𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A Recirculatory Model with Enterohepatic Circulation by Measuring Portal and Systemic Blood Concentration Difference

✍ Scribed by Toshiya Moriwaki; Hiroyuki Yasui; Akira Yamamoto


Book ID
111540901
Publisher
Springer
Year
2003
Tongue
English
Weight
179 KB
Volume
30
Category
Article
ISSN
1573-8744

No coin nor oath required. For personal study only.


πŸ“œ SIMILAR VOLUMES


A recirculatory model for local absorpti
✍ Toshiya Moriwaki; Hiroyuki Yasui; Yukie Shigemoto; Nagahiro H. Yoshida πŸ“‚ Article πŸ“… 2002 πŸ› John Wiley and Sons 🌐 English βš– 153 KB

A recirculatory model for the portalΒ±systemic blood concentration difference (PΒ±S difference) was developed to separately evaluate the rate and extent of absorption from the gastrointestinal tract into the portal system and disposition of a drug in the body. To apply this model to pharmacokinetic an

Saliva and serum samples were collected
Saliva and serum samples were collected from eight healthy volunteers every two hours during a 26-hour period. Melatonin concentrations were measured by radioimmunoassay after chloroform extraction using radioiodinated melatonin as a tracer. Five of the subjects had high serum melatonin levels at night (peak levels higher than 75 pg/ml); in three subjects the highest serum melatonin concentration was 20-40 pg/ml. All subjects had low levels (P <0.001, was obtained for all detectable value pairs (n= 73). The regression and correlation coefficients were almost equal for the peak values of melatonin and during the rising and descending phases of the secretion patterns. However, no significant correlation was found between low daytime salivary and serum concentrations when calculated separately. In the five high-secretors the melatonin levels in saliva reflected reliably the changes in serum, but in the three low-secretors the correlation between salivary and serum melatonin was not significant. The proportion of melatonin found in saliva decreased with increasing serum melatonin levels. Circadian rhythm parameters were estimated by single cosinor analysis. The acrophases did not differ significantly within a subject in the concomitant measurements of serum and salivary melatonin. The measurements of salivary melatonin levels seem valid for studies on melatonin rhythms, but the melatonin concentrations measured in saliva do not always consistently reflect the absolute concentrations in blood.
✍ Maija-Liisa Laakso; Tarja Porkka-Heiskanen; Aino Alila; Dag Stenberg; Gunnar Joh πŸ“‚ Article πŸ“… 1990 πŸ› John Wiley and Sons 🌐 English βš– 622 KB