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In addition to an increase in contractility, contracted fibers and small and electron-dense mitochondria have suggested an increase of cytosolic Ca2+ within the cremaster muscles (CM) associated with undescended testis. Therefore, the Ca2+ content of CM associated with an undescended testis was determined and compared with the Ca2+ content associated with inguinal hernia and hydrocele and in internal oblique muscles. CM samples from boys with undescended testis (n = 9), inguinal hernia (n = 15), and hydrocele (n = 7) and from girls with inguinal hernia (n = 8) were obtained. The calcium contents of these samples and of samples from internal oblique muscle (n = 6) were determined by atomic absorption spectrophotometry. While the Ca2+ contents of CM from boys with undescended testis and from girls with inguinal hernia were similar (p > 0.05), the internal oblique muscle and the CM from boys with inguinal hernia and hydrocele contained more Ca2+ than CM from boys with undescended testis (p < 0.05). Despite evidence of an increase in cytosolic calcium, the decrease in total calcium content suggests a decrease in the adenylyl cyclase activity, thus inhibition of influx of Ca2+, but an increase in phospholipase C activity, and generation of more inositol 1,4,5-trisphosphate and mobilization of calcium from internal stores. Since the sympathetic system acts through adenylyl cyclase in striated muscles and is sexually dimorphic, similar Ca2+ contents as encountered in girls suggest an alteration in the balance of autonomic innervation against the sympathetic system in boys with undescended testis.

Benactyzine and drofenine are widely used anticholinergic drugs. Benactyzine is used to treat organophosphate poisoning and drofenine acts on smooth muscle to stop muscle spasms. Both of these drugs are esters. After they enter the bloodstream, they will interact with butyrylcholinesterase (BChE; acylcholine acyl hydrolase: EC 3.1.1.8), which has an ability to hydrolyze a wide variety of esters. Therefore, the kinetic analysis of their inhibitory effects on human serum BChE was examined using butyrylthiocholine as substrate. Both drugs were competitive inhibitors of BChE and the Ki values of benactyzine and drofenine were calculated to be 0.010 ± 0.001 and 0.003 ± 0.000 mM, respectively, using the Systat (version 5.03, 1991) nonlinear regression analysis software package. According to these parameters, drofenine is a more potent competitive inhibitor of BChE than benactyzine.

Butyrylcholinesterase (BChE, EC 3.1.1.8) has been purified about 6600-fold from human serum with a procedure including ammonium sulfate fractionation (55–70%) with acid step at pH 4.5 and procainamide–Sepharose 4B affinity chromatography. The purified enzyme exhibited negative cooperativity with respect to butyrylthiocholine (BTCh) binding at pH 7.5. KS was found to be 0.128±0.012 mM. Inhibition kinetics of the enzyme by Cd2+, Zn2+ and Al3+ were studied in detail. The 1/v vs 1/[BTCh] plots in the absence (control plot) and in the presence of different concentrations of cations intersected above 1/[BTCh]-axis. The data were analyzed by means of a nonlinear curve fitting program. The results demonstrated that all of the three cations are the linear mixed-type inhibitors of BChE. Ca2+ and Mg2+ had no effect on the enzyme activity in the experimental conditions. But when the enzyme was inhibited by 0.5 mM Cd2+ or Zn2+, Ca2+ and Mg2+ partially reactivated the inhibited allosteric form of BChE. Results were compared with data obtained from brain BChE purified from sheep.

Tosylphenylalanine chloromethyl ketone (TPCK) and tosyllysine chloromethyl ketone (TLCK) are irreversible modifiers of histidine which is located in the catalytic triad of chymotrypsin and trypsin, respectively. The effects of TPCK and TLCK on the histidine in the catalytic triad of the desensitized butyrylcholinesterase (BChE), prepared from human serum by heating at 45 degrees C for 24 h, were investigated in detail. It is found that these reagents do not modify, but reversibly inhibit the desensitized enzyme as a function of time. Just as it is for the native enzyme, TPCK is a hyperbolic mixed-type inhibitor of the desensitized BChE with Ki, alpha and beta values of 0.017 +/- 0.003 mM, 3.942 +/- 1.125 and 0.524 +/- 0.070, respectively. However, TLCK is the pure competitive inhibitor of the desensitized BChE with a Ki value of 0.008 +/- 0.000 mM, while it is hyperbolic mixed-type inhibitor of the native form. These findings show that the conformation of the active site cavity of desensitized BChE is different from that of the native enzyme.

The effects of Ni2+, Co2+, and Mn2+ on human serum butyrylcholinesterase (BChE, acylcholine acylhydrolase E.C. 3.1.1.8) were investigated in this study. Inhibition kinetics of BChE were studied using butyrylthiocholine (BTCh) as substrate. The "1/v" versus "1/[BTCh]" plots in the absence (control plot) and in the presence of the metal ions intersected above 1/[BTCh]-axis for all trace elements. In addition, when the concentrations of the cations were increased at 4 mM BTCh, velocities decreased and drove to zero at high concentrations of the trace elements. These results demonstrate that Ni2+, Co2+, and Mn2+ are linear mixed-type inhibitors of BChE. alphaK(i) values have been determined as 53.20 mM,152.25 mM, and 190.24 mM for Ni2+, Mn2+, and Co2+, respectively, by using nonlinear regression analysis. From the comparison of alphaK(i) values of the trace elements, it can be said that BChE has more affinty to binding Ni2+ than Co2+ and Mn2+.

Introduction: Inguinal hernia and hydrocele are suggested to result from the persistence of smooth muscle (SM) which should undergo programmed cell death (PCD) after presenting transiently to propel the testis. Since Ca2+ is involved in PCD, the Ca2+ contents of the peritoneum and sacs associated with undescended testis, inguinal hernia and hydrocele were determined and compared. Materials and Methods: Sacs were obtained from boys with undescended testis (n = 11), inguinal hernia (n = 22) and hydrocele (n = 10), and girls with inguinal hernia (n = 7). The calcium content of the sacs and peritoneal samples (n = 6) was determined through atomic absorption spectrophotometry. Calcium contents were compared according to their sources using the Mann-Whitney U test and p values of Results: While revealing similar Ca2+ contents as the peritoneum, sacs associated with undescended testis and hydrocele contained more Ca2+ contents than the sacs of boys and girls with inguinal hernia (p < 0.05). Conclusions: Sacs associated with inguinal hernia, which are known to contain SM all around the mesothelial layer, contain the least Ca2+. Despite the decrease in SM, sacs associated with hydrocele contain more Ca2+. Since PCD is associated with Ca2+ overload and inhibition of Ca2+ load inhibits PCD, differences in Ca2+ content may reflect the inhibition of PCD at different stages and for different reasons in inguinal hernia or hydrocele of childhood.

Glutathione reductase from human leukocytes has been purified 570-fold by using the methods of ammonium sulfate fractionation (35–70%), CM-Sephadex column chromatography, and affinity chromatography. The molecular weight of the enzyme was determined by gel filtration on Sephadex G-200 and found to be 120,000 ⊣ 5000. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the enzyme had a molecular weight of 19,000 ± 2000 when dissolved in 1% sodium dodecyl sulfate and 1% 2-mercaptoethanol. Velocity versus pH curve indicated that the enzyme may be a diprotic system.