Reproduction and aging in marmosets and tamarins.

This chapter presents data on the relations between reproduction and aging in both captive and free-ranging marmosets and tamarins. The relationship is examined from two perspectives. First, the relation of age to physiological impairments in reproductive function is explored. Callitrichid females, in common with many other nonhuman primates, begin to display anovulation associated with follicular depletion at a point relatively close to the maximum life span. Unlike Old World primates, however, they continued to display significant steroidogenic activity in the ovary. There are age effects on some reproductive output variables, such as litter size and inter-birth interval, though the effects are often small. Like other mammals, male marmosets display a change in levels of androgens with age, although the magnitude of the decrease is not large and they actually mount an elevated response to GnRH challenge as they age. We also examined whether age affects either the establishment or maintenance of a breeding position, the factors most important in determining lifetime reproductive success. Infant mortality did increase with increasing parturitions, suggesting that there may have been aging or parturition effects on lactation. Generally, marmoset females were well past the age of sexual maturity at the beginning of the tenure and approaching 8-9 years at the end of it. Reproductive decline did not appear to be a gradual process, but a rather abrupt one, often causing the dismantling of the group. There are potentially interesting relations among maternal age, mass and declining reproductive performance, given the known importance of mass as a determinant of reproductive success in female callitrichids.

Hematologic iron analyte values as an indicator of hepatic hemosiderosis in Callitrichidae.

Hepatic hemosiderosis is one of the most common postmortem findings in captive callitrichid species. Noninvasive evaluation of hematologic iron analytes has been used to diagnose hepatic iron storage disease in humans, lemurs, and bats. This study evaluated the relationship between hematologic iron analyte values (iron, ferritin, total iron binding capacity, and percent transferrin saturation) and hepatic hemosiderosis in callitrichids at the Wildlife Conservation Society's Central Park and Bronx Zoos. Results revealed that both ferritin and percent transferrin saturation levels had strong positive correlations with hepatic iron concentration (P<0.001, r=0.77, n=20; P<0.001, r=0.85, n=10, respectively). Serum iron levels positively correlated with hepatic iron concentration (P=0.06, r=0.56, n=11), but this finding was not significant. Serum total iron binding capacity did not significantly correlate with hepatic iron concentration (P=0.47, r=0.25, n=10). Both ferritin and hepatic iron concentration positively correlated with severity of hepatic iron deposition on histology (P<0.05, r=0.49, n=21; P<0.001, r=0.67, n=21, respectively). This study suggests that ferritin, serum iron concentration, and percent transferrin saturation are convenient, noninvasive, antemortem methods for assessing severity of hemosiderosis in callitrichids.

Development of an enzyme-immunoassay (EIA) for the measurement of follicle-stimulating-hormone (FSH) in Callitrichid primates using a monoclonal antibody against the human-FSH-beta-subunit.

Despite the importance of Callitrichid primates in both biomedical and conservation research, practical and reliable immunoassays for the measurement of follicle-stimulating hormone (FSH) have not yet been described. A panel of monoclonal antibodies against specific peptide fragments within either the alpha or beta subunit of human FSH was evaluated for their ability to recognize FSH from Callitrichid and other New World primates. One of these, monoclonal antibody 46.3h6.b7 raised against human FSH, was selected due to its ability to recognize marmoset monkey FSH and its low crossreactivity with other gonadotrophins. The antibody formed the basis of an enzymeimmunoassay using a highly purified human urinary FSH (Metrodin, Serono) preparation coupled to biotin as label and unmodified as standard. After 24 h incubation, antibody bound label was visualized by addition of streptavidin-peroxidase followed by the appropriate substrate. Parallelism was obtained between the standard and dilutions of pituitary extracts, urine and plasma from the common marmoset (Callithrix jacchus) as well as from two tamarin species (Saguinus fuscicollis and S. oedipus) and one squirrel monkey (Saimiri sciureus). Profiles of plasma and urinary FSH during the follicular phase are shown for two individual marmosets. The ability to measure FSH in Callitrichidae provides new opportunities for studies of the reproductive biology of these New World primate species.

ABO blood groups in natural populations of callitrichidae (Platyrrhini, primates)

Foram coletadas amostras de sangue e saliva de 88 Saguinus fuscicollis weddelli e 47 Callithrix emiliae, capturados às margens do rio Jamari (Rondônia), e 35 Callithrix jacchus, capturados no estado do Rio Grande do Norte. A existência de substâncias ABH foi investigada em amostras de saliva, através do método convencional de inibiçäo da hemaglutinaçäo. As três espécies apresentaram-se monomórficas para o sistem ABO,s endo os indivíduos classificados como pertencentes ao grupo sangüneo A. Esses resultados säo semelhantes a maioria dos estudos realizados anteriormente na família Callitrichidae. As amostras de plasma foram utilizadas na detecçäo de aglutininas naturais do sistema ABO, tendo-se observado discrepâncias entre os fenótipos salivar e séricos nas três espécies

Isolation and characterization of several plasma apolipoproteins of common marmoset monkey.

To explore the potential of the common marmoset monkey (Callithrix jacchus) as a model for human plasma lipoprotein metabolism, several marmoset apolipoproteins were isolated and characterized in this study. Based on several properties, including molecular weight, amino acid composition, and sequence, the marmoset apolipoproteins are strikingly similar to human apolipoprotein (apo) A-I, A-II, C-III, and A-IV. The first 54 residues of marmoset apo A-I showed 87% sequence identity with the corresponding region of human apo A-I. Amino-terminal sequence analysis of a minor basic apo A-I isoform revealed that it contained an amino-terminal hexapeptide extension (Arg-His-Phe-Gln-Gln-) identical to that found in human proapo A-I. Like apo A-II in most nonhuman primates, marmoset apo-A-II differed from human apo A-II in that it did not contain cysteine and therefore existed as a monomer. The complete amino acid sequence of marmoset apo A-II was deduced. The protein contains 77 amino acids, as does human apo A-II, and showed an 82% identity with its human equivalent. In both species, apo C-III and E had similar amino-terminal sequences and amino acid compositions. Like human apo E, marmoset apo E contained minor sialylated isoforms. However, unlike human apo C-III, no sialyated isoforms of marmoset apo C-III were observed. In addition, the marmoset possessed an apolipoprotein whose molecular weight and amino acid composition were similar to those of human apo A-IV. The close structural similarities between corresponding marmoset and human apolipoproteins indicate that the marmoset monkey will be useful as a model for human lipoprotein metabolism.

Isolation and characterization of plasma lipoproteins of common marmoset monkey. Comparison of effects of control and atherogenic diets.

This study examines the potential of the common marmoset monkey (Callithrix jacchus) to serve as a model for human lipoprotein metabolism and atherosclerosis. The lipoproteins of animals fed a low-fat, low-cholesterol diet and a high-fat (12% wt/wt lard), high-cholesterol (0.34% wt/wt) diet were characterized by the combination of sequential ultracentrifugation and Pevikon block electrophoresis. Based on chemical and physical properties, equivalents of human very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL), including and HDL-with apolipoprotein E subclass, were demonstrated. In control animals, whose plasma cholesterol concentration was 140.1 +/- 20.2 mg/dl (means +/- SD), approximately 40% of the plasma cholesterol was transported by LDL as compared with approximately 70% in humans. The cholesterol-fed marmosets segregated into two groups: hypo- and hyper-responders. The hyper-responders had plasma cholesterol levels of 450 to 970 mg/ml. The hypercholesterolemia was associated with elevated concentrations of VLDL, intermediate density lipoproteins, and LDL; in addition, these lipoproteins were enriched in cholesteryl esters relative to lipoproteins isolated from control animals. The HDL (d greater than 1.09 g/ml) levels did not change in response to cholesterol feeding, although the HDL-with apolipoprotein E found in the d = 1.02 to 1.09 g/ml fraction increased approximately fivefold. Based on immunological characteristics and sialic acid content, the common marmoset appeared to lack a lipoprotein(a) equivalent. The results of a short-term feeding study (11 months) suggest that this monkey was susceptible to the development of diet-induced atherosclerosis. The hyper-responsive animals developed foam cell lesions and moderately proliferative intimal lesions, predominantly within the thoracic aorta. In summary, the results of our studies indicate that the common marmoset monkey potentially is a useful model for the study of both lipoprotein metabolism and diet-induced atherosclerosis.

Plasma vitamins A and E and hydrogen peroxide-induced in vitro erythrocyte haemolysis in common marmosets (Callithrix jacchus).

Plasma total lipid, cholesterol, all-trans retinol (vitamin A) and alpha-tocopherol (vitamin E) concentrations, and the susceptibility of erythrocytes to hydrogen peroxide-induced haemolysis in vitro were investigated in healthy laboratory-bred common marmosets (Callithrix jacchus). The concentrations of alpha-tocopherol and total cholesterol were similar to those of control human subjects. The mean lipid concentration was higher (P less than 0.025) and the retinol concentration lower (P less than 0.001) in the marmosets. The susceptibility of the erythrocytes of the marmosets to hydrogen peroxide-induced haemolysis was high, both in absolute value and relative to the controls. Changes in phospholipid and fatty acid composition might have rendered the red cells susceptible to oxidative stress.

The diagnostic usefulness of isocitrate dehydrogenase (ICDH) in the marmoset (Callithrix jacchus).

Marmosets were given either a hepatotoxin, carbon tetrachloride, orally or an i.m. injection of a mytoxin, chlorpromazine. Although muscle damage alone caused small increases in the plasma levels of lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase and isocitrate dehydrogenase (ICDH), only the isoenzyme analysis of ICDH can differentiate definitely between liver and muscle damage. Only very severe muscle damage can increase the plasma concentration of this enzyme but, in this case, the elevation of plasma creatinine kinase levels helps differentiation. It is recommended that the elevation of ICDH is the most specific indicator of hepatic damage in the marmoset.

Heinz bodies do not modify the membrane characteristics of common marmoset (Callithrix jacchus) erythrocytes.

The possibility was examined that the membrane function of erythrocytes obtained from healthy common marmosets (Callithrix jacchus) was modified by the presence in the cells of Heinz bodies. No significant differences were found in erythrocyte endogenous free malonyl dialdehyde (MDA) or reduced glutathione (GSH) between normal human erythrocytes and marmoset erythrocytes containing Heinz bodies. Membrane fluorescent chromolipids, surface charge and thiol levels were similar in both species but average membrane bulk lipid fluidity was slightly elevated in the marmosets. It was concluded that, in contrast to the situation in human erythrocytes, the presence of Heinz bodies in red cells of marmosets does not adversely affect the properties of the membrane.

[Canonical discriminant analysis for pregnancy-related changes in hematological and serum biochemical values in tamarins (Saguinus spp].

Hematological and biochemical values obtained from 9 monkeys (Saguinus labiatus and S. mistax) during pre- and postpartum periods were analyzed by canonical discriminant analysis (discriminant analysis with reduction of dimensionality). All animals used were of wild origin and had been maintained under uniform environmental conditions at N. I. H., Japan. The items examined were as follows: white blood cell count (WBC), red blood cell count (RBC), hematocrit value (Ht), hemoglobin concentration (Hb), total protein concentration (TP), blood urea nitrogen (BUN), albumin concentration (ALB), albumin-globulin ratio (A/G), glutamic oxaloacetic transaminase activity (GGT), glutamic pyruvic transaminase activity (GPT), alkaline phosphatase activity (ALP) and total cholesterol concentration (CHO). The data obtained in the pre- and postpartum periods were divided into six chronological groups. The prepartum period was divided into Group I: weeks 15-10; Group II: weeks 9-7; Group III: weeks 6-4; and Group IV: weeks 3-0. The postpartum period was divided into Group V: weeks 0-4 and Group VI: weeks 5-7). In the later pregnancy period (Groups III and IV), significant decreases in RBC, Ht, Hb, TP and ALB, and a significant increase in CHO were observed. These values in the blood and serum continued after delivery (Groups V and VI). Results of canonical discriminant analysis showed that the value of the first canonical variate decreased according to the progress of pregnancy. The postpartum groups showed negative values. Although groups in the early

Long-term blood sampling technique in the marmoset.

A simple and reliable method for long-term blood sampling from the restrained marmoset is described. Cannulae were chronically inserted into the internal jugular vein, exteriorized and housed in a backpack system. The cannulae remained patent for 1-7 months. This system allows for rapid collection of blood samples and hence detailed analysis of circulating hormone levels.

ABO blood groups in a natural population of black-handed tamarins (Saguinus midas niger).

Eighty-one black-handed tamarins from the Tucurui region were tested for human type ABO blood groups by salivary inhibition tests. Eleven belonged to the A group, 45 to B, and 25 to AB. The serum samples were tested for the presence of agglutinins having specificities like those of humans. The ABO system appeared to be polymorphic, with three alleles occurring at the following frequencies: A = 0.26, B = 0.66, and O = 0.08. The observed distribution fitted the expected on the basis of Hardy-Weinberg equilibrium.

Local myotoxicity of ketamine hydrochloride in the marmoset.

An investigation of raised plasma aspartate aminotransferase (AST) in marmosets after intramuscular ketamine injection suggested a local myotoxicity. This was confirmed by a range of histopathological findings from myofibrillar striation loss to necrosis. In addition to the elevations in AST levels, creatine kinase and the lactate dehydrogenase-5 isoenzyme levels were elevated. It was further demonstrated that, although the physical properties of the injectable solution (pH, osmolality) and to a lesser extent the injection procedure itself caused slight changes in plasma enzyme levels, the ketamine was predominantly responsible for the lesion. No hepatic interactions were seen. This effect should be taken into consideration when this anaesthetic is used in the marmoset if the primary objectives of the experiment entail routine blood analyses.

Evaluation of serum parameters relevant to vitamin D status in tamarins.

Serum levels of 25(OH)D, alkaline phosphatase (AP), and parathormone (PTH) were evaluated to investigate the vitamin D requirement of Saguinus fuscicollis. Diets with various vitamin D content were fed 4 weeks and longer. The values of 25(OH)D (30-300 nmol/l), AP (less than 300 U/l), and PTH (less than or equal to 1,000 equl/l) considered as normal were obtained with 2,000 IU D3/kg diet, or 33 IU/animal/day, which we regard as the level required. Animals depleted of vitamin D for 215 days developed a secondary hyperparathyroidism.

Difference in serum ascorbate in two species of Callithricidae.

In one species each of the subfamilies marmosets and tamarins of the New World monkey family Callithricidae, serum levels of ascorbic acid were compared. Although the feeding regimen had been the same for both species for several years, the average concentration of serum ascorbate in the tamarins Saguinus fuscicollis (n = 21; 0.54 +/- 0.29 mg/100 ml) was only one-fifth that of the marmosets Callithrix jacchus (n = 19; 2.56 +/- 1.07 mg).

Platelet measurements in the common marmoset, Callithrix jacchus.

Platelet counts and mean platelet volumes were determined for 39 male and 32 female adult marmoset whole blood samples and these results are compared with previously published data. There is no evidence of a difference between sexes but there is some evidence of a relationship between platelet count and mean platelet volume in the Callithrix jacchus population studied.

Serum protein electrophoretic patterns of the marmoset, Callithrix jacchus.

Three electrophoretic procedures were used to separate protein fractions of marmoset serum. The albumin of marmoset serum migrated further than that of human serum with all three procedures and the number and size of the globulin fractions differed with species and with procedure.

Susceptibility of tamarin (Saguinus labiatus) red blood cell membrane lipids to oxidative stress: implications for wasting marmoset syndrome.

Captive Callitrichids frequently suffer a fatal wasting disease, wasting marmoset syndrome (WMS), of unexplained cause. This paper describes studies on the erythrocytes from animals in a breeding colony of tamarins (Saguinus labiatus), in which deaths from anaemia and wasting were occurring, to seek evidence for biochemical changes which could lead to oxidative damage and premature cell lysis. In only one animal of 33 studied did the red blood cell lipids show an increased susceptibility to oxidative damage. This animal, with some degree of certainty, could be diagnosed as having WMS. It was concluded that evidence for a primary deficiency of antioxidants as a cause of unexplained deaths, or WMS, in the colony could not at present be substantiated.

Plasma aminotransferase measurements in the marmoset (Callithrix jacchus).

Plasma aminotransferase values were measured in a large number of samples from male and female marmosets. There were no differences due to age or sex for either AST or ALT. Haemolysis affected values for both enzymes, though the effect on ALT was greater.