Single oral dose toxicity test of polycalcium, a mixed composition of polycan and calcium lactate-gluconate 1:9 (G/G) in SD rat.

The object of this study was to obtain acute oral toxicity information of Polycalcium, a mixed composition of Polycan and Calcium lactate-gluconate 1:9 (g/g), in Sprague-Dawely (SD) rats. In order to investigate the toxicity and identify target organs, Polycalcium were once orally administered to female and male SD rats at dose levels of 2000, 1000, 500 and 0 (control) mg/kg body weights. The mortality, changes on body weight and clinical signs were monitored during 14 days after treatment with gross observation, changes on the organ weights and histopathology of principle organs and treatment sites based on the recommendation of KFDA Guidelines [2009-116, 2009]. As the results of single oral treatment of Polycalcium, no treatment related mortalities were observed within 14 days after end of treatment up to 2000 mg/kg, the limited dosage of rodents in the both genders. In addition, no Polycalcium treatment related changes on the body and organ weights, clinical signs, necropsy and histopathological findings were detected. The results obtained in this study suggest that the Polycalcium is non-toxic in rats. The LD50 and approximate LD in rats after single oral dose of Polycalcium were considered over 2000 mg/kg in both female and male, respectively.

Effects of hypercalcemia on serum concentrations of magnesium, potassium, and phosphate and urinary excretion of electrolytes in horses.

OBJECTIVE: To determine effects of experimentally induced hypercalcemia on serum concentrations and urinary excretion of electrolytes, especially ionized magnesium (iMg), in healthy horses. ANIMALS: 21 clinically normal mares. PROCEDURES: Horses were assigned to 5 experimental protocols (1, hypercalcemia induced with calcium gluconate; 2, hypercalcemia induced with calcium chloride; 3, infusion with dextrose solution; 4, infusion with sodium gluconate; and 5, infusion with saline [0.9% NaCl] solution). Hypercalcemia was induced for 2 hours. Dextrose, sodium gluconate, and saline solution were infused for 2 hours. Blood samples were collected to measure serum concentrations of electrolytes, creatinine, parathyroid hormone, and insulin. Urine samples were collected to determine the fractional excretion of ionized calcium (iCa), iMg, sodium, phosphate, potassium, and chloride. RESULTS: Hypercalcemia induced by administration of calcium gluconate or calcium chloride decreased serum iMg, potassium, and parathyroid hormone concentrations; increased phosphate concentration; and had no effect on sodium, chloride, and insulin concentrations. Hypercalcemia increased urinary excretion of iCa, iMg, sodium, phosphate, potassium, and chloride; increased urine output; and decreased urine osmolality and specific gravity. Dextrose administration increased serum insulin; decreased iMg, potassium, and phosphate concentrations; and decreased urinary excretion of iMg. Sodium gluconate increased the excretion of iCa, sodium, and potassium. CONCLUSIONS AND CLINICAL RELEVANCE: Hypercalcemia resulted in hypomagnesemia, hypokalemia, and hyperphosphatemia; increased urinary excretion of calcium, magnesium, potassium, sodium, phosphate, and chloride; and induced diuresis. This study has clinical implications because hypercalcemia and excessive administration of calcium have the potential to increase urinary excretion of electrolytes, especially iMg, and induce volume depletion.

Production of microliths and sialadenitis in rats by a short combined course of isoprenaline and calcium gluconate.

The relationship between microliths and sialadenitis in man is unclear, so an attempt was made to investigate it experimentally in rats with the use of isoprenaline and calcium gluconate either alone or combined. The acini of the submandibular and parotid glands of rats that were given isoprenaline were enlarged, and degenerate acinar cells were seen, with extravasated secretions in the submandibular gland. Similar changes were seen in the submandibular and parotid glands of rats that were given isoprenaline combined with calcium gluconate; in addition, ductal microliths with regions of atrophic sialadenitis were observed. The results suggest that there is temporary obstruction to the salivary flow after isoprenaline is injected, and in the rats that were also given calcium gluconate some of the stagnant saliva calcified to form microliths, which produced a lasting obstruction and obstructive sialadenitis. This supports the possibility that microliths, which are present in normal salivary glands of man, are a primary etiologic factor in sialadenitis.

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol.

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol.

Examination of toxicity of diisopropylammonium dichloracetate (DADA), remedies for cardiac diseases, toward isolated rat hepatocytes.

Oxygen uptake (OU) and cell viability (CV) of isolated rat hepatocytes as a part of the indexes of hepatopathy were determined following treatment with DADA, the active principle of pangamic acid. DADA increased OU at high concentrations, but not at low ones. However, CV became higher as the concentration became lower. DADA led to no remarkable toxicity when used alone. When the mixture of DADA and calcium gluconate was tested, DADA showed no palliative action; nor did it when combined with other hepatotoxins such as trapidil, rifampicin, hexobarbital, thiopental sodium, and Citanest-octapressin.

Role of the loop segment in the urinary concentrating defect of hypercalcemia.

Hypercalcemia is associated with impaired urinary concentrating ability. To explore the mechanism(s) by which hypercalcemia impairs chloride transport in the loop of Henle, we carried out in vivo microperfusion of the loop segment in Sprague-Dawley rats rendered acutely hypercalcemic (12.1 +/- 0.1 mg/dliter) by calcium gluconate infusion. Control rats were infused with sodium gluconate and had normal plasma calcium (8.0 +/- 0.2 mg/dliter). Compared to control, fractional chloride reabsorption was decreased (61 +/- 4 to 50 +/- 3%; P less than 0.05) and early distal chloride increased 74 +/- 6 to 98 +/- 3 mEq/liter (P less than 0.001) in hypercalcemia. During hypercalcemia, infusion of verapamil failed to increase fractional chloride reabsorption (49 +/- 4%; P less than 0.05) or decrease early distal chloride (95 +/- 2; P less than 0.05) toward control values. Similarly, indomethacin did not improve fractional chloride reabsorption (48 +/- 4%; P less than 0.05) or distal chloride concentration (93 +/- 7; P less than 0.05). In control rats infused with Ringers HCO3, the addition of calcium 8.0 mEq/liter to the perfusate increased early distal calcium (9.22 to 3.11 mEq/liter) but was associated with no change in fractional chloride reabsorption (-6 +/- 6%) and a slight decrease in early distal chloride (-9 +/- 3 mEq/liter; P less than 0.05). These data are consistent with the hypothesis that an elevated plasma, not luminal calcium, concentration impairs chloride reabsorption in the loop segment, primarily the ADH-stimulated component. This may have an important role in the urinary concentrating defect of hypercalcemia.

[Cytological analysis of a population of thyroid parafollicular cells]. / Tsitologicheskii analiz populiatsii parafollikuliarnykh kletok shchitovidnoi zhelezy.

With the aid of Sevier-Munger silver stain, parafollicular thyrocytes (C-cells) of rat males were investigated within the period of 10 minutes to 8 hours after the intraperitoneal injection of calcium gluconate solution. In the thyroid glands of both control and experimental animals four types of C-cells at different stages of their secretory cycle were described. Relative rates of these cellular types were found to be objective quantitative criteria of the functional activity of parafollicular cell population.