Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The concept of classical endocrine control of ovarian function has now been extended to a more complex regulator system, including paracrine and autocrine modulating mechanisms. Among many factors, locally produced intraovarian insulin-like growth factors (IGFs) and the binding proteins (IGFBPs) and renin-angiotensin system (RAS) have been shown to play an important role in the control of folliculogenesis and ovulation. Growth hormone (GH) amplified gonadotropin actions in the process of follicular development and ovulation, at least in part, stimulating ovarian IGF-I production. IGF-I as well as IGFBPs were produced by ovarian granulosa cells. IGF-I acted synergistically with gonadotropins in the stimulation of a variety of granulosa cell functions, including estradiol (E2) and progesterone production and plasminogen activator (PA) activity. Furthermore, rabbit ovarian cells and rat granulosa cells possessed specific IGF type I receptors. The biological effects of IGF-I, including intrafollicular PA activities and ovarian steroidogenesis, were modulated by a family of IGFBPs in a complex manner. In the ovary IGFBP-3 appeared to neutralize the actions of gonadotropin and IGF-I, probably via its ability to sequester IGF-I, in the process of follicular growth, oocyte maturation, and ovulation. A functional local RAS is also known to exist in the ovary. Angiotensin II (Ang II) at 2-h intervals induced oocyte maturation, ovulation, and the production of E2 and prostaglandins (PGs) in the in vitro perfused rabbit ovaries in the absence of gonadotropin. In addition, the intrafollicular Ang II content and renin-like activity were enhanced during the ovulatory process by exposure to hCG, and the concomitant addition of saralasin inhibited hCG-induced ovulation in a dose-dependent manner. Captopril, an inhibitor of angiotensin converting enzyme, significantly inhibited the resumption of meiosis in the ovulated ova and follicular oocytes stimulated by hCG. Autoradiographic study revealed that AT2 receptors were predominantly located in granulosa cells, whereas AT1 receptors were more concentrated in the stroma and the thecal layers. Ang II-stimulated production of E2 and PGs and ovulation were significantly blocked by PD123319, a selective nonpeptide antagonist for AT2 receptors. The increase in ovarian IGF-I synthesis by exposure to hCG or GH induced the stimulation of intrafollicular PA activities. IGFBP-3 blocked the stimulatory effects of gonadotropin in the ovulatory process by neutralizing endogenously produced IGF-I, resulting in reduced intrafollicular PA activities. The increase in intrafollicular PA activities significantly stimulated the generation of Ang II in the preovulatory follicles by an activation of prorenin to renin and/or by the direct cleavage of angiotensinogen.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Regulatory system and physiological significance of local factors in the ovary during follicular development and maturation]. 759 85

The aim of this study was to characterize the acute effect of euglycemic (glucose 5.2 +/- 0.6 mmol/l) hyperinsulinemia (mean 118 +/- 32 mU/l) on fibrinolytic variables, free fatty acids (FFA) and counterregulatory hormones. In addition, the effect of chronic treatment with metformin, an oral antidiabetic agent which enhances insulin action, and metoprolol CR, a relatively beta 1-selective adrenergic antagonist, was also evaluated. A randomized, double-blind, placebo-controlled, cross-over study including 18 non-obese men, aged 53 +/- 6 years, was performed. The investigations were performed after each treatment period of 6 weeks in both the postabsorptive state and during a euglycemic, hyperinsulinemic clamp. Compared to the postabsorptive state, plasminogen activator inhibitor (PAI-1) activity and antigen, tissue plasminogen activator (t-PA) antigen and FFA decreased (p < 0.001) after 120 min of euglycemic hyperinsulinemia. In addition, t-PA activity increased (p < 0.01) while blood levels of lipoprotein (a), catecholamines and cortisol remained unchanged. Growth hormone increased during the clamps and this was most pronounced after treatment with metoprolol CR. When the effect of treatment was compared, postabsorptive levels of C-peptide, FFA and t-PA antigen were lower after metformin than after the placebo period (p < 0.05). t-PA antigen also remained lower during the clamp after metformin treatment. No significant effects of metformin or metoprolol CR were seen on insulin-stimulated glucose uptake during the clamps or on postabsorptive levels of counterregulatory hormones, PAI-1 or Lp(a).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effects of metformin and metoprolol CR on hormones and fibrinolytic variables during a hyperinsulinemic, euglycemic clamp in man. 797 48

mPEG-PLA and PLA-PEG-PLA copolymeric nanoparticles with three different PLA to PEG ratios are synthesized and used for encapsulation of recombinant human Growth hormone (rhGH). The structure and composition of the synthesized copolymers were analyzed by 1H NMR and GPC techniques. Moreover, morphology, encapsulation efficiency (EE), cytotoxicity, release profile and stability of the encapsulated rhGH were measured. Structural analysis of the prepared copolymers showed that they were successfully synthesized with approximately expected molecular weight and relatively low size distribution. It was also revealed that by increasing amounts of PLA/PEG ratio, EE content and size of nanoparticles were increased. Release profile evaluation of rhGH from both formulations indicated that copolymeric nanoparticles of Di-B2 and Tri-B2 exhibited the best results among the synthesized nanospheres, by having initial burst release of 17.5% and 28% and then slow and constant release of rhGH up to 65% and 77% of the encapsulated drug, respectively. Furthermore, results of HPLC, SDS-PAGE and CD analyses showed stability of rhGH during encapsulation and release from nanoparticles. Finally, the results showed that these two formulations provided safe and efficient sustained release of rhGH for more than a month and they have the potential to do further studies under in vivo conditions.
 ...
PMID:mPEG-PLA and PLA-PEG-PLA nanoparticles as new carriers for delivery of recombinant human Growth Hormone (rhGH). 3147 88