Blood As Part Of A Glandular Secretion

Often the secretions of defensive glands are fortified with blood. The mechanism by which blood penetrates the defensive gland preparatory to being discharged remains to be determined, and indeed, the exact function of the blood itself is not known.

Arctiid moths (e.g., Arctia caja) discharge odoriferous froths from prothoracic glands, and these exudates contain pharmacologically active choline esters that are accompanied by blood. A similar system characterizes the pyrgomorphid grasshopper P. bufonius. Nymphs of this species possess abdominal defensive glands that sequester two of the six compounds ingested from their milkweed hosts and, in addition, synthesize high concentrations of histamine. These compounds are accompanied by blood as a normal component of the secretion.

0 0

Post a comment