Adrenocortical function was assessed in 27 Beagle pups at 2, 4, 6, 8, 10, and 12 weeks of age by determination of plasma sodium, potassium, and chloride concentrations; serum aldosterone and cortisol concentrations; and plasma ACTH concentrations. Serum cortisol concentration was measured before and 1 and 2 hours after IM administration of 2.2 IU of ACTH/kg of body weight. Serum progesterone concentration also was determined for all pups at 2, 4, and 6 weeks of age. Mean baseline cortisol concentration was lower for pups 8 weeks old or younger than for mature dogs. Nevertheless, mean serum ACTH-stimulated cortisol concentration in dogs of all age groups increased into the adult reference range after administration of ACTH. For pups 4 weeks old or younger, increase in cortisol concentration was maximal at 2 hours after ACTH administration. However, in pups between 6 and 12 weeks of age, the increase in cortisol concentration was maximal 1 hour after ACTH administration in about a third of the pups, whereas the remaining pups had peak values at 2 hours. Mean plasma sodium, potassium, and chloride concentrations for each age group were within the reference ranges established for mature dogs, with the exception of lower mean plasma sodium and chloride concentrations in pups 4 weeks old or younger. Mean serum aldosterone concentration in pups of each age group was substantially higher than the range of aldosterone concentrations for clinically normal mature dogs. Median progesterone concentration was uniformly less than 0.2 ng/ml for all pups 6 weeks old or younger. The normal endogenous ACTH concentration and adequate cortisol responses to exogenous ACTH seen in our pups would support functional pituitary gland and adrenal cortex for cortisol production. The low baseline cortisol concentration observed in the pups of this study may be related to reduced binding of cortisol to plasma proteins, as exists in human infants.

Ouabain, a cardiac glycoside, binds to the Na+-K+i-adenosine triphosphatase (Na+ pump) and prevents active transport of Na+ and K+ across cell membranes. We used [3H]ouabain to quantify the number and affinity of Na+ pumps in skeletal muscle from Quarter Horses with the muscular disorder hyperkalemic periodic paralysis (HYPP). [3H]Ouabain-binding properties of gluteal muscle from clinically normal and affected horses were used to determine whether altered Na+ pump number or affinity could contribute to the pathologic features of muscle in affected horses. Foals and adult horses with HYPP were compared with age-matched clinically normal horses. The number of [3H]ouabain-binding sites in adult gluteal muscle was not different between the 2 types of horses (85.7 +/- 8.9 pmol of [3H]ouabain-binding sites/g [wet muscle weight] in horses with HYPP vs 100.2 +/- 8.8 pmol/g in clinically normal adult horses). Gluteal muscles in HYPP-affected and clinically normal foals also contained a similar number of [3H]ouabain-binding sites (222.3 +/- 21.0 pmol/g vs 225.3 +/- 24.2 pmol/g, respectively). The affinity of these binding sites for ouabain was not different, between adults or foals, in clinically normal or affected horses. Our results indicate that membrane events underlying the periodic episodes of paralysis in horses with HYPP are not attributable to quantitative changes in Na+ pump number or affinity. Our data cannot exclude the possibility that the specific activity of the Na+ pump is altered in muscle from HYPP-affected horses.

Samples of serum and urine were obtained simultaneously from 56 healthy lactating cows to determine ranges of fractional excretion (FE) of calcium (Ca), phosphate (PO4), magnesium (Mg), sodium (Na), potassium (K), and chloride (Cl). Samples were obtained at 3 stages of lactation: period 1 = 1 to 7 days, 2 = 83 to 112 days, and 3 = 175 to 197 days. The FE of electrolytes were significantly different among periods 1, 2, and 3 for Ca (P < 0.001), PO4 (P < 0.025) and Mg (P < 0.025), but were not significantly different for Na, K, and Cl. Least squares mean FE of Ca was lowest in period 1 and not significantly different for periods 2 and 3, whereas mean FE values for PO4 and Mg were highest in period 2 and not significantly different for periods 1 and 3. The mean FE values of Na, K, and Cl did not change with stage of lactation. Age and category of milk production (high, medium, and low) did not influence the FE values of the electrolytes.

The present study was conducted in order to get the normal blood chemical values of Korean Jindo dogs. Blood samples were taken from 160 (male 34, female 126) healthy Jindo dogs in Jindo area. The mean values of serum total protein (TP), albumin (Alb) and globulin (Glb) content, cholesterol (Chole), magnesium (Mg), calcium (Ca), inorganic phosphate (P), potassium (K), sodium (Na) and chloride (Cl) concentration in the group of less than one year old were 6.64 (male 6.62, female 6.64), 3.63 (male 3.57, female 3.65) and 3.00 (male 3.05, female 2.99) g/100ml, 170.97 (male 166.46, female 172.68) mg/100ml, 1.45 (male 1.43, female 1.46), 5.76 (male 5.62, female 5.81), 4.80 (male 4.95, female 4.75), 4.84 (male 4.72, female 4.89), 148.93 (male 148.79, female 148.98) and 110.22 (male 110.42, female 110.14) mEq/L, respectively, whereas the TP, Alb and Glb content, Chole Mg, Ca, P, K, Na and Cl concentration in the group of one year old and more were 6.88 (male 6.84, female 6.89), 3.65 (male 3.63, female 3.66) and 3.23 (male 3.21, female 3.23) g/100ml, 167.48 (male 173.80, female 166.48) mg/100ml, 1.40 (male 1.36, female 1.40), 5.69 (male 5.53, female 5.71), 4.62 (male 4.73, female 4.60), 4.88 (male 4.90, female 4.87), 149.86 (male 149.60, female 149.90)and 110.03 (male 110.70, female 109.92) mEq/L, respectively. The ratios of mean serum albumin to globulin (A/G), calcium to inorganic phosphate (Ca/P) and sodium to potassium (Na/K) in the group of less than one year old were 1.21 (male 1.17, female 1.22), 1.20 (male 1.14, female 1.22) and 30.77 (male 31.52, female 30.47), respectively, whereas the A/G, Ca/P and Na/K in the group of one year old and more were 1.13 (male 1.13, female 1.13), 1.23 (male 1.17, female 1.24) and 30.71 (male 30.53, female 30.78), respectively. The mean values of Alb content, Mg, Ca and K concentration, A/G and Ca/P ratio appeared to be higher in the female than in the male, whereas the reverse was the case with P concentration. No differences were found between male and female in the TP and Glb content, Chole, Na and Cl concentration and Na/K ratio.

The changes of acid-base status in vitro of the venous blood for 24 hrs in ten Korean native goats were investigated. The acid-base parameters were measured within ten minutes after collection of the blood, and every hour during the first six hours and finally after twenty-four hours of storage. Blood samples were stored at two different temperatures (0-4 deg C and 21-24 deg C). Twelve goats were induced acute acid-base disturbances by intravenous infusion of either hydrochloric acid or sodium bicarbonate and inhalated with CO2 gas mixture (20% C02, 80% O2) or hyperventilation were performed by means of respirator.