Activated coagulation time for rhesus monkeys (Macaca mulatta)

The activated coagulation time test provided a rapid yet accurate measurement of the intrinsic clotting system in rhesus monkey (Macaca mulatta) whole blood. Other advantages of this test included reproducibility, no requirement for control samples, low cost and commercial availability. The mean activated coagulation time value for 60 normal rhesus monkeys was 96 seconds with a range of 77 to 125 seconds. There were no significant differences due to sex, venipuncture site and time of blood collection.

Serum concentrations of chorionic gonadotrophin, oestradiol-17 beta and progesterone during early pregnancy in the south Indian bonnet monkey (Macaca radiata)

Serum concentrations of chorionic gonadotrophin (CG) during early pregnancy in the bonnet monkey (Macaca radiata), were determined by a radioimmunoassay validated for measuring monkey chorionic gonadotrophin. The earliest time at which CG could be detected was on the 28th day of a fertile cycle and it could not be detected beyond the 50th day. During a fertile cycle, mean values of oestradiol-17 beta, in addition to exhibiting a preovulatory peak around Days 9-10 of cycle, exhibited a secondary peak around Day 30 of the cycle. Serum progesterone levels remained elevated throughout the period of study from Day 18 to Day 50 and at no time did the levels fall below 2 ng/ml.

Identification and quantitation of steroids in sulfate fractions from plasma of pregnant chimpanzee, orangutan, and rhesus monkey

Steroids in the mono- and disulfate fractions from plasma of pregnant chimpanzees (Pan troglodytes), orangutans (Pongo pygmaeus), and a rhesus monkey (Macaca mulatta) were identified by gas chromatography/mass spectrometry and quantitated by gas-liquid chromatography on open tubular glass capillary columns. Whereas the average total concentrations were 4-5 times lower, 2.3-5.5 mumol X 1(-1) vs. 10.7-19.8 mumol X 1(-1), the pattern of steroid sulfates in the chimpanzees and orangutans were very similar to that previously found in pregnant women. Twenty one steroids were identified. The 3 beta-hydroxy-5-ene steroids were the same as in humans. Saturated pregnane derivatives were predominant and increased with time during pregnancy. Four isomers each of 3-hydroxypregnan-20-one and pregnane-3,20 alpha-diol were found, having 3 alpha, 5 alpha, 3 beta, 5 beta, 3 alpha, 5 beta, and 3 beta, 5 alpha stereochemistry, respectively. The relative proportion of disulfates was slightly lower in the great apes (15-28% of the total steroid sulfates) than in humans (23-33%). The monosulfate of 5 beta-pregnane-3 alpha, 20 alpha-diol constituted 12-14% of the total in chimpanzees and 3-4% in orangutans and humans. The monosulfate of 5 alpha-pregnane-3 beta, 20 alpha-diol constituted 5-7% in chimpanzees and 11-16% in orangutans and humans, whereas the disulfate was relatively less abundant in the great apes, 4-8%, than in humans, 10-18%. Although difficult to quantitate accurately, the chromatograms indicated that the proportion of 3 beta, 5 beta-isomers was higher in great apes than in women. The presence of 5 alpha-pregnane-3 beta, 16 alpha, 20 alpha-triol and 5 alpha-pregnane-3 alpha, 20 alpha, 21-triol indicated that hydroxylations of steroid sulfates in the great apes were similar to those in pregnant women. The steroid sulfate pattern in the rhesus monkey was completely different, 3 beta-hydroxy-5-ene steroids constituting over 95% of the total. Dehydroepiandrosterone sulfate was by far the predominant steroid, followed by the disulfates of 5-androstene-3 beta, 17 beta-diol and 5-pregnene-3 beta, 20 alpha-diol and the monosulfate of 5-androstene-3 beta, 16 alpha, 17 beta-triol. The results are discussed in relation to previous knowledge of progesterone metabolism in different animal species. So far, great apes are the only species showing the same pattern of steroid sulfates in plasma as humans.

Purification and characterization of the sex steroid binding protein from macaque serum. Comparison with the human protein

The sex steroid binding protein (SBP) of Macaca mulatta and Macaca nemestrina sera has been purified to homogeneity and chemically characterized. The native protein is a glycoprotein having a molecular weight of approximately 88 000 and is composed of two similar subunits of molecular weight 47 000 as estimated by sodium dodecyl sulfate gel electrophoresis. One molecule of 5 alpha-dihydrotestosterone is bound per dimer with a KD equal to 1.6 nM at 11 degrees C. Isoelectric focusing patterns reveal the presence of at least 12 different forms of dimeric SBP molecules probably resulting from the presence of different amounts or types of carbohydrate side chains. The data indicate a very close similarity in molecular and steroid-binding properties to human SBP and establish the macaque monkey as a valuable animal model to study the physiological role of SBP in humans.

An inverse relationship between plasma carnitine and triglycerides in selected Macaca arctoides and Macaca nemistrina fed a low-fat chow diet

Plasma carnitine and triglycerides were measured in five male Macaca arctoides and one female Macaca nemistrina during the course of feeding a low-fat (5.2% w/w), high carbohydrate diet and a high-fat (15.9% w/w), low carbohydrate diet. For each individual monkey, an inverse relationship was observed between plasma carnitine and triglyceride levels when the low-fat diet was fed but not when the high-fat diet was fed. The mechanism of the different responses to diet was not investigated but may be related to the primary source of the plasma triglycerides (i.e. endogenous origin or exogenous origin) or to differing hormonal effects. A close coupling between carnitine and triglyceride metabolism may be part of a sensitive homeostatic control mechanism that responds to endogenously-synthesized triglyceride.

Measurement of apolipoprotein A-I concentration in nonhuman primate serum by enzyme-linked immunosorbent assay (ELISA)

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for nonhuman primate serum apolipoprotein A-I (apoA-I) is described. The assay is a noncompetitive, sandwich ELISA in which polystyrene microtiter plates were used with purified, monospecific goat anti-monkey apoA-I antibodies adsorbed on the wells. The serum samples were added to the coated wells, incubated, and after washing, antibodies conjugated to horseradish peroxidase were added. After further washing, the bound label was assayed. A heat treatment step, 52 degrees C for 3 hr, was used to maximize the apoA-I immunoreactive sites in diluted serum. Serum samples extracted with chloroform-methanol, delipidated with tetramethylurea, or denatured by heating gave essentially equivalent results. The working range of the apoA-I standards was 0.5 to 5 ng and parallel responses were observed for apoA-I in serum, in isolated HDL, and in buffer as a purified apoprotein. Recovery of apoA-I added to serum was quantitative (106 +/- 3%). The intra- and interassay coefficients of variation were 6.2 and 6.9%, respectively. The enzyme immunoassay yielded values that compared favorably with those obtained by radial immunodiffusion (r = 0.84). ApoA-I concentration in African green monkey serum was highly correlated with the HDL cholesterol concentration (r = 0.86). It is concluded that this ELISA is an accurate and precise method for determination of apoA-I concentrations in primate serum.

Naloxone stimulation of luteinizing hormone secretion in the female monkey: influence of endocrine and experimental conditions

It is known that opiate administration results in the inhibition of LH release. In this paper, we examine the role of endogenous opiates in the regulation of gonadotropin secretion during the menstrual cycle of the monkey. The objectives of these experiments were to determine the experimental and endocrine conditions that are conducive to increased gonadotropin secretion in response to endogenous opiate antagonism. In Exp 1, naloxone was administered during the luteal phase to three groups of monkeys under three different experimental conditions. When naloxone (2 mg, iv) was injected into conscious unrestrained or sedated animals, LH secretion increased 2- to 3-fold. In contrast, the same dose of naloxone failed to stimulate LH secretion in monkeys restrained in primate chairs. In Exp 2, the gonadotropin response to acute naloxone administration on each day of the menstrual cycle was determined. A significant increase in the serum LH concentration (greater than or equal to 20% within 40 min of injection) was observed after naloxone administration in 60% of the trials conducted during the luteal phase. Significant increases occurred in only 13% of the saline-treated control trials during this stage of the menstrual cycle. Mean LH levels increased from 14.4 +/- 1.3 to 31.2 +/- 4.3 ng/ml after naloxone injection. In contrast, naloxone had no effect on LH secretion during the follicular phase. Although small LH increments were noted after naloxone injection in 40 +/- 8% of the trials, neither the frequency nor the amplitude of these increases was different from that in follicular phase controls. We conclude from these results that the ability of naloxone to stimulate LH secretion is limited to the luteal phase. Previous findings from our laboratory indicate that hypothalamic beta-endorphin activity, as reflected by its concentration in hypophyseal portal blood, is increased by ovarian steroids and that its greatest activity occurs during the luteal phase. Since the response of LH to naloxone administration was limited to the luteal phase, we believe that these results support the conclusion that hypothalamic beta-endorphin is a physiological modulator of LH secretion in the monkey.

Rhesus macaque red blood cells frozen with 40% glycerol and stored at -80 C

Red blood cells of rhesus macaques cryopreserved with 40% (w/v) glycerol and stored at -80 C had freeze-thaw-wash recovery values of 87%, 24-hour posttransfusion survival values of 85%, and life-span values of 13 days. Liquid and freezing methods of preserving RBC were studied in the macaques.

Lipoprotein profiles in rhesus monkeys with divergent responses to dietary cholesterol

From a group of 53 rhesus monkeys, we selected 12 animals, the six with the highest and the six with the lowest response to a high cholesterol diet, and we made detailed analyses of their cholesterol and apolipoprotein profile. The high responders differed from the low responders in several ways. During the high cholesterol diet period, the high responders had much higher plasma apolipoprotein B and E concentrations and much lower plasma apolipoprotein A-I concentrations than did the low responders. Nearly all the increase in plasma cholesterol and apolipoproteins B and E concentrations in the high responders occurred in the lower density fractions (d = 1.006-1.030 g/ml), while the decrease in plasma apolipoprotein A-I concentrations in the high responders was confined to the lower density fraction of the high density lipoproteins (HDL), i.e., HDL2 (d = 1.063-1.125 g/ml). In the low responders, on the other hand, the slight increase in cholesterol concentrations was evenly distributed between the lower density fractions and HDL, and the increase in apolipoprotein A-I concentration of the lower density fractions is related to the decrease in the concentration in the HDL2 in the high responders.

The BP graded blood group system of the baboon: its relationship with macaque red cell antigens

The first blood group system to be defined in baboons by means of isoimmune agglutinating reagents is composed of five graded types: B4, B3, B2, B1 and b, inherited, as postulated, by five allelic genes with decreasing dominance order. There are significant differences in distribution of the BP blood groups between hamadryas baboons on the one hand, and cynocephalus and anubis on the other, which may serve as auxiliary taxonomic criteria. Antibodies of specificities related to the BP graded antigens are found in the sera of presumably nonimmunized baboons, and also in the rhesus isoimmune antisera that detect one of the subtypes of the so-called Drh graded system of macaques. These findings point to ubiquity of the BP or BP-like antigens, and to the close serological relationship between BP baboon and Drh macaque red cell antigens, perhaps as evidence of a common ancestral antigen which gave rise to a diverging set of graded subspecificities of baboon and macaque red cells, respectively.

Hematologic characterization of naturally occurring malaria (Plasmodium inui) in cynomolgus monkeys (Macaca fascicularis)

Twenty of 47 recently imported cynomolgus monkeys (Macaca fascicularis) were found to have malarial infections. The agent identified was Plasmodium inui. All infections were subclinical in nature. Parasitemias ranged from 10 to 900 parasites/mm3 of whole blood. Pre- and post-treatment hematologic values were evaluated following treatment with chloroquine. Treatment was effective in clearing parasitemias from 13 of 14 infected monkeys. Pretreatment values of hematocrit, hemoglobin, and mean corpuscular volume were significantly different in infected animals compared to noninfected animals. While post-treatment hemoglobin and hematocrit values returned to noninfected control levels, mean corpuscular volume values of infected animals remained significantly lower in the post-treatment period.

Effects of capture and venipuncture on serum levels of prolactin, growth hormone and cortisol in outdoor compound-housed female rhesus monkeys (Macaca mulatta)

The effects of capture and repeated venipuncture on serum levels of prolactin (Prl), growth hormone (GH) and cortisol (F) were assessed in outdoor, open compound-housed, socially-living female rhesus monkeys. In animals unaccustomed to capture, blood samples obtained soon after capture (time zero) contained relatively high concentrations of both Prl and GH (Prl>30 ng/ml, GH> 10 ng/ml) which declined dramatically over the next 60 min. Mean levels of serum Prl in capture-naive lactators (n=6) and non-lactators (n=5) were 83 ± 28 (sem) and 32 ± 11 ng/ml at time zero and fell significantly (P < 0.01) within 60 min to 28 ± 10 and 6 ± 2 ng/ml, respectively. GH levels in serum also decreased over time and the time-dependent reductions in serum Prl and GH were unaffected by intervening venipuncture or caging. In contrast, serum F rose after capture reaching peak values (330 – 515 ng/ml) 60 min later. The delayed rise in serum F could reflect the time required for pituitary trophic stimulation of the adrenals after capture. Capture-acclimated, lactating females displayed lower levels of Prl at time zero with values approximating those found at 90 min in the capture-naive group. Furthermore, capture-acclimated pregnant animals exhibited a significant rise in Prl levels after parturition in the spring. These studies suggest a non-specific, capture-related release of pituitary hormones in capture-naive, compound-housed female rhesus. However, animals that have been captured and bled repeatedly over some weeks or months show lower, physiological levels of Prl, indicating an acclimation to the procedure. Thus, outdoor-housed rhesus monkeys which have been acclimated to capture can be a useful model for studying the involvement of Prl in reproduction in this species.

The effect of diet on plasma carnitine, triglyceride, cholesterol and arterial carnitine levels in cynomolgus monkeys

Plasma carnitine, cholesterol, and triglycerides were measured over a 13-week period in male cynomolgus monkeys (M. fascicularis) that were fed a control diet (Purina Monkey Chow, n = 5) and a semisynthetic hypercholesterolemic diet (n = 15). Plasma cholesterol levels rose from 100 +/- 5 to 743 +/- 50 mg/dl in the cholesterol-fed group during the 13-week period but remained below 133 +/- 13 mg/dl in the control group. Plasma triglyceride levels tended to be lower in the cholesterol-fed group, particularly at 4 week (28 +/- 3 vs 42 +/- 7 mg/dl, P less than 0.05). Plasma carnitine levels rose from 43 +/- 4 to 53 +/- 5 nmol/ml within two weeks in the cholesterol-fed group and remained above control values for the duration of the study. Carnitine levels were significantly higher in the carotid arteries of cholesterol-fed animals relative to control (224 +/- 25 vs 109 +/- 15 pmol/mm in situ length, P less than 0.01). Higher mean values of carnitine were also found in iliac, subclavian, and coronary arteries of cholesterol-fed animals but not in femoral arteries.

A striking diurnal variation in plasma testosterone concentrations in infantile male rhesus monkeys (Macaca mulatta)

Testosterone (T) was measured by radioimmunoassay in blood samples taken at 09.00 and 21.00 h in infantile male rhesus monkeys maintained in individual cages with their mothers under a controlled photoperiod (lights on 06.00-18.00 h). During the first 6 weeks of life, concentrations of plasma T at night (3.9 +/- 1.7-7.0 +/- 0.8 ng/ml; mean +/- SEM) were approximately 3- to 6-fold greater than those in the morning (0.8 +/- 0.1-2.0 +/- 0.6 ng/ml). The nocturnal elevation in circulating T then declined progressively until approximately 30 weeks of age when plasma T concentrations in the morning and evening reached their nadir and became indistinguishable. Bilateral orchidectomy at 1 week of age completely abolished the nighttime elevation in plasma T concentration. This striking diurnal variation in testicular T secretion in the infantile rhesus monkey appears to be similar to that in the fully adult animal. These findings provide further evidence in support of the view that, in this species, the hypothalamic-pituitary apparatus that governs testicular function is fully mature by the neonatal stage of development.

[Application of an automatic blood cell analyzer "MICROX" to the blood of experimental animals. I. Differential counts of white blood cells in monkeys and dogs]

Automatic blood cell analyzer "MICROX" was examined for possible applicability to the differential count of white blood cell in the monkey and in the dog. Spun blood smear slides prepared from 42 monkeys and 60 dogs were stained with Wright's dye and totals of 4971 white blood cells of the monkey and 7189 cells of the dog were counted, respectively. The identification rate of MICROX was checked by the cell by cell counting method on a monitor TV of the instrument. Analysis of the data was made to examine correlationship between the results of MICROX and of optical microscopy on the same slides. 1) Identification rates and misclassification rates were 97.0% and 3.0% respectively in monkeys and 96.4% and 3.6% in dogs. 2) A high degree of correlation was observed between the results by MICROX and by optical microscopy in respect of segmented neutrophils and lymphocytes. 3) There were an average of 15.5 cells counted as unknown cells in monkey blood and 16.5 in dog blood per 100 cells, respectively. Of the unknown cells about 40 to 50% were closely disposed leukocytes within the same counting squares and almost all of atypical lymphocytes and erythroblasts were also counted as unknown cells on the analyzer. The data support the feasibility of the use of MICROX for the differential count of white blood cells of normal monkeys and dogs.

Differential effects of chemical and physical restraint on carbohydrate tolerance testing in nonhuman primates

Ketamine hydrochloride, used during glucose or lactose tolerance tests to aid restraint of rhesus and stumptail macaques unconditioned to handling, prevented the establishment of definitive baseline plasma glucose tolerance curves from which meaningful interpretations could be derived. Repetition of the tests after the animals were restraint-chair conditioned provided clear baseline control data. It is suggested that ketamine might invalidate those carbohydrate tolerance tests which are based on the absorption of glucose from the gastrointestinal tract.

Study on the interaction between hemoglobin Izu (Macaca) and organic phosphates by spin labeling

ESR spectra of the carbonmonoxy, oxy, and deoxy derivatives of hemoglobin Izu [Hb Izu (Macaca): beta 83 (EF 7) Gly leads to Cys] labeled at cysteine beta 83 with maleimide spin label have been observed in the presence and absence of 2,3-diphosphoglycerate and inositol hexaphosphate. The tau c values obtained from the spectra indicated that inositol hexaphosphate binds to all the derivatives of Hb Izu, but 2,3-diphosphoglycerate only to the deoxy derivatives.

Transfusion of incompatible blood in rhesus monkeys and baboons

Four pairs of rhesus monkeys and five pairs of baboons were cross-transfused with large volumes of blood given at intervals varying from 3 weeks to 30 months. Although no acute transfusion reactions were observed, there was a significant reduction in survival rate of the transfused erythrocytes correlated with the level of antibodies in recipient's serum. The immune response of the recipient animal depended on the interval between transfusions and, to some extent, on the number and kind of erythrocyte incompatibilities between the recipient and the donor. These results emphasize the importance of blood group and compatibility testing prior to transfusion.

Survey of serum cholesterol and triglyceride concentration and lipoprotein electrophoretic pattern in rhesus monkeys (Macaca mulatta)

Serum lipids and lipoproteins were surveyed during quarantine of a group of 811 wild-caught rhesus monkeys. No abnormalities indicative of dyslipoproteinemia analogous to the familial hyperlipoproteinemias in man were observed. Males had significantly lower mean cholesterol (134 mg/dl) and higher mean triglyceride (41.9 mg/dl) concentrations than females (155 and 37.5 mg/dl, respectively). Electrophoretic distribution of lipoproteins differed with sex. Cholesterol concentration and electrophoretic pattern had not attained steady state by ten weeks either in animals recently imported or in those conditioned in another laboratory for six months or more after import.

Maternal and fetal plasma levels of 3-methylhistidine in pregnant nonhuman primates

Available data indicate little reutilization of 3-methylhistidine (3-MH) in the rat and man. These data led to the use of urinary 3-MH excretion as a measure of muscle protein catabolism in those animal species. However, 3-MH excretion does not accurately measure protein catabolism in the sheep, pig, and rabbit. This is due, at least in part, to the fact that renal amino acid (AA) transport systems reabsorb 3-MH from the glomerular filtrate. The monkey differs from man in that its plasms contains significant quantities of 3-MH, suggesting an active renal transport system for this AA. The present study measured maternal and fetal plasma 3-MH levels in 33 pregnant rhesus monkeys to determine whether the non-human primate placenta contained transport sites concentrating this AA to the fetal plasma. Mean fetal plasma 3-MH concentrations were 16.4 +/- 6.71 micrometers/100 ml, while maternal levels were 9.45 +/- 3.69 micrometers/100 ml. The fetal to maternal gradient was maintained between 1.6 to 1.7 during the course of maternal infusions of various AA. Since placental AA transport systems are similar to those in the kidney and intestine, the data also suggest the presence of AA transport systems for 3-MH in the monkey, indicating that urinary 3-MH excretion would be a poor method for measuring muscle protein catabolism in this species.

Inhibition of the postcastration rise of luteinizing hormone and follicle-stimulating hormone in female rhesus monkeys (Macaca mulatta) by the administration of a luteinizing hormone-releasing hormone inhibitory analog ([N-Ac-D-Trp1-3,D-p-Cl-phe2,D-Phe6,D-Ala10]-LH-RH)

Regularly cycling rhesus monkeys were bilaterally oophorectomized for study of postcastration rise of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The animals were divided in two groups, control animals, which received vehicle, and experimental animals, which received intramuscularly 1 mg of a potent luteinizing hormone-releasing hormone (LHRH) inhibitory analog ([N-Ac-D-Trp1-3,D-p-Cl-phe2,D-Phe6,D-Ala10]-LH-RH) from the day of castration for 10 days. The controls showed significant elevations of FSH and LH 3 to 4 days after castration, but in the experimental animals the rise in gonadotropins was blocked until the LHRH antagonist administration was discontinued. The dynamics of gonadotropin elevation after the discontinuation of [N-Ac-D-Trp1-3,D-p-Cl-phe2,D-Phe6,D-Ala10]-LH-RH administration were similar to those observed in control animals after castration. The availability of a compound that selectively inhibits FSH and LH secretion in primates opens a new approach to contraception and for the treatment of conditions in which gonadotropin inhibition is desired.