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N. F. GOLDSMITH, H. HUGGEL AND H. K. URY 



In this paper \ve estimate the gradients in pH, electrolytes and clotting 

 factors in normal rats after hemorrhage by sequential cardiac puncture. Compared 

 to control animais, rats injected with norethynodrel with mestranol have a dimin- 

 ished magnésium shift with hemorrhage. 



METHODS 



Sprague-Dawley rats, weight between 100-200 g, were maintained on pre- 

 scribed diets for five days. Three diets were used: a standard laboratory cbow 

 (Girard ground pellets, magnésium 0.3 ° , Ca/Mg = 10); an enriched formula 

 with added vitamins and trace minerais (Altromin, magnésium 1.5 %, Ca/Mg = 9); 

 and a magnesium-poor, enriched formula (Altromin-Mg, magnésium 0.01 %). 

 Groups included controls after 5 days on the diet (day controls), rats injected 

 subcutaneously with corn oil 0.1 ml per day for 3 or 4 additional days (oil-injected), 

 or with Enovid in corn oil, 1 mg per kg per day (Enovid-injected) and non-injected 

 controls. 



After ether anesthesia, the chest was opened and the animal was bled by 

 repeated cardiac punctures at différent sites in the right ventricle. Separate sili- 

 conized 2 ml syringes and needles were used for each blood sample; syringes coated 

 with siliconized oil were used for the pH study. Sample volumes were noted to 

 0.1 ml. The syringes when calibrated with distilled water had a coefficient of 

 variation of less than 1 percent. Blood samples were randomly numbered in 

 expts. 2-8. 



Glass capillary clotting time was tested on fresh whole blood taken from the 

 needle tip; other clotting tests were determined on citrated blood the same day. 

 Potassium was analyzed in fresh sérum; other ions were analyzed after storage 

 at — 30 C. Clotting tests included glass capillary clotting time read at 15-second 

 intervais (Lee and White, 1913), fibrinogen (Clauss, 1957), thromboelastographic 

 amplitude after 25 minutes, TEGa. and thromboelastographic recalcification 

 time, TEGr ( (von Kaulla, 1962; Goldsmith et ai, 1966). TEG amplitude, a 

 measure of clot elasticity, is augmented by increased in fibrinogen, platelets and 

 fibrin stabilizing factor (De Nicola, 1957; SiGG and Duckert, 1963); TEGr is 

 prolonged by decreases in prothrombin and calcium. Counts were made of plate- 

 lets, leucocytes and red cells (Rees and Ecker, 1923; Lelenberger and Lorenz, 

 1959). 



Sérum magnésium and calcium were analyzed by atomic absorption spectro- 

 photometry (Willis, 1963), potassium by tlame photometry (Evans, 1965), phos- 

 phate by the micro method of Baginski and Zak (1960), blood pH with the Sanz 

 apparatus using two standard bufTers. Ion déterminations were made in duplicate. 

 The Wilcoxon matched pairs signed rank test and Studcnt's / were used to test 

 for significance (SlEGEL, 1956). 



