[Concepts of "urinary bladder" and "vesicles (bao)" , "jin ye" (fluid and humor) and "urine" and other associated issues].

In the Huang di nei jing(Huangdi's Internal Classic), jin ye (fluid and humor) is described in two senses, broad and narrow, though not so strictly.Sometimes, jin ye is explained ambiguously as "sweat" and "urine" , as in the phrase "the bladder, being a house of jin ye" , here "jin ye" refers to the urine. In the Qi jue lun pian of Su wen (Chapter on Qi-Syncope of Plain Questions) , the "bao" in the sentence "heat of bao moved to bladder" refersto the uterus. In the Shi cong rong lun pian (Chapter of Readily Inspecting) of Plain Questions, the "bladder" in the phrase "gallbladder, stomach, large intestine, small intestine, spleen, bao and bladder" , which, being an annotation of "bao" originally, is mistakenly incorporated into the text of the Classic. In the Wu wei lun of Ling shu (On Five Tastes in Miraculous Pivot) , the "bao" in "bao of bladder" refers to the external hou (external manifestation) of the bladder, that is the scrotum. In the Bei ji qian jin yao fang (Essential Prescriptions Worth a Thousand Gold for Emergencies) , the short sentence "pang guang zou bao" is an error in itself. In the sentence of "settled in the bao and zhi causing to dream of defecation and urination" in the Yin xie fa meng (Dreams due to Evils) of Miraculous Pivot, "bao" refers to uterus, and "zhi" to anus. In Bi lun pian(Chapter on Impediment) of Plain Questions, "the man suffered bao bimight feel internal pain when the lesser abdomen and bladder are pressed" , here, "bao" refers to the bladder. In the Wu yin wu wei(Chapter on Five Sound and Five Tastes) of Miraculous Pivot, the "bao" in the sentence "thoroughfare vessel and conception vessel all starts from bao" , again, "bao" here refers to the bladder, rather than to the uterus. From the above descriptions of "bladder" and "bao" in the Huangdi's Internal Classic, the "bladder" in ancient medical books refers to the substantial bladder, an anatomical organ, and "bao" refers to cystiform organs, including the bladder, uterus, scrotum etc.

[Effect of IGF-II on progesterone production by cultured rat luteal cells in vitro].

It has been reported recently that IGF-II plays an important role in the regulation of ovarian function. The aim of this study is to investigate whether IGF-II can affect progesterone production by cultured rat luteal cells. The results showed that IGF-II could significantly stimulate basal progesterone production in a dose-dependent manner without altering the cAMP content. IGF-II could enhance 3H-leu incorporation into protein and 3H-TdR incorporation into DNA of the luteal cells, but these effects could be inhibited by CYX and Act D. The above results suggest that stimulating effect of IGF-II on progesterone production by rat luteal cells may be related to enhanced protein and DNA synthesis.

Identifying substrate motifs of protein kinases by a random library approach.

Protein phosphorylation is an important posttranslational modification process that plays a crucial role in signal transduction. There are many protein kinases involved in cell signaling. However, substrate motifs of many protein kinases in signal transduction are not well-known. Traditional methodologies for identifying these motifs are often difficult and inefficient. In the present study, we developed a novel approach for discovering linear substrate motifs of protein kinases. This method is based on the screening of random synthetic combinatorial peptide libraries on beads where each bead expresses only one peptide entity [Lam et al. (1991) Nature 354, 82-84]. We chose cyclic AMP-dependent protein kinase (cAPK) as a model system in the present study since it is a well-studied enzyme. Random pentapeptide and heptapeptide libraries were screened with the addition of [gamma-32P]ATP and cAPK. 32P-Labeled peptide-beads were then isolated for microsequencing. The identified peptide motif for cAPK was RRXS and is identical to that reported in the literature. Kinetic studies of the best three peptides indicate that they are efficient substrates for cAPK discovered from random synthetic combinatorial peptide libraries. Our results also suggest that this method is potentially useful for identifying substrate motifs of various protein kinases with high sensitivity and specificity. In addition, this method can also be used as a general method for identifying linear substrate motifs for various posttranslational modifications.

[Effect of tyrosine on progesterone and hCG production by human trophoblast cells in vitro].

The purpose of the present study was to investigate the effect of tyrosine on progesterone and hCG production by human placental cells in vitro. The results showed that the three concentrations (0.02 mmol/L, 0.2 mmol/L and 2mmol/L) of tyrosine inhibited progesterone secretion by trophoblast cells in vitro. While progesterone secretion was suppressed by tyrosine, hCG secretion was unchanged. Thus, it seems unlikely that the suppression of progesterone production by tyrosine was due to a decrease in hCG production. It was further demonstrated that tyrosine inhibited 3 beta-HSD activity of trophoblast cells, indicating that the progesterone production inhibition by them might be due to the decreased 3 beta-HSD activity of trophoblast cells.