Turkey acrosin. I. Isolation, purification, and partial characterization

Acrosin was extracted from turkey spermatozoa by use of urea together with sonication and freezing, and purified approximately 18-fold by sequential use of chromatofocusing and affinity chromatography. The use of chromatofocusing for the initial purification step proved to be superior to preparative isoelectric focusing. Similar to acrosin from many mammalian species, turkey acrosin was found to be a glycoprotein possessing characteristics of serine proteases. Polyacrylamide gel electrophoresis (PAGE) of the enzyme indicated the presence of two isozymes. Sodium-dodecyl sulfate PAGE under reducing conditions revealed three subunits with approximate molecular weights of 11,700, 13,900, and 15,900.     

Effect of antigravity suit inflation on cardiovascular, PRA, and PVP responses in humans

Blood pressure, pulse rate (PR), serum osmolality and electrolytes, as well as plasma vasopressin (PVP) and plasma renin activity (PRA), were measured in five men and two women [mean age 38.6 +/- 3.9 (SE) yr] before, during, and after inflation of an antigravity suit that covered the legs and abdomen. After 24 h of fluid deprivation the subjects stood quietly for 3 h: the 1st h without inflation, the 2nd with inflation to 60 Torr, and the 3rd without inflation. A similar control noninflation experiment was conducted 10 mo after the inflation experiment using five of the seven subjects except that the suit was not inflated during the 3-h period. Mean arterial pressure increased by 14 +/- 4 (SE) Torr (P less than 0.05) with inflation and decreased by 15 +/- 5 Torr (P less than 0.05) after deflation. Pulse pressure (PP) increased by 7 +/- 2 Torr (P less than 0.05) with inflation and PR decreased by 11 +/- 5 beats/min (P less than 0.05); PP and PR returned to preinflation levels after deflation. Plasma volume decreased by 6.1 +/- 1.5% and 5.3 +/- 1.6% (P less than 0.05) during hours 1 and 3, respectively, and returned to base line during inflation. Inflation decreased PVP from 6.8 +/- 1.1 to 5.6 +/- 1.4 pg/ml (P less than 0.05) and abolished the significant rise in PRA during hour 1. Both PVP and PRA increased significantly after deflation: delta = 18.0 +/- 5.1 pg/ml and 4.34 +/- 1.71 ng angiotensin I X ml-1 X h-1, respectively. Serum osmolality and Na+ and K+ concentrations were unchanged during the 3 h of standing.(ABSTRACT TRUNCATED AT 250 WORDS)     

A simplified method for the preparation of rat thyroxine-binding prealbumin. Factors influencing its circulating level

Rat thyroxine-binding prealbumin (TBPA) was isolated in three simple steps by means of a serum precipitation by a 5% phenol solution and two consecutive semi-preparative polyacrylamide gel electrophoreses. The overall yield was 15% and the TBPA preparation contained less than 1% impurities. In addition a monospecific antiserum was raised in the rabbit. In polyacrylamide gel, rat TBPA, as with its human counterpart, migrated anodally to albumin while in agarose gel, its electrophoretic mobility was similar to that of albumin. Serum TBPA measured in adult male Wistar rats did not exhibit a circadian rhythm. However, a significant 13% decrease was observed between 9 and 15 h, followed by the restoration of the initial value by 21 h. TBPA concentration was measured in 1-, 15- and 28-day-old male and female pups as well as in adult rats. The level of this protein increased from 1 to 28 days of age and did not display any sexual difference. Yet, while TBPA concentrations in adult males were similar to those recorded in the 28-day-old pups, for adult females, they returned to the levels measured in the 1-day-old pups.     

Distribution and fate of free and liposome-encapsulated [3H]nor-muramyl dipeptide and [3H]muramyl tripeptide phosphatidylethanolamine in mice

The pharmacokinetics and metabolism of i.v. administered free (unencapsulated) or liposome-encapsulated hydrophilic [3H]-labeled nor-muramyl dipeptide (nor-MDP) and lipophilic [3H]-labeled muramyl tripeptide phosphatidylethanolamine (MTP-PE) were evaluated. In addition we also examined the distribution and fate of these immunomodulators subsequent to intranasal (i.n.) administration. Unique patterns of circulatory clearance, organ distribution, metabolism, and excretion were observed for each of the four preparations. Nor-MDP in saline was rapidly cleared from the circulation and excreted in the urine as intact molecules. MTP-PE dissolved in saline was cleared from the circulation at a slow rate and found within various organs as intact MTP-PE, lyso-MTP-PE, and MDP. Following the i.v. administration of nor-MDP or MTP-PE in liposomes, patterns of clearance and organ distribution corresponded to that of liposome distribution, i.e., the reticuloendothelial system. Extensive dissociation of hydrophilic nor-MDP from the carrier liposomes occurred, and the immunomodulator was recovered in the urine. In contrast, MTP-PE entrapped in liposomes was retained in target organs for the duration of the study. The i.n. instillation of radiolabeled nor-MDP or MTP-PE was associated with the accumulation of these immunomodulators in the brain. Our results demonstrate the feasibility of targeting hydrophilic and lipophilic immunomodulators to cells of the macrophage-histiocyte series.     

Kinetics of unscheduled DNA synthesis in UV-irradiated chicken embryo fibroblasts

Unscheduled DNA synthesis induced by 254-nm UV radiation in chicken embryo fibroblasts was examined for 24 h following irradiation, while cells were kept in the dark. The effect on this repair process of a 2-4 h exposure to photoreactivating light immediately after UV was studied. Initial [3H]thymidine incorporation in the light-treated cells was only slightly different from that in cells not exposed to light, but a distinct difference in rate and cumulative amount of unscheduled DNA synthesis was seen several hours after irradiation. By varying the UV dose and the time allowed for photoreactivation, the amount of dimers (determined as sites sensitive to a M. luteus UV-endonuclease) and non-dimers could be changed. The results of these experiments suggest that excision repair of dimers, rather than non-dimer products, is responsible for the unscheduled DNA synthesis seen after UV irradiation.     

The influence of multiple inseminations and multiple foundresses on social evolution

The breeding biology of a population determines the way in which individuals are distributed within and between progeny groups and, thus, affects the genetic variation within and between these groups. The breeding biology of any organism can be characterized by the distribution of the numbers of mates of females, the apportionment of paternity among males, the distribution of the numbers of females reproducing in common nests, and the apportionment of total fecundity within a nest among founding females. In addition, the possibility of genetic correlations among mates or among founding females is an important consideration and will be addressed in a later paper. The influence of the breeding biology on social evolution was evaluated by deriving the necessary conditions for the spread of genes for social behaviors and the rate of spread of these genes for populations with different breeding biologies. The first step in this derivation is to demonstrate that selection for genes determining social behavior can be represented as the covariance between gene frequency and relative fitness. Secondly, it is shown that this covariance can be formally partitioned into within and between group components. Thirdly, each covariance component is shown to be equivalent to the product of a genetic variance and a coefficient of linear regression of relative fitness on gene frequency. Lastly, specific models for the genotype fitnesses and breeding biologies are assumed and the necessary conditions for the increase in the frequency of altruistic alleles are obtained. The theory illustrates that variation in the numbers of mates per female has less of an effect on the evolution of social behaviors than does variation in the numbers of reproductive females per nest. In addition, it points out that the harmonic mean number of mates per female or of females per nest is a more useful summary statistic for characterizing populations with respect to the expected degree of evolved sociality than is the arithmetic mean.     

Effect of brief vascular perfusion on the ultrastructure and activity of mitochondria isolated from the rat heart

Summary Mitochondria isolated from heart tissue after a 1-min perfusion with Hanks medium were found to have significantly lower rates of State-3 respiration and respiratory control ratios compared to mitochondria isolated from non-perfused hearts. Examination of the mitochondrial preparations by electron microscopy revealed that a large proportion of the mitochondria isolated from perfused heart tissue were swollen and broken compared to mitochondria from non-perfused hearts.     

Characterization of a ribonuclease-sensitive nucleoside triphosphatase activity from HeLa nuclei.

Approximately one-third of the total ATP-hydrolysis activity in isolated HeLa nuclei is sensitive to RNAase (ribonuclease). This activity is selectively extracted with pulse-labelled RNA. In the extracts it co-sediments with various particles with sedimentation coefficients from 10S to 50S, but especially with 24S and 40S particles. ATP hydrolysis by the isolated particles was inhibited extensively (greater than 80%) by RNAase A, heparin and 0.2 M-NaCl. The activity of RNAase-treated particles was recovered when poly(A) was added, but not when DNA was added. The isolated particles exhibited RNAase-sensitive hydrolysis activities for dATP, GTP, CTP and UTP as well as for ATP, and the UTPase activity in the extracts showed nearly the same sedimentation distribution as the ATPase activity. When samples of isolated particles were irradiated with u.v. light in the presence of [alpha-32P]ATP, a 39 kDa polypeptide with a broad distribution from 10S to 50S like that of the ATPase and a 55 kDa polypeptide with a sharp distribution at 24S were photolabelled. Taken together, the data suggest that ATP-hydrolysis activity found in nuclear ribonucleoprotein subfractions appears to be the result of one or two RNA-dependent NTPases that are normally associated with endogenous RNA in a wide variety of particles.