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Biomedical subjects

M T Curtis

Publications and source records attributed to M T Curtis.

21 records · Page 2Linked to original sources
PubMed1982

Tissue uptake of 3H-naloxone in control and in hemorrhagic shock cats.

Tissue uptake and plasma levels of 3H-naloxone were studied in normotensive control cats, as well as in hemorrhagic hypotensive cats. Intravenous injection of naloxone resulted in a rapid and extensive uptake of naloxone label from plasma by several tissues. Plasma half-life of the radiolabel was determined to be 137 min. One and two hours after injection, large amounts of naloxone label were found in the liver, pancreas, adrenal, kidney and lung, with tissue/plasma ratios ranging from 2 to 30. Brain tissue displayed the lowest tissue/plasma ratios of any organ sampled. Infusion of 8 mg/kg -1.hr-1 naloxone resulted in an increase in concentration of radiolabel over a 2 hr period. Hemorrhagic shock did not significantly retard uptake of naloxone by tissues. Splanchnic organs displayed high uptake of naloxone even during hemorrhagic shock. Brain tissue in cats subjected to hemorrhagic shock had the lowest uptake naloxone of all tissues sampled. The degree of uptake of naloxone by tissues is consistent with its proposed role in lysosomal membrane stabilization and prevention of proteolysis during hemorrhagic shock.

Animals↗
PubMed1980

Protective actions of naloxone in hemorrhagic shock.

The opiate antagonist, naloxone, was infused at 8 mg x kg-1 x h-1 in cats to determine its effect in hemorrhagic shock. Hemorrhaged cats treated with naloxone maintained postreinfusion mean arterial blood pressure at a higher value compared to those receiving only the vehicle. Final pressures were 77 +/- 9 mmHg for cats receiving vehicle compared to 120 +/- 6 mmHg for cats receiving naloxone. These values represent 58 +/-7 and 98 +/- 6% of initial pressures for vehicle- and naloxone-treated cats, respectively (P < 0.001). Naloxone also moderated increases in circulating lysosomal hydrolase activity (4- vs. 23-fold increase) and total plasma proteolysis (33 vs. 100% increase). Plasma myocardial depressant factor activity was also significantly reduced in naloxone-treated hemorrhaged cats compared to shock cats given 0.9% NaCl (16 +/- 3 vs. 58 +/- 4 U, respectively; P < 0.001). Studies on cat papillary muscles demonstrated that naloxone at concentrations slightly higher than estimated plasma values during shock exerted a moderate positive inotropic effect. Our results show that naloxone improved the hemodynamic and biochemical state of cats in hemorrhagic shock. Inhibition of proteolysis and stabilization of lysosomal membranes appear to be ivolved in the protective action of naloxone, along with the well-known opiate-antagonistic action of this agent.

Animals↗