appeared at 3.3 +/- 1.1 hours. Amplitudes were 6.31 +/- 4.45 and 6.57 +/- 3.08 U/kg/h, for the first and the second peaks, respectively. The quantity of CK liberated from control muscle was 0.69 +/- 0.12 U/kg/h, corresponding to a normal daily catabolism of 5.8 +/- 1.0 mg of muscle/kg. From these results, the following equation can be proposed to determine the corresponding mean equivalent of destroyed muscle (Qmuscle, test article) after IM administration of a test article: Qmuscle, test article (g/kg) = 4.41 X 10(-6) AUC (U/h/L), with AUC being the CK plasma activity area under the curve.

There was studied the feature of hematological and biochemical blood indicators of rats at action of acute ionising radiation against acute stress influences. Results of research of hematological and biochemical blood indicators of rats developing under influence of stress and radiating factors are presented. It is established, that on 4 days twenty-four-hour period after the influence of pointed ionizing radiation against a background of pointed stress impact some changes become evident. They appear in reducing of total number of leucocytes, haemoglobin, hematocrit and general albumen, and also in increase of such ferment activity as lactate dehydrogenase, creatine phosphokinase, aspartate aminotransferase, alanine aminotransferase. | Целью исследования является изучение особенности гематологических и биохимических показателей крови крыс при действии острого ионизирующего излучения на фоне острого стрессорного воздействия. Представлены результаты исследования гематологических и биохимических показателей крови крыс, развивающихся под влиянием стрессорного и радиационного факторов. Установлено, что на 4 сутки после действия острого ионизирующего излучения на фоне острого стрессорного воздействия отмечаются изменения, выражающиеся в снижении общего количества лейкоцитов, гемоглобина, гематокрита и общего белка, а также увеличении активности ферментов лактатдегидрогеназы, креатинфосфокиназы, аспартатаминотрансферазы и аланинаминотрансферазы.