Enzymatic analysis of the gingival crevicular fluid in hypoxia of high altitude (Everest).

The aim of this study is to determine the qualitative and quantitative changes of alkaline phosphatase (ALP) that occur in the Gingival Crevicular Fluid (GCF) in hypobaric-hypoxic conditions (high altitude). Hypoxia affects systemic adaptation responses in different organs. We examined 17 Caucasians subjects, of whom 13 were mountain climbers (1 female and 12 males), and 4 Tibetans (2 females and 2 males) following exposure to the hypoxia environment of high altitude. The study was conducted at different altitudes (0 m control, 1000 m, 5200 m above sea level) on Mount Everest. The protocol consisted of withdrawing crevicular fluid through the use of cones made of endodontic paper size 30 sectioned to 15 mm from the apex, inserted for 30 seconds in the gingival sulcus (about 2 mm). The analyzed sites were the mesial and distal, buccal and palatal of tooth 1.1 and 2.1. Blood exams were performed on the subjects using I-Stat, furnishing analysis in real time (about 2 mins). In agreement with other results reported in literature, in all the subjects we found an increase in the hematocrit and hemoglobin with a large range of values between them, and with significant differences, as analysed with the Fisher, Scheffe and Bonferroni/Dunn statistical methods. The enzymatic analysis of the GFC showed an increase of the levels of ALP at each altitude studied. With this preliminary study we show that hypoxic environment determines not only the well known cardiovascular systemic responses, but also crevicular fluid adaptation.

cAMP phosphodiesterase activity in diabetic rats eyes in normoxic, hypoxic and hyperoxic conditions.

Phosphodiesterase activity was tested on homogenized eyes of pre-diabetic rats kept in normoxic, hypoxic and hyperoxic conditions, with the aim of correlating any difference in PDE activity with variations in atmospheric oxygen contents. The activity of the cAMP phosphodiesterase (cAMP-PDE) was tested. Phosphodiesterases seem to be particularly susceptible to variations in oxygen tension, suggesting an important role of cyclic nucleotides in adaptive processes of the cell. cAMP-PDE activity increases slightly in normoxic, hypoxic and hyperoxic conditions in pre-diabetic rats. The second messenger, cAMP, plays important roles in mediating the biological effects of a wide variety of first messengers. The intracellular levels of cyclic nucleotides depend upon rates of synthesis and degradation, of cyclases and phosphodiesterase (PDEs), respectively. Therefore, PDEs seem to play an important role in a wide variety of physiological processes.