Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Clinical Pathology in Green Iguanas and Other Herps

Nothing is as easy as it seems...including lab values.

Abstracts compiled by Melissa Kaplan

Tissue and plasma enzyme activities in juvenile green iguanas.
Wagner RA; Wetzel R. Division of Laboratory Animal Resources, University of Pittsburgh, PA 15261, USA.. Am J Vet Res 1999 Feb;60(2):201-3

OBJECTIVE: To determine activities of intracellular enzymes in 8 major organs in juvenile green iguanas and to compare tissue and plasma activities. ANIMALS: 6 green iguanas < 1 year old.

PROCEDURE: Lysates of liver, kidney, epaxial muscle, heart, lung, spleen, small intestine, and pancreas were analyzed for alkaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyltransferase (GGT), creatine kinase (CK), glutamate dehydrogenase (GMD), and amylase (AMS) activities.

RESULTS: In general, low tissue enzyme activity coincided with low plasma activity. The CK activity was high in epaxial muscle and the heart and low in all other tissues tested. The AMS activity was found exclusively in the pancreas. Moderate LDH and AST activities were found in all tissues. Low ALT and ALP activities were found in a variety of tissues. Plasma and tissue activities of GGT and GMD were low or undetectable.

CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that plasma CK activity may be muscle specific in iguanas, but high values may not always indicate overt muscle disease. The AMS activity may be specific for the pancreas, but the wide range of plasma activity would likely limit its diagnostic usefulness. Activities of AST and LDH may reflect tissue damage or inflammation, but probably do not reflect damage to specific tissues or organs.

Isolation, amino acid sequence determination and binding properties of two fatty-acid-binding proteins from axolotl (Ambistoma mexicanum) liver. Evolutionary relationship.
Di Pietro SM; Veerkamp JH; Santome JA. Instituto Quimica y Fisicoquimica Biologicas, Facultad de Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Argintina. Eur J Biochem 1999 Jan;259(1-2):127-34

Up until now, the primary structure of fatty-acid-binding proteins (FABPs) from the livers of four mammalian (rat, human, cow and pig) and three nonmammalian (chicken, catfish and iguana) species has been determined. Based on amino acid sequence comparisons, it has been suggested that mammalian and nonmammalian liver FABPs may be paralogous proteins that originated by gene duplication, rather than as a consequence of mutations of the same gene. In this paper we report the isolation and amino acid sequence determination of two FABPs from axolotl (Ambistoma mexicanum) liver. One of them is similar to mammalian liver FABPs (L-FABPs) and the other to chicken, catfish and iguana liver FABPs (Lb-FABPs). The finding of both L-FABP and Lb-FABP in a single species, as reported here, indicates that they are paralogous proteins. The time of divergence of these two liver FABP types is estimated to be of approximately 694 million years ago. The ligand-binding properties of axolotl liver FABPs were studied by means of parinaric-acid-binding and parinaric-acid-displacement assays. L-FABP binds two fatty acids per molecule but Lb-FABP displays a fatty-acid-conformation-dependent binding stoichiometry; L-FABP shows a higher affinity for fatty acids, especially oleic acid, while Lb-FABP has a higher affinity for other hydrophobic ligands, especially retinoic acid. In addition, the tissue-expression pattern is different, L-FABP is present in liver and intestinal mucosa while the expression of Lb-FABP is restricted to liver. Data indicate distinct functional properties of both liver FABP types.

Regulation of skeletal muscle metabolism in the lizard Dipsosaurus dorsalis by fructose-2,6-bisphosphate.
Scholnick DA; Gleeson TT. University of Colorado, Department of Environmental Population and Organismic Biology, Boulder 80309-0334, USA. Am J Physiol 1996 Nov;271(5 Pt 2):R1447-51

Changes in liver and skeletal muscle fructose-2,6-bisphosphate (Fru-2,6-P2) concentrations were compared during fasting, exercise, and recovery in the lizard Dipsosaurus dorsalis and in outbred mice (Mus musculus). We present the first correlative evidence that suggests that a decrease in the content of Fru-2,6-P2 may mediate elevated gluconeogenesis in lizard skeletal muscle. Contents of Fru-2,6-P2 in lizard gastrocnemius and red and white iliofibularis (IF) were significantly lower (as much as 55% in white IF) during recovery from exhaustive exercise than at rest. Recovery from exhaustive exercise had no significant effect on Fru-2,6-P2 concentrations in any mouse muscle examined. Fasting significantly depressed lizard and mouse liver Fru-2,6-P2 contents and decreased lizard red IF by over 84% from the fed condition. Lizard red and white muscle fiber bundles incubated in 20 mM lactate had significantly lower Fru-2,6-P2 (94 and 61% depression, respectively) than those incubated in 8.5 mM glucose. These results are consistent with the hypothesis that Fru-2,6-P2 acts as a signal for controlling gluconeogenesis in lizard skeletal muscle.

Calcitonin gene-related peptide relaxes cholecystokinin-induced tension in Iguana iguana gallbladder strips.
Kline LW; Pang PK. Department of Oral Biology, University of Alberta, Edmonton, Canada. Gen Comp Endocrinol 1994 Sep;95(3):381-6

The presence of a calcitonin gene-related peptide (CGRP)-like material was demonstrated in the iguana, Iguana iguana, gallbladder using immunocytochemistry. An intense reaction was observed in nerves located in the smooth muscle layers and associated blood vessels but no immunoreactive cell bodies were found. In vitro tension studies using gallbladder strips showed that chicken CGRP was more potent in relaxing cholecystokinin-induced tension than either human or rat CGRP. The use of glibenclamide and L-NG-nitro-arginine methyl ester suggested that this relaxation is mediated by either nitric oxide release from nerves stimulated by CGRP or by CGRP acting directly on the gallbladder smooth muscle.

 The amino acid sequence of iguana (Iguana iguana) pancreatic ribonuclease.
Zhao W; Beintema JJ; Hofsteenge J; Biochemisch Laboratorium, Rijksuniversiteit, Groningen. Eur J Biochem 1994 Jan 15;219(1-2):641-6

The pyrimidine-specific ribonuclease superfamily constitutes a group of homologous proteins so far found only in higher vertebrates. Four separate families are found in mammals, which have resulted from gene duplications in mammalian ancestors. To learn more about the evolutionary history of this superfamily, the primary structure and other characteristics of the pancreatic enzyme from iguana (Iguana iguana), a herbivorous lizard species belonging to the reptiles, have been determined. The polypeptide chain consists of 119 amino acid residues. The positions of insertions and deletions in the sequence are identical to those in the enzyme from snapping turtle. However, the two enzymes differ at 54% of the amino acid positions. Iguana ribonuclease contains no carbohydrate, although the enzyme possesses three recognition sites for carbohydrate attachment, and has a high number of acidic residues in a localized part of the sequence.