Prothrombin activity of turtle blood and the effect of a synthetic vitamin k derivative

Abstract

WITH THE ASSISTANCE OF D. EIIKLI('H il lie Ikpczrfrrirnl of &ology, Tke Jo/k?u Bop1,zn.v Unzzievstly and T~P 1) eparlment of C~i n c c c i~Laboratorzes, Xercy Hospetal, Balterizorr, Maryland INTRODTJC'I'TOISThe recent isolation and chemical chaiuacterization of vitamin K (tlie antihemorrhagic vitamin) has stimulated rcnewcd interest in the study of factors involved in tlie phenomenon of blood coagulation. Currcrit investigations have shown that prothrombin is one of the most essential constituents to this process. To date, the chemical nature of prothrombin is unknown, its magnitude is ascertained in terms of the coagulation activity of blood or plasma. Simplified procedures for measuring thc prothrombin activity of blood liave I m n introduced with the resnll that many investigations are now extant. Warner, Rrinkhous and Smith ( '36) suggest that the blood clotting mechanism in lower animals is a rutlimentayv mechanism and that there is a gradual evolution through the various classes of vertebrates. Warmblooded animals, i.e., mammals and to a lcsscr extent birds, have beer1 the subject of rather intensive investigation. Blood eoagnlation in colilblooded animals and hiberiiating vertebrates on tlie other liand has received very little attention.Two distinct lines of evidence are available for experimental derangcment of the coagulation mechanism of blood. IIemorrhage resulting from a reduced prothrombin activity of the blood was first produced in birds (chicks) by t i dietary (vitamin I<) deficiency (Dam, '35; Almquist, '36). This same condition has becn obtained in dogs surgically (bilc fistula, Smith et al., '36) and complete hepatcctomy (Andrus et al., '40) and chemically (chloroform and phosphorus poisoning, Smith et al., '36) indicating that the liver plays a significant role in this proccss.

Investigations on Blood Coagulation in the Green Iguana (Iguana iguana)

“…The results of this study show, in general, considerably longer times for the PT, APTT, thrombin time, DRVVT, reptilase time and KCT in the green iguana than in the dog and man. These results seem to underline the statement by different authors that blood from many reptilian species generally clots more slowly in vitro than blood from mammals (Brambel, 1941;Fantl, 1961;Lewis, 1964Lewis, , 1996Hackett and Hann, 1967;Denson, 1976;Nahas et al, 1981). Because the clotting times were widely scattered and to a great part at the limit of measurability, the use of commercial test kits as described in this study is limited in iguana blood coagulation diagnostics.…”

“…Together with the marked variability in the other resonance thrombograms, this method does not allow a diagnosis of possible clotting disorders. Like the long clotting times of the PT, APTT, thrombin time and KCT, the long reaction times of the resonance thrombograms confirmed the slow in vitro coagulation observed in studies of other reptilian species (Brambel, 1941;Fantl, 1961) and may indicate a minor intrinsic factor activity in the iguana. The broad curve of the iguana resonance thrombogram when compared with a canine resonance thrombogram reflected the species-specific instability of the iguana fibrin clot.…”

Effects of brodifacoum and diphacinone exposure on four species of reptiles: tissue residue levels and survivorship

“…Reptiles, and other poikilotherms, have noteworthy differences in physiology and specifically blood chemistry compared to their mammalian counterparts. There are numerous reports stating that clotting time in reptiles is greatly increased when compared to mammals . Although reptiles have the extrinsic clotting pathway, differences in many of the other factors have been reported .…”

“…There are numerous reports stating that clotting time in reptiles is greatly increased when compared to mammals. [25][26][27][28][29][30][31] Although reptiles have the extrinsic clotting pathway, differences in many of the other factors have been reported. 32 Spectacled caimans are missing factors V, VII, IX, and XI of the intrinsic (vitamin K dependent) pathway.…”