A possible mechanism of heinz body hemolytic anemia induced by DQ-2511, a new gastroprokinetic drug, in dogs

Avoiding Hemolytic Anemia by Understanding the Effect of the Molecular Architecture of Gemini Surfactants on Hemolysis

Hemolytic behavior of a series of different categories of Gemini surfactants was determined in their low concentration range. Cationic Gemini surfactants of different molecular architectures prove to be highly cytotoxic even at 0.1 mM. Anionic and amino acid-based Gemini surfactants were minimally cytotoxic, although their toxicity was concentration-dependent. With respect to monomeric surfactants of comparable hydrocarbon chain lengths, cationic Gemini surfactants were much more toxic than anionic Gemini surfactants. Incubation temperature was another important parameter that significantly drove the hemolysis irrespective of the molecular structure of the surfactant. Results indicated that the surface activity or liquid-blood cell membrane adsorption tendency of a surfactant molecule determined the degree of hemolytic anemia. Greater surface activity induced greater cytotoxicity, especially when the surfactant possessed a stronger ability to interact with the membrane proteins through hydrophilic interactions. That provided cationic Gemini surfactants a higher ability for hemolytic anemia because they were able to interact with an electronegative cell membrane with favorable interactions in comparison to anionic or amino acid-based Gemini surfactants. These findings are expected to help in designing surface-active drugs with a suitable molecular architecture that can avoid hemolytic anemia.

Successful management of Heinz body hemolytic anemia associated with leek (Allium ampeloprasum) ingestion in a South American coati (Nasua nasua)

OBJECTIVE

To describe the diagnosis, management, and outcome of Heinz body hemolytic anemia in a South American coati (Nasua nasua) secondary to suspected leek (Allium ampeloprasum) toxicosis.

CASE SUMMARY

A South American coati presented with Heinz body hemolytic anemia following addition of leeks to its diet for 2-5 days prior to initial presentation. Administration of a whole blood transfusion from an animal of the same species (conspecific) and supportive care resulted in immediate improvement in clinical signs. Normal behavior fully returned within 6 days of transfusion. Hematological evidence of anemia resolved by 4 weeks and there were no significant features of oxidative injury present by 8 weeks following initial presentation.

NEW INFORMATION PROVIDED

This is the first reported case of Heinz body hemolytic anemia, suspected leek toxicosis, and administration of a blood transfusion in this species.

Pharmacology of the gastric pro-kinetic drug ecabapide (DQ-2511)

The pharmacology of ecabapide (DQ-2511; 3-[2-(3,4-dimethoxyphenyl)ethylcarbamoylmethyl]amino-N-methylbe nzamide) is reviewed. Evidence from basic studies in animal models suggests that the drug acts on peripheral mechanisms of neural control. In the stomach, ecabapide acts to suppress firing in vagal afferent nerves and thereby reduce the flow of sensory information into the dorsal vagal complex. The enhancement of the efferent discharge provoked by ecabapide was completely blocked by bilateral vagotomy, as suggested by increased firing in vagal efferent fibres, preceded by suppression of activity in the sensory limb of the putative vago-vagal reflex pathway. The mechanism of action of ecabapide in suppressing discharge in vagal afferent terminals appears to mimic that of nitric oxide by stimulating formation of cGMP and activation of an inhibitory transduction cascade in the sensory fibres. In this respect the mechanism of its pro-kinetic action differs from other promoter agents. In addition to selective actions in the stomach, evidence from electrophysiological studies of enteric neurons in the small intestine suggests that ecabapide might have actions similar to those of other substituted benzamides on synaptic transmission in the intramural nervous system of this specialized region of the digestive tract. These actions include enhanced release of acetylcholine at excitatory synapses and suppression of the release of noradrenaline at inhibitory synapses.