Lipoprotein lipase activity in adipose tissue and skeletal muscle of human diabetics during insulin deprivation and restoration.

Twelve insulin-dependent diabetic patients were deprived of insulin for 12 h, and thereafter given an 8-h i.v. infusion of insulin. Lipoprotein lipase (LPL) activity was determined from heparin eluates of adipose tissue and skeletal muscle before and after insulin infusion. In spite of development of marked hyperglycemia and hyperketonaemia during the insulin deprivation the LPL activity of the two tissues remained mostly within normal range. During the subsequent insulin administration the LPL activity of adipose tissue increased by 36% (p less than 0.05) whereas the skeletal muscle LPL remained unchanged. The result is compatible with the view that human adipose tissue LPL is more sensitive to insulin than the corresponding enzyme of muscle.

Aminotransferases in post-mortem cochlear fluids.

Aspartate and alanine aminotransferase (ASAT, ALAT) activities were measured in human post-mortem sera, cerebrospinal fluid (CSF), perilymph and endolymph. Due to heart and/or liver morbidity during a terminal illness, the ASAT and ALAT serum activities were considerably increased as compared with normal and both were 20--30 times higher (p less than 0.001) than in CSF or inner ear fluids. CSF and inner ear fluids showed mutually similar values.

Middle ear specific proteins in glue ears.

Two rabbits were immunized with a pool of mocoid secretion from glue ears. The ear fluids formed up to three specific protein precipitation lines with the absorbed immune serum. One of these proteins was identified as containing acid and another as containing neutral glycoproteins, the third component remained unidentified. The data bring out new evidence of the active secretory capacity of the middle ear mucosa in secretory otitis media.