Dopamine blockade attenuates the natriuresis of saline loading in the adrenalectomized rat.

Dopamine blockade with the dopamine-1/dopamine-2 antagonist cis-flupenthixol (CF) attenuates sodium excretion associated with saline loading in both innervated and denervated kidneys of the rat. Blockade of adrenal dopamine-2 receptors prevents the decrease in aldosterone secretion associated with saline loading and may also be responsible for the reduction in sodium excretion induced by CF. Therefore, to determine the role of adrenal dopamine-2 receptors in the attenuated natriuresis induced by CF, the effect of CF or vehicle treatment was examined in two groups of saline-loaded rats 80 (group I) and 120 min (group II) after adrenalectomy. In both groups, CF decreased glomerular filtration rate and sodium excretion after adrenalectomy. It is concluded that dopamine blockade attenuates the natriuresis associated with sodium loading by a direct effect in the kidney.

Dopamine receptors modulate sodium excretion in denervated kidney.

Dopamine (DA) modulates sodium excretion by the innervated kidney. To examine the role of DA in the denervated (DNX) kidney the effects of the DA1/DA2 antagonist cis-flupenthixol (group 2, n = 7) (10 nmol X kg-1 X min-1), given intravenously in saline-loaded Wistar-Kyoto rats after acute unilateral left DNX, were compared with a placebo group (group 1, n = 7) and a group that received the DA1 antagonist SCH 23390 (group 3, n = 7) at 2.5 nmol X kg-1 X min-1. Pentobarbital sodium anesthesia was employed. Adequacy of DNX was assessed by a natriuresis and decrease in renal norepinephrine content in the DNX kidney and an antinatriuresis in the innervated right kidney. Mean arterial pressure slightly decreased in the placebo group (group 1, 106.7 +/- 2.2 vs. 99.3 +/- 2.4 mmHg) and after cis-flupenthixol (group 2, 108.8 +/- 2.7 vs. 92.8 +/- 1.8 mmHg) but not after SCH 23390 (group 3, 105.6 +/- 1.6 vs. 103 +/- 1.1 mmHg). Glomerular filtration rate was not affected by placebo or SCH 23390 in the DNX or innervated kidney but did slightly decrease after cis-flupenthixol in the DNX kidney. Sodium and water excretion after drug administration differed among the groups. In the DNX kidney urine flow decreased only in group 2, whereas fractional sodium excretion decreased modestly (P less than 0.05 paired t test) with SCH 23390 (3.53 +/- 0.34 vs. 2.89 +/- 0.20%) markedly with cis-flupenthixol (3.18 +/- 0.50 vs. 1.21 +/- 0.18%) and was unchanged in the placebo group (3.25 +/- 0.61 vs. 3.45 +/- 0.45%).(ABSTRACT TRUNCATED AT 250 WORDS)

Controlled comparison of radio wave regional hyperthermia and peritoneal lavage rewarming after immersion hypothermia.

Anesthetized random source dogs were cooled by ice-water immersion to a stable core temperature of 25 degrees C and subsequently rewarmed with normal saline peritoneal lavage (43 degrees C, 175 ml/kg/hr) or radio frequency electromagnetic-induced regional hyperthermia (4-6 watts/kg). The mean time required for core rewarming to 30 degrees C was 183 +/- 79 minutes for lavage and 58 +/- 13 minutes for radio wave therapy (p less than 0.01). There was no evidence of tissue damage with either modality. These data suggest radio wave regional hyperthermia is superior to peritoneal lavage for core rewarming of rapidly induced immersion hypothermia.

Button battery ingestion: assessment of therapeutic modalities and battery discharge state.

Button batteries immersed in a simulated gastric environment (0.1N hydrochloric acid) demonstrated less crimp dissolution (corrosion of the metal can) after the addition of neutralizing doses of eight of nine antacids tested. Of 64 ingestion episodes in dogs, clinical manifestations of button battery-induced injury were limited to a single animal developing guaiac-positive stools. Endoscopic lesions included only mild gastritis, occurring with a frequency comparable to that observed in dogs prior to battery ingestion. After ingestion blood mercury levels were not significantly elevated. Crimp dissolution was absent in discharged cells, implying a decreased risk of electrolyte leakage or subsequent tissue injury in patients who ingest spent cells. No protective effect of metoclopramide, cimetidine, or magnesium citrate could be demonstrated in the canine model.

Comparison of rewarming by radio wave regional hyperthermia and warm humidified inhalation.

Anesthetized random source dogs were cooled by ice water immersion to a stable core temperature of 25 degrees C and subsequently rewarmed with warm humidified inhalation (43 degrees C, 450 cc of min ventilation X kg-1) or radio-frequency induction hyperthermia (4-6 watts X kg-1). The mean time required for core rewarming to 30 degrees C was 280 +/- 114 min for ventilation and 58 +/- 13 min for radio wave therapy (p less than 0.001). There was no evidence of tissue damage with either modality. These data suggest radio wave heating is superior to warm humidified inhalation therapy for core rewarming of rapidly induced immersion hypothermia.

Controlled comparison of humidified inhalation and peritoneal lavage in rewarming of immersion hypothermia.

Random source dogs were anesthetized and cooled by immersion in ice water to a stable core temperature of 25 degrees C and subsequently rewarmed with either normal saline peritoneal lavage (43 degrees C, 175 ml/kg/h) or warmed humidified inhalation (43 degrees C, 450 ml/kg/min ventilation). The time required for core rewarming to 30 degrees C was 192 +/- 61 minutes for lavage and 331 +/- 96 minutes for inhalation therapy (P less than 0.03). These data suggest that peritoneal lavage is superior to inhalation therapy for core rewarming of rapidly induced immersion hypothermia.