Isolation and characterizartion of alginic acid from commercially cultured Nemacystus decipiens (Itomozuku).

An alginate was isolated from commercially cultured Nemacystus decipiens which had been harvested in Yonashiro Town (Okinawa, Japan). The yield of the alginate was 1.6% (w/w of wet alga), and the uronic acid, ash and moisture contents of the alginate were 86.0%, 12.0%, and 2.3% (w/w), respectively. The molecular mass of the alginate was estimated to be about 1.5 x 10(5). The infrared spectrum and optical rotation of the alginate were in agreement with those of the standard alginate. D-Mannuronic acid and L-guluronic acid were identified by 1H- and 13C-NMR spectroscopy, the molar ratio of both sugar residues being estimated to be 0.72:1.00.

The presence of giant granules in the juxtaglomerular cells of beige rats may affect plasma renin activity and blood pressure.

Chediak-Higashi syndrome (CHS) is an autosomal recessive disorder, characterized histopathologically by giant granules in various cells. Since little is known about the juxtaglomerular (JG) cells of CHS, the present study was undertaken as a morphological investigation of the JG cell of Beige rats, which were found to be a new animal model of CHS. In addition, we measured the blood pressure and plasma renin activity. The blood pressure of Beige rats is similar to that of DA rats, the mother strain of Beige rats. However, the plasma renin activity of Beige rats increases with age, whereas that of DA rats decreases. Morphologically, JG cells of Beige rats gave no evidence of hyperplasia and hypertrophy. The most conspicuous change was a small number of giant JG granules. Ultrastructurally, JG granules of Beige rats were large, irregular, and varied in size at 2 months of age, but no age-dependent changes were detected. These results suggested that giant JG granule formation slightly increases renin release with age, but does not affect blood pressure.