Cerebrospinal fluid and serum were obtained from 17 adult, healthy llamas (9 males, 1 castrated male, and 7 females). Osmolality; activities of lactate dehydrogenase and creatine kinase; and concentrations of glucose, sodium, chloride, potassium, total protein, and albumin were determined in serum and CSF. Total and differential cell counts were determined in CSF, and electrophoresis of CSF proteins was performed. Total nucleated cell count was low, 0 to 3/microliter, which is lower than that reported for other domestic species and is similar to values in healthy people. Differential leukocyte percentages were disparate depending on the degree of blood contamination. Blood contamination influenced the percentage of neutrophils and eosinophils in CSF. Samples with few erythrocytes had differential leukocyte distribution similar to that of other species: mostly lymphocytes, fewer monocytoid cells, and scant neutrophils. Older llamas had a few eosinophils in the CSF. Total protein, albumin, and gamma-globulin concentrations in llamas were similar to values in cattle and were higher than values in most domestic species. Glucose concentration in CSF was approximately 40% of the value in serum (nonruminant animals and people typically have CSF glucose concentration that is approximately 60 to 80% of the serum glucose concentration). Sodium and Cl concentrations in CSF were higher than those in serum, whereas K concentration was lower in CSF, compared with serum. Activities of creatine kinase and lactate dehydrogenase in CSF were markedly lower than those in serum, and the ranges of values in this group of healthy llamas were narrow.

Collagen type I was purified from equine skin and flexor tendon, and type II collagen was purified from equine articular cartilage. The proteoglycans in these tissues were extracted, using guanidine HCl; the collagens were solubilized, using pepsin digestion, then were selectively precipitated with Nacl. Gel electrophoresis indicated that the precipitates contained only type I or type II collagen. Amino acid analysis indicated that collagen constituted > 97% of the total protein in the precipitates. Hydroxylation of proline was 42.0 t 0.6% (mean SEM) in alpha 1(I) and alpha 2(I), and was 48.1 +/- 1.3% in alpha 1(II) chains. The hydroxylation of lysine was 23.2 +/- 0.7% in alpha 1(I) and 34.1 0.9% in alpha 2(I) chains from tendon, and 49.6 +/- 4.3% in alpha 1(II) chains from cartilage. The cyanogen bromide (CB)-peptide patterns of chromatographically purified equine alpha 2(I) and alpha 1(II) chains were similar to those published previously for rat, bovine, and human alpha 2 and alpha 1 chains. However, the CB-peptide pattern of the equine alpha 1(I) chain resembled the guinea pig alpha 1(I) chain, which has no methionine between CB7 and CB6. Purified equine alpha 1(I)CB7,6 contained no methionine, methionine sulfoxide, or homoserine lactone. Mass of 42.26 kd was determined by use of mass spectrometry, and N-terminal sequence analysis established that the first 12 amino acids of this CB7,6 were identical to the sequence of human alpha 1(I)CB7. Because of this species specific difference in structure of the alpha 1(I) chain, equine Cb-peptides should be used as standards in studies of variations in the proportions of type I and type II collagens in equine tissues expressing the phenotype of fibrous tissue and cartilage.

To determine the effects of age on each analyte, CSF variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential WBC counts, RbC count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of age in 4 foals. Each foal was tested only once, to avoid any effects of CSF sample collection on subsequent analysis. Regression analysis confirmed age-related effects on CSF glucose, protein, and magnesium concentrations, but did not indicate an effect of age on CSF sodium and potassium concentrations or cell counts. Results indicate that CSF glucose concentration decreases with age; foals < 2 days old had the highest CSF glucose values, 98.8 +/- 12.0 mg/dl (mean +/- 1 SD). In foals 10 to 14 days old, CSF glucose concentration was 67.3 +/- 12.0 mg/ dl, was 65.3 +/- 4.5 mg/dl in foals 21 to 22 days old, was 70.0 +/- 5.4 mg/dl in foals 31 to 42 days old, and was 51.1 +/- 2.5 mg/dl in adults. Protein values in CSF also decreased with age: 109.0 +/- 9.7 mg/dl in foals < 2 days old, 81.0 +/- 22.8 mg/dl in foals 10 to 14 days old, 60.5 +/- 22.4 mg/dl in foals 21 to 22 days old, and 58.5 +/- 17.0 mg/di in foals 31 to 42 days old. The CSF protein concentration was 60.3 +/- 10.8 mg/dl in adult horses. Magnesium concentration in CSF increased slightly with age, then decreased after 22 days of life. In foals < 2 days old, the value was 2.43 +/- 0.16 mg/dl. Values in older foals and horses were: 2.51 +/- 0.08 mg/dl in foals 10 to 14 days old, 2.65 +/- 0.05 mg/dl in 21- to 22-day-old foals, 2.55 +/- 0.05 mg/dl in 31- to 42-day-old foals, and 2.35 +/- 0.09 mg/dl in adult horses. Mean CSF sodium and potassium concentrations were 151.7 +/- 3.7 mmol/L and 3.14 +/- 0.54 mmol/L, respectively, for all ages. There was no effect of age on these analytes. Values for CSF enzymes were considered invalid for the assay technique used and were not further analyzed.

High molecular weight (MW) hyaluronate (HA) is an integral part of synovial fluid (SF), regulating many important physiologic and pathophysiologic mechanisms. Many of its effects depend on, or are reflected in, the concentration and MW of HA. High-performance liquid chromatography was used to assess simultaneously the concentration and MW of HA in SF obtained from horses with various arthritides: acute traumatic arthritis; chronic traumatic arthritis, including degenerative joint disease (DJD); and infectious arthritis. The size-exclusion column was calibrated, using appropriate HA concentration and MW standards, before the high-performance liquid chromatographic assays of the SF samples. Calibration of the column disclosed that the maximal limit for MW estimation of HA was around 3 million. In control joints, MW of HA ranged from 2 to 3 X 10(6) (mean 2.5 X 10(6)) and did not differ significantly from MW of HA in SF from horses with acute or chronic traumatic arthritis (mean 2 x 10(6); range 1.5 to 3 x 10(6)). Interestingly, a small amount of HA of moderately high MW (approx 1 to 1.5 x 10(6)) was detected in chromatograms of SF from infected joints. This degree of polymerization of SF HA was significantly (P < 0.01) lower, compared with that for control joints. There was no difference in mean (+/- SD) concentration of HA between control joints and joints with acute or chronic traumatic arthritis (0.33 +/- 0.12 g/L vs 0.18 +/- 0.03 g/L or 0.23 +/- 0.12 g/L), indicating that SF HA concentration probably should not be used as a diagnostic marker for the condition. However, the SF HA concentration was significantly (P < 0.01) lower in joints with infectious arthritis (0.07 +/- 0.03 g/L) and in the joints with radiographic evidence of DJD (0.12 +/- 0.01 g/L), compared with control joints.