Charge selectivity and urine amylase isoenzymes

The urinary excretions of salivary and pancreatic amylase were studied in 718 type I diabetic patients and 51 control subjects, as part of a multicenter study on diabetic nephropathy in 15 Spanish hospitals. It was found that the urinary ratio of salivary to pancreatic amylase (S/P ratio), that in normal subjects is always below 1, was elevated in 35.4% of diabetic patients, whereas microalbuminuria was present in 19.8%. The prevalence of elevated S/P ratio was also higher than that of microalbuminuria at the first years from the onset of the disease, but the prevalence of microalbuminuria was higher in patients with a long duration of the disease. alpha 1-microglobulin and microalbuminuria paralleled their prevalences during the disease, when measured in a group of patients. Overnight urine samples were obtained on three consecutive weeks from the diabetic patients, and a nested ANOVA analysis showed that the intra-individual variation of the urine parameters measured (albumin, salivary and pancreatic amylase, and beta-NAG) was very small and not statistically significant. All these findings suggest that in type I diabetes mellitus, loss of negative charges of GBM would induce preferential excretion of the anionic salivary amylase over the more cationic pancreatic amylase, and that this phenomenon is more frequent and appears earlier than microalbuminuria. The mechanisms for the increased excretion of salivary amylase and albumin into urine seem to be at least partly different. On the contrary, increase in urinary excretion of albumin and alpha 1-microglobulin in these patients are correlated, suggesting a tubular participation in the mechanisms of production of microalbuminuria.

Early changes of urinary amylase isoenzymes in diabetes mellitus

The altered excretion of isoenzymes of amylase in urine was used as an early indicator of the loss of electric charges in the glomerular basement membrane, in 202 juvenile-onset insulin-dependent diabetic patients, compared with the pattern of excretion in 51 normal subjects matched for age and sex. Diabetics showed an increased excretion of salivary amylase. The salivary to pancreatic amylase ratio in urine (S/P ratio) was always below 1 in control subjects, but was elevated in 33.2% of diabetics, although microalbuminuria was present in only 26.2% of diabetic patients. The concentrations of other proteins in urine were within the reference ranges in nearly all patients, indicating that the kidney was not seriously affected. The increased salivary amylase excretion was not due to changes in the plasma concentration of any of the isoamylases, but to a real increase in excretion, as its fractional excretion in relation to creatinine clearance was clearly increased (1.0 +/- 0.7 vs. 1.52 +/- 1.99, p < 0.05), and the ratio of their clearances was also increased (0.35 +/- 0.18 vs. 0.49 +/- 0.61, p > 0.05). Moreover, the prevalence of altered S/P ratios was higher than the prevalence of microalbuminuria (36.6% vs. 18.8% of patients in the first decade of evolution of insulin-dependent diabetes mellitus). Altered S/P ratios were most prevalent in the first decade, whereas microalbuminuria was most prevalent in the second decade of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Hematological and serum chemical characteristics of the Iberian lynx (Lynx pardina) in southwestern Spain

Hematological and serum chemical values were determined for 16 wild Iberian lynxes, Lynx pardina (5 adult males, 4 adult females, 4 juvenile males, and 3 juvenile females) captured with box traps and coil-spring traps. The results include reference values, analysis of sex and age differences, and data on the influence of capture method on blood values. Males had higher red blood cell counts (p = 0.03) and packed cell volumes (p = 0.06) than females, which presented higher mean corpuscular hemoglobin levels (p = 0.08) and mean corpuscular hemoglobin concentrations (p = 0.07) than males. Juveniles had higher serum levels of alkaline phosphatase (p = 0.01), urea (p = 0.02), and cholesterol (p = 0.02) and lower levels of creatinine (p = 0.07) than adults. Four hematological variables (mean platelet volume, platelet size distribution, white blood cell count, and mean corpuscular volume) and two serum variables (concentrations of amylase and calcium) were influenced by capture method. The use of standard procedures to assess base-line blood values in wild carnivores is encouraged.

The effect of human placental lactogen upon the metabolism of rat and human adipose tissue

The metabolic effects of human placental lactogen (HPL) on rat and human white fat were tested in vitro. When tested against rat tissue, HPL resembled insulin in stimulating uptake of glucose and incorporation of [14C] glucose into CO2, triglyceride and glycogen, but differed from insulin in stimulating glycerol release and in failing to stimulate the incorporation of [14C] The stimulation of [14C] glucose incorporation and the inhibition of glycerol release by insulin were antagonized by HPL. The effects of HPL on human white fat resembled those on rat white fat,except that glycerol release was not stimulated in human tissue. The possible role of HPL in causing the diabetogenic stress of pregnancy is discussed in the light of these findings.

Loss of immunological and biological activity of insulin with a human muscle extract

The isolation of a human muscle extract that degrades insulin to products incapable of any immunological or biological activity is reported. The extract Km value for human insulin is 0.79, and 1.43 for porcine proinsulin. It does not degrade Human Growth Hormone at the concentrations tested, it is inactivated by N-ethyl-maleimide, Trasylol, and heat, and it does not require glutathione for its action. Human muscle, therefore can contain an enzyme similar to "insulin-specific-protease" present in rat muscle.