Studies on the Physiology of Hemolymph Coagulation in Perioplaneta Americana (L.)
Studies on the Physiology of Hemolymph Coagulation in Perioplaneta Americana (L.)
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Date
1964
Authors
Wheeler, Ronald Earl
Advisor
Jones, Jack Colvard
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Abstract
In the cockroach, Periplaneta americana (L.), hemolymph coagulation
(a) is inhibited for as long as 30 minut es at 0° to 4°c, (b) is
initiated at 5°c, (c) is permanently inhibited at 60°c, and (d) takes
place in 6 distinct stages. Hemocyte agglutination and transformation
is inhibited at 0° to 4°C, is permanently prevented at 55°c, and is independent
of plasmal factors. Live plasmatocytes, granular hemocytes,
and cystocytes are structurally identical, but differ functionally in
their capacity to phagocytize and in their fragility. The cystocyte's
primary function is the initiation of coagulation and/or precipitation
of the plasma by ejecting cytoplasmic material, including mitochondria,
into the surrounding plasma. Hemocyte-free plasma will not spontaneously
precipitate, but requires either ionic calcium released from transforming
hemocytes, and/or material from exploded cystocyte mitochondria .
Substances inside mitochondria may well be t he source of a coagulation-inducing
substance that initiates plasma precipitation and veil formation.
Substances involved in P. americana coagulation are present in the plasma
of 9 other species of cockroach which react to P. americana cystocytes.
Substances in the plasma of Tenebrio molitor, Galleria mellonella, or
Rhodnius prolixus do not precipitate in the presence of P. americana
cystocytes. The amount and/or effectiveness of a coagulation-inducing substance released from cystocytes presumably determines the degree of
plasma precipitation. Physiologically active substances contained in
and/or released from the corpora allata and c. cardiaca, but lacking in
the brain, may regulate the percentage of circulating cystocytes, thereby
influencing the coagulability of the hemolymph.