Role of extralaryngeal muscles in phonation of subhuman primates

1. The electromyographic activity of eight external laryngeal and hyoid muscles was recorded during vocalization in the squirrel monkey (Saimiri sciureus). Calls of different types were elicited by electrical stimulation of the central grey of the midbrain in narcotized animals.
2. Peeping, a short, high-pitched call with minor frequency modulations, is associated with a marked activity in the cricothyroid, a moderate activity in the thyrohyoid, a weak activity in the sternohyoid and no activity in the sternothyroid, omohyoid, mylohyoid and anterior digastric muscles.
3. Chuck, a short, plosive call with a steep frequency descent over several kHz, is associated with a marked activity in the cricothyroid, a moderate activity in the thyrohyoid, sternothyroid and mylohyoid, a weak activity in the sternohyoid and omohyoid, and no or rare activity in the anterior digastric and inferior pharyngeal constrictor, respectively.
4. Cackling, a long and loud call consisting of alternating high- and low-pitched elements which follow each other repetitively in a 12–14 Hz rhythm, is associated with a similar muscular activity pattern as chuck except that the sternohyoid activity is relatively stronger.
5. Cawing, a short low-pitched call with a fundamental frequency of 200–700 Hz, shows a moderate activity in the sternothyroid, an occasional activity in the thyrohyoid and no activity in the cricothyroid, sternohyoid, omohyoid, anterior digastric and inferior pharyngeal constrictor.

     

Regulation of amylase activity in Drosophila melanogaster: Effects of dietary carbohydrate

The level of amylase activity in larvae and adults of Drosophila melanogaster is dependent on the dietary carbohydrate source; flies or larvae from a food medium containing starch show higher levels of activity than individuals from a food containing simple sugars. This is shown to be due to repression of activity by sugars rather than enhancement of activity by starch. Moreover, the changes in enzyme activity reflect a change in enzyme quantity rather than a change in catalytic efficiency. The seeming stimulation of amylase activity by sucrose in some experiments is due, simply, to comparisons with "starvation" diets which cause a large nonspecific reduction in enzyme activity. Though all strains tested showed repression of enzyme activity by simple sugars, the degree of repression varies between strains. Also, in those strains which carry a duplication of the amylase structural gene, the two isozymal forms of amylase can be differentially repressed by dietary sugars.     

Daily activity profiles over the lifespan of female medflies as biomarkers of aging and longevity

The relationship between the early-age activity of Mediterranean fruit flies (medflies) or other fruit flies and their lifespan has not been much studied, in contrast to the connections between lifespan and diet, sexual signaling, and reproduction. The objective of this study is to assess intra-day and day-to-day activity profiles of female Mediterranean fruit flies and their role as biomarker of longevity as well as to explore the relationships between these activity profiles, diet, and age-at-death throughout the lifespan. We use advanced statistical methods from functional data analysis (FDA). Three distinct patterns of activity variations in early-age activity profiles can be distinguished. A low-caloric diet is associated with a delayed activity peak, while a high-caloric diet is linked with an earlier activity peak. We find that age-at-death of individual medflies is connected to their activity profiles in early life. An increased risk of mortality is associated with increased activity in early age, as well as with a higher contrast between daytime and nighttime activity. Conversely, medflies are more likely to have a longer lifespan when they are fed a medium-caloric diet and when their daily activity is more evenly distributed across the early-age span and between daytime and nighttime. The before-death activity profile of medflies displays two characteristic before-death patterns, where one pattern is characterized by slowly declining daily activity and the other by a sudden decline in activity that is followed by death.     

The effect of progesterone on the activity-wheel running of ovariectomized rats

Progesterone treatment failed to significantly depress activity-wheel activity elicited by food deprivation in either ovariectomized or ovariectomized estrogen-treated rats. These results indicate: (1) that the lack of effect of progesterone on the activity of ovariectomized rats is not due only to their already low level of activity; and (2) that the depressant effect of progesterone on activity in the estrogen-treated ovariectomized rat is, to a large extent, a specific inhibition of estrogen facilitation of activity, rather than a nonspecific activity depressant effect.     

Purine nucleoside phosphorylase (NP) of bovine erythrocytes: genetic control of electrophoretic variants

A genetic polymorphism of the purine nucleoside phosphorylase is described in red cells of cattle. Electrophoresis distinguishes two types, one associated with a high activity (H), the other with a low activity (L). Breeding tests suggest the segregation of two alleles: a dominant allele for high activity ( H ) and a recessive allele for low activity (L). On the basis of quantitative estimation of enzyme activity, the individuals of the H phenotype can be separated in two classes, the enzyme activity in one class being twice as high as the activity in the other class. It is suggested that the class with the highest enzymatic activity corresponds to the homozygote for the H allele, the other class to the heterozygote. In fact, an A.I. bull (H phenotype and with the highest enzymatic activity) mated with cows of the L phenotype, gave offspring of the H phenotype, only. The decline of activity, with age, is stressed. Four breeds have been typed. The Charolais breed is characterized by a high frequency of the H allele.     

Clearing-factor lipase in adipose tissue. Distinction of different states of the enzyme and the possible role of the fat cell in the maintenance of tissue activity

1. Incubation of intact epididymal adipose tissue from fed rats at 37 degrees in an albumin solution at pH7.4 in vitro results in rapid loss of clearing-factor lipase activity until a low activity, stable to prolonged incubation, is attained. The clearing-factor lipase activity of intact tissue from starved rats, which is initially much less than that of tissue from fed rats, is mainly stable to incubation at 37 degrees . 2. Much of the clearing-factor lipase activity of intact epididymal adipose tissue from fed rats is inactivated by collagenase. The enzyme activity of intact tissue from starved rats is not inactivated by collagenase. 3. The clearing-factor lipase activity of fat cells isolated from the epididymal adipose tissue of fed rats is stable to prolonged incubation at 37 degrees . It represents only a small proportion of the total activity of the intact tissue. In starved rats, the isolated fat cells contain a much higher proportion of the activity of the intact tissue. Their activity is also stable at 37 degrees . 4. Incubation of isolated fat cells in a serum-based medium leads to a progressive rise in clearing-factor lipase activity. Actinomycin increases the extent of this rise in activity. No rise in clearing-factor lipase activity occurs when stromal-vascular cells isolated from epididymal adipose tissue are incubated in the medium. 5. The findings indicate that less than 20% of the activity of intact adipose tissue from fed rats is retained when fat cells are isolated from the tissue by collagenase treatment. The activity that is lost could be that which normally functions in the uptake of triglyceride fatty acids by the tissue.     

Effect of Environmental Conditions on Extracellular Protease Activity in Lignolytic Cultures of Phanerochaete chrysosporium

Two different types of extracellular protease activity were identified in the culture fluid of Phanerochaete chrysosporium wild-type BKM-F grown in submerged batch culture on N-limited media. The first activity, which appears to be inherent to the active growth phase, displayed a maximum on day 2 and decreased to a very low level on day 4. The second activity, which appeared at day 8 following the peak of ligninase activity, seems to be characteristic of late secondary metabolism and is stimulated by carbon starvation. Cultures started with half the amount of glucose of other cultures showed a remarkably earlier development of secondary activity. In contrast, the fed-batch addition of glucose started when ligninase activity was at a maximum (day 6) completely repressed secondary protease activity and enhanced ligninase production. The addition of exogenous veratryl alcohol increased the level of secondary protease activity, whereas the oxygen supply pattern significantly affected both the time course and the level of overall proteolytic activity. The addition of phenylmethylsulfonyl fluoride to growing cultures (0, 1, or 6 days) diminished overall protease activity, while it significantly enhanced ligninase activity. In all cases, the time courses of protease and ligninase activities were negatively correlated, indicating that protease activity promotes the decline of ligninase activity in batch culture.     

The development of the acinar heterotopic pattern of phosphoenolpyruvate carboxykinase activity in the newborn rat

Summary The postnatal appearance of phosphoenolpyruvate carboxykinase activity (PEPCK) and acinar heterotopy was investigated in newborn rats aged 2 h, 12 h, 24 h and 3 days, as well as in juvenile rats aged 25 days. The livers showed an almost homogeneous distribution of activity along the sinusoidal length at the beginning of extrauterine life where energy needs are greatest. Compared to rats aged 2 h, the PEPCK activity was higher in the livers from rats aged 12 h. The increase in activity was most pronounced in the intermediary zone. After 24 h of extrauterine life the activity decreased again creating a homogeneous acinar activity pattern. By day 3 activity had increased in the periportal zone, while decreasing in the perivenous zone, resulting in a periportal to perivenous gradient. By day 25 total activity had reached highest values both in males and females, due to a relatively high perivenous activity. The more prominent acinar gradient corresponded approximately to the one seen in adult animals.     

Enhanced resolution of histochemical distribution of glucose-6-phosphate dehydrogenase activity in rat neural tissue by use of a semipermeable membrane

We examined the histochemical distribution of glucose-6-phosphate dehydrogenase (G6PD) activity in neural tissue using different diffusion barriers. Although polyvinyl alcohol and agar overlays permitted regional localization of G6PD, a semipermeable membrane revealed cellular differences in G6PD activity within populations of neurons. Distribution of G6PD activity in selected regions of the nervous system was examined using the membrane technique. White matter usually exhibited strong G6PD activity. The neuronal somata of the dorsal root ganglia (L4-L6) and anterior horns of the spinal lumbar enlargement demonstrated a variation in activity which was independent of somal size. Satellite cells showed intense activity when the membrane technique was used. Hippocampal pyramidal and granular cells of the dentate gyrus exhibited moderate, uniform G6PD activity, but only weak activity was seen in hippocampal and dentate molecular layers. High levels of activity were observed in the vascular endothelial cells of the brain, spinal cord, and choroid plexus, and in the ependymal cells of the spinal central canal and ventricles of the brain. The superior vestibular nucleus appeared to have little G6PD activity in either the neuron cell bodies or the surrounding parenchyma. The use of a semipermeable membrane for localization of G6PD activity in neural tissues permits enhanced resolution of neuron elements and may provide a more accurate assessment of G6PD activity in histological preparations.     

Preferential inhibition of paraoxonase activity of human paraoxonase 1 by negatively charged lipids

To determine the causes responsible for a preferential decrease of paraoxonase activity, which has been observed in the serum of patients with cardiovascular diseases, the inactivation or inhibition of paraoxonase 1 (PON1) by various endogenous factors was examined using paraoxon or phenyl acetate as a substrate. When purified PON1 was incubated with various endogenous oxidants or aldehydes, they failed to cause a preferential reduction of paraoxonase activity, suggesting no participation of the inactivation mechanism in the preferential loss of paraoxonase activity. Next, when we examined the inhibition of PON1 activity by endogenous lipids, monoenoic acids such as palmitoleic acid or oleic acid inhibited paraoxonase activity preferentially, in contrast to a parallel inhibition of both activities by polyunsaturated or saturated acids. Noteworthy, oleoylglycine inhibited paraoxonase activity, but not arylesterase activity, complying with the selective inhibition of paraoxonase activity. Moreover, such a selective inhibition of paraoxonase activity was also expressed by lysophosphatidylglycerol or lysophosphatidylinositol, but not by lysophosphatidylserine or lysophosphatidylcholine, indicating the importance of the type of head group. Furthermore, such a preferential or selective inhibition of paraoxonase activity was also observed with PON1 associated with HDL or plasma. These data suggest that some negatively charged lipids may correspond to factors causing the preferential inhibition of paraoxonase activity of PON1.     

Characterization of calmodulin-activated protein kinase activity of rat adipocyte endoplasmic reticulum fraction

Calmodulin-activated protein kinase activity in the endoplasmic reticulum fraction of rat adipocytes was identified and characterized. The major endogenous protein substrate of the calmodulin-activated kinase activity has an apparent molecular weight of 54,000 as determined by sodium dodecyl sulfate gel electrophoresis. The calmodulin-activated component of the activity was saturated at 10 microM ATP. Calcium or calmodulin alone did not increase the activity, but the simultaneous presence of calcium and calmodulin increased activity three to four-fold. Half-maximal activation of this activity occurred at 8 microM Ca2+. The addition of increasing amounts of calmodulin caused a concentration-dependent activation in the presence of calcium, which was saturable at high calmodulin concentrations. Magnesium was required for activity, with half-maximal activity occurring at 230 microM. The antipsychotic drug trifluoperazine inhibited the activation of the protein kinase activity by calmodulin, but had a negligible effect on the basal activity. Half-maximal inhibition occurred at 63 microM. Phosphorylation of the 54,000 mol. wt band was independent of cAMP, cGMP and the combination of cAMP and cAMP-dependent protein kinase. Calmodulin-activated protein kinase phosphorylated both phosphoserine and phosphothreonine residues in the 54,000 mol. wt substrate. These experiments have partially characterized a calmodulin-activated protein kinase activity from adipocytes, which appears to be a unique activity of unknown function.     

Effect of water activities of heating and recovery media on apparent heat resistance of Bacillus cereus spores

Spores of Bacillus cereus were heated and recovered in order to investigate the effect of water activity of media on the estimated heat resistance (i.e., the D value) of spores. The water activity (ranging from 0.9 to 1) of the heating medium was first successively controlled with three solutes (glycerol, glucose, and sucrose), while the water activity of the recovery medium was kept near 1. Reciprocally, the water activity of the heating medium was then kept at 1, while the water activity of the recovery medium was controlled from 0.9 to 1 with the same depressors. Lastly, in a third set of experiments, the heating medium and the recovery medium were adjusted to the same activity. As expected, added depressors caused an increase of the heat resistance of spores with a greater efficiency of sucrose with respect to glycerol and glucose. In contrast, when solutes were added to the recovery medium, under an optimal water activity close to 0.98, a decrease of water activity caused a decrease in the estimated D values. This effect was more pronounced when sucrose was used as a depressor instead of glycerol or glucose. When the heating and the recovery media were adjusted to the same water activity, a balancing effect was observed between the protective influence of the solutes during heat treatment and their negative effect during the recovery of injured cells, so that the overall effect of water activity was reduced, with an optimal value near 0.96. The difference between the efficiency of depressors was also less pronounced. It may then be concluded that the overall protective effect of a decrease in water activity is generally overestimated.     

Possible involvement of angiotensin I-converting enzyme in the inactivation of bradykinin by intact macrophages

As intact macrophages inactivated bradykinin, the subcellular localization of the bradykinin-inactivating activity was studied using guinea-pig macrophages. The bradykinin-inactivating activity was found to be present in membrane and cytosol fractions but not in granular and nuclear fractions. The bradykinin-inactivating activity of the membrane fraction was inhibited by captopril, a specific inhibitor of angiotensin I-converting enzyme, whereas that of the cytosol fraction was hardly inhibited by various proteinase inhibitors used. Angiotensin I-converting enzyme activity was located predominantly in the membrane fraction and its activity was inhibited by captopril. Angiotensin I-converting enzyme activity measured with a synthetic substrate was competitively inhibited by bradykinin, suggesting that bradykinin is a possible substrate for macrophage angiotensin I-converting enzyme. When macrophages were modified chemically by diazotized sulfanilic acid, a poorly permeant reagent, both the bradykinin-inactivating activity and the angiotensin I-converting enzyme activity of macrophages decreased significantly without any inhibition of the cytosol bradykinin-inactivating activity. These findings seem to suggest that the angiotensin I-converting enzyme would be responsible for the inactivation of bradykinin in intact macrophages.     

The effect of sex hormones on the acinar distribution pattern of phosphoenolpyruvate carboxykinase activity in rat liver

The intra-acinar distribution pattern of phosphoenolpyruvate carboxykinase activity (PEPCK) was investigated in microdissected samples of livers from normal, castrated, castrated and estradiol- or testosterone-treated, and uncastrated and testosterone- or estradiol-treated male and female rats. The total PEPCK activity showed a marked sex dependency, with 1.8 times higher activity in males. The intra-acinar distribution profiles were also sex-dependent. The periportal-to-perivenous gradient was steeper in males. Castration resulted in an approximation of PEPCK activity and its acinar distribution pattern between the sexes due to a reduction in males and an increase in females. Estrogen treatment of castrated males had no further effect on PEPCK activity and its acinar gradient, whereas in ovariectomized animals the activity was reduced to levels near normal. Testosterone treatment of castrated male or female animals led to a marked increase in enzyme activity with a concomitant steepening of the acinar gradient. Administration of estradiol to normal male rats also led to a reduction in activity, together with a change in the acinar activity gradient. Testosterone treatment of normal females resulted in an induction of PEPCK activity which was most prominent in the periportal zone. The most drastic changes were observed in the perivenous zones. In all experiments a periportal-to-perivenous activity gradient persisted thus marking the periportal zone as the area with highest gluconeogenic capacity.     

Phospholipase of rat intestine: mode of action]

Phospholipase activities of rat intestinal mucosa homogenate have been determined from lysophosphatidylcholines [14C] and phosphatidylcholines [-3H-14C]. In the presence of phosphatidylcholines, at pH 6.5, the homogenate has a phospholipase B activity. At pH 8.5, a phospholipase A2 activity was shown. In the presence of lysophospatidylcholines, at pH 6.5, we notice a lysophospholipase A1 activity. A kinetic study of the reactions allows us to separate the activity B into a phospholipase A2 activity and a lysophospholipase A1 activity. Thus, it appears that the total phospholipase activity of rat intestinal mucosa would results from a phospholipase A2 activity and a lysophospholipase A1 activity.     

Wheel-Running Activity Patterns of Five Species of Desert Rodents

In contrast to the extensive laboratory data on activity patterns in rodent species inhabiting temperate zones, much less is known about the activity patterns of desert rodents. In order to address this issue, we measured wheel-running activity patterns in males and females of five species of wild-trapped desert rodents (Dipodillus dasyurus, Gerbillus andersoni, Gerbillus pyramidum, Meriones shawi, and Acomys cahirinus) in long 'summer-like' and short, 'winter-like' day lengths. The specific goals of the present study were to characterize activity patterns in several desert rodent species in the laboratory and to determine if activity patterns are expressed in a seasonal or sexually dimorphic manner. Specifically, wheel-running was measured for 11 weeks in long days followed by 11 weeks in short days to test for photoperiodic entrainment as well as responsiveness to changes in the light-dark cycle. All animals exhibited rhythmic patterns of wheel-running with consistent onsets and offsets that had well-defined relations with the light-dark cycle. All individuals of G. andersoni showed nocturnal activity patterns. Most individuals of G. pyramidum had nocturnal activity patterns, but some individuals showed a short bout of activity at the beginning of the light period. Most individuals of D. dasyurus and M. shawi showed bimodal (i.e., nocturnal and diurnal) activity patterns, although some showed markedly nocturnal activity patterns. There was no sexual dimorphism in wheel running activity rhythms in any of the species examined. As expected, decreases in day length resulted in an overall increase in the duration of activity in all species. Collectively, these data provide an initial characterization of activity patterns within desert rodents in a controlled laboratory setting.     

Muscle fibre composition of the eye muscles of the carp (Cyprinus carpio L.) defined on the base of histochemical observations

A histochemical study has been carried out on the eye muscles of the carp. On the base of the ATP-ase and SDH activity and with regard to the localization and diameter of muscle fibres six types of muscle fibres situated in the defined zones can be distinguished. The type 1 and 2 fibres display a moderately high ATP-ase activity at pH 9.4 and rather low activity after alkaline and acid preincubation. Type 1 shows a high SDH activity in contrast to type 2 with a low SDH activity. The other four types of fibres have the high ATP-ase activity at pH 9.4. Type 3 contains fibres with a moderately high ATP-ase activity after alkaline preincubation with a rather low activity after acid preincubation and with a low SDH activity. The fibres of type 4 characterized by the high ATP-ase activity after alkaline and acid preincubation and by the high SDH activity. The fibres of type 5 display high ATP-ase activity after alkaline and acid preincubation and the low SDH activity. They are situated in the white and intermediate fibre zones. The fibres of type 6 are comparable to the fibres of type 5, however they differ diameter and localization, i.e. they are situated in small diameter fibre zone. Using the electron microscope four types of fibres (A, B, C, and D) are found. They vary in the localization of T system, the organization of Z-line and in M-line appearance. In the type B of muscle fibres two different localizations of T system have been discerned.     

Seasonal dependence of the activity of antioxidant defence enzymes in the ground squirrel (Citellus citellus): the effect of cold.

1. The activity of antioxidant defense enzymes (SOD, CAT, GSH-Px and GST) was analysed during the autumn and winter in the ground squirrel adapted to 30 degrees C and subsequently exposed to cold for 6 and 24 hr. 2. The liver CAT activity as well as the IBAT CAT and GSH-Px activities differed between animals adapted to 30 degrees C, studied in autumn, and those studied in winter. 3. MnSOD activity in the liver was increased in autumn but decreased in winter after 6 hr cold exposure reaching the control level 24 hr later. Cold exposure induced a decrease in CAT activity (except after 24 hr cold exposure in winter) and an increase in GSH-Px activity. Lower GST activity was found after 24 hr exposure to cold in winter. 4. The IBAT SOD activity decreased under the influence of cold during both seasons with a tendency to return to the control level only in winter. Cold exposure produced a decrease in GST in both seasons and CAT activity in autumn. GSH-Px activity was increased in winter only. 5. The results indicate a seasonal dependence of the activity of antioxidant defence enzymes in the ground squirrel. Seasonal influence was evidenced in animals exposed to cold as well.     

NADPH-dependent reduction of 2,6-dichlorophenol-indophenol by the phagocytic vesicles of pig polymorphonuclear leucocytes.

NADPH-dependent 2,6-dichlorophenol-indophenol (DCIP) reductase activity in the homogenate of phagocytosing pig polymorphonuclear leucocytes was twice that of the resting cells and the activity in the phagocytic vesicles corresponded to the activity increment due to phagocytosis. The apparent Km value of the reductase activity in the vesicles for NADPH was 30 microM, which is similar to that of the NADPH-dependent superoxide (O2-) formation. Increasing the DCIP reductase activity by increasing the DCIP concentration caused a decrease in the O2- -forming activity, the NADPH oxidation rate being constant and independent of the dye concentration. p-Chloromercuribenzoate and cetyltrimethylammonium bromide at low concentrations inhibited the O2- -forming activity of the vesicles without inhibiting the DCIP reductase. Quinacrine inhibited both O2- formation and DCIP reduction. The DCIP reductase activity could be extracted with a mixture of deoxycholate and Tween-20, which extracts the O2- -forming activity. The reductase activity in the extract was enhanced 2-fold by the addition of FAD, and its apparent Km was 0.085 microM. These results indicate that the NADPH-dependent DCIP reductase activity of the phagocytic vesicles is catalysed by a flavin-containing component of the O2- -forming system.     

Lipase Production and Activity as a Function of Incubation Time, pH and Temperature of Four Lipolytic Micro-organisms

S ummary . The lipolytic activity in supernatant fractions of cultures of Saccharomycopsis lipolytica, Micrococcus caseolyticus, Bacillus licheniformis , and a Staphylococcus sp. was studied. Nutrient broth with and without emulsified olive oil was used as substrate. Optimal pH values and temperatures for the lipase produced by the 4 different micro-organisms were determined. The lipolytic activity generally reached a maximum after incubation for 2–6 days. The subsequent decrease in the lipolytic activity was associated with a high proteolytic activity only for Micrococcus caseolyticus . The lipolytic activity was decreased by the presence of olive oil in the medium. Determination of the lipolytic activity after a certain time of incubation, the maximal lipolytic activity and a time-integrated lipolytic activity are compared as estimators for the potential hydrolytic capacity of micro-organisms.